CN217985465U

CN217985465U - High-efficiency LED drive circuit with full-voltage high-power factor

Info

Publication number: CN217985465U
Application number: CN202222163169.1U
Authority: CN
Inventors: 梁智锋
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2022-12-06
Anticipated expiration: 2032-08-16

Abstract

The utility model relates to a high-efficient LED drive circuit of full voltage high power factor, include: the AC input end and the rectifying circuit convert AC alternating current at the AC input end into DC direct current through the rectifying circuit and output the DC direct current from the output end of the rectifying circuit; the voltage identification circuit identifies the output voltage of the rectifying circuit and further sends an identification signal to the feedback input end of the booster circuit, the booster circuit controls the boosting amplitude of the booster circuit according to the identification signal after receiving the identification signal and outputs corresponding voltage, and then the current output by the LED driving circuit is kept constant through the constant current circuit; the input voltage is identified through the voltage identification circuit, the boosting amplitude of the boosting circuit is changed, and therefore the power conversion efficiency is improved under the condition that the LED lamp can be normally used when the output voltage of the LED driving circuit is met.

Description

High-efficiency LED drive circuit with full-voltage high-power factor

Technical Field

The utility model relates to a LED drive power supply technical field especially relates to a high-efficient LED drive circuit of full voltage high power factor.

Background

With the continuous development of energy-saving technology, the LED lighting is widely applied to people in an energy-saving, environment-friendly and durable manner, replaces the traditional fluorescent lamp tube or tungsten filament bulb, and becomes the mainstream energy-saving lighting product at present.

In the use process of the LED lighting lamp, the power supply is often required to be converted into a specific constant current to drive the LED to emit light, so the LED driving circuit is an indispensable component of the LED lighting lamp, and in the daily use process of the LED lamp, in order to meet the light emitting requirement of the LED lamp, voltages with different levels are often required to be input into the LED driving circuit, and a constant current LED power supply current is output through the LED driving circuit.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a high-efficient LED drive circuit of full voltage high power factor to how to provide one kind in solving above-mentioned background art and when not only satisfying the normal work demand of LED lamp, can also satisfy the requirement of high power factor according to input voltage automatically regulated output voltage, cause the too much LED drive circuit of energy loss when preventing to step up the range too high.

In order to solve the technical problems, the following technical scheme is proposed:

a full voltage high power factor high efficiency LED driver circuit, comprising:

an AC input;

a rectifying circuit for rectifying AC alternating current input from the AC input terminal and outputting the rectified AC alternating current as DC direct current;

the voltage identification circuit identifies the output voltage at the output end of the rectifying circuit and outputs an identification signal;

the input end of the booster circuit is coupled with the output end of the rectifying circuit, the feedback input end of the booster circuit is coupled with the output end of the voltage identification circuit, and the booster circuit controls the boosting amplitude of the booster circuit according to the identification signal so as to control the output voltage of the booster circuit;

and the input end of the constant current circuit is coupled with the output end of the booster circuit, and the output end of the constant current circuit is coupled with the output end of the LED.

Preferably, the connection point of the boost circuit and the constant current circuit is further coupled to an electrolytic capacitor for low-frequency filtering, the anode of the electrolytic capacitor is coupled to the output end of the boost circuit, and the cathode of the electrolytic capacitor is grounded.

Preferably, the voltage identification circuit includes an NPN transistor, a voltage reduction module, and a sampling module, one end of the voltage reduction module is coupled to the output end of the rectification circuit, the other end of the voltage reduction module is coupled to the base of the NPN transistor, an input end of the sampling module is coupled to the output end of the rectification circuit, a first output end of the sampling module is coupled to the feedback input end of the voltage boost circuit, a second output end of the sampling module is coupled to the collector of the NPN transistor, and an emitter of the NPN transistor is grounded.

Preferably, the sampling module includes a first resistor, a second resistor, a third resistor, and a fourth resistor, which are coupled in sequence, where one end of the first resistor is coupled to the output end of the rectifying circuit, one end of the fourth resistor is grounded, a connection point of the third resistor and the fourth resistor is coupled to the feedback input end of the voltage boost circuit, a connection point of the third resistor and the fourth resistor is further coupled to a fifth resistor, and the other end of the fifth resistor is coupled to a collector of the NPN triode.

Preferably, a connection point of the second resistor and the third resistor is coupled to an overvoltage protection input terminal of the voltage boost circuit.

Preferably, the boost circuit comprises a first transformer, a first freewheeling diode and a boost chip, one end of the first transformer is coupled with the output end of the rectification circuit, the other end of the first transformer is coupled with the anode of the first freewheeling diode, the cathode of the first freewheeling diode is coupled with the input end of the constant current circuit, and the connection point of the first transformer and the first freewheeling diode is also coupled with a pin of the boost chip DRAIN.

Preferably, the boost chip is a BP2606 chip.

Preferably, the constant current circuit comprises a second transformer, a second freewheeling diode, a filter capacitor and a constant current chip, wherein one end of the second transformer is coupled with the negative electrode of the filter capacitor, the other end of the second transformer is coupled with the positive electrode of the second freewheeling diode, the negative electrode of the second freewheeling diode is coupled with the positive electrode of the filter capacitor, and a foot DRAIN of the constant current chip is connected between the positive electrode of the second freewheeling diode and the transformer.

Preferably, the constant current chip comprises a BP2866 chip

Has the beneficial effects that: the utility model relates to a high-efficient LED drive circuit of full voltage high power factor, include: the AC input end and the rectifying circuit convert AC alternating current at the AC input end into DC direct current through the rectifying circuit and output the DC direct current from the output end of the rectifying circuit; the voltage identification circuit identifies the output voltage of the rectification circuit and further sends an identification signal to the feedback input end of the booster circuit, after receiving the identification signal, the booster circuit controls the boosting amplitude of the booster circuit according to the identification signal and outputs corresponding voltage, and then the current output by the LED drive circuit is kept constant through the constant current circuit; the input voltage is identified through the voltage identification circuit, the boosting amplitude of the boosting circuit is changed, and therefore the power conversion efficiency is improved under the condition that the LED lamp can be normally used when the output voltage of the LED driving circuit is met.

Drawings

Fig. 1 is a system architecture diagram of the present invention;

fig. 2 is a schematic circuit diagram of the present invention.

Detailed Description

To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the attached drawings in the embodiments of the present invention are combined to clearly and completely describe the technical solution in the embodiments of the present invention, and obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

The following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The utility model relates to a high-efficient LED drive circuit of full voltage high power factor please refer to fig. 1-2, include: an AC input terminal and rectifying circuit DB1 which rectifies an alternating current input from the AC input terminal received by the input terminal and outputs a direct current from the output terminal; the AC input end is connected with commercial power and transmits the commercial power to the rectifying circuit DB1 (commercial power is AC alternating current), the rectifying circuit DB1 converts the AC alternating current into DC direct current, and the DC direct current is output from the output end of the rectifying circuit DB 1; the LED driving circuit also comprises a voltage identification circuit, a booster circuit and a constant current circuit, wherein the input end of the voltage identification circuit and the input end of the booster circuit are respectively coupled with the output end of the rectification circuit DB1, the feedback input end of the booster circuit is coupled with the output end of the voltage identification circuit, the input end of the constant current circuit is coupled with the output end of the booster circuit, and the output end of the constant current circuit is coupled with the output end of the LED; the voltage identification circuit is used for identifying the output voltage of the rectifying circuit DB1 and further sending an identification signal to the feedback input end of the booster circuit, the booster circuit controls the boosting amplitude of the booster circuit according to the identification signal after receiving the identification signal and outputs corresponding voltage, and then the current output by the LED driving circuit is kept constant through the constant current circuit; the voltage identification circuit identifies the input voltage and changes the boosting amplitude of the boosting circuit, so that the boosting amplitude of the LED driving circuit is reduced under the condition that the LED lamp can be normally used while the output voltage is met, and the power conversion efficiency is improved. Preferably, the rectifier circuit DB1 is a bridge rectifier circuit DB1 having a simple structure and high efficiency.

In the embodiment, the output voltage of the booster circuit is 280V-410V, and when 110V alternating current is input in the daily use process of the LED lamp, the output voltage of the booster circuit is 280V; when 220V alternating current input is used, the output voltage of the booster circuit is 410V, the boosting amplitude is changed according to the increase of the AC input voltage, and the energy loss of the booster circuit in the boosting process is greatly reduced. The output voltage of 280V-410V can meet the input requirement of the constant current circuit, thereby achieving the purpose of effective energy saving.

In this embodiment, a low-frequency filter circuit is further coupled to a connection point of the boost circuit and the constant current circuit, so that the direct current output by the circuit is smoother through the low-frequency filter circuit, and further, the stroboflash of the LED lamp is reduced. More preferably, the low frequency filter circuit includes electrolytic capacitor C3, and electrolytic capacitor C3's positive pole is coupled with boost circuit's output, and negative pole ground connection is through electrolytic capacitor C3 who has great electric capacity for the electric current of output becomes the nearly pure direct current of ultralow ripple, makes the stroboscopic can not appear in the LED lamp.

In this embodiment, the voltage identification circuit includes NPN triode Q1, step-down module and sampling module, and the one end of step-down module is coupled with rectifier circuit DB 1's output, and the other end is coupled with NPN triode Q1's base, and sampling module's input is coupled with rectifier circuit DB 1's output, and sampling module's first output and boost circuit's feedback input, and sampling module's second output is coupled with NPN triode Q1's collecting electrode, and NPN triode Q1's emitter ground.

In this embodiment, the sampling module includes a first resistor R15, a second resistor R14, a third resistor R13, and a fourth resistor R10, which are coupled in sequence, where the other end of the first resistor R15 is coupled to the output terminal of the rectifying circuit DB1, the other end of the fourth resistor R10 is grounded, a connection point of the third resistor R13 and the fourth resistor R10 is coupled to the feedback input terminal of the boost circuit, a connection point of the third resistor R13 and the fourth resistor R10 is further coupled to a fifth resistor R21, and the other end of the fifth resistor R21 is coupled to the collector of the NPN triode Q1.

In this embodiment, the voltage dropping module includes a sixth resistor R20, a seventh resistor R19, and an eighth resistor R23 that are sequentially coupled, another end of the sixth resistor R20 is coupled to the output end of the rectifying circuit DB1, another end of the eighth resistor R23 is coupled to the base of the NPN transistor Q1 and the ninth resistor R22, another end of the ninth resistor R22 is grounded, a tenth resistor R24 is further coupled to a connection point of the seventh resistor R19 and the eighth resistor R23, and another end of the tenth resistor R24 is grounded.

In this embodiment, the connection point of the second resistor R14 and the third resistor R13 is coupled to the overvoltage protection input terminal of the voltage boost circuit, so that the input voltage can be effectively prevented from suddenly increasing and exceeding the insulation strength and the voltage withstanding value of the voltage boost circuit, and the voltage boost circuit is heated and broken down to burn out.

In this embodiment, the voltage boost circuit includes a first transformer T1, a first freewheeling diode D2 and a voltage boost chip U1, one end of the first transformer T1 is coupled to the output end of the rectifier circuit, the other end is coupled to the anode of the first freewheeling diode D2, the cathode of the first freewheeling diode D2 is coupled to the input end of the constant current circuit, the connection point of the first transformer T1 and the first freewheeling diode D2 is further coupled to the DRAIN pin of the voltage boost chip U1, the voltage identification circuit is coupled to the FB pin of the voltage boost chip U1, and the VDD pin of the voltage chip U1 is coupled to the output end of the rectifier circuit.

In this embodiment, the boost circuit includes a BP2606 chip U1, and receives the identification signal through the BP2606 chip U1, so as to control the boost amplitude of the output voltage, thereby reducing the energy loss generated during the large-amplitude boost.

In this embodiment, the constant current circuit includes a second transformer T2, a second freewheeling diode D3, a filter capacitor C4, and a constant current chip U2. One end of the second transformer is coupled with the negative electrode of the filter capacitor, the other end of the second transformer is coupled with the positive electrode of the second fly-wheel diode D3, the negative electrode of the second fly-wheel diode D3 is coupled with the positive electrode of the filter capacitor, and a constant current chip DRAIN pin is connected between the positive electrode of the second fly-wheel diode and the transformer.

In the embodiment, the constant current circuit comprises a constant current chip U2, and the model of the constant current chip U2 is a BP2866 chip.

The working principle is as follows:

the AC input end is connected with a mains supply, AC alternating current is rectified into DC direct current through the rectifying circuit DB1, the voltage value of the output end of the rectifying circuit DB1 is identified through the voltage identification circuit, a corresponding identification signal is output to the BP2606 chip U1, the BP2606 chip U1 outputs corresponding high voltage according to the identification signal, the electrolytic capacitor C3 obtains a direct current voltage higher than the input voltage, and after the C3 electrolytic capacitor C3 obtains a direct current higher than the input voltage, the LED constant current circuit consisting of the U2 and peripheral circuits thereof works to provide stable direct current for the LED.

When the voltage value input by the AC input end is 100-120V, the sampling resistor is used for: the NPN triode Q1Q1 is in non-conduction after the voltage is divided by a seventh resistor R19, a sixth resistor R20, a ninth resistor R22, an eighth resistor R23 and a tenth resistor R24, and the value obtained in the Q1 triode is less than 0.5V. The FB terminal voltage value of the BP2606 chip U1 is sampled and determined by the fourth resistor R10, the first resistor R15, the second resistor R14 and the third resistor R13, the sampling result is input to the feedback input end (namely, the FB end) of the BP2606 chip U1, the BP2606 chip U1 determines the boosting amplitude according to the received sampling result, the output voltage of the voltage circuit is about 280V at the moment, the direct current voltage of the C3 capacitor is kept at a lower voltage value, the higher power conversion efficiency is ensured on the premise of low voltage input, and the normal use requirements of the LED lamp are met.

When the voltage value input by the AC input end exceeds 200V, the voltage value obtained by the base electrode of the NPN triode Q1 is greater than 0.5V through the partial voltage of the sampling resistors, namely the seventh resistor R19, the sixth resistor R20, the ninth resistor R22, the eighth resistor R23 and the tenth resistor R24, and the NPN triode Q1 is conducted. The FB terminal voltage value of the BP2606 chip U1 is sampled and determined by the fourth resistor R10, the first resistor R15, the second resistor R14, the third resistor R13 and the fifth resistor R21, the sampling result is input to the feedback input end (i.e., the FB terminal) of the BP2606 chip U1, the BP2606 chip U1 determines the boosting amplitude according to the received sampling result, and the output voltage of the voltage circuit is about 410V at this time, thereby ensuring higher power conversion efficiency on the premise of high voltage input. While also achieving a high power factor.

When the voltage value input at the AC input end is between 120 and 200V, the sampling resistor is used for: the seventh resistor R19, the sixth resistor R20, the ninth resistor R22, the eighth resistor R23 and the tenth resistor R24 divide voltage, a voltage value which changes from low to high is obtained at the base of the NPN triode Q1, and the NPN triode Q1 can be in a process of cut-off, amplification and conduction. Because of the effect of the fifth resistor R21 on the FB voltage of the BP2606 chip U1, the dc voltage obtained by the electrolytic capacitor C3 will also rise synchronously, and automatically change with the change of the input voltage. The power conversion keeps high efficiency, and high power factors can be guaranteed.

After the electrolytic capacitor C3 obtains a 280-410V direct-current voltage, a working voltage is provided for the U2 constant-current chip through the resistors R5 and R6, the U2 constant-current chip works, the constant-current value of output current is set through the resistors R3 and R4, and the flow direction of the constant-current is from the anode C3, the cathode L4, the cathode LED +, the cathode T2, the cathode U2, the cathode R3 and the cathode C3. And realizing constant-current power supply to the LED.

The advantages are that:

1. the utility model discloses can pass through voltage identification circuit automatic identification input voltage.

2. The utility model discloses when input voltage is lower, the DC voltage of boost circuit output is lower relatively, can reduce effectively because of the produced energy loss that steps up by a wide margin.

3. The utility model discloses when input voltage is higher, the DC voltage of boost circuit output risees automatically, also can keep having higher conversion efficiency when satisfying high power factor.

The above disclosure is only for the specific embodiments of the present invention, but the present invention is not limited thereto, and any changes that can be made by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A full-voltage high-power factor high-efficiency LED driving circuit, comprising:

an AC input terminal;

2. A full-voltage high-power-factor high-efficiency LED driving circuit according to claim 1, wherein a connection point between the voltage boosting circuit and the constant current circuit is further coupled to an electrolytic capacitor for low-frequency filtering, an anode of the electrolytic capacitor is coupled to an output terminal of the voltage boosting circuit, and a cathode of the electrolytic capacitor is grounded.

3. The full-voltage high-power-factor high-efficiency LED driving circuit according to claim 1, wherein the voltage identification circuit comprises an NPN transistor, a voltage-dropping module and a sampling module, wherein one end of the voltage-dropping module is coupled to the output end of the rectifying circuit, the other end of the voltage-dropping module is coupled to the base of the NPN transistor, the input end of the sampling module is coupled to the output end of the rectifying circuit, the first output end of the sampling module is coupled to the feedback input end of the voltage-boosting circuit, the second output end of the sampling module is coupled to the collector of the NPN transistor, and the emitter of the NPN transistor is grounded.

4. A full-voltage high-power-factor high-efficiency LED driving circuit according to claim 3, wherein the sampling module comprises a first resistor, a second resistor, a third resistor, and a fourth resistor, which are sequentially coupled to each other, one end of the first resistor is coupled to the output terminal of the rectifying circuit, one end of the fourth resistor is grounded, a connection point of the third resistor and the fourth resistor is coupled to the feedback input terminal of the boosting circuit, a connection point of the third resistor and the fourth resistor is further coupled to a fifth resistor, and the other end of the fifth resistor is coupled to the collector of the NPN transistor.

5. A full-voltage high-power-factor high-efficiency LED driving circuit according to claim 4, wherein a connection point of the second resistor and the third resistor is coupled to an overvoltage protection input terminal of the voltage boosting circuit.

6. A full-voltage high-power-factor high-efficiency LED driving circuit according to claim 1, wherein the voltage boost circuit comprises a first transformer, a first freewheeling diode and a voltage boost chip, the first transformer is coupled to the output terminal of the rectifying circuit at one end, and is coupled to the anode of the first freewheeling diode at the other end, the cathode of the first freewheeling diode is coupled to the input terminal of the constant current circuit, the connection point of the first transformer and the first freewheeling diode is further coupled to a pin DRAIN of the voltage boost chip, and the voltage identification circuit is coupled to the FB pin of the voltage boost chip.

7. The full-voltage high-power-factor high-efficiency LED driving circuit according to claim 6, wherein the boost chip is a BP2606 chip.

8. The full-voltage high-power-factor efficient LED driving circuit according to claim 1, wherein the constant current circuit comprises a second transformer, a second freewheeling diode, a filter capacitor, and a constant current chip, wherein one end of the second transformer is coupled to a negative electrode of the filter capacitor, the other end of the second transformer is coupled to a positive electrode of the second freewheeling diode, a negative electrode of the second freewheeling diode is coupled to a positive electrode of the filter capacitor, and a DRAIN pin of the constant current chip is connected between the positive electrode of the second freewheeling diode and the second transformer.

9. A full-voltage high-power-factor high-efficiency LED driving circuit according to claim 8, wherein the constant current chip is a BP2866 chip.