CN107801274B - Constant-power output LED driving power supply and constant-power output method thereof - Google Patents

Constant-power output LED driving power supply and constant-power output method thereof Download PDF

Info

Publication number
CN107801274B
CN107801274B CN201711106571.3A CN201711106571A CN107801274B CN 107801274 B CN107801274 B CN 107801274B CN 201711106571 A CN201711106571 A CN 201711106571A CN 107801274 B CN107801274 B CN 107801274B
Authority
CN
China
Prior art keywords
output
real
voltage
control chip
power
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201711106571.3A
Other languages
Chinese (zh)
Other versions
CN107801274A (en
Inventor
蔡锐茂
刘雄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SHENZHEN LONGYUN LIGHTING ELECTRIC APPLIANCES CO Ltd
Original Assignee
SHENZHEN LONGYUN LIGHTING ELECTRIC APPLIANCES CO Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SHENZHEN LONGYUN LIGHTING ELECTRIC APPLIANCES CO Ltd filed Critical SHENZHEN LONGYUN LIGHTING ELECTRIC APPLIANCES CO Ltd
Priority to CN201711106571.3A priority Critical patent/CN107801274B/en
Publication of CN107801274A publication Critical patent/CN107801274A/en
Application granted granted Critical
Publication of CN107801274B publication Critical patent/CN107801274B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection

Landscapes

  • Circuit Arrangement For Electric Light Sources In General (AREA)
  • Led Devices (AREA)

Abstract

The invention discloses a constant-power output LED driving power supply and a constant-power output method thereof. The invention calculates the real-time output power through the control chip, and controls the output voltage adjusting module and the output current adjusting module to adjust the voltage and/or the current by utilizing the control chip when the real-time output power is inconsistent with the preset target output power, thereby realizing the constant power output, avoiding the LED light source from being impacted by the overvoltage, overcurrent and overshoot voltage when the LED light source is started, ensuring the service life of the LED light source, ensuring the reliability of illumination, being beneficial to the standardization of products, facilitating the selection of users and saving the cost at the same time.

Description

Constant-power output LED driving power supply and constant-power output method thereof
Technical Field
The invention relates to the field of LED driving, in particular to a constant-power output LED driving power supply and a constant-power output method thereof.
Background
The existing LED driving power supply mainly uses a constant current source, which is determined by the volt-ampere characteristic of the LED, and is beneficial to the stable work of the LED light source. Because the LED light sources are not standardized, the combination of LED light sources with different forward voltage drop values (VF values) and different forward current values (IF values) can be considered as the most available, so that the LED power supply with corresponding requirements has eight gates, which brings great trouble to the design of the LED driving power supply, and in view of this, a constant current source outputting wide voltage, for example, the output current is 350mA, and the output voltage is 10V-36V, and the power supply has the following characteristics:
1) the output power range is wide;
2) the input power range is wide;
3) the light source is subjected to transient current impact by overlarge voltage and current at the moment of electrifying, and the service life of the light source is influenced.
The requirement of a user is met to a certain extent, some problems are brought about, the input power range is wide, all design margins are required to be designed according to the maximum value when a power supply is designed, and the selection of components and parts of a product and the selection of the appearance structure of the product are not exceptional, so that great waste is caused in most application occasions, or the product is too large and cannot be installed.
Thus, the prior art has yet to be improved and enhanced.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide a constant-power-output LED driving power supply and a constant-power-output method thereof, which can ensure the constant output power and save the cost.
In order to achieve the purpose, the invention adopts the following technical scheme:
a constant power output LED driving power supply, comprising:
the output voltage adjusting module is used for feeding back the first voltage sampling signal to the control chip and adjusting the real-time output voltage of the LED driving power supply;
the output current adjusting module is used for feeding back the second voltage sampling signal to the control chip and adjusting the real-time output current of the LED driving power supply;
the control chip is used for receiving the first voltage sampling signal and the second voltage sampling signal and calculating the real-time output power of the LED driving power supply, and when the real-time output power is smaller than the preset target output power of the control chip, the control chip controls the output voltage adjusting module to adjust the voltage and/or controls the output current adjusting module to adjust the current so as to enable the real-time output power of the LED driving power supply to reach the preset target output power;
the control chip is connected with the output voltage adjusting module and the output current adjusting module at the same time.
In the constant power output LED driving power supply, the control chip includes:
the voltage calculating unit is used for calculating the real-time output voltage of the LED driving power supply according to the first voltage sampling signal;
the current calculating unit is used for receiving the second voltage sampling signal to calculate the real-time output current of the LED driving power supply;
the power calculation unit is used for calculating the real-time output power of the LED driving power supply according to the real-time output voltage and the real-time output current;
and the power adjusting unit is used for comparing the real-time output power with the output power preset by the control chip, and controlling the output voltage adjusting module to perform voltage adjustment and/or controlling the output current adjusting module to perform current adjustment when the real-time output power is smaller than the preset target output power, so that the real-time output power of the LED driving power supply reaches the preset target output power.
In the constant-power output LED driving power supply, the control chip is further used for outputting an abnormal closing signal when the real-time output voltage is greater than the preset maximum output voltage of the control chip, or when the real-time output current is greater than the preset maximum output current of the control chip, or when the real-time output power is greater than the preset maximum output power of the control chip or the preset current output power of the control chip.
Constant power output LED drive power supply in, output voltage adjustment module includes first resistance, second resistance, third resistance, first MOS pipe and first comparator, drive power supply's secondary positive end is connected to the one end of first resistance, the one end of second resistance, the one end of third resistance, the inverting input of first comparator and control chip's 7 th foot are connected to the other end of first resistance, the source electrode of current adjustment module and first MOS pipe is connected to the other end of second resistance, control chip's 3 rd foot is connected to the grid of first MOS pipe, the other end of third resistance is connected to the drain electrode of first MOS pipe, the first reference voltage of inphase input of first comparator, the output feedback of first comparator is to drive power supply's elementary, control circuit's output.
The constant power output LED driving power supply, among the output current adjustment module includes fourth resistance, fifth resistance, second MOS pipe and second comparator, the 6 th pin of control chip is connected to the grid of second MOS pipe, the one end of fifth resistance and the secondary negative terminal of driving power supply are connected through the fourth resistance to the source electrode of second MOS pipe, the other end of second resistance, the other end of fifth resistance, the 5 th pin of control chip and the inverting input of second comparator are connected to the drain electrode of second MOS pipe, the inphase input end input second reference voltage of second comparator, the output feedback of second comparator is to driving power supply's elementary, control circuit's output.
In the constant power output LED driving power supply, the model of the control chip is PIC12F 683.
In the constant-power output LED driving power supply, the first MOS tube and the second MOS tube are both N-channel MOS tubes.
A constant power output method adopting the constant power LED driving power supply comprises the following steps:
the control chip receives a first voltage sampling signal fed back by the output voltage adjusting module and a second voltage sampling signal fed back by the output current adjusting module;
the control chip calculates the real-time output power of the LED driving power supply;
the control chip compares the real-time output power with a preset target output power, and controls the output voltage adjusting module to adjust the voltage and/or controls the output current adjusting module to adjust the current when the real-time output power is smaller than the preset target output power of the control chip, so that the real-time output power of the LED driving power supply reaches the preset target output power.
In the constant power output method, the step of calculating the real-time output power of the LED driving power by the control chip specifically includes:
the voltage calculating unit calculates the real-time output voltage of the LED driving power supply according to the first voltage sampling signal;
the current calculating unit calculates the real-time output current of the LED driving power supply according to the first voltage sampling signal;
and the power calculating unit calculates the real-time output power of the LED driving power supply according to the real-time output voltage and the real-time output current.
The constant power output method further comprises the following steps:
and the control chip outputs an abnormal closing signal when the real-time output voltage is greater than the preset maximum output voltage of the control chip, or when the real-time output current is greater than the preset maximum output current of the control chip, or when the real-time output power is greater than the preset maximum output power of the control chip or the preset current output power of the control chip.
Compared with the prior art, the constant power output LED driving power supply and the constant power output method thereof provided by the invention comprise an output voltage adjusting module for feeding back a first voltage sampling signal to a control chip and adjusting the real-time output voltage of the LED driving power supply, an output current adjusting module for feeding back a second voltage sampling signal to the control chip and adjusting the real-time output current of the LED driving power supply, and a control module for receiving the first voltage sampling signal and the second voltage sampling signal and calculating the real-time output power of the LED driving power supply, wherein when the real-time output power is smaller than the preset target output power of the control chip, the control module adjusts the voltage and/or controls the output current adjusting module to adjust the current so as to enable the real-time output power of the LED driving power supply to reach the preset target output power and the control chip, the control chip is connected with the output voltage adjusting module and the output current adjusting module at the same time. The invention calculates the real-time output power through the control chip, and controls the output voltage adjusting module and the output current adjusting module to adjust the voltage and/or the current by utilizing the control chip when the real-time output power is inconsistent with the preset target output power, thereby realizing the constant power output, avoiding the LED light source from being impacted by the overvoltage, overcurrent and overshoot voltage when the LED light source is started, ensuring the service life of the LED light source, ensuring the reliability of illumination, being beneficial to the standardization of products, facilitating the selection of users and saving the cost at the same time.
Drawings
Fig. 1 is a schematic diagram of a constant power output LED driving power supply provided by the present invention.
Fig. 2 is a block diagram of a structure of the control chip in the constant power output LED driving power supply provided by the present invention.
Fig. 3 is a graph of output characteristics of a MOS transistor.
Fig. 4 is a flowchart of a constant power output method provided by the present invention.
Fig. 5 is a flowchart of the step S200 in the constant power output method provided in the present invention.
Fig. 6 is a flowchart of a constant power output method according to a preferred embodiment of the present invention.
Detailed Description
The invention provides a constant power output LED driving power supply and a constant power output method thereof, and in order to make the purpose, technical scheme and effect of the invention clearer and clearer, the invention is further described in detail by referring to the attached drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Referring to fig. 1, the constant power output LED driving power supply provided by the present invention includes an output voltage adjusting module 1, an output current adjusting module 2, and a control chip 3, wherein the control chip 3 is connected to the output voltage adjusting module 1 and the output current adjusting module 2 at the same time.
Specifically, the output voltage adjusting module 1 is configured to feed back a first voltage sampling signal to the control chip 3 and adjust a real-time output voltage of the LED driving power supply; the output current adjusting module 2 is used for feeding back a second voltage sampling signal to the control chip 3 and adjusting the real-time output current of the LED driving power supply; the control chip 3 is used for receiving the first voltage sampling signal and the second voltage sampling signal and calculating the real-time output power of the LED driving power supply, and when the real-time output power is smaller than the preset target output power of the control chip, the control output voltage adjusting module 1 is controlled to adjust the voltage and/or the control output current adjusting module 2 is controlled to adjust the current, so that the real-time output power of the LED driving power supply reaches the preset target output power.
In other words, the output voltage of the secondary winding of the transformer is subjected to voltage sampling through the output voltage adjusting module 1, the output voltage adjusting module 1 sends a first voltage sampling signal to a primary flyback circuit of the transformer, so that the maximum output voltage of the secondary winding of the transformer is limited, meanwhile, the output voltage adjusting module 1 also sends the first voltage sampling signal to the control chip 3, and the control chip 3 calculates the output voltage of the LED driving power supply; similarly, the output current of the secondary winding of the transformer is sampled by the output current adjusting module 2, the output current adjusting module 2 sends a second voltage sampling signal to the primary flyback circuit of the transformer, so that the maximum output current of the secondary winding of the transformer is limited, meanwhile, the output current adjusting module 2 also sends the second voltage sampling signal to the control chip 3, and the control chip 3 calculates the output current of the LED driving power supply; the control chip 3 further calculates the real-time output power of the LED driving power supply by calculating the real-time output voltage and the real-time output current of the LED driving power supply, compares the real-time output power with a preset target output power, controls the output voltage adjusting module 1 to perform voltage adjustment and/or controls the output current adjusting module 2 to perform current adjustment when the real-time output power is smaller than the preset target output power, specifically changes the sampling resistance value of the output voltage adjusting module 1 and/or the output current adjusting module 2, thereby changing the first voltage sampling signal and/or the second voltage sampling signal, further changing the output voltage and the output current of the LED driving power supply, further making the real-time output power of the LED driving power supply reach the preset target output power, preferably, the model of the control chip 3 is PIC12F683, the processing speed is fast, the performance is stable, and of course, in other embodiments, the control chip 3 may also be a control chip of other types, which is not limited in the present invention.
The invention calculates the real-time output power by using the control chip, controls the output voltage adjusting module and the output current adjusting module to adjust the voltage and/or the current by using the control chip when the real-time output power is inconsistent with the preset target output power, thereby realizing the constant power output, avoiding the LED light source from being impacted by the overvoltage, overcurrent and overshoot voltage when the LED light source is started, ensuring the service life of the LED light source, ensuring the reliability of illumination, being beneficial to the standardization of products, facilitating the selection of users and saving the cost.
Further, referring to fig. 2, the control chip 3 includes:
the voltage calculating unit 301 is configured to calculate a real-time output voltage of the LED driving power supply according to the first voltage sampling signal;
the current calculating unit 302 is configured to receive the second voltage sampling signal and calculate a real-time output current of the LED driving power supply;
the power calculation unit 303 is used for calculating the real-time output power of the LED driving power supply according to the real-time output voltage and the real-time output current;
the power adjusting unit 304 is configured to compare the real-time output power with a preset output power of the control chip, and when the real-time output power is smaller than a preset target output power, control the output voltage adjusting module to perform voltage adjustment and/or control the output current adjusting module to perform current adjustment, so that the real-time output power of the LED driving power supply reaches the preset target output power.
The voltage calculation unit 301 and the current calculation unit 302 are simultaneously connected to the power calculation unit 303, and the power calculation unit 303 is further connected to the power adjustment unit 304.
According to the invention, the voltage calculation unit 301 is used for processing the first voltage sampling signal, and further calculating the real-time output voltage of the LED driving power supply; the current calculating unit 302 is used for processing the second voltage sampling signal to further calculate the real-time output current of the LED driving power supply, the power calculating unit 303 multiplies the real-time output voltage by the real-time output current to obtain the real-time output power of the LED driving power supply, the power adjusting unit 304 is used for comparing the real-time output power with the target output power preset by the control chip, and when the real-time output power is smaller than the preset target output power, the output voltage adjusting module is controlled to perform voltage adjustment and/or the output current adjusting module is controlled to perform current adjustment, so that the real-time output power of the LED driving power supply reaches the preset target output power.
Further, the control chip 3 is further configured to output an abnormal shutdown signal when the real-time output voltage is greater than a preset maximum output voltage of the control chip, or when the real-time output current is greater than a preset maximum output current of the control chip, or when the real-time output power is greater than a preset maximum output power of the control chip or a preset current output power of the control chip, so as to remind a user that the output of the LED driving power supply is abnormal or the power supply of the LED driving power supply is directly cut off, thereby well preventing the LED light source from being impacted by an overvoltage, overcurrent and overshoot voltage during startup, ensuring the service life of the LED light source, ensuring the reliability of illumination, and protecting electrical components in the circuit from being damaged.
With reference to fig. 1, the output voltage adjustment module 1 includes a first resistor R1, a second resistor R2, a third resistor R3, a first MOS transistor V1, and a first comparator AMP1, one end of the first resistor R1 is connected with the positive end of the secondary of the driving power supply, the other end of the first resistor R1 is connected with one end of the second resistor R2, one end of the third resistor R3, the inverting input end of the first comparator AMP1 and the 7 th pin of the control chip 3, the other end of the second resistor R2 is connected with the current adjusting module 2 and the source of the first MOS transistor V1, the grid electrode of the first MOS tube V1 is connected with the 3 rd pin of the control chip 3, the drain electrode of the first MOS tube V1 is connected with the other end of the third resistor R3, a non-inverting input terminal of the first comparator AMP1 inputs a first reference voltage Vref1, the output end of the first comparator AMP1 is fed back to the primary stage of the driving power supply, and the output end of the control circuit.
Specifically, the invention utilizes the resistance value change of the drain of the MOS transistor to adjust the resistance value of the sampling resistor, so as to change the output first voltage sampling signal, and further change the real-time output voltage, as shown in fig. 3, the drain resistance value (Rds) of the MOS transistor is changed, that is, the variable resistance region, so that after the first MOS transistor V1 is connected into the circuit, the first MOS transistor V1 is equivalent to an adjustable resistor, the conduction depth of the first MOS transistor is controlled by the control signal output by the control chip 3, the maximum value of the output voltage can be set by the first resistor R1, the second resistor R2 and the third resistor R3, that is, the maximum value of the output voltage when the first MOS transistor is completely conducted, thereby preventing the LED light source from being damaged due to the excessively high voltage at the initial stage of power supply, the control chip 3 sends different control signals to control the first MOS transistor to realize different conduction states, thereby changing the resistance value of the sampling resistor, further causing the voltage output by the flyback circuit to change.
With reference to fig. 1, the output current adjusting module 2 includes a fourth resistor R4, a fifth resistor R5, a second MOS transistor V2 and a second comparator AMP2, a gate of the second MOS transistor V2 is connected to the 6 th pin of the control chip 3, a source of the second MOS transistor V2 is connected to one end of the fifth resistor R5 and a negative terminal of a secondary side of the driving power supply through a fourth resistor R4, a drain of the second MOS transistor V2 is connected to the other end of the second resistor R2, the other end of the fifth resistor R5, the 5 th pin of the control chip 3 and an inverting input terminal of the second comparator AMP2, a non-inverting input terminal of the second comparator AMP2 inputs a second reference voltage Vref2, and an output terminal of the second comparator AMP2 is fed back to the primary side of the driving power supply to control an output of the circuit.
Specifically, the resistance value of the sampling resistor is adjusted by using the change of the resistance value of the drain electrode of the second MOS transistor, so that the output second voltage sampling signal is changed, and further the real-time output current is changed, after the second MOS transistor V2 is connected into the circuit, the second MOS transistor V2 is equivalent to an adjustable resistor, the control chip 3 outputs a control signal to control the conduction depth of the second MOS transistor V2, the fourth resistor R4 and the fifth resistor R5 can set the maximum value of the output current, that is, the maximum value of the output current when the second MOS transistor is completely conducted, so that the LED light source is prevented from being damaged due to excessive current at the power-on initial stage, the control chip 3 sends different control signals to control the second MOS transistor to realize different conduction states, so that the resistance value of the sampling resistor is changed, and the current output by the flyback circuit is further changed.
Specifically, the first MOS transistor and the second MOS transistor are both N-channel MOS transistors.
In this embodiment, the process of adjusting the real-time output power by the control chip 3 is a process of gradually analyzing and increasing, and specifically, when it is determined that the real-time output power is greater than a target output power preset by the control chip, the control chip controls the output voltage adjustment module to increase an output voltage with an amplitude, calculates the output power at that time, compares the calculated output power with the target output power, continues to control the output voltage adjustment module to increase the output voltage with an amplitude when the output power at that time is still less than the target output power, and so on until the real-time output power is equal to the target output power, and when the output voltage adjustment module adjusts the output voltage to the maximum output voltage and the real-time output power is still less than the target output power, the control chip controls the output current adjustment module to increase an output current with an amplitude, and calculating the output power at the moment, comparing the calculated output power with the target output power, and when the output power at the moment is still smaller than the target output power, continuing to control the output current adjusting module to increase the output current by an amplitude, and so on until the real-time output power is equal to the target output power and then stopping, thereby avoiding the impact caused by sudden overlarge change of the current or voltage in the circuit.
Based on the constant-power output LED driving power supply, the present invention further provides a constant-power output method of the constant-power output LED driving power supply, and please refer to fig. 4, where the method includes:
s100, the control chip receives a first voltage sampling signal fed back by the output voltage adjusting module and a second voltage sampling signal fed back by the output current adjusting module;
s200, calculating the real-time output power of the LED driving power supply by the control chip;
s300, the control chip compares the real-time output power with a preset target output power, and when the real-time output power is smaller than the preset target output power of the control chip, the control chip controls the output voltage adjusting module to perform voltage adjustment and/or controls the output current adjusting module to perform current adjustment, so that the real-time output power of the LED driving power supply reaches the preset target output power.
Referring to fig. 5, the step S200 specifically includes:
s201, a voltage calculating unit calculates real-time output voltage of the LED driving power supply according to a first voltage sampling signal;
s202, calculating real-time output current of the LED driving power supply by a current calculating unit according to the first voltage sampling signal;
and S203, calculating the real-time output power of the LED driving power supply by the power calculating unit according to the real-time output voltage and the real-time output current.
Further, the constant power output method further includes:
and the control chip outputs an abnormal closing signal when the real-time output voltage is greater than the preset maximum output voltage of the control chip, or when the real-time output current is greater than the preset maximum output current of the control chip, or when the real-time output power is greater than the preset maximum output power of the control chip or the preset current output power of the control chip.
Since the constant power LED driving power supply has been described in detail above, the constant power output method of the constant power LED driving power supply is not described herein again.
For better understanding of the present invention, the following detailed description of the technical solution of the present invention is provided with reference to fig. 6:
step 10, configuring a maximum value of an output voltage, a maximum value of an output current, a minimum value of an output voltage, a minimum value of an output current, and a target output power Pc, wherein the maximum value of the output voltage Vomax = (R1+ R2// R3)/(R2// R3) × Vref1 (///: represents that resistors are connected in parallel, the same shall apply hereinafter), the maximum value of the output current Iomax = Vref2/(R4// R5), the minimum value of the output voltage Vomin = (R1+ R2)/R2 × Vref1, and the minimum value of the output current Iomin = Vref 2/R4;
step 20, calculating an initial output power Po of the LED driving power supply, where the initial output power Po = Io Vo, where Io is an initial output current value and Vo is an initial output voltage value;
step 30, judging whether the initial output voltage value is greater than the maximum value of the output voltage, or whether the initial output current value is greater than the maximum value of the output current, or whether the initial output power is greater than the target output power, if so, executing step 40, otherwise, executing step 50;
step 40, controlling the chip to output an abnormal closing signal;
step 50, calculating the real-time output power Pt of the LED driving power supply, judging whether the real-time output power is larger than the target output power, and if so, executing step 40; otherwise, go to step 60;
step 60, controlling the output voltage adjusting module to increase the output voltage Vadd with one amplitude;
step 70, judging whether the increased output voltage value Vt is smaller than the maximum value of the output voltage, if so, executing step 80, otherwise, executing step 90;
step 80, judging whether the output power at the moment is smaller than the target output power, if so, executing step 60;
step 90, controlling the output current adjusting module to increase the output current Iadd with one amplitude;
step 100, judging whether the increased output current value It is smaller than the maximum value of the output current, if so, executing step 80.
Finally, in the constant power output LED driving power supply and the constant power output method thereof provided by the present invention, the constant power output LED driving power supply includes an output voltage adjusting module, an output current adjusting module, and a control chip, and the control chip is simultaneously connected to the output voltage adjusting module and the output current adjusting module. The invention calculates the real-time output power through the control chip, and controls the output voltage adjusting module and the output current adjusting module to adjust the voltage and/or the current by utilizing the control chip when the real-time output power is inconsistent with the preset target output power, thereby realizing the constant power output, avoiding the LED light source from being impacted by the overvoltage, overcurrent and overshoot voltage when the LED light source is started, ensuring the service life of the LED light source, ensuring the reliability of illumination, being beneficial to the standardization of products, facilitating the selection of users and saving the cost at the same time.
It should be understood that equivalents and modifications of the technical solution and inventive concept thereof may occur to those skilled in the art, and all such modifications and alterations should fall within the scope of the appended claims.

Claims (8)

1. A constant power output LED driving power supply, comprising:
the output voltage adjusting module is used for feeding back the first voltage sampling signal to the control chip and adjusting the real-time output voltage of the LED driving power supply;
the output current adjusting module is used for feeding back the second voltage sampling signal to the control chip and adjusting the real-time output current of the LED driving power supply;
the control chip is used for receiving the first voltage sampling signal and the second voltage sampling signal and calculating the real-time output power of the LED driving power supply, and when the real-time output power is smaller than the preset target output power of the control chip, the control chip controls the output voltage adjusting module to adjust the voltage and/or controls the output current adjusting module to adjust the current so as to enable the real-time output power of the LED driving power supply to reach the preset target output power;
the control chip is simultaneously connected with the output voltage adjusting module and the output current adjusting module;
the output voltage adjusting module comprises a first resistor, a second resistor, a third resistor, a first MOS (metal oxide semiconductor) tube and a first comparator, wherein one end of the first resistor is connected with the positive end of the secondary of the driving power supply, the other end of the first resistor is connected with one end of the second resistor, one end of the third resistor, the inverting input end of the first comparator and the 7 th pin of the control chip, the other end of the second resistor is connected with the current adjusting module and the source electrode of the first MOS tube, the grid electrode of the first MOS tube is connected with the control chip, the drain electrode of the first MOS tube is connected with the other end of the third resistor, the non-inverting input end of the first comparator inputs a first reference voltage, and the output end of the first comparator is fed back to the primary of the driving power supply and the output of the control circuit;
setting a maximum value of an output voltage through the first resistor, the second resistor and the third resistor;
the voltage output by the flyback circuit is changed by changing the resistance value of the sampling resistor;
the output current adjusting module comprises a fourth resistor, a fifth resistor, a second MOS tube and a second comparator, wherein the grid electrode of the second MOS tube is connected with a pin 6 of the control chip, the source electrode of the second MOS tube is connected with one end of the fifth resistor and the negative end of the secondary of the driving power supply through the fourth resistor, the drain electrode of the second MOS tube is connected with the other end of the second resistor, the other end of the fifth resistor, the control chip and the reverse-phase input end of the second comparator, a second reference voltage is input to the non-inverting input end of the second comparator, and the output end of the second comparator is fed back to the primary of the driving power supply and the output of the control circuit;
setting a maximum value of an output current through the fourth resistor and the fifth resistor;
the voltage output by the flyback circuit is changed by changing the resistance value of the sampling resistor;
the control chip controls the output voltage adjusting module to increase output voltage with an amplitude, calculates output power at the moment and compares the output voltage with target output power, when the output power at the moment is still less than the target output power, the control chip continuously controls the output voltage adjusting module to increase the output voltage with the amplitude until the real-time output power is equal to the target output power and stops, when the output voltage is adjusted to the maximum output voltage by the output voltage adjusting module and the real-time output power is still less than the target output power, the control chip controls the output current adjusting module to increase output current with the amplitude, calculates the output power at the moment and compares the output power with the target output power, and when the output power at the moment is still less than the target output power, the control chip continuously controls the output current adjusting module to increase the output current with the amplitude, stopping until the real-time output power is equal to the target output power; the control chip is used for controlling the resistance value of the sampling resistor in the output voltage adjusting module and the resistance value of the sampling resistor in the output current adjusting module to adjust the output voltage and/or the output current, so that constant power output is realized, and the LED light source is prevented from being impacted by overvoltage, overcurrent and overshoot voltage during starting.
2. The constant power output LED driving power supply according to claim 1, wherein the control chip comprises:
the voltage calculating unit is used for calculating the real-time output voltage of the LED driving power supply according to the first voltage sampling signal;
the current calculating unit is used for receiving the second voltage sampling signal to calculate the real-time output current of the LED driving power supply;
the power calculation unit is used for calculating the real-time output power of the LED driving power supply according to the real-time output voltage and the real-time output current;
and the power adjusting unit is used for comparing the real-time output power with the output power preset by the control chip, and controlling the output voltage adjusting module to perform voltage adjustment and/or controlling the output current adjusting module to perform current adjustment when the real-time output power is smaller than the preset target output power, so that the real-time output power of the LED driving power supply reaches the preset target output power.
3. The constant-power-output LED driving power supply according to claim 2, wherein the control chip is further configured to output an abnormal turn-off signal when the real-time output voltage is greater than a preset maximum output voltage of the control chip, or when the real-time output current is greater than a preset maximum output current of the control chip, or when the real-time output power is greater than a preset maximum output power of the control chip or a preset current output power of the control chip.
4. The constant power output LED driving power supply as claimed in claim 1, wherein the model number of the control chip is PIC12F 683.
5. The constant-power-output LED driving power supply according to claim 4, wherein the first MOS transistor and the second MOS transistor are both N-channel MOS transistors.
6. A constant power output method using the constant power output LED driving power supply according to any one of claims 1 to 5, comprising the steps of:
the control chip receives a first voltage sampling signal fed back by the output voltage adjusting module and a second voltage sampling signal fed back by the output current adjusting module;
the control chip calculates the real-time output power of the LED driving power supply;
the control chip compares the real-time output power with a preset target output power, and controls the output voltage adjusting module to adjust the voltage and/or controls the output current adjusting module to adjust the current when the real-time output power is smaller than the preset target output power of the control chip, so that the real-time output power of the LED driving power supply reaches the preset target output power.
7. The constant power output method according to claim 6, wherein the step of calculating the real-time output power of the LED driving power supply by the control chip specifically comprises:
the voltage calculating unit calculates the real-time output voltage of the LED driving power supply according to the first voltage sampling signal;
the current calculating unit calculates the real-time output current of the LED driving power supply according to the first voltage sampling signal;
and the power calculating unit calculates the real-time output power of the LED driving power supply according to the real-time output voltage and the real-time output current.
8. The constant power output method according to claim 7, further comprising:
and the control chip outputs an abnormal closing signal when the real-time output voltage is greater than the preset maximum output voltage of the control chip, or when the real-time output current is greater than the preset maximum output current of the control chip, or when the real-time output power is greater than the preset maximum output power of the control chip or the preset current output power of the control chip.
CN201711106571.3A 2017-11-10 2017-11-10 Constant-power output LED driving power supply and constant-power output method thereof Active CN107801274B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201711106571.3A CN107801274B (en) 2017-11-10 2017-11-10 Constant-power output LED driving power supply and constant-power output method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201711106571.3A CN107801274B (en) 2017-11-10 2017-11-10 Constant-power output LED driving power supply and constant-power output method thereof

Publications (2)

Publication Number Publication Date
CN107801274A CN107801274A (en) 2018-03-13
CN107801274B true CN107801274B (en) 2020-05-26

Family

ID=61534783

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201711106571.3A Active CN107801274B (en) 2017-11-10 2017-11-10 Constant-power output LED driving power supply and constant-power output method thereof

Country Status (1)

Country Link
CN (1) CN107801274B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111083848B (en) * 2019-12-31 2022-07-08 华域视觉科技(上海)有限公司 Overload protection method, device, equipment and medium for automobile LED lamp
CN113131589B (en) * 2021-05-24 2023-05-30 山西暗石电子技术有限公司 Constant power supply module and integrated circuit

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101577430A (en) * 2008-05-08 2009-11-11 湖北盛佳电器设备有限公司 Power factor compensating device
CN201995170U (en) * 2011-01-12 2011-09-28 巢湖凯达照明技术有限公司 Large power light-emitting diode (LED) constant power source
CN103096601B (en) * 2013-01-25 2015-03-18 海林火地电气科技有限公司 Light emitting diode (LED) power self-adaptive driver
CN205982418U (en) * 2016-09-08 2017-02-22 广东美的生活电器制造有限公司 Power discrepancy correcting device
CN106507547B (en) * 2016-12-27 2018-01-16 苏州纽克斯电源技术股份有限公司 A kind of LED dimming control systems

Also Published As

Publication number Publication date
CN107801274A (en) 2018-03-13

Similar Documents

Publication Publication Date Title
US9052728B2 (en) Start-up circuit and method thereof
US20170110966A1 (en) Systems and methods for enhanced efficiency auxiliary power supply module
US9083237B2 (en) Circuits and methods for controlling a DC/DC converter
CN109861329B (en) Linear charging system, constant-current constant-voltage control circuit and voltage following control method thereof
US8576529B2 (en) Power stage control circuit
US9867240B2 (en) Filter circuit
JP2008160933A (en) Chopper regulator circuit
US10218195B2 (en) Switching-type charging circuit capable of quickly dropping the voltage at the input end to zero
CN107801274B (en) Constant-power output LED driving power supply and constant-power output method thereof
US9069366B2 (en) Switching regulator
TW201523187A (en) Voltage regulator
US9240716B2 (en) Switching power supply circuit
CN105763055A (en) Power circuit
US7579813B2 (en) Power regulator having a voltage regulator module and having a voltage buffer module to provide a constant voltage output
US9006979B2 (en) Protection circuit with low energy-consumption and driving circuit thereof
US9055649B2 (en) Control circuit and control method of light emitting device circuit
CN210838444U (en) Laser driving power supply for dynamically tracking and adjusting current and voltage
US20230065848A1 (en) Efuse circuit and control method thereof
CN211506288U (en) Low dropout discrete voltage stabilizing circuit
CN107453200B (en) Output current regulation and control device of laser power supply
CN114094660A (en) Linear charging system with high-voltage turn-off function
US10470266B1 (en) LED dimming load sudden change suppression circuit
CN109412411B (en) Boost chip with self-adaptive multi-section boosting and automatic current-limiting protection functions
TWI581548B (en) Auto-adjustment current limiting circuit of a non-isolation switching power circuit
TW201725859A (en) Feedback control circuit and method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant