CN111885782A

CN111885782A - Linear constant current control circuit and two linear constant current LED lamp circuits

Info

Publication number: CN111885782A
Application number: CN202010704581.2A
Authority: CN
Inventors: 邹嘉祥; 俞贤晓; 许柏华
Original assignee: Yingtan Yankon Lighting Co ltd; Zhejiang Sunlight Illuminating Lamp Co ltd; Zhejiang Yankon Group Co Ltd
Current assignee: Yingtan Yankon Lighting Co ltd; Zhejiang Sunlight Illuminating Lamp Co ltd; Zhejiang Yankon Group Co Ltd
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2020-11-03

Abstract

The invention discloses a linear constant current control circuit and two linear constant current LED lamp circuits, wherein the two linear constant current LED lamp circuits are realized by adopting a linear constant current control circuit, the output end of the linear constant current control circuit is provided with a working voltage threshold and a maximum working current, when the linear constant current control circuit is applied to the linear constant current LED lamp circuit, the output end of the linear constant current control circuit periodically generates the lowest voltage along with the commercial power alternating current voltage accessed by the linear constant current LED lamp circuit, when the lowest voltage is generated, the linear constant current control circuit compares the lowest voltage of the output end with the working voltage threshold, and the current size of the output end of the linear constant current control circuit is automatically set according to the comparison result, so that the stroboflash of the linear constant current LED lamp; the linear constant current LED lamp circuit has the advantages that the stroboflash of the linear constant current LED lamp circuit is reduced on the basis of not reducing the luminous efficiency of the linear constant current LED lamp circuit, and the linear constant current LED lamp circuit is low in cost.

Description

Linear constant current control circuit and two linear constant current LED lamp circuits

Technical Field

The invention relates to a linear constant current control circuit, in particular to a linear constant current control circuit and two linear constant current LED lamp circuits.

Background

The linear constant-current LED lamp is convenient to process and low in cost, and is popular with people. Along with the improvement of the illumination requirements of people, the light emitting stroboflash of the linear constant-current LED lamp is more and more concerned by people.

As shown in fig. 1, the conventional linear constant current LED lamp circuit generally includes a rectifying and filtering circuit, an LED light emitting circuit and a linear constant current circuit, wherein the rectifying and filtering circuit has a live wire input end, a zero line input end, an output end and a ground end, the LED light emitting circuit has a positive electrode and a negative electrode, the linear constant current circuit at least has an output end and a negative electrode, a maximum working current and a working voltage threshold of the output end of the linear constant current circuit are preset in the linear constant current circuit, the live wire input end of the rectifying and filtering circuit is connected to a live wire of a commercial power, the zero line input end of the rectifying and filtering circuit is connected to a zero line of the commercial power, the output end of the rectifying and filtering circuit is connected to the positive electrode of the LED light emitting circuit, the negative electrode of the. When the rectifying and filtering circuit is connected with the alternating-current voltage of the mains supply, the rectifying and filtering circuit converts the alternating-current voltage of the mains supply into direct-current voltage and outputs the direct-current voltage at the output end of the rectifying and filtering circuit, the direct-current voltage is loaded to the output end of the linear constant-current circuit after passing through the LED light-emitting circuit, if the voltage connected to the output end of the linear constant-current circuit is larger than or equal to the working voltage threshold value of the linear constant-current circuit, the current flowing into the output end of the linear constant-current circuit is the maximum working current of the linear constant-current circuit, and if the voltage connected to the output end of the linear constant-current. The luminous intensity of the LED luminous circuit is in direct proportion to the magnitude of the flowing current, and the magnitude of the flowing current of the LED luminous circuit is equal to the current flowing into the output end of the linear constant current circuit, so if the current flowing into the output end of the linear constant current circuit cannot keep a constant value, the luminous intensity of the LED luminous circuit changes, and stroboscopic phenomenon is generated. The alternating current voltage of a mains supply connected to the linear constant-current LED lamp circuit changes in a sine wave mode, the direct current voltage output by the rectifying and filtering circuit also changes periodically, in each period, the direct current voltage output by the rectifying and filtering circuit has the highest voltage and the lowest voltage respectively, wherein the highest voltage is the peak voltage of the alternating current voltage of the mains supply, the lowest voltage is related to the current output by the output end of the period, the smaller the output current is, the higher the lowest voltage is, the closer the peak voltage of the alternating current voltage of the mains supply is, the larger the output current is, and the lower the lowest voltage is.

In a linear constant current LED lamp circuit, when low-frequency flash light is emitted, the lowest voltage of the output end of the linear constant current circuit is required to be larger than or equal to the working voltage threshold value of the linear constant current circuit. If the voltage connected to the output end of the linear constant current circuit cannot be guaranteed to be larger than or equal to the working voltage threshold value, the current flowing into the output end of the linear constant current circuit is reduced, and the luminous intensity of the LED luminous circuit is also reduced. Therefore, under the condition of being connected with the alternating current of the mains supply, the luminous brightness of the linear constant-current LED lamp circuit can generate periodic brightness change, namely stroboflash.

Under the requirement of low stroboscopic, if the maximum current value of the output end of the linear constant current circuit is kept unchanged, the maximum voltage value and the minimum voltage value of the direct current voltage output by the rectifying and filtering circuit keep a fixed large difference value. There are currently two main solutions to reduce stroboflash. The first solution is to reduce the working voltage of the LED lighting circuit, and when the ac voltage of the connected mains supply is at a negative deviation value of the rated voltage, or when the voltage of the LED lighting circuit is at a positive deviation of the working voltage, the working voltage of the LED lighting circuit is far lower than the minimum voltage of the dc voltage output by the rectifying and filtering circuit, so as to avoid the occurrence of stroboflash, but the solution can reduce the luminous efficiency of the linear constant current LED lamp circuit when the rated ac voltage is input. The second solution is to connect a stroboscopic removing circuit between the cathode of the LED light-emitting circuit and the output end of the linear constant current circuit, and when the current at the output end of the linear constant current circuit fluctuates, the stroboscopic removing circuit converts the fluctuating current into a constant current. Although the solution achieves the purpose of not reducing the luminous efficiency of the linear constant current LED lamp circuit, the cost of the linear constant current LED lamp circuit is greatly increased.

Disclosure of Invention

One of the technical problems to be solved by the present invention is to provide a linear constant current control circuit, which is applied to a linear constant current LED lamp circuit, and when the ac voltage of the utility power is low, the minimum voltage output by a rectification filter circuit inside the linear constant current LED lamp circuit is increased by reducing the current at the output end of the linear constant current LED lamp circuit on the basis of not reducing the luminous efficiency of the linear constant current LED lamp circuit, so as to reduce the stroboflash of the linear constant current LED lamp circuit and reduce the cost of the linear constant current LED lamp circuit.

The technical scheme adopted by the invention for solving one of the technical problems is as follows: a linear constant current control circuit at least has an output end and a negative electrode, the output end is provided with a working voltage threshold value and a maximum working current, when the linear constant current control circuit is applied to a linear constant current LED lamp circuit, the output end of the linear constant current control circuit periodically generates the lowest voltage along with the commercial power alternating current voltage accessed by the linear constant current LED lamp circuit, when the lowest voltage is generated, the linear constant current control circuit compares the lowest voltage of the output end with the working voltage threshold value, and the current size of the output end is automatically set according to the comparison result: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is larger than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, the current of the output end is kept unchanged, if the current of the output end is smaller than the maximum working current at the moment, the current of the output end is continuously increased until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, the current is kept unchanged, and when the current is increased to be equal to the maximum working current, the maximum working current is kept unchanged.

The linear constant current control circuit comprises a linear constant current circuit and a voltage control circuit; the linear constant current circuit is provided with an output end, an anode, a cathode and a current control end, the current control end of the linear constant current circuit is used for accessing an analog voltage, the analog voltage is used for setting the current of the output end of the linear constant current circuit, the current control end of the linear constant current circuit is provided with a control voltage threshold value, when the voltage of the output end of the linear constant current circuit is more than or equal to the working voltage threshold value, if the voltage connected to the current control end is greater than or equal to the control voltage threshold value, the current of the current control end is the maximum working current, if the voltage at its current control terminal is less than the control voltage threshold, then the current at its current control terminal is less than the maximum operating current, the current of the current control terminal is related to the analog voltage accessed by the current control terminal, the higher the accessed analog voltage is, the larger the current is, and the lower the accessed analog voltage is, the smaller the current is; the voltage control circuit is provided with an input end, an output end and a negative electrode, the voltage control circuit detects the lowest voltage of the input end in each period, adjusts the analog voltage output by the output end according to the lowest voltage of the input end, reduces the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is smaller than a working voltage threshold value, keeps the analog voltage of the output end unchanged when the lowest voltage of the input end of the voltage control circuit is equal to the working voltage threshold value, and increases the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is larger than the working voltage threshold value; the output end of the linear constant current circuit is connected with the input end of the voltage control circuit, the connecting end of the linear constant current circuit is the output end of the linear constant current control circuit, the output end of the voltage control circuit is connected with the current control end of the linear constant current circuit, the cathode of the voltage control circuit is connected with the cathode of the linear constant current circuit, and the connecting end of the voltage control circuit is the cathode of the linear constant current control circuit; the voltage control circuit detects the lowest voltage of the output end of the linear constant current circuit in each period, adjusts the analog voltage output by the output end of the linear constant current circuit according to the lowest voltage of the output end of the linear constant current circuit, if the lowest voltage of the output end of the linear constant current circuit is larger than or equal to a working voltage threshold value, and the lowest voltage of the output end of the voltage control circuit is larger than or equal to a control voltage threshold value of the current control end of the linear constant current circuit, the current of the output end of the linear constant current circuit is not increased and is kept as the maximum working current, if the lowest voltage of the output end of the linear constant current circuit is smaller than the working voltage threshold value, the analog voltage of the output end of the voltage control circuit is reduced to be smaller than the control voltage threshold value, and the current of the output end of the linear constant current circuit is reduced, until the voltage control circuit detects that the lowest voltage of the output end of the linear constant current circuit is equal to the working voltage threshold value, and the balance state is maintained.

The linear constant current circuit comprises a first integrated circuit chip, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor, wherein the first integrated circuit chip adopts a linear constant current chip with a simulation DIM port, the reference model is RM9010E, one end of the first resistor is the anode of the linear constant current circuit, the other end of the first resistor is connected with the 8 th pin of the first integrated circuit chip, the 6 th pin of the first integrated circuit chip is connected with one end of the third resistor, the connecting end of the first resistor is the output end of the linear constant current circuit, the other end of the third resistor, one end of the fourth resistor, one end of the first capacitor are connected with the 3 rd pin of the first integrated circuit chip, the 2 nd pin of the first integrated circuit chip is the current control end of the linear constant current circuit, the 4 th pin of the first integrated circuit chip is connected with one end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor and the 1 st pin of the first integrated circuit chip are connected, and the connecting end of the first capacitor and the 1 st pin of the first integrated circuit chip is the cathode of the linear constant current circuit. The linear constant current circuit has the function of compensating and adjusting the current of the output end of the linear constant current circuit by the average voltage of the output end, when the average voltage of the output end is increased, the maximum working current of the output end is reduced, and as long as the voltage of the output end is not lower than the working voltage threshold value, when the voltage of the output end is periodically changed, the current flowing into the output end is kept constant.

The voltage control circuit comprises a fifth resistor, a sixth resistor, a second capacitor and a first diode, wherein the first diode is a voltage stabilizing diode, the cathode of the first diode is the input end of the voltage control circuit, the anode of the first diode is connected with one end of the fifth resistor, the other end of the fifth resistor, one end of the sixth resistor and one end of the second capacitor are connected, the connecting end of the fifth resistor and one end of the second capacitor are the output end of the voltage control circuit, the other end of the sixth resistor and the other end of the second capacitor are connected, and the connecting end of the sixth resistor and the other end of the second capacitor are the cathode of the voltage control circuit. The voltage control circuit converts the voltage changed at the input end into stable average voltage through the RC circuit, namely, the voltage is reduced through the voltage stabilizing diode, and the working voltage threshold value of the output end of the linear constant current circuit corresponds to the control voltage range of the voltage adjusting end of the linear constant current circuit through resistance voltage division.

Compared with the prior art, the linear constant current control circuit has the advantages that the output end of the linear constant current control circuit is provided with the working voltage threshold and the maximum working current, when the linear constant current control circuit is applied to the linear constant current LED lamp circuit, the output end of the linear constant current control circuit periodically generates the lowest voltage along with the commercial power alternating current voltage accessed by the linear constant current LED lamp circuit, when the lowest voltage occurs, the linear constant current control circuit compares the lowest voltage of the output end with the working voltage threshold, and the current of the output end is automatically set according to the comparison result: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged; therefore, when the linear constant-current control circuit is applied to a linear constant-current LED lamp circuit, when rated alternating-current voltage or higher voltage is connected, the linear constant-current control circuit has the same stroboflash-free characteristic as a linear constant-current LED lamp adopting the prior art; when the voltage of the accessed mains supply is lower than the rated voltage, the lowest voltage of the linear constant current LED lamp circuit is improved by reducing the current of the output end of the linear constant current LED lamp circuit, so that the stroboflash of the linear constant current LED lamp circuit is reduced on the basis of not reducing the luminous efficiency of the linear constant current LED lamp circuit, and the linear constant current LED lamp circuit is lower in cost.

The second technical problem to be solved by the present invention is to provide a linear constant current LED lamp circuit which can reduce the stroboflash and has low cost on the basis of not reducing the light emitting efficiency.

The second technical solution adopted by the present invention to solve the above technical problems is: the utility model provides a linear constant current LED lamp circuit, includes rectifier filter circuit, LED lighting circuit and linear constant current control circuit, rectifier filter circuit have live wire input, zero line input, output and earthing terminal, LED lighting circuit have positive pole and negative pole, linear constant current control circuit have output, positive pole and negative pole, its output is provided with operating voltage threshold value and maximum operating current, linear constant current control circuit when being applied to linear constant current LED lamp circuit, its output is along with the commercial power alternating voltage periodic minimum voltage that appears that linear constant current LED lamp circuit inserts, when the minimum voltage appears, linear constant current control circuit with the output minimum voltage and operating voltage threshold value compare, according to the current size of its output of comparative result automatic setting: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged;

the input end of the live wire of the rectification filter circuit is connected with the live wire of commercial power, the input end of the zero line of the rectification filter circuit is connected with the zero line of the commercial power, the output end of the rectification filter circuit is respectively connected with the anode of the linear constant-current control circuit and the anode of the LED light-emitting circuit, the cathode of the LED light-emitting circuit is connected with the output end of the linear constant-current control circuit, and the cathode of the linear constant-current control circuit is connected with the grounding end of the rectification filter circuit; the rectifying and filtering circuit comprises a first full-bridge rectifying circuit and a first electrolytic capacitor, wherein the 1 st pin of the first full-bridge rectifying circuit is the live wire input end of the rectifying and filtering circuit, the 3 rd pin of the first full-bridge rectifying circuit is the zero line input end of the rectifying and filtering circuit, the 2 nd pin of the first full-bridge rectifying circuit is connected with the positive electrode of the first electrolytic capacitor, the connecting end of the first full-bridge rectifying circuit is the output end of the rectifying and filtering circuit, the 4 th pin of the first full-bridge rectifying circuit is connected with the negative electrode of the first electrolytic capacitor, and the connecting end of the first full-bridge rectifying circuit is the grounding end of the rectifying and filtering circuit;

when the alternating-current voltage of the commercial power accessed by the rectifying and filtering circuit is equal to the rated voltage of the commercial power or greater than the rated voltage, and when the current at the output end of the linear constant-current control circuit is the maximum working current, the lowest voltage output by the rectifying and filtering circuit is loaded at the output end of the linear constant-current control circuit through the LED light-emitting circuit, and is greater than the working voltage threshold value, the current at the output end of the linear constant-current control circuit is kept as the maximum working current, and the light emission of the LED light-emitting circuit is the highest brightness of low-frequency flash; when the alternating-current voltage of the mains supply connected to the rectifying and filtering circuit is lower than the rated voltage of the mains supply, when the voltage of the highest voltage output by the rectifying and filtering circuit and loaded on the output end of the linear constant-current control circuit through the LED light-emitting circuit is larger than the working voltage threshold value of the linear constant-current control circuit, if the lowest voltage of the output end of the linear constant-current control circuit is lower than the working voltage threshold value of the linear constant-current control circuit, the current of the output end of the linear constant-current control circuit is reduced, so that the lowest voltage of the output end of the linear constant-current control circuit is increased to the working voltage threshold value of the linear constant-current control circuit, and if the lowest voltage of; if the current of the output end of the linear constant-current control circuit is equal to the maximum working current at the moment, keeping the current of the output end of the linear constant-current control circuit unchanged, if the current of the output end of the linear constant-current control circuit is smaller than the maximum working current at the moment, continuously increasing the current of the output end of the linear constant-current control circuit until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, keeping the current unchanged when the lowest voltage is equal to the working voltage threshold, keeping the maximum working current unchanged when the current is increased to be equal to the maximum working current, and keeping the LED light-emitting circuit to emit light by low; when the alternating current voltage of the accessed mains supply is too low, the LED light-emitting circuit cannot emit light, or light-emitting stroboflash can occur when the light-emitting brightness is very low.

The linear constant current control circuit comprises a linear constant current circuit and a voltage control circuit; the linear constant current circuit is provided with an output end, an anode, a cathode and a current control end, wherein the current control end of the linear constant current circuit is used for accessing an analog voltage, the analog voltage is used for setting the current of the output end of the linear constant current circuit, and the current control end of the linear constant current circuit is provided with a control voltage threshold value. When the voltage of the output end of the linear constant current circuit is greater than or equal to the working voltage threshold, if the voltage accessed by the current control end of the linear constant current circuit is greater than or equal to the control voltage threshold, the current of the current control end of the linear constant current circuit is the maximum working current, if the voltage of the current control end of the linear constant current circuit is less than the control voltage threshold, the current of the current control end of the linear constant current circuit is less than the maximum working current, the current of the current control end of the linear constant current circuit is related to the magnitude of the analog voltage accessed by the current control end, the higher the accessed analog voltage is, the larger the; the voltage control circuit is provided with an input end, an output end and a negative electrode, the voltage control circuit detects the lowest voltage of the input end in each period, adjusts the analog voltage output by the output end according to the lowest voltage of the input end, reduces the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is smaller than a working voltage threshold value, keeps the analog voltage of the output end unchanged when the lowest voltage of the input end of the voltage control circuit is equal to the working voltage threshold value, and increases the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is larger than the working voltage threshold value; the output end of the linear constant current circuit is connected with the input end of the voltage control circuit, the connecting end of the linear constant current circuit is the output end of the linear constant current control circuit, the output end of the voltage control circuit is connected with the current control end of the linear constant current circuit, the cathode of the voltage control circuit is connected with the cathode of the linear constant current circuit, and the connecting end of the voltage control circuit is the cathode of the linear constant current control circuit; the voltage control circuit detects the lowest voltage of the output end of the linear constant current circuit in each period, adjusts the analog voltage output by the output end of the linear constant current circuit according to the lowest voltage of the output end of the linear constant current circuit, if the lowest voltage of the output end of the linear constant current circuit is larger than or equal to a working voltage threshold value, and the lowest voltage of the output end of the voltage control circuit is larger than or equal to a control voltage threshold value of the current control end of the linear constant current circuit, the current of the output end of the linear constant current circuit is not increased and is kept as the maximum working current, if the lowest voltage of the output end of the linear constant current circuit is smaller than the working voltage threshold value, the analog voltage of the output end of the voltage control circuit is reduced to be smaller than the control voltage threshold value, and the current of the output end of the linear constant current circuit is reduced, until the voltage control circuit detects that the lowest voltage of the output end of the linear constant current circuit is equal to the working voltage threshold value, and the balance state is maintained.

The linear constant current circuit comprises a first integrated circuit chip, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor, wherein the first integrated circuit chip adopts a linear constant current chip with a simulation DIM port, the reference model is RM9010E, one end of the first resistor is the anode of the linear constant current circuit, the other end of the first resistor is connected with the 8 th pin of the first integrated circuit chip, the 6 th pin of the first integrated circuit chip is connected with one end of the third resistor, the connecting end of the first resistor is the output end of the linear constant current circuit, the other end of the third resistor, one end of the fourth resistor, one end of the first capacitor are connected with the 3 rd pin of the first integrated circuit chip, the 2 nd pin of the first integrated circuit chip is the current control end of the linear constant current circuit, the 4 th pin of the first integrated circuit chip is connected with one end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor are connected with the 1 st pin of the first integrated circuit chip, and the connecting end of the first capacitor is the negative electrode of the linear constant current circuit; the voltage control circuit comprises a fifth resistor, a sixth resistor, a second capacitor and a first diode, wherein the first diode is a voltage stabilizing diode, the cathode of the first diode is the input end of the voltage control circuit, the anode of the first diode is connected with one end of the fifth resistor, the other end of the fifth resistor, one end of the sixth resistor and one end of the second capacitor are connected, the connecting end of the fifth resistor and one end of the second capacitor are the output end of the voltage control circuit, the other end of the sixth resistor and the other end of the second capacitor are connected, and the connecting end of the sixth resistor and the other end of the second capacitor are the cathode of the voltage control circuit. The linear constant current circuit has the function of compensating and adjusting the current of the output end of the linear constant current circuit by the average voltage of the output end, when the average voltage of the output end is increased, the maximum working current of the output end is reduced, and when the voltage of the output end is periodically changed, the current flowing into the output end is kept constant as long as the voltage of the output end is not lower than the working voltage threshold; the voltage control circuit converts the changed voltage of the input end into stable average voltage through the RC circuit, namely, the voltage is reduced through the voltage stabilizing diode, and the working voltage threshold value of the output end of the linear constant current circuit corresponds to the control voltage range of the voltage adjusting end of the linear constant current circuit through resistance voltage division.

Compared with the prior art, the linear constant current control circuit has the advantages that the output end of the linear constant current control circuit is provided with the working voltage threshold and the maximum working current, when the linear constant current control circuit is applied to the linear constant current LED lamp circuit, the output end of the linear constant current control circuit periodically generates the lowest voltage along with the commercial power alternating current voltage accessed by the linear constant current LED lamp circuit, when the lowest voltage occurs, the linear constant current control circuit compares the lowest voltage of the output end with the working voltage threshold, and the current of the output end is automatically set according to the comparison result: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged; the input end of the live wire of the rectification filter circuit is connected with the live wire of the commercial power, the input end of the zero line of the rectification filter circuit is connected with the zero line of the commercial power, the output end of the rectification filter circuit is respectively connected with the anode of the linear constant-current control circuit and the anode of the LED light-emitting circuit, the cathode of the LED light-emitting circuit is connected with the output end of the linear constant-current control circuit, and the cathode of the linear constant-current control circuit is connected with the grounding end of the rectification filter circuit; the rectifying and filtering circuit comprises a first full-bridge rectifying circuit and a first electrolytic capacitor, wherein the No. 1 pin of the first full-bridge rectifying circuit is the live wire input end of the rectifying and filtering circuit, the No. 3 pin of the first full-bridge rectifying circuit is the zero line input end of the rectifying and filtering circuit, the No. 2 pin of the first full-bridge rectifying circuit is connected with the positive electrode of the first electrolytic capacitor, the connecting end of the first full-bridge rectifying circuit is the output end of the rectifying and filtering circuit, the No. 4 pin of the first full-bridge rectifying circuit is connected with the negative electrode of the first electrolytic capacitor, and the connecting end of the first; when the alternating-current voltage of the commercial power connected to the rectifying and filtering circuit is equal to the rated voltage of the commercial power or greater than the rated voltage, and the current at the output end of the linear constant-current control circuit is the maximum working current, the lowest voltage output by the rectifying and filtering circuit is loaded on the LED light-emitting circuit, the lowest voltage at the output end of the linear constant-current control circuit is greater than the working voltage threshold value of the linear constant-current control circuit, the current at the output end of the linear constant-current control circuit is kept to be the maximum working current, and the light emission of the LED light-emitting circuit is; when the alternating-current voltage of the commercial power accessed by the rectifying and filtering circuit is lower than the rated voltage of the commercial power, the highest voltage output by the rectifying and filtering circuit is loaded on the LED light-emitting circuit when the voltage of the output end of the linear constant-current control circuit is larger than the working voltage threshold value of the linear constant-current control circuit, if the lowest voltage of the output end of the linear constant-current control circuit is lower than the working voltage threshold value of the linear constant-current control circuit, the current of the output end of the linear constant-current control circuit is reduced, so that the lowest voltage of the output end of the linear constant-current control circuit is increased to the working voltage threshold value of; if the current of the output end of the linear constant-current control circuit is equal to the maximum working current, the current of the output end of the linear constant-current control circuit is kept unchanged, if the current of the output end of the linear constant-current control circuit is smaller than the maximum working current, the current of the output end of the linear constant-current control circuit is continuously increased until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, the current is kept unchanged, when the current is increased to be equal to the maximum working current, the maximum working current is kept unchanged, and the LED light-emitting circuit; when the alternating voltage of the accessed mains supply is too low, the LED light-emitting circuit cannot emit light, or light-emitting stroboflash can occur when the light-emitting brightness is very low; if the lowest alternating current voltage keeping the low stroboscopic light-emitting state in the LED light-emitting circuit is called as low-stroboscopic lowest voltage, when the rated alternating current voltage or higher voltage is switched in, the LED light-emitting circuit has the same stroboscopic-free characteristic as a linear constant-current LED lamp adopting the prior art; when the alternating-current voltage of the accessed mains supply is lower than the rated voltage and is more than or equal to the lowest voltage of the low-frequency flash, when the linear constant-circuit LED lamp circuit in the prior art can generate the flash, the linear constant-circuit LED lamp circuit keeps low-flash light emission by reducing the brightness, and when the alternating-current voltage of the accessed mains supply is lower than the lowest voltage of the low flash, the linear constant-circuit LED lamp circuit can not emit light or emits light with certain flash low brightness; therefore, the invention can reduce stroboflash and has lower cost on the basis of not reducing the luminous efficiency.

The invention aims to solve the third technical problem of providing a linear constant-current LED lamp circuit which can reduce stroboflash and has lower cost on the basis of not reducing luminous efficiency.

The technical scheme adopted by the invention for solving the third technical problem is as follows: a linear constant current LED lamp circuit comprises a rectifying filter circuit, an LED light-emitting circuit, a linear constant current module and a linear constant current control circuit, the rectification filter circuit is provided with a live wire input end, a zero line input end, an output end and a grounding end, the LED light-emitting circuit is provided with an anode and a cathode, the linear constant current module is provided with an output end, a control end and a cathode, the linear constant current control circuit is provided with an output end, an anode and a cathode, the output end of the linear constant current control circuit is provided with a working voltage threshold value and a maximum working current, when the linear constant current control circuit is applied to a linear constant current LED lamp circuit, the output end of the linear constant current LED lamp circuit periodically generates the lowest voltage along with the commercial power alternating voltage which is connected in, when the lowest voltage appears, the linear constant current control circuit compares the lowest voltage of the output end with the working voltage threshold value, and automatically sets the current magnitude of the output end according to the comparison result: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged;

the input end of the live wire of the rectification filter circuit is connected with the live wire of commercial power, the input end of the null wire of the rectification filter circuit is connected with the null wire of the commercial power, the output end of the rectification filter circuit is respectively connected with the anode of the linear constant current control circuit and the anode of the LED light-emitting circuit, the cathode of the LED light-emitting circuit is connected with the output end of the linear constant current control circuit, the LED light-emitting circuit comprises a first LED light-emitting circuit and a second LED light-emitting circuit, the first LED light-emitting circuit and the second LED light-emitting circuit are respectively provided with an anode and a cathode, the anode of the first LED light-emitting circuit is the anode of the LED light-emitting circuit, the cathode of the second LED light-emitting circuit is the cathode of the LED light-emitting circuit, and the cathodes of the first LED light-emitting circuit and the second LED light-emitting circuit are connected with the output end of the linear module, the control end of the linear constant current module is connected with the negative electrode of the linear constant current control circuit, the negative electrode of the linear constant current module is connected with the negative electrode of the rectification filter circuit, the rectification filter circuit comprises a second full-bridge rectification circuit and a second electrolytic capacitor, the 1 st pin of the second full-bridge rectification circuit is the live wire input end of the rectification filter circuit, the 3 rd pin of the second full-bridge rectification circuit is the zero line input end of the rectification filter circuit, the 2 nd pin of the second full-bridge rectification circuit is connected with the positive electrode of the second electrolytic capacitor, the connecting end of the second full-bridge rectification circuit is the output end of the rectification filter circuit, the 4 th pin of the second full-bridge rectification filter circuit is connected with the negative electrode of the second electrolytic capacitor, and the connecting end of the second full-bridge rectification filter circuit is the grounding end of the rectification filter circuit; the linear constant current module comprises a second integrated circuit chip and a seventh resistor, the second integrated circuit chip adopts a universal linear constant current chip, the linear constant current chip is provided with three connecting ends which are respectively an output end, a negative electrode and a current regulating end, the output end of the linear constant current chip is the output end of the linear constant current module, the current regulating end of the linear constant current chip is connected with one end of the seventh resistor, the connecting end of the linear constant current chip is the control end of the linear constant current module, the negative electrode of the linear constant current chip is connected with the other end of the seventh resistor, the connecting end of the linear constant current chip is the negative electrode of the linear constant current module, and the maximum working current of the output end of the linear constant current chip is determined by regulating the resistance value of the seventh resistor; when the current of the output end of the linear constant current control circuit is larger than or equal to the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is zero, and when the current of the output end of the linear constant current control circuit is smaller than the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is equal to the current obtained by subtracting the current of the output end of the linear constant current control circuit from the maximum working current of the output end of the linear constant current control circuit; when the alternating-current voltage of the commercial power accessed by the rectifying and filtering circuit is equal to the rated voltage of the commercial power or greater than the rated voltage, the lowest voltage of the output end of the linear constant-current control circuit is greater than the working voltage threshold value of the linear constant-current control circuit, the current of the output end of the linear constant-current control circuit is the maximum working current, the current of the output end of the linear constant-current control circuit is zero at the moment, and the light emission of the first LED light-emitting circuit and the second LED light-emitting circuit is the highest brightness of low-frequency flash;

when the alternating-current voltage of the mains supply accessed by the rectifying and filtering circuit is lower than the rated voltage of the mains supply, and the voltage of the highest voltage output by the rectifying and filtering circuit at the output end of the linear constant-current control circuit is higher than the working voltage threshold value of the linear constant-current control circuit through the LED light-emitting circuit, the linear constant-current control circuit compares the lowest voltage received by the output end of the linear constant-current control circuit with the working voltage threshold value to adjust the output current of the linear constant-current control circuit, namely when the lowest voltage is lower than the working voltage threshold value, the current at the output end of the linear constant-current control circuit is continuously reduced until the lowest voltage is equal to the working voltage threshold; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged to keep the low-frequency flash light emission of the second LED light-emitting circuit; at this time, if the current of the output end of the linear constant current control circuit is greater than or equal to the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is zero, and the first LED light-emitting circuit and the second LED light-emitting circuit have the same light-emitting brightness and emit light with low stroboflash; if the current of the output end of the linear constant current control circuit is smaller than the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is not zero, the current flowing through the second LED light-emitting circuit is the current of the output end of the linear constant current control circuit, and the light-emitting circuit emits light in a low stroboscopic mode; the current flowing through the first LED light-emitting circuit is the current of the output end of the linear constant current module, and the first LED light-emitting circuit emits light with low stroboflash because the lowest voltage of the output end of the linear constant current module is greater than the working voltage threshold value and the output end of the linear constant current module is constant current; the linear constant current LED lamp circuit is low-frequency flash light; when the accessed mains supply alternating-current voltage is continuously reduced, the highest voltage output by the rectifying and filtering circuit cannot drive the first LED light-emitting circuit and the second LED light-emitting circuit to emit light at the same time, and after the lowest voltage output by the rectifying and filtering circuit passes through the first LED light-emitting circuit, the lowest voltage at the output end of the linear constant-circuit module is kept to be larger than or equal to the working voltage threshold value, then the driving current of the first LED light-emitting circuit is constant current, the first LED light-emitting circuit emits light in a low-frequency flash mode, the second LED light-emitting circuit does not emit light, the lowest mains supply alternating-current voltage when only the first LED light-emitting circuit keeps the low-frequency flash mode is called as the low-frequency flash lowest voltage, then the low-frequency flash lowest voltage is far smaller than the mains supply rated voltage, and the linear constant-current LED lamp circuit has wider mains supply voltage adaptability.

The linear constant current circuit comprises a first integrated circuit chip, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor, wherein the first integrated circuit chip adopts a linear constant current chip with a simulation DIM port, the reference model is RM9010E, one end of the first resistor is the anode of the linear constant current circuit, the other end of the first resistor is connected with the 8 th pin of the first integrated circuit chip, the 6 th pin of the first integrated circuit chip is connected with one end of the third resistor, the connecting end of the first resistor is the output end of the linear constant current circuit, the other end of the third resistor, one end of the fourth resistor, one end of the first capacitor are connected with the 3 rd pin of the first integrated circuit chip, the 2 nd pin of the first integrated circuit chip is the current control end of the linear constant current circuit, the 4 th pin of the first integrated circuit chip is connected with one end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor are connected with the 1 st pin of the first integrated circuit chip, and the connecting end of the first capacitor is the negative electrode of the linear constant current circuit; the voltage control circuit comprises a fifth resistor, a sixth resistor, a second capacitor and a first diode, wherein the first diode is a voltage stabilizing diode, the cathode of the first diode is the input end of the voltage control circuit, the anode of the first diode is connected with one end of the fifth resistor, the other end of the fifth resistor, one end of the sixth resistor and one end of the second capacitor are connected, the connecting end of the fifth resistor and one end of the second capacitor are the output end of the voltage control circuit, the other end of the sixth resistor and the other end of the second capacitor are connected, and the connecting end of the sixth resistor and the other end of the second capacitor are the cathode of the voltage control circuit. The linear constant current circuit has the function of compensating and adjusting the maximum working current of the output end of the linear constant current circuit by the average voltage of the output end, when the average voltage of the output end is increased, the current of the output end is reduced, and when the voltage of the output end is periodically changed, the current flowing into the output end is kept constant as long as the voltage of the output end is not lower than the working voltage threshold; the voltage control circuit converts the changed voltage of the input end into stable average voltage through the RC circuit, namely, the voltage is reduced through the voltage stabilizing diode, and the working voltage threshold value of the output end of the linear constant current circuit is connected with the control voltage range of the voltage adjusting end of the linear constant current circuit through resistance voltage division.

Compared with the prior art, the second linear constant current LED lamp circuit has the advantages that the linear constant current LED lamp circuit is constructed by the rectifying filter circuit, the LED light-emitting circuit, the linear constant current module and the linear constant current control circuit, the rectifying filter circuit is provided with a live wire input end, a zero line input end, an output end and a grounding end, the LED light-emitting circuit is provided with a positive electrode and a negative electrode, the linear constant current module is provided with an output end, a control end and a negative electrode, the linear constant current control circuit is provided with an output end, a positive electrode and a negative electrode, the output end of the linear constant current control circuit is provided with a working voltage threshold value and a maximum working current, when the linear constant current control circuit is applied to the linear constant current LED lamp circuit, the output end of the linear constant current control circuit periodically generates the lowest voltage along with the commercial power alternating current voltage accessed by the linear constant current LED lamp, and automatically setting the current magnitude of the output end of the power supply according to the comparison result: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged; the input end of the live wire of the rectification filter circuit is connected with the live wire of commercial power, the input end of the null wire of the rectification filter circuit is connected with the null wire of the commercial power, the output end of the rectification filter circuit is respectively connected with the anode of the linear constant current control circuit and the anode of the LED light-emitting circuit, the cathode of the LED light-emitting circuit is connected with the output end of the linear constant current control circuit, the LED light-emitting circuit comprises a first LED light-emitting circuit and a second LED light-emitting circuit, the first LED light-emitting circuit and the second LED light-emitting circuit are both provided with an anode and a cathode, the anode of the first LED light-emitting circuit is the anode of the LED light-emitting circuit, the cathode of the second LED light-emitting circuit is the cathode of the LED light-emitting circuit, the cathode of the first LED light-emitting circuit, the anode of the second LED light-emitting circuit and the output end of the linear constant current module are connected, the control end, the rectifying and filtering circuit comprises a second full-bridge rectifying circuit and a second electrolytic capacitor, wherein the No. 1 pin of the second full-bridge rectifying circuit is the live wire input end of the rectifying and filtering circuit, the No. 3 pin of the second full-bridge rectifying circuit is the zero line input end of the rectifying and filtering circuit, the No. 2 pin of the second full-bridge rectifying circuit is connected with the positive electrode of the second electrolytic capacitor, the connecting end of the second full-bridge rectifying and filtering circuit is the output end of the rectifying and filtering circuit, the No. 4 pin of the second full-bridge rectifying and filtering circuit is connected with the negative electrode of the second electrolytic capacitor, and the connecting end of; the linear constant current module comprises a second integrated circuit chip and a seventh resistor, the second integrated circuit chip adopts a universal linear constant current chip, the linear constant current chip is provided with three connecting ends which are respectively an output end, a negative electrode and a current regulating end, the output end of the linear constant current chip is the output end of the linear constant current module, the current regulating end of the linear constant current chip is connected with one end of the seventh resistor, the connecting end is the control end of the linear constant current module, the negative electrode of the linear constant current chip is connected with the other end of the seventh resistor, the connecting end is the negative electrode of the linear constant current module, and the maximum working current of the output end of the linear constant current chip is determined by regulating the resistance value of the seventh resistor; when the current of the output end of the linear constant current control circuit is larger than or equal to the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is zero, and when the current of the output end of the linear constant current control circuit is smaller than the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is equal to the current obtained by subtracting the current of the output end of the linear constant current control circuit from the maximum working current of the; when the alternating-current voltage of the commercial power connected to the rectifying and filtering circuit is equal to or greater than the rated voltage of the commercial power, the voltage of the output end of the linear constant-current control circuit is greater than the working voltage threshold value of the linear constant-current control circuit, the current of the output end of the linear constant-current control circuit is the maximum working current, the current of the output end of the linear constant-current module is zero at the moment, and the light emission of the first LED light-emitting circuit and the second LED light-emitting circuit is the highest brightness; when the alternating-current voltage of the mains supply connected to the rectifying and filtering circuit is lower than the rated voltage of the mains supply, and the highest voltage output by the rectifying and filtering circuit is higher than the working voltage threshold value of the linear constant-current control circuit through the LED light-emitting circuit, the linear constant-current control circuit compares the lowest voltage received by the output end of the linear constant-current control circuit with the working voltage threshold value and adjusts the output current of the linear constant-current control circuit, namely when the lowest voltage is lower than the working voltage threshold value, the current of the output end of the linear constant-current control circuit is continuously reduced until the lowest voltage is equal to the working voltage threshold value, and the current is; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged; to maintain low frequency flash of the second LED lighting circuit; at the moment, if the current of the output end of the linear constant current control circuit is greater than or equal to the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is zero, and the first LED light-emitting circuit and the second LED light-emitting circuit have the same luminance and are both low-stroboscopic light-emitting; if the current of the output end of the linear constant current control circuit is smaller than the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is not zero, and the current flowing through the second LED light-emitting circuit is the current of the output end of the linear constant current control circuit and is low-frequency flash light-emitting; the current flowing through the first LED light-emitting circuit is the current of the output end of the linear constant-current module, and the first LED light-emitting circuit emits light in a low-frequency flash manner because the lowest voltage of the output end of the linear constant-current module is greater than the working voltage threshold value and the output end of the linear constant-current module is constant current; the linear constant current LED lamp circuit is low-frequency flash light; when the connected commercial power alternating-current voltage is continuously reduced, the highest voltage output by the rectifying and filtering circuit cannot drive the first LED light-emitting circuit and the second LED light-emitting circuit to emit light simultaneously, and after the lowest voltage output by the rectifying and filtering circuit passes through the first LED light-emitting circuit, the lowest voltage at the output end of the linear constant-circuit module is kept to be greater than or equal to the working voltage threshold value, so that the driving current of the first LED light-emitting circuit is constant current, the first LED light-emitting circuit emits light in a low-frequency flash mode, the second LED light-emitting circuit does not emit light, the lowest commercial power alternating-current voltage when only the first LED light-emitting circuit keeps low-frequency flash light is called as low-frequency flash lowest voltage, the low-frequency flash lowest voltage is far smaller than the commercial power rated voltage, and the linear constant-current LED lamp circuit; therefore, when the alternating-current voltage of the mains supply connected into the LED constant-current circuit is equal to the rated voltage of the mains supply or greater than the rated voltage, the LED constant-current circuit has the same characteristics as the linear constant-current circuit in the prior art, namely, the light emission of the first LED light-emitting circuit and the second LED light-emitting circuit is the highest brightness of low-frequency flash, but in the voltage interval that the alternating-current voltage of the mains supply is reduced to the lowest voltage of the low-frequency flash, although the brightness is changed, the low-frequency flash light-emitting state is always kept, so that the circuit has wider adaptability to the mains supply voltage when the low-frequency flash works, can reduce the flash on the basis of not reducing.

Drawings

Fig. 1 is a structural diagram of a conventional linear constant current LED lamp circuit;

FIG. 2 is a block diagram of a linear constant current control circuit of the present invention;

FIG. 3 is a circuit diagram of a linear constant current control circuit of the present invention;

FIG. 4 is a block diagram of a first linear constant current LED lamp circuit of the present invention;

fig. 5 is a structural diagram of a second linear constant current LED lamp circuit of the present invention.

Detailed Description

The present invention provides a linear constant current control circuit, which is described in detail below with reference to the accompanying drawings.

Example (b): the utility model provides a linear constant current control circuit, has output and negative pole at least, and its output is provided with operating voltage threshold value and maximum operating current, and linear constant current control circuit is when being applied to linear constant current LED lamp circuit, and the output is along with the commercial power alternating voltage periodic minimum voltage that appears that linear constant current LED lamp circuit inserts, and when the minimum voltage appears, linear constant current control circuit compares the minimum voltage and the operating voltage threshold value of output, according to the current size of its output of comparative result automatic setting: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is larger than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, the current of the output end is kept unchanged, if the current of the output end is smaller than the maximum working current at the moment, the current of the output end is continuously increased until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, the current is kept unchanged, and when the current is increased to be equal to the maximum working current, the maximum working current is kept unchanged.

In this embodiment, as shown in fig. 2, the linear constant current control circuit includes a linear constant current circuit and a voltage control circuit; the linear constant current circuit is provided with an output end, an anode, a cathode and a current control end, wherein the current control end of the linear constant current circuit is used for accessing analog voltage, the analog voltage is used for setting the current magnitude of the output end of the linear constant current circuit, the current control end of the linear constant current circuit is provided with a control voltage threshold, when the voltage of the output end of the linear constant current circuit is greater than or equal to a working voltage threshold, if the voltage accessed by the current control end of the linear constant current circuit is greater than or equal to the control voltage threshold, the current of the current control end of the linear constant current circuit is the maximum working current, if the voltage of the current control end of the linear constant current circuit is less than the control voltage threshold, the current of the current control end of the linear constant current circuit is less than the maximum working current, the current magnitude of the current control end of the linear; the voltage control circuit is provided with an input end, an output end and a negative electrode, the voltage control circuit detects the lowest voltage of the input end in each period and adjusts the analog voltage output by the output end according to the lowest voltage of the input end, when the lowest voltage of the input end of the voltage control circuit is smaller than a working voltage threshold value, the analog voltage of the output end is reduced, when the lowest voltage of the input end of the voltage control circuit is equal to the working voltage threshold value, the analog voltage of the output end is kept unchanged, and when the lowest voltage of the input end of the voltage control circuit is larger than the working voltage threshold value, the analog voltage of the output end is increased; the output end of the linear constant current circuit is connected with the input end of the voltage control circuit, the connecting end of the linear constant current circuit is the output end of the linear constant current control circuit, the output end of the voltage control circuit is connected with the current control end of the linear constant current circuit, the negative electrode of the voltage control circuit is connected with the negative electrode of the linear constant current circuit, and the connecting end of the voltage control circuit is the negative electrode of the linear constant current control circuit; the voltage control circuit detects the lowest voltage of the output end of the linear constant current circuit in each period, adjusts the analog voltage output by the output end of the linear constant current circuit according to the lowest voltage of the output end of the linear constant current circuit, if the lowest voltage of the output end of the linear constant current circuit is larger than or equal to the working voltage threshold value, and the lowest voltage of the output end of the voltage control circuit is larger than or equal to the control voltage threshold value of the current control end of the linear constant current circuit, the current of the output end of the linear constant current circuit is not increased any more and is kept as the maximum working current, if the lowest voltage of the output end of the linear constant current circuit is smaller than the working voltage threshold value, the analog voltage of the output end of the voltage control circuit is reduced to be smaller than the control voltage threshold value, the current of the output end of the linear constant, and is maintained in this equilibrium state.

As shown in fig. 3, in the present embodiment, the linear constant current circuit includes a first integrated circuit chip U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a first capacitor C1, the first integrated circuit chip U1 is a linear constant current chip with an analog DIM port, the reference model is RM90 9010E, one end of the first resistor R1 is the positive electrode of the linear constant current circuit, the other end of the first resistor R1 is connected to the 8 th pin of the first integrated circuit chip U1, the 6 th pin of the first integrated circuit chip U1 and one end of the third resistor R3 are connected and the connection end thereof is the output end of the linear constant current circuit, the other end of the third resistor R3, one end of the fourth resistor R4, one end of the first capacitor C1 and the 3 rd pin of the first integrated circuit chip U1 are connected, the 2 nd pin of the first integrated circuit chip U1 is the output end of the linear constant current circuit, and the first integrated circuit chip U1 and the second pin 2 and the second integrated circuit chip R3526, the other end of the second resistor R2, the other end of the fourth resistor R4 and the other end of the first capacitor C1 are connected with the 1 st pin of the first integrated circuit chip U1, and the connection end of the first capacitor C1 is the negative electrode of the linear constant current circuit.

As shown in fig. 3, in this embodiment, the voltage control circuit includes a fifth resistor R5, a sixth resistor R6, a second capacitor C2, and a first diode D1, the first diode D1 is a zener diode, a cathode of the first diode D1 is an input terminal of the voltage control circuit, an anode of the first diode D1 is connected to one end of the fifth resistor R5, another end of the fifth resistor R5, one end of the sixth resistor R6, and one end of the second capacitor C2 are connected, and a connection end thereof is an output terminal of the voltage control circuit, another end of the sixth resistor R6 is connected to another end of the second capacitor C2, and a connection end thereof is a cathode of the voltage control circuit.

The invention provides a first linear constant current LED lamp circuit realized by adopting the linear constant current control circuit, and the first linear constant current LED lamp circuit is further described in detail in the following with reference to the embodiment of the attached drawings.

Example (b): as shown in fig. 4, a linear constant current LED lamp circuit includes a rectifying filter circuit, an LED light emitting circuit and a linear constant current control circuit, the rectifying filter circuit has a live wire input end, a zero line input end, an output end and a ground end, the LED light emitting circuit has a positive electrode and a negative electrode, the linear constant current control circuit has an output end, a positive electrode and a negative electrode, the output end is provided with a working voltage threshold and a maximum working current, when the linear constant current control circuit is applied to the linear constant current LED lamp circuit, the output end of the linear constant current control circuit periodically presents a minimum voltage along with a mains supply ac voltage accessed by the linear constant current LED lamp circuit, when the minimum voltage appears, the linear constant current control circuit compares the minimum voltage of the output end with the working voltage threshold, and automatically sets a current magnitude of the: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged; the input end of the live wire of the rectification filter circuit is connected with the live wire of the commercial power, the input end of the zero line of the rectification filter circuit is connected with the zero line of the commercial power, the output end of the rectification filter circuit is respectively connected with the anode of the linear constant-current control circuit and the anode of the LED light-emitting circuit, the cathode of the LED light-emitting circuit is connected with the output end of the linear constant-current control circuit, and the cathode of the linear constant-current control circuit is connected with the grounding end of the rectification filter circuit; the rectifying and filtering circuit comprises a first full-bridge rectifying circuit and a first electrolytic capacitor, wherein the No. 1 pin of the first full-bridge rectifying circuit is the live wire input end of the rectifying and filtering circuit, the No. 3 pin of the first full-bridge rectifying circuit is the zero line input end of the rectifying and filtering circuit, the No. 2 pin of the first full-bridge rectifying circuit is connected with the positive electrode of the first electrolytic capacitor, the connecting end of the first full-bridge rectifying circuit is the output end of the rectifying and filtering circuit, the No. 4 pin of the first full-bridge rectifying circuit is connected with the negative electrode of the first electrolytic capacitor, and the connecting end of the first; when the alternating-current voltage of the commercial power connected to the rectifying and filtering circuit is equal to the rated voltage of the commercial power or greater than the rated voltage, and the current at the output end of the linear constant-current control circuit is the maximum working current, the lowest voltage output by the rectifying and filtering circuit is loaded on the LED light-emitting circuit, the lowest voltage at the output end of the linear constant-current control circuit is greater than the working voltage threshold value of the linear constant-current control circuit, the current at the output end of the linear constant-current control circuit is kept to be the maximum working current, and the light emission of the LED light-emitting circuit is; when the alternating-current voltage of the mains supply connected to the rectifying and filtering circuit is lower than the rated voltage of the mains supply, when the highest voltage output by the rectifying and filtering circuit is loaded on the voltage of the output end of the linear constant-current control circuit through the LED light-emitting circuit and is larger than the working voltage threshold value of the linear constant-current control circuit, if the lowest voltage of the output end of the linear constant-current control circuit is lower than the working voltage threshold value of the linear constant-current control circuit, the current of the output end of the linear constant-current control circuit is reduced, so that the lowest voltage of the output end of the linear constant-current control circuit is increased to the working voltage threshold value; if the current of the output end of the linear constant-current control circuit is equal to the maximum working current, the current of the output end of the linear constant-current control circuit is kept unchanged, if the current of the output end of the linear constant-current control circuit is smaller than the maximum working current, the current of the output end of the linear constant-current control circuit is continuously increased until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, the current is kept unchanged, when the current is increased to be equal to the maximum working current, the maximum working current is kept unchanged, and the LED light-emitting circuit; when the alternating voltage of the connected commercial power is too low, the LED light-emitting circuit cannot emit light, or the light-emitting stroboflash can occur when the light-emitting brightness is very low.

In this embodiment, as shown in fig. 2, the linear constant current control circuit includes a linear constant current circuit and a voltage control circuit; the linear constant current circuit is provided with an output end, an anode, a cathode and a current control end, wherein the current control end of the linear constant current circuit is used for accessing analog voltage, the analog voltage is used for setting the current of the output end of the linear constant current circuit, and the current control end of the linear constant current circuit is provided with a control voltage threshold. When the voltage of the output end of the linear constant current circuit is greater than or equal to the working voltage threshold, if the voltage accessed by the current control end of the linear constant current circuit is greater than or equal to the control voltage threshold, the current of the current control end of the linear constant current circuit is the maximum working current, if the voltage of the current control end of the linear constant current circuit is less than the control voltage threshold, the current of the current control end of the linear constant current circuit is less than the maximum working current, the current of the current control end of the linear constant current circuit is related to the magnitude of the analog voltage accessed by the current control end, the higher the accessed analog voltage is, the; the voltage control circuit is provided with an input end, an output end and a negative electrode, the voltage control circuit detects the lowest voltage of the input end in each period and adjusts the analog voltage output by the output end according to the lowest voltage of the input end, when the lowest voltage of the input end of the voltage control circuit is smaller than a working voltage threshold value, the analog voltage of the output end is reduced, when the lowest voltage of the input end of the voltage control circuit is equal to the working voltage threshold value, the analog voltage of the output end is kept unchanged, and when the lowest voltage of the input end of the voltage control circuit is larger than the working voltage threshold value, the analog voltage of the output end is increased; the output end of the linear constant current circuit is connected with the input end of the voltage control circuit, the connecting end of the linear constant current circuit is the output end of the linear constant current control circuit, the output end of the voltage control circuit is connected with the current control end of the linear constant current circuit, the negative electrode of the voltage control circuit is connected with the negative electrode of the linear constant current circuit, and the connecting end of the voltage control circuit is the negative electrode of the linear constant current control circuit; the voltage control circuit detects the lowest voltage of the output end of the linear constant current circuit in each period, adjusts the analog voltage output by the output end of the linear constant current circuit according to the lowest voltage of the output end of the linear constant current circuit, if the lowest voltage of the output end of the linear constant current circuit is larger than or equal to the working voltage threshold value, and the lowest voltage of the output end of the voltage control circuit is larger than or equal to the control voltage threshold value of the current control end of the linear constant current circuit, the current of the output end of the linear constant current circuit is not increased any more and is kept as the maximum working current, if the lowest voltage of the output end of the linear constant current circuit is smaller than the working voltage threshold value, the analog voltage of the output end of the voltage control circuit is reduced to be smaller than the control voltage threshold value, the current of the output end of the linear constant, and is maintained in this equilibrium state.

As shown in fig. 3, in the present embodiment, the linear constant current circuit includes a first integrated circuit chip U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a first capacitor C1, the first integrated circuit chip U1 is a linear constant current chip with an analog DIM port, the reference model is RM90 9010E, one end of the first resistor R1 is the positive electrode of the linear constant current circuit, the other end of the first resistor R1 is connected to the 8 th pin of the first integrated circuit chip U1, the 6 th pin of the first integrated circuit chip U1 and one end of the third resistor R3 are connected and the connection end thereof is the output end of the linear constant current circuit, the other end of the third resistor R3, one end of the fourth resistor R4, one end of the first capacitor C1 and the 3 rd pin of the first integrated circuit chip U1 are connected, the 2 nd pin of the first integrated circuit chip U1 is the output end of the linear constant current circuit, and the first integrated circuit chip U1 and the second pin 2 and the second integrated circuit chip R3526, the other end of the second resistor R2, the other end of the fourth resistor R4 and the other end of the first capacitor C1 are connected with the 1 st pin of the first integrated circuit chip U1, and the connection end of the first capacitor C1 is the negative electrode of the linear constant current circuit; the voltage control circuit comprises a fifth resistor R5, a sixth resistor R6, a second capacitor C2 and a first diode D1, the first diode D1 is a voltage stabilizing diode, the cathode of the first diode D1 is an input end of the voltage control circuit, the anode of the first diode D1 is connected with one end of the fifth resistor R5, the other end of the fifth resistor R5, one end of the sixth resistor R6 and one end of the second capacitor C2 are connected, the connection end of the first diode D5 is an output end of the voltage control circuit, the other end of the sixth resistor R6 is connected with the other end of the second capacitor C2, and the connection end of the sixth resistor R6 is the cathode of the voltage control circuit.

The invention provides a second linear constant current LED lamp circuit implemented by using the above linear constant current control circuit, and the second linear constant current LED lamp circuit of the invention is further described in detail with reference to the accompanying drawings.

Example (b): as shown in fig. 5, a linear constant current LED lamp circuit includes a rectifying filter circuit, an LED light emitting circuit, a linear constant current module, and a linear constant current control circuit, the rectifying filter circuit has a live line input terminal, a zero line input terminal, an output terminal, and a ground terminal, the LED light emitting circuit has a positive electrode and a negative electrode, the linear constant current module has an output terminal, a control terminal, and a negative electrode, the linear constant current control circuit has an output terminal, a positive electrode, and a negative electrode, the output end of the linear constant current control circuit is provided with a working voltage threshold value and a maximum working current, when the linear constant current control circuit is applied to a linear constant current LED lamp circuit, the output end of the linear constant current LED lamp circuit periodically generates the lowest voltage along with the commercial power alternating voltage which is connected in, when the lowest voltage appears, the linear constant current control circuit compares the lowest voltage of the output end with a working voltage threshold value, and automatically sets the current magnitude of the output end according to a comparison result: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged; the input end of the live wire of the rectification filter circuit is connected with the live wire of commercial power, the input end of the null wire of the rectification filter circuit is connected with the null wire of the commercial power, the output end of the rectification filter circuit is respectively connected with the anode of the linear constant current control circuit and the anode of the LED light-emitting circuit, the cathode of the LED light-emitting circuit is connected with the output end of the linear constant current control circuit, the LED light-emitting circuit comprises a first LED light-emitting circuit and a second LED light-emitting circuit, the first LED light-emitting circuit and the second LED light-emitting circuit are both provided with an anode and a cathode, the anode of the first LED light-emitting circuit is the anode of the LED light-emitting circuit, the cathode of the second LED light-emitting circuit is the cathode of the LED light-emitting circuit, the cathode of the first LED light-emitting circuit, the anode of the second LED light-emitting circuit and the output end of the linear constant current module are connected, the control end, the rectifying and filtering circuit comprises a second full-bridge rectifying circuit and a second electrolytic capacitor, wherein the No. 1 pin of the second full-bridge rectifying circuit is the live wire input end of the rectifying and filtering circuit, the No. 3 pin of the second full-bridge rectifying circuit is the zero line input end of the rectifying and filtering circuit, the No. 2 pin of the second full-bridge rectifying circuit is connected with the positive electrode of the second electrolytic capacitor, the connecting end of the second full-bridge rectifying and filtering circuit is the output end of the rectifying and filtering circuit, the No. 4 pin of the second full-bridge rectifying and filtering circuit is connected with the negative electrode of the second electrolytic capacitor, and the connecting end of; the linear constant current module comprises a second integrated circuit chip and a seventh resistor, the second integrated circuit chip adopts a universal linear constant current chip, the linear constant current chip is provided with three connecting ends which are respectively an output end, a negative electrode and a current regulating end, the output end of the linear constant current chip is the output end of the linear constant current module, the current regulating end of the linear constant current chip is connected with one end of the seventh resistor, the connecting end is the control end of the linear constant current module, the negative electrode of the linear constant current chip is connected with the other end of the seventh resistor, the connecting end is the negative electrode of the linear constant current module, and the maximum working current of the output end of the linear constant current chip is determined by regulating the resistance value of the seventh resistor; when the current of the output end of the linear constant current control circuit is larger than or equal to the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is zero, and when the current of the output end of the linear constant current control circuit is smaller than the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is equal to the current obtained by subtracting the current of the output end of the linear constant current control circuit from the maximum working current of the; when the alternating-current voltage of the commercial power connected to the rectifying and filtering circuit is equal to or greater than the rated voltage of the commercial power, the lowest voltage of the output end of the linear constant-current control circuit is greater than the working voltage threshold value of the linear constant-current control circuit, the current of the output end of the linear constant-current control circuit is the maximum working current, the current of the output end of the linear constant-current module is zero at the moment, and the light emitting of the first LED light-emitting circuit and the second LED light-emitting circuit is the highest brightness; when the alternating-current voltage of the mains supply connected to the rectifying and filtering circuit is lower than the rated voltage of the mains supply, and the highest voltage output by the rectifying and filtering circuit is higher than the working voltage threshold value of the linear constant-current control circuit through the LED light-emitting circuit, the linear constant-current control circuit compares the lowest voltage received by the output end of the linear constant-current control circuit with the working voltage threshold value and adjusts the output current of the linear constant-current control circuit, namely when the lowest voltage is lower than the working voltage threshold value, the current of the output end of the linear constant-current control circuit is continuously reduced until the lowest voltage is equal to the working voltage threshold value, and the current is; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged to keep the low-frequency flash light emission of the second LED light-emitting circuit; at the moment, if the current of the output end of the linear constant current control circuit is greater than or equal to the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is zero, and the first LED light-emitting circuit and the second LED light-emitting circuit have the same luminance and are both low-stroboscopic light-emitting; if the current of the output end of the linear constant current control circuit is smaller than the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is not zero, and the current flowing through the second LED light-emitting circuit is the current of the output end of the linear constant current control circuit and is low-frequency flash light-emitting; the current flowing through the first LED light-emitting circuit is the current of the output end of the linear constant-current module, and the first LED light-emitting circuit emits light in a low-frequency flash manner because the lowest voltage of the output end of the linear constant-current module is greater than the working voltage threshold value and the output end of the linear constant-current module is constant current; the linear constant current LED lamp circuit is low-frequency flash light; when the connected commercial power alternating-current voltage is continuously reduced, the highest voltage output by the rectifying and filtering circuit cannot drive the first LED light-emitting circuit and the second LED light-emitting circuit to emit light simultaneously, and after the lowest voltage output by the rectifying and filtering circuit passes through the first LED light-emitting circuit, the lowest voltage at the output end of the linear constant-circuit module is kept to be larger than or equal to the working voltage threshold value, the driving current of the first LED light-emitting circuit is constant, the first LED light-emitting circuit emits light in a low-frequency flash mode, the second LED light-emitting circuit does not emit light, the lowest commercial power alternating-current voltage when only the first LED light-emitting circuit keeps low-frequency flash mode is called as the lowest low-frequency flash voltage, the lowest low-frequency flash voltage is far smaller than the commercial power rated voltage, and the linear constant-current LED lamp circuit has wider.

Claims

1. The linear constant-current control circuit at least comprises an output end and a negative electrode, and is characterized in that the output end of the linear constant-current control circuit is provided with a working voltage threshold and a maximum working current, when the linear constant-current control circuit is applied to a linear constant-current LED lamp circuit, the output end of the linear constant-current control circuit periodically generates the lowest voltage along with the commercial power alternating-current voltage accessed by the linear constant-current LED lamp circuit, when the lowest voltage is generated, the linear constant-current control circuit compares the lowest voltage of the output end with the working voltage threshold, and the current of the output end is automatically set according to the comparison result: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is larger than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, the current of the output end is kept unchanged, if the current of the output end is smaller than the maximum working current at the moment, the current of the output end is continuously increased until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, the current is kept unchanged, and when the current is increased to be equal to the maximum working current, the maximum working current is kept unchanged.

2. The linear constant current control circuit of claim 1, wherein the linear constant current control circuit comprises a linear constant current circuit and a voltage control circuit; the linear constant current circuit is provided with an output end, an anode, a cathode and a current control end, the current control end of the linear constant current circuit is used for accessing an analog voltage, the analog voltage is used for setting the current of the output end of the linear constant current circuit, the current control end of the linear constant current circuit is provided with a control voltage threshold value, when the voltage of the output end of the linear constant current circuit is more than or equal to the working voltage threshold value, if the voltage connected to the current control end is greater than or equal to the control voltage threshold value, the current of the current control end is the maximum working current, if the voltage at its current control terminal is less than the control voltage threshold, then the current at its current control terminal is less than the maximum operating current, the current of the current control terminal is related to the analog voltage accessed by the current control terminal, the higher the accessed analog voltage is, the larger the current is, and the lower the accessed analog voltage is, the smaller the current is; the voltage control circuit is provided with an input end, an output end and a negative electrode, the voltage control circuit detects the lowest voltage of the input end in each period, adjusts the analog voltage output by the output end according to the lowest voltage of the input end, reduces the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is smaller than a working voltage threshold value, keeps the analog voltage of the output end unchanged when the lowest voltage of the input end of the voltage control circuit is equal to the working voltage threshold value, and increases the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is larger than the working voltage threshold value; the output end of the linear constant current circuit is connected with the input end of the voltage control circuit, the connecting end of the linear constant current circuit is the output end of the linear constant current control circuit, the output end of the voltage control circuit is connected with the current control end of the linear constant current circuit, the cathode of the voltage control circuit is connected with the cathode of the linear constant current circuit, and the connecting end of the voltage control circuit is the cathode of the linear constant current control circuit; the voltage control circuit detects the lowest voltage of the output end of the linear constant current circuit in each period, adjusts the analog voltage output by the output end of the linear constant current circuit according to the lowest voltage of the output end of the linear constant current circuit, if the lowest voltage of the output end of the linear constant current circuit is larger than or equal to a working voltage threshold value, and the lowest voltage of the output end of the voltage control circuit is larger than or equal to a control voltage threshold value of the current control end of the linear constant current circuit, the current of the output end of the linear constant current circuit is not increased and is kept as the maximum working current, if the lowest voltage of the output end of the linear constant current circuit is smaller than the working voltage threshold value, the analog voltage of the output end of the voltage control circuit is reduced to be smaller than the control voltage threshold value, and the current of the output end of the linear constant current circuit is reduced, until the voltage control circuit detects that the lowest voltage of the output end of the linear constant current circuit is equal to the working voltage threshold value, and the balance state is maintained.

3. The linear constant current control circuit of claim 2, wherein the linear constant current circuit comprises a first integrated circuit chip, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor, the first integrated circuit chip is a linear constant current chip with an analog DIM port, the reference model is RM9010E, one end of the first resistor is the positive electrode of the linear constant current circuit, the other end of the first resistor is connected with the 8 th pin of the first integrated circuit chip, the 6 th pin of the first integrated circuit chip is connected with one end of the third resistor, the connection end of the first integrated circuit chip is the output end of the linear constant current circuit, the other end of the third resistor, one end of the fourth resistor, one end of the first capacitor is connected with the 3 rd pin of the first integrated circuit chip, the 2 nd pin of the first integrated circuit chip is a current control end of the linear constant current circuit, the 4 th pin of the first integrated circuit chip is connected with one end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor and the 1 st pin of the first integrated circuit chip are connected, and the connecting end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor and the 1 st pin of the first integrated circuit chip is a negative electrode of the linear constant current circuit.

4. The linear constant current control circuit of claim 2, wherein the voltage control circuit comprises a fifth resistor, a sixth resistor, a second capacitor and a first diode, the first diode is a zener diode, the cathode of the first diode is the input terminal of the voltage control circuit, the anode of the first diode is connected to one end of the fifth resistor, the other end of the fifth resistor, one end of the sixth resistor and one end of the second capacitor are connected, the connection terminal of the fifth resistor, one end of the sixth resistor and one end of the second capacitor is the output terminal of the voltage control circuit, the other end of the sixth resistor and the other end of the second capacitor are connected, and the connection terminal of the sixth resistor and the other end of the second capacitor are the cathode of the voltage control circuit.

5. The utility model provides a linear constant current LED lamp circuit, its characterized in that includes rectification filter circuit, LED lighting circuit and linear constant current control circuit, rectification filter circuit have live wire input, zero line input, output and earthing terminal, LED lighting circuit have positive pole and negative pole, linear constant current control circuit have output, positive pole and negative pole, its output is provided with operating voltage threshold and maximum operating current, linear constant current control circuit when being applied to linear constant current LED lamp circuit, its output is along with the commercial power alternating voltage periodic minimum voltage that appears that linear constant current LED lamp circuit inserts, when appearing minimum voltage, linear constant current control circuit with the output minimum voltage and operating voltage threshold compare, according to the current size of its output of comparative result automatic setting: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged; the input end of the live wire of the rectification filter circuit is connected with the live wire of commercial power, the input end of the zero line of the rectification filter circuit is connected with the zero line of the commercial power, the output end of the rectification filter circuit is respectively connected with the anode of the linear constant-current control circuit and the anode of the LED light-emitting circuit, the cathode of the LED light-emitting circuit is connected with the output end of the linear constant-current control circuit, and the cathode of the linear constant-current control circuit is connected with the grounding end of the rectification filter circuit; the rectifying and filtering circuit comprises a first full-bridge rectifying circuit and a first electrolytic capacitor, wherein the 1 st pin of the first full-bridge rectifying circuit is the live wire input end of the rectifying and filtering circuit, the 3 rd pin of the first full-bridge rectifying circuit is the zero line input end of the rectifying and filtering circuit, the 2 nd pin of the first full-bridge rectifying circuit is connected with the positive electrode of the first electrolytic capacitor, the connecting end of the first full-bridge rectifying circuit is the output end of the rectifying and filtering circuit, the 4 th pin of the first full-bridge rectifying circuit is connected with the negative electrode of the first electrolytic capacitor, and the connecting end of the first full-bridge rectifying circuit is the grounding end of the rectifying and filtering circuit; when the alternating-current voltage of the commercial power accessed by the rectifying and filtering circuit is equal to the rated voltage of the commercial power or greater than the rated voltage, and when the current at the output end of the linear constant-current control circuit is the maximum working current, the lowest voltage output by the rectifying and filtering circuit is loaded at the output end of the linear constant-current control circuit through the LED light-emitting circuit, and is greater than the working voltage threshold value, the current at the output end of the linear constant-current control circuit is kept as the maximum working current, and the light emission of the LED light-emitting circuit is the highest brightness of low-frequency flash; when the alternating-current voltage of the mains supply connected to the rectifying and filtering circuit is lower than the rated voltage of the mains supply, when the voltage of the highest voltage output by the rectifying and filtering circuit and loaded on the output end of the linear constant-current control circuit through the LED light-emitting circuit is larger than the working voltage threshold value of the linear constant-current control circuit, if the lowest voltage of the output end of the linear constant-current control circuit is lower than the working voltage threshold value of the linear constant-current control circuit, the current of the output end of the linear constant-current control circuit is reduced, so that the lowest voltage of the output end of the linear constant-current control circuit is increased to the working voltage threshold value of the linear constant-current control circuit, and if the lowest voltage of; if the current of the output end of the linear constant-current control circuit is equal to the maximum working current at the moment, keeping the current of the output end of the linear constant-current control circuit unchanged, if the current of the output end of the linear constant-current control circuit is smaller than the maximum working current at the moment, continuously increasing the current of the output end of the linear constant-current control circuit until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, keeping the current unchanged when the lowest voltage is equal to the working voltage threshold, keeping the maximum working current unchanged when the current is increased to be equal to the maximum working current, and keeping the LED light-emitting circuit to emit light by low; when the alternating current voltage of the accessed mains supply is too low, the LED light-emitting circuit cannot emit light, or light-emitting stroboflash can occur when the light-emitting brightness is very low.

6. The linear constant-current LED lamp circuit according to claim 5, wherein the linear constant-current control circuit comprises a linear constant-current circuit and a voltage control circuit; the linear constant current circuit is provided with an output end, an anode, a cathode and a current control end, wherein the current control end of the linear constant current circuit is used for accessing an analog voltage, the analog voltage is used for setting the current of the output end of the linear constant current circuit, and the current control end of the linear constant current circuit is provided with a control voltage threshold value. When the voltage of the output end of the linear constant current circuit is greater than or equal to the working voltage threshold, if the voltage accessed by the current control end of the linear constant current circuit is greater than or equal to the control voltage threshold, the current of the current control end of the linear constant current circuit is the maximum working current, if the voltage of the current control end of the linear constant current circuit is less than the control voltage threshold, the current of the current control end of the linear constant current circuit is less than the maximum working current, the current of the current control end of the linear constant current circuit is related to the magnitude of the analog voltage accessed by the current control end, the higher the accessed analog voltage is, the larger the; the voltage control circuit is provided with an input end, an output end and a negative electrode, the voltage control circuit detects the lowest voltage of the input end in each period, adjusts the analog voltage output by the output end according to the lowest voltage of the input end, reduces the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is smaller than a working voltage threshold value, keeps the analog voltage of the output end unchanged when the lowest voltage of the input end of the voltage control circuit is equal to the working voltage threshold value, and increases the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is larger than the working voltage threshold value; the output end of the linear constant current circuit is connected with the input end of the voltage control circuit, the connecting end of the linear constant current circuit is the output end of the linear constant current control circuit, the output end of the voltage control circuit is connected with the current control end of the linear constant current circuit, the cathode of the voltage control circuit is connected with the cathode of the linear constant current circuit, and the connecting end of the voltage control circuit is the cathode of the linear constant current control circuit; the voltage control circuit detects the lowest voltage of the output end of the linear constant current circuit in each period, adjusts the analog voltage output by the output end of the linear constant current circuit according to the lowest voltage of the output end of the linear constant current circuit, if the lowest voltage of the output end of the linear constant current circuit is larger than or equal to a working voltage threshold value, and the lowest voltage of the output end of the voltage control circuit is larger than or equal to a control voltage threshold value of the current control end of the linear constant current circuit, the current of the output end of the linear constant current circuit is not increased and is kept as the maximum working current, if the lowest voltage of the output end of the linear constant current circuit is smaller than the working voltage threshold value, the analog voltage of the output end of the voltage control circuit is reduced to be smaller than the control voltage threshold value, and the current of the output end of the linear constant current circuit is reduced, until the voltage control circuit detects that the lowest voltage of the output end of the linear constant current circuit is equal to the working voltage threshold value, and the balance state is maintained.

7. The linear constant current LED lamp circuit according to claim 6, wherein the linear constant current circuit comprises a first integrated circuit chip, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor, the first integrated circuit chip is a linear constant current chip with an analog DIM port, the reference model is RM9010E, one end of the first resistor is the positive electrode of the linear constant current circuit, the other end of the first resistor is connected with the 8 th pin of the first integrated circuit chip, the 6 th pin of the first integrated circuit chip is connected with one end of the third resistor, the connection end of the first integrated circuit chip is the output end of the linear constant current circuit, the other end of the third resistor, one end of the fourth resistor, one end of the first capacitor is connected with the 3 rd pin of the first integrated circuit chip, the 2 nd pin of the first integrated circuit chip is a current control end of the linear constant current circuit, the 4 th pin of the first integrated circuit chip is connected with one end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor are connected with the 1 st pin of the first integrated circuit chip, and the connecting end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor and the 1 st pin of the first integrated circuit chip are connected with each other; the voltage control circuit comprises a fifth resistor, a sixth resistor, a second capacitor and a first diode, wherein the first diode is a voltage stabilizing diode, the cathode of the first diode is the input end of the voltage control circuit, the anode of the first diode is connected with one end of the fifth resistor, the other end of the fifth resistor, one end of the sixth resistor and one end of the second capacitor are connected, the connecting end of the fifth resistor and one end of the second capacitor are the output end of the voltage control circuit, the other end of the sixth resistor and the other end of the second capacitor are connected, and the connecting end of the sixth resistor and the other end of the second capacitor are the cathode of the voltage control circuit.

8. A linear constant current LED lamp circuit is characterized by comprising a rectifying filter circuit, an LED light-emitting circuit, a linear constant current module and a linear constant current control circuit, wherein the rectifying filter circuit is provided with a live wire input end, a zero line input end, an output end and a grounding end, the LED light-emitting circuit is provided with an anode and a cathode, the linear constant current module is provided with an output end, a control end and a cathode, the linear constant current control circuit is provided with an output end, an anode and a cathode, the output end of the linear constant current control circuit is provided with a working voltage threshold value and a maximum working current, when the linear constant current control circuit is applied to the linear constant current LED lamp circuit, the output end of the linear constant current control circuit periodically generates the lowest voltage along with the commercial power alternating current voltage accessed by the linear constant current LED lamp circuit, and when the lowest voltage occurs, the linear constant current control circuit compares, and automatically setting the current magnitude of the output end of the power supply according to the comparison result: when the lowest voltage is equal to the working voltage threshold, the current of the output end of the low-voltage power supply keeps the current setting unchanged; when the lowest voltage is smaller than the working voltage threshold, the current of the output end of the low-voltage transformer is continuously reduced until the lowest voltage is equal to the working voltage threshold, and the current is kept unchanged; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged; the input end of the live wire of the rectification filter circuit is connected with the live wire of commercial power, the input end of the null wire of the rectification filter circuit is connected with the null wire of the commercial power, the output end of the rectification filter circuit is respectively connected with the anode of the linear constant current control circuit and the anode of the LED light-emitting circuit, the cathode of the LED light-emitting circuit is connected with the output end of the linear constant current control circuit, the LED light-emitting circuit comprises a first LED light-emitting circuit and a second LED light-emitting circuit, the first LED light-emitting circuit and the second LED light-emitting circuit are respectively provided with an anode and a cathode, the anode of the first LED light-emitting circuit is the anode of the LED light-emitting circuit, the cathode of the second LED light-emitting circuit is the cathode of the LED light-emitting circuit, and the cathodes of the first LED light-emitting circuit and the second LED light-emitting circuit are connected with the output end of the linear module, the control end of the linear constant current module is connected with the negative electrode of the linear constant current control circuit, the negative electrode of the linear constant current module is connected with the negative electrode of the rectification filter circuit, the rectification filter circuit comprises a second full-bridge rectification circuit and a second electrolytic capacitor, the 1 st pin of the second full-bridge rectification circuit is the live wire input end of the rectification filter circuit, the 3 rd pin of the second full-bridge rectification circuit is the zero line input end of the rectification filter circuit, the 2 nd pin of the second full-bridge rectification circuit is connected with the positive electrode of the second electrolytic capacitor, the connecting end of the second full-bridge rectification circuit is the output end of the rectification filter circuit, the 4 th pin of the second full-bridge rectification filter circuit is connected with the negative electrode of the second electrolytic capacitor, and the connecting end of the second full-bridge rectification filter circuit is the grounding end of the rectification filter circuit; the linear constant current module comprises a second integrated circuit chip and a seventh resistor, the second integrated circuit chip adopts a universal linear constant current chip, the linear constant current chip is provided with three connecting ends which are respectively an output end, a negative electrode and a current regulating end, the output end of the linear constant current chip is the output end of the linear constant current module, the current regulating end of the linear constant current chip is connected with one end of the seventh resistor, the connecting end of the linear constant current chip is the control end of the linear constant current module, the negative electrode of the linear constant current chip is connected with the other end of the seventh resistor, the connecting end of the linear constant current chip is the negative electrode of the linear constant current module, and the maximum working current of the output end of the linear constant current chip is determined by regulating the resistance value of the seventh resistor; when the current of the output end of the linear constant current control circuit is larger than or equal to the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is zero, and when the current of the output end of the linear constant current control circuit is smaller than the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is equal to the current obtained by subtracting the current of the output end of the linear constant current control circuit from the maximum working current of the output end of the linear constant current control circuit; when the alternating-current voltage of the commercial power accessed by the rectifying and filtering circuit is equal to the rated voltage of the commercial power or greater than the rated voltage, the lowest voltage of the output end of the linear constant-current control circuit is greater than the working voltage threshold value of the linear constant-current control circuit, the current of the output end of the linear constant-current control circuit is the maximum working current, the current of the output end of the linear constant-current control circuit is zero at the moment, and the light emission of the first LED light-emitting circuit and the second LED light-emitting circuit is the highest brightness of low-frequency flash; when the alternating-current voltage of the mains supply accessed by the rectifying and filtering circuit is lower than the rated voltage of the mains supply, and the voltage of the highest voltage output by the rectifying and filtering circuit at the output end of the linear constant-current control circuit is higher than the working voltage threshold value of the linear constant-current control circuit through the LED light-emitting circuit, the linear constant-current control circuit compares the lowest voltage received by the output end of the linear constant-current control circuit with the working voltage threshold value to adjust the output current of the linear constant-current control circuit, namely when the lowest voltage is lower than the working voltage threshold value, the current at the output end of the linear constant-current control circuit is continuously reduced until the lowest voltage is equal to the working voltage threshold; when the lowest voltage is greater than the working voltage threshold, if the current of the output end is equal to the maximum working current at the moment, keeping the current of the output end unchanged, if the current of the output end is less than the maximum working current at the moment, continuously increasing the current of the output end until the lowest voltage is equal to the working voltage threshold or the current is increased to be equal to the maximum working current, when the lowest voltage is equal to the working voltage threshold, keeping the current unchanged, and when the current is increased to be equal to the maximum working current, keeping the maximum working current unchanged to keep the low-frequency flash light emission of the second LED light-emitting circuit; at this time, if the current of the output end of the linear constant current control circuit is greater than or equal to the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is zero, and the first LED light-emitting circuit and the second LED light-emitting circuit have the same light-emitting brightness and emit light with low stroboflash; if the current of the output end of the linear constant current control circuit is smaller than the maximum working current of the output end of the linear constant current module, the current of the output end of the linear constant current module is not zero, the current flowing through the second LED light-emitting circuit is the current of the output end of the linear constant current control circuit, and the light-emitting circuit emits light in a low stroboscopic mode; the current flowing through the first LED light-emitting circuit is the current of the output end of the linear constant current module, and the first LED light-emitting circuit emits light with low stroboflash because the lowest voltage of the output end of the linear constant current module is greater than the working voltage threshold value and the output end of the linear constant current module is constant current; the linear constant current LED lamp circuit is low-frequency flash light; when the accessed mains supply alternating-current voltage is continuously reduced, the highest voltage output by the rectifying and filtering circuit cannot drive the first LED light-emitting circuit and the second LED light-emitting circuit to emit light at the same time, and after the lowest voltage output by the rectifying and filtering circuit passes through the first LED light-emitting circuit, the lowest voltage at the output end of the linear constant-circuit module is kept to be larger than or equal to the working voltage threshold value, then the driving current of the first LED light-emitting circuit is constant current, the first LED light-emitting circuit emits light in a low-frequency flash mode, the second LED light-emitting circuit does not emit light, the lowest mains supply alternating-current voltage when only the first LED light-emitting circuit keeps the low-frequency flash mode is called as the low-frequency flash lowest voltage, then the low-frequency flash lowest voltage is far smaller than the mains supply rated voltage, and the linear constant-current LED lamp circuit has wider mains supply voltage adaptability.

9. The linear constant current LED lamp circuit according to claim 8, wherein the linear constant current control circuit comprises a linear constant current circuit and a voltage control circuit; the linear constant current circuit is provided with an output end, an anode, a cathode and a current control end, wherein the current control end of the linear constant current circuit is used for accessing an analog voltage, the analog voltage is used for setting the current of the output end of the linear constant current circuit, and the current control end of the linear constant current circuit is provided with a control voltage threshold value. When the voltage of the output end of the linear constant current circuit is greater than or equal to the working voltage threshold, if the voltage accessed by the current control end of the linear constant current circuit is greater than or equal to the control voltage threshold, the current of the current control end of the linear constant current circuit is the maximum working current, if the voltage of the current control end of the linear constant current circuit is less than the control voltage threshold, the current of the current control end of the linear constant current circuit is less than the maximum working current, the current of the current control end of the linear constant current circuit is related to the magnitude of the analog voltage accessed by the current control end, the higher the accessed analog voltage is, the larger the; the voltage control circuit is provided with an input end, an output end and a negative electrode, the voltage control circuit detects the lowest voltage of the input end in each period, adjusts the analog voltage output by the output end according to the lowest voltage of the input end, reduces the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is smaller than a working voltage threshold value, keeps the analog voltage of the output end unchanged when the lowest voltage of the input end of the voltage control circuit is equal to the working voltage threshold value, and increases the analog voltage of the output end when the lowest voltage of the input end of the voltage control circuit is larger than the working voltage threshold value; the output end of the linear constant current circuit is connected with the input end of the voltage control circuit, the connecting end of the linear constant current circuit is the output end of the linear constant current control circuit, the output end of the voltage control circuit is connected with the current control end of the linear constant current circuit, the cathode of the voltage control circuit is connected with the cathode of the linear constant current circuit, and the connecting end of the voltage control circuit is the cathode of the linear constant current control circuit; the voltage control circuit detects the lowest voltage of the output end of the linear constant current circuit in each period, adjusts the analog voltage output by the output end of the linear constant current circuit according to the lowest voltage of the output end of the linear constant current circuit, if the lowest voltage of the output end of the linear constant current circuit is larger than or equal to a working voltage threshold value, and the lowest voltage of the output end of the voltage control circuit is larger than or equal to a control voltage threshold value of the current control end of the linear constant current circuit, the current of the output end of the linear constant current circuit is not increased and is kept as the maximum working current, if the lowest voltage of the output end of the linear constant current circuit is smaller than the working voltage threshold value, the analog voltage of the output end of the voltage control circuit is reduced to be smaller than the control voltage threshold value, and the current of the output end of the linear constant current circuit is reduced, until the voltage control circuit detects that the lowest voltage of the output end of the linear constant current circuit is equal to the working voltage threshold value, and the balance state is maintained.

10. The linear constant current LED lamp circuit according to claim 9, wherein the linear constant current circuit comprises a first ic chip, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor, the first ic chip is a linear constant current chip with an analog DIM port, the reference model is RM9010E, one end of the first resistor is the positive electrode of the linear constant current circuit, the other end of the first resistor is connected to the 8 th pin of the first ic chip, the 6 th pin of the first ic chip is connected to one end of the third resistor, and the connection end of the first ic chip is the output end of the linear constant current circuit, the other end of the third resistor, one end of the fourth resistor, one end of the first capacitor is connected to the 3 rd pin of the first ic chip, the 2 nd pin of the first integrated circuit chip is a current control end of the linear constant current circuit, the 4 th pin of the first integrated circuit chip is connected with one end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor are connected with the 1 st pin of the first integrated circuit chip, and the connecting end of the second resistor, the other end of the fourth resistor, the other end of the first capacitor and the 1 st pin of the first integrated circuit chip are connected with each other; the voltage control circuit comprises a fifth resistor, a sixth resistor, a second capacitor and a first diode, wherein the first diode is a voltage stabilizing diode, the cathode of the first diode is the input end of the voltage control circuit, the anode of the first diode is connected with one end of the fifth resistor, the other end of the fifth resistor, one end of the sixth resistor and one end of the second capacitor are connected, the connecting end of the fifth resistor and one end of the second capacitor are the output end of the voltage control circuit, the other end of the sixth resistor and the other end of the second capacitor are connected, and the connecting end of the sixth resistor and the other end of the second capacitor are the cathode of the voltage control circuit.