CN108990216B

CN108990216B - LED lamp power supply device and dimming method thereof

Info

Publication number: CN108990216B
Application number: CN201811007435.3A
Authority: CN
Inventors: 李喜发; 王平
Original assignee: Dalian Chang Zheng Electro-Optical Technology Inc (us) 62 Martin Road Concord Massachusetts 017
Current assignee: Dalian Chang Zheng Electro-Optical Technology Inc (us) 62 Martin Road Concord Massachusetts 017
Priority date: 2018-08-31
Filing date: 2018-08-31
Publication date: 2020-01-10
Anticipated expiration: 2038-08-31
Also published as: CN108990216A

Abstract

The invention belongs to the technical field of illumination, and relates to a power supply device of an LED lamp and a dimming method thereof, wherein the dimming method comprises the following steps: (1) the voltage signal is sent to the input end of the voltage follower through the singlechip, (2) the output current of the power supply is controlled, and (3) the output signals of the voltage and current sampling comparator are sent to the input end of the optical coupler. The maximum output power of the power supply is 150W, and the current is 1.4A; the output power can be set to be 13-150W; the automatic dimming output power is suitable for 13-150W; when 100V alternating current is input, the power factor is not less than 0.96 and is 13-150W; when 220V alternating current is input, the power factor is not less than 0.94 and the power output power is 13-150W without screen flash, wherein the power factor is 50-150W. When the light is sufficient, the power supply power is reduced to 10W, and the power supply power can be automatically adjusted according to the intensity of the light, so that the LED street lamp is suitable for mining lamps, tunnel lamps, street lamps and the like.

Description

LED lamp power supply device and dimming method thereof

Technical Field

The invention relates to a power supply device of an LED lamp and a dimming method thereof, belonging to the technical field of illumination.

Background

The current 150W LED power supply on the market has two forms, one is a capacitance LED driving power supply, and the power supply scheme adopts third harmonic injection to remove an electrolytic capacitor in alternating current and direct current conversion so as to prolong the service life of the power supply. The efficiency of a 120W street lamp lighting power supply produced by a typical brand product, namely, the Seamingtai semiconductor company is more than 90%. However, it is difficult to achieve more than 150W in this design scheme, and a PFC operation mode and a control method are proposed in a hangzhou electronic scientific paper, "150W electrolytic capacitor-free LED driving power supply design", and a BOOST (BOOST) PFC circuit is implemented by using a peak current control method in a proximity conduction mode. The power factor of the active PFC circuit is 0.92 at 85V, 0.89 at 220V, 400V at output voltage, 36V at DC/DC output voltage, 4.17A at output current, 150W at output power, 0.85 at efficiency and 7% of total harmonic.

The other is a power supply of the LED street lamp, the power supply is still wide in voltage input, the output voltage after DC/DC conversion is less than or equal to 50V, the control mode of the output power is PWM, the power supply of the LED street lamp with 150W is most widely applied, and typical manufacturers have UEL260-OP series power supplies produced by Fuhua electronics of Stone dragon of Dongguan, such as UEL260-SO54481-OP, the output voltage of the power supply is 41-54V, the current is 4.81A, and the efficiency is 0.94. The feedback signals of the two LED street lamp power supplies are only values of voltage transmission quantity, the characteristics of the feedback signals cannot be accurately expressed, and in addition, the two LED street lamp power supplies do not have an automatic dimming function.

The currently developed power supply is a wide voltage input, and adopts a two-stage structure AC/DC and DC/DC mode. The pre-stage PFC function is a voltage mode power correction controller designed to drive a high efficiency pre-converter to achieve internal input linearity regulation compliance. The stage can meet the output of 150W power and the high power factor close to the value of 1 when the stage works in a CRM current mode, and simultaneously reduces the total harmonic wave quantity of input current by 5 percent. The later-stage DC/DC adopts a frequency/voltage conversion mode, the frequency value can be more accurately controlled by using a frequency sampling method, the conversion efficiency is 0.95, and the power factor, the total current harmonic wave amount and the conversion efficiency of the power supply are all improved compared with the three indexes of the two LED power supplies.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide an LED lamp power supply device and a dimming method thereof. The invention introduces the concept of sampling the signal frequency by the A/D converter, and the FFT processing is carried out after the sampling of the signal frequency enters the singlechip, and the result is output by the D/A converter to the signal processing circuit by applying the PID technology, so that the characteristics of the feedback signal can be expressed more accurately, and the control purpose is achieved.

In order to achieve the above purpose and solve the problems existing in the prior art, the invention adopts the technical scheme that: a kind of LED lamps and lanterns power supply unit, including AC/DC converter, DC/DC converter, LED load and microprocessor unit, the said DC/DC converter, including half bridge type series resonator, rectification filter circuit, L6599 chip, driver circuit, current, voltage sampling circuit, signal processing circuit, photoelectric coupling circuit, the said microprocessor unit, including A/D converter, D/A converter, CP1 one-chip computer, memorizer, photosensitive resistance that the photoelectricity receives, the said CP1 one-chip computer couples to A/D converter, D/A converter, memorizer, photosensitive resistance that the photoelectricity receives respectively, the microprocessor unit has output power and automatic dimming function that can presume the power through the report controller; the output end of the AC/DC converter is connected with the input end of a half-bridge serial resonator, the output end of the half-bridge serial resonator is connected with the input end of a rectifier filter circuit, the output end of the rectifier filter circuit is connected with the input end of an LED load, the output end of the rectifier filter circuit is also connected with the input end of a current and voltage sampling circuit, the output ends of the current and voltage sampling circuit are respectively connected with the input end of an A/D converter and the input end of a signal processing circuit, the output end of the D/A converter is connected with the input end of the signal processing circuit, the output end of the signal processing circuit is connected with the input end of a photoelectric coupling circuit, the output end of the photoelectric coupling circuit is connected with the input end of an L6599 chip; the direct current voltage obtained by the AC/DC converter is transmitted to a half-bridge series resonator, wherein one output is transmitted to a rectifying and filtering circuit and is loaded to an LED load through the output of the rectifying and filtering circuit; the other path of output of the rectifying and filtering circuit is sent to a current and voltage sampling circuit, the sampled signal is sent to a signal processing circuit, in addition, an A/D converter is used for sampling the signal frequency, FFT processing is carried out after the signal frequency enters a CP1 singlechip, the result is output by a D/A converter and sent to the signal processing circuit by using a PID (proportion integration differentiation) technology, the signal frequency is sent to a photoelectric coupling circuit after being processed, the isolated signal voltage is loaded on an L6599 chip and is used for controlling the power of an LED load and ensuring the constancy of the set output power of the LED load; and a switching signal output by the L6599 chip is loaded on the half-bridge type serial resonator through a driver circuit, so that a feedback loop with controllable LED load power is formed, and the purpose of control is achieved.

A dimming method of an LED lamp power supply device comprises the following steps:

step 1, sending a voltage signal to an input end of a voltage follower through a single chip microcomputer, combining an overall circuit diagram of a power supply device of an LED lamp, when the power supply device is lighted by a remote controller, receiving the light intensity of ambient light through a photoresistor H1 in a microprocessor unit, sending the voltage detected by the photoresistor to a pin 4 of a single chip microcomputer CP1 of the microprocessor unit, converting the voltage into a digital quantity through an internal A/D converter of the single chip microcomputer, judging the magnitude of the voltage value through a program, if the voltage is greater than a set value, reducing the output power of the power supply through the program, and otherwise, adjusting the output power of the power supply through the program in a PID mode; then the voltage signal processing unit consisting of U4A and U4B converts the amplitude of the voltage sent by the singlechip CP1 and sends the voltage signal to the input end of the U3D voltage follower;

step 2, controlling the output current of the power supply, wherein the input of the voltage follower U3D is the voltage set by the singlechip CP1 or automatically dimming, and is also the corrected voltage of the power supply output power after frequency sampling; the output of the U3D is sent to the non-inverting input terminal of the current control comparator of U3C, the non-inverting input terminal is connected with one end of a current sampling resistor R52 through a resistor R77, and the other end of the current sampling resistor R52 is grounded; in addition, the non-inverting terminal of U3C is also connected with one end of a parallel circuit consisting of a potentiometer W2 and a resistor R78, the other end of the parallel circuit is connected to the output terminal of the U3D voltage follower through a resistor R80, and is also connected to a 2.5V reference voltage through a resistor R79; the inverting terminal of U3C is grounded through resistor R76 and is also connected with one terminal of current sampling resistor R52, U3C is the current sampling comparator of the power supply, it is controlled by the output of U3D and also provides a threshold voltage by the program to control the output current of the power supply; U3A is a voltage sampling comparator, the output of which is in logical and relation with the output of the U3C current sampling comparator, the in-phase end of U3A is connected with 2.5V reference voltage through a resistor R71, the inverting end of the U3A is connected with two series sampling resistors R73 and R74 through a resistor R72 and then connected with a potentiometer W1 through a resistor R75, and a capacitor C43 is connected with the two ends of the two series sampling resistors R73 and R74 in parallel and is used for sampling ripple voltage;

step 3, output signals of the voltage and current sampling comparator are sent to an input end of the optical coupler, and the process is to convert output signal voltages of the power supply secondary U3A and U3C into photoelectric form for transmission, so that the isolation problem of different public ends between the primary and secondary of the power supply is solved; the output of U3A, U3C connects one end of the input end of the U1 optical coupler, another end of the input end connects the positive 12V of the secondary through the resistance R60, one end of the output end of the optical coupler connects the primary common terminal, another end of the output end connects one end of the resistance R61, another end of the resistance R61, on one hand connect the common end of the secondary through resistance R32 and R29, and another end of R32 connects the 2V voltage that provides for the chip on the 4 th pin RF of the L6599 chip, on the other hand connect to the 5 th pin of the L6599 chip through the resistance R31, the output through the optical coupler can change the voltage on the 5 th pin of the L6599 chip, this voltage that changes is the output frequency of the chip, realize and regulate the output voltage of the secondary through changing the frequency, also regulate the output power of the power, finally reach the automatic dimming purpose.

The invention has the beneficial effects that: a power supply device of an LED lamp and a dimming method thereof are provided, wherein the dimming method comprises the following steps: (1) the voltage signal is sent to the input end of the voltage follower through the singlechip, (2) the output current of the power supply is controlled, and (3) the output signals of the voltage and current sampling comparator are sent to the input end of the optical coupler. Compared with the prior art, the maximum output power of the power supply is 150W, and the current is 1.4A; the output power can be set to be 13-150W; the automatic dimming output power is suitable for 13-150W; when 100V alternating current is input, the power factor is not less than 0.96 and is 13-150W; when 220V alternating current is input, the power factor is not less than 0.94 and the power output power is 13-150W without screen flash, wherein the power factor is 50-150W. When the light is sufficient, the power supply power is reduced to 10W, and the power supply power can be automatically adjusted according to the intensity of the light, so that the LED street lamp is suitable for mining lamps, tunnel lamps, street lamps and the like.

Drawings

Fig. 1 is a general functional block diagram of the present invention.

Fig. 2 is an overall circuit diagram of the present invention.

FIG. 3 is a flow chart of the method steps of the present invention.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1, an LED lamp power supply device includes an AC/DC converter, a DC/DC converter, an LED load, and a microprocessor unit, where the DC/DC converter includes a half-bridge series resonator, a rectifying and filtering circuit, an L6599 chip, a driver circuit, a current and voltage sampling circuit, a signal processing circuit, and a photoelectric coupling circuit, the microprocessor unit includes an a/D converter, a D/a converter, a CP1 single chip, a memory, a photoelectric receiving tube, and a photoresistor, the CP1 single chip is respectively connected with the a/D converter, the D/a converter, the memory, the photoelectric receiving tube, and the photoresistor, and the microprocessor unit has a function of setting output power and automatic dimming of a power supply through a remote controller; the output end of the AC/DC converter is connected with the input end of a half-bridge serial resonator, the output end of the half-bridge serial resonator is connected with the input end of a rectifier filter circuit, the output end of the rectifier filter circuit is connected with the input end of an LED load, the output end of the rectifier filter circuit is also connected with the input end of a current and voltage sampling circuit, the output ends of the current and voltage sampling circuit are respectively connected with the input end of an A/D converter and the input end of a signal processing circuit, the output end of the D/A converter is connected with the input end of the signal processing circuit, the output end of the signal processing circuit is connected with the input end of a photoelectric coupling circuit, the output end of the photoelectric coupling circuit is connected with the input end of an L6599 chip; the direct current voltage obtained by the AC/DC converter is transmitted to a half-bridge series resonator, wherein one output is transmitted to a rectifying and filtering circuit and is loaded to an LED load through the output of the rectifying and filtering circuit; the other path of output of the rectifying and filtering circuit is sent to a current and voltage sampling circuit, the sampled signal is sent to a signal processing circuit, in addition, an A/D converter is used for sampling the signal frequency, FFT processing is carried out after the signal frequency enters a CP1 singlechip, the result is output by a D/A converter and sent to the signal processing circuit by using a PID (proportion integration differentiation) technology, the signal frequency is sent to a photoelectric coupling circuit after being processed, the isolated signal voltage is loaded on an L6599 chip and is used for controlling the power of an LED load and ensuring the constancy of the set output power of the LED load; and a switching signal output by the L6599 chip is loaded on the half-bridge type serial resonator through a driver circuit, so that a feedback loop with controllable LED load power is formed, and the purpose of control is achieved.

As shown in fig. 3, a dimming method of a power supply apparatus of an LED lamp includes the following steps:

step 1, sending a voltage signal to an input end of a voltage follower through a singlechip, combining an overall circuit diagram 2 of a power supply device of an LED lamp, when the power supply device is lighted by a remote controller, receiving the light intensity of ambient light by a photoresistor H1 in a microprocessor unit, sending the voltage detected by the photoresistor to a pin 4 of a singlechip CP1 of the microprocessor unit, converting the voltage into a digital quantity by an internal A/D converter of the singlechip, judging the magnitude of the voltage value by a program, if the voltage is greater than a set value, reducing the output power of the power supply by the program, otherwise, adjusting the output power of the power supply by the program in a PID mode; then the voltage signal processing unit consisting of U4A and U4B converts the amplitude of the voltage sent by the singlechip CP1 and sends the voltage signal to the input end of the U3D voltage follower;

step 2, controlling the output current of the power supply, wherein the input of the voltage follower U3D is the voltage set by the singlechip CP1 or automatically dimming, and is also the corrected voltage of the power supply output power after frequency sampling; the output of the U3D is sent to the non-inverting input terminal of the current control comparator of U3C, the non-inverting input terminal is connected with one end of a current sampling resistor R52 through a resistor R77, and the other end of the current sampling resistor R52 is grounded; in addition, the non-inverting terminal of U3C is also connected with one end of a parallel circuit consisting of a potentiometer W2 and a resistor R78, the other end of the parallel circuit is connected to the output terminal of the U3D voltage follower through a resistor R80, and is also connected to a 2.5V reference voltage through a resistor R79; the inverting terminal of U3C is grounded through resistor R76 and is also connected with one terminal of current sampling resistor R52, U3C is the current sampling comparator of the power supply, it is controlled by the output of U3D and also provides a threshold voltage by the program to control the output current of the power supply; U3A is a voltage sampling comparator, the output of which is in logical and relation with the output of the U3C current sampling comparator, the in-phase end of U3A is connected with 2.5V reference voltage through a resistor R71, the inverting end of the U3A is connected with two series sampling resistors R73 and R74 through a resistor R72 and then connected with a potentiometer W1 through a resistor R75, and a capacitor C43 is connected in parallel with the two ends of the two series sampling resistors R73 and R74 and is used for sampling ripple voltage;

Claims

1. A dimming method of an LED lamp power supply device comprises an AC/DC converter, a DC/DC converter, an LED load and a microprocessor unit, wherein the DC/DC converter comprises a half-bridge type series resonator, a rectifying and filtering circuit, an L6599 chip, a driver circuit, a current and voltage sampling circuit, a signal processing circuit and a photoelectric coupling circuit, the microprocessor unit comprises an A/D converter, a D/A converter, a singlechip CP1, a memory and a photoelectric receiving photoresistor, and the dimming method is characterized in that: the single chip microcomputer CP1 is respectively connected with the A/D converter, the D/A converter, the memory and the photoelectric receiving photoresistor, and the microprocessor unit has the functions of setting the output power of the power supply and automatically dimming through a remote controller; the output end of the AC/DC converter is connected with the input end of a half-bridge serial resonator, the output end of the half-bridge serial resonator is connected with the input end of a rectifier filter circuit, the output end of the rectifier filter circuit is connected with the input end of an LED load, the output end of the rectifier filter circuit is also connected with the input end of a current and voltage sampling circuit, the output ends of the current and voltage sampling circuit are respectively connected with the input end of an A/D converter and the input end of a signal processing circuit, the output end of the D/A converter is connected with the input end of the signal processing circuit, the output end of the signal processing circuit is connected with the input end of a photoelectric coupling circuit, the output end of the photoelectric coupling circuit is connected with the input end of an L6599 chip; the direct current voltage obtained by the AC/DC converter is transmitted to a half-bridge series resonator, wherein one output is transmitted to a rectifying and filtering circuit and is loaded to an LED load through the output of the rectifying and filtering circuit; the other path of output of the rectifying and filtering circuit is sent to a current and voltage sampling circuit, the sampled signal is sent to a signal processing circuit, in addition, an A/D converter is used for sampling the signal frequency, FFT processing is carried out after the signal frequency enters a singlechip CP1, the result is output by a D/A converter and sent to the signal processing circuit by applying PID technology, the signal frequency is sent to a photoelectric coupling circuit after being processed, the isolated signal voltage is loaded on an L6599 chip and used for controlling the power of an LED load and ensuring the constancy of the set output power of the LED load; the switching signal output by the L6599 chip is loaded on the half-bridge series resonator through the driver circuit, so that a feedback loop with controllable LED load power is formed, and the purpose of control is achieved;

the method is characterized by comprising the following steps:

step 1, a voltage signal is sent to an input end of a voltage follower through a singlechip, when the power supply device is lighted by a remote controller, a photoresistor H1 in a microprocessor unit receives the light intensity of ambient light, the voltage detected by the photoresistor is sent to a pin 4 of the singlechip CP1 of the microprocessor unit, the voltage is converted into a digital quantity by an internal A/D converter of the singlechip, the size of the voltage value is judged by a program, if the voltage is greater than a set value, the program reduces the output power of the power supply, otherwise, the program adjusts the output power of the power supply in a PID mode; the voltage signal processing unit converts the amplitude of the voltage sent by the singlechip CP1 and sends the voltage signal to the input end of the U3D voltage follower;

step 2, controlling the output current of the power supply, wherein the input of the voltage follower U3D is the voltage set by the singlechip CP1 or automatically dimming, and is also the corrected voltage of the power supply output power after frequency sampling; the output of U3D is sent to the non-inverting input terminal of the current control comparator of U3C, the non-inverting input terminal of the current control comparator of U3C is connected with one end of a current sampling resistor R52 through a resistor R77, and the other end of the current sampling resistor R52 is grounded; in addition, the non-inverting terminal of U3C is also connected with one end of a parallel circuit consisting of a potentiometer W2 and a resistor R78, the other end of the parallel circuit is connected to the output terminal of the U3D voltage follower through a resistor R80, and is also connected to a 2.5V reference voltage through a resistor R79; the inverting terminal of U3C is grounded through resistor R76 and is also connected with one terminal of current sampling resistor R52, U3C is the current sampling comparator of the power supply, it is controlled by the output of U3D and also provides a threshold voltage by the program to control the output current of the power supply; U3A is a voltage sampling comparator, the output of which is in logical and relation with the output of the U3C current sampling comparator, the in-phase end of U3A is connected with 2.5V reference voltage through a resistor R71, the inverting end of the U3A is connected with two series sampling resistors R73 and R74 through a resistor R72 and then connected with a potentiometer W1 through a resistor R75, and a capacitor C43 is connected in parallel with the two ends of the two series sampling resistors R73 and R74 and is used for sampling ripple voltage;

step 3, output signals of the voltage and current sampling comparator are sent to an input end of the optical coupler, and output signals of U3A and U3C are sent to the input end of the optical coupler, wherein the process is to convert output signal voltages of the secondary power supply U3A and U3C into a photoelectric form for transmission, so that the problem of isolation of different public ends between the primary power supply and the secondary power supply is solved; the output of U3A, U3C connects one end of the input end of the U1 optical coupler, another end of the input end connects the positive 12V of the secondary through the resistance R60, one end of the output end of the optical coupler connects the primary common terminal, another end of the output end connects one end of the resistance R61, another end of the resistance R61, on one hand connect the common end of the secondary through resistance R32 and R29, and another end of R32 connects the 2V voltage that provides for the chip on the 4 th pin RF of the L6599 chip, on the other hand connect to the 5 th pin of the L6599 chip through the resistance R31, the output through the optical coupler can change the voltage on the 5 th pin of the L6599 chip, this voltage that changes is the output frequency of the chip, realize and regulate the output voltage of the secondary through changing the frequency, also regulate the output power of the power, finally reach the automatic dimming purpose.