CN103379701A - LED driving circuit and LED lamp - Google Patents

Abstract

The invention is applicable to the field of electronic lighting, and provides an LED driving circuit and an LED lamp. In the present invention, by adopting the LED comprising a voltage divider filter module, a first flyback drive module, a second flyback drive module, a secondary rectification filter module, an electrical parameter detection and feedback module, an isolation transmission module and a switching power supply circuit module The drive circuit is composed of two series-connected flyback drive modules to undertake the same voltage and power output respectively, and can provide sufficient power drive for high-power LED loads without using a high-power transformer, with low power loss and high power utilization. High efficiency and low circuit cost, thereby solving the problems of low power utilization efficiency, large power consumption and high cost in the prior art.

Description

A kind of LED drive circuit and LED lamp

technical field

The invention belongs to the field of electronic lighting, and in particular relates to an LED driving circuit and an LED lamp.

Background technique

At present, as a new type of light source, LED has been widely used in various fields due to its advantages of low energy consumption, high brightness and long life.

In the existing high-power LED lamps (rated power is above 150W), the forward circuit is generally used to drive the LED to emit light, and the forward circuit needs to use a high-power transformer and a high-voltage driven MOS tube, so the entire forward circuit The power consumption is large and the cost is high; and in the existing low-power LED lamps (rated power is below 150W), a single flyback circuit is used to drive the LED to achieve the purpose of lighting. However, the flyback circuit is driving the LED The power consumed when emitting light is relatively high, which will lead to a reduction in the power usage efficiency of the whole machine.

To sum up, the prior art has the problems of low power utilization efficiency, large power consumption and high cost.

Contents of the invention

The purpose of the present invention is to provide an LED driving circuit, aiming at solving the problems of low power utilization efficiency, large power consumption and high cost in the prior art.

The present invention is achieved in this way, an LED drive circuit includes a switching power supply circuit module connected to a DC power supply and an LED load, and the LED drive circuit also includes:

The voltage dividing filter module has a first output terminal and a second output terminal, and the input terminal is connected to the output terminal of the DC power supply, and is used to divide the DC power output by the DC power supply, and then output the DC power from the first output terminal respectively. The output terminal and the second output terminal output two direct currents with equal voltages;

The first flyback drive module, the input terminal is connected to the first output terminal of the voltage dividing filter module, and is used to perform voltage conversion and rectification processing on the direct current output by the first output terminal of the voltage dividing filter module and output it;

The second flyback drive module, the input terminal is connected to the second output terminal of the voltage dividing filter module, and is used to perform voltage conversion and rectification processing on the direct current output by the second output terminal of the voltage dividing filter module and output it;

The secondary rectification and filtering module, the first input end and the second input end are respectively connected to the output end of the first flyback drive module and the output end of the second flyback drive module, and the third input end and the fourth input end are connected to the output end of the second flyback drive module The input end is respectively connected to the loop end of the first flyback drive module and the loop end of the second flyback drive module, and the output end and the loop end are respectively connected to the input end and the output end of the LED load. superimposing and rectifying and filtering the DC coupling outputted by the first flyback drive module and the second flyback drive module;

Electrical parameter detection and feedback module, the first detection terminal and the second detection terminal are respectively connected to the output terminal and the loop terminal of the secondary rectification and filtering module, and the output terminal is connected to the first feedback terminal of the switching power supply module for Perform voltage and current detection on the direct current output by the secondary rectification and filtering module, and output a feedback signal to the switching power supply circuit module accordingly;

An isolated transmission module, the input terminal is connected to the output terminal of the switching power supply circuit module, and the first drive signal terminal and the second drive signal terminal are respectively connected to the control signal terminal of the first flyback drive module and the second flyback drive The control signal terminals of the modules are connected, and the first loop terminal and the second loop terminal are respectively connected to the loop terminal of the first flyback drive module and the loop terminal of the second flyback drive module, for connecting the switching power supply The driving control signal output by the circuit module is isolated and transmitted to the first flyback driving module and the second flyback driving module.

In the present invention, by adopting the voltage dividing filter module, the first flyback drive module, the second flyback drive module, the secondary rectification filter module, the electrical parameter detection and feedback module, The isolated transmission module and the LED drive circuit of the switching power supply circuit module are respectively responsible for the same voltage and power output by two series-connected flyback drive modules, and can realize high-power output without using a high-power transformer. The LED load provides sufficient electric energy drive, low power loss, high electric energy utilization rate and low circuit cost, thereby solving the problems of low electric energy utilization efficiency, large power consumption and high cost existing in the prior art.

Description of drawings

FIG. 1 is a block diagram of an LED drive circuit provided by an embodiment of the present invention;

Fig. 2 is an example circuit structure diagram of the LED driving circuit provided by the embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

In the embodiment of the present invention, by adopting a voltage divider filter module, a first flyback drive module, a second flyback drive module, a secondary rectification filter module, an electrical parameter detection and feedback module, an isolation transmission module and a switching power supply circuit module The LED drive circuit consists of two series-connected flyback drive modules that undertake the same voltage and power output respectively, and can provide sufficient power drive for high-power LED loads without the need for high-power transformers, with low power loss. The power utilization rate is high and the circuit cost is low.

Figure 1 shows the module structure of the LED drive circuit provided by the embodiment of the present invention. For the convenience of description, only the parts related to the embodiment of the present invention are shown, and the details are as follows:

The LED drive circuit 100 includes a switching power supply circuit module 101 connected to the DC power supply 200 and the LED load 300, and the LED drive circuit 100 also includes:

The voltage-dividing filter module 102 has a first output terminal and a second output terminal, and the input terminal is connected to the output terminal of the DC power supply 200, and is used to divide the DC power output by the DC power supply 200, and obtain the output from the first output terminal and the second output terminal respectively. The second output terminal outputs two direct currents with equal voltages;

The first flyback drive module 103, the input terminal is connected to the first output end of the voltage dividing filter module 102, and is used to perform voltage conversion and rectification processing on the direct current output by the first output end of the voltage dividing filter module 102 and output it;

The second flyback drive module 104, the input terminal is connected to the second output end of the voltage dividing filter module 102, and is used to perform voltage conversion and rectification processing on the direct current output by the second output end of the voltage dividing filter module 102 and output it;

The secondary rectification filter module 105, the first input end and the second input end are respectively connected with the output end of the first flyback drive module 103 and the output end of the second flyback drive module 104, the third input end and the fourth input end terminals are respectively connected to the loop terminal of the first flyback drive module 103 and the loop terminal of the second flyback drive module 104, and the output terminal and the loop terminal are respectively connected to the input terminal and the output terminal of the LED load 300 for connecting the first The direct current coupling outputted by the flyback drive module 103 and the second flyback drive module 104 is superimposed and output after being rectified and filtered;

The electrical parameter detection and feedback module 106, the first detection terminal and the second detection terminal are respectively connected to the output terminal and the loop terminal of the secondary rectification and filtering module 105, and the output terminal is connected to the first feedback terminal of the switching power supply module 101, which is used for secondary Perform voltage and current detection on the direct current output by the rectification and filtering module 105, and output a feedback signal to the switching power supply circuit module 101 accordingly;

The isolation transmission module 107, the input terminal is connected to the output terminal of the switching power supply circuit module 101, the first drive signal terminal and the second drive signal terminal are respectively connected to the control signal terminal of the first flyback drive module 103 and the second flyback drive module 104 The control signal terminals are connected, and the first loop terminal and the second loop terminal are respectively connected to the loop terminal of the first flyback drive module 103 and the loop terminal of the second flyback drive module 104 for driving the output of the switching power supply circuit module 101 The control signal is isolated and transmitted to the first flyback driving module 103 and the second flyback driving module 104 .

LED driving circuit 100 also includes:

Transformer T1, the first end 1 and the second end 2 of the primary winding are respectively connected to the loop end of the first flyback drive module 103 and the input end of the second flyback drive module 104, the first end 3 and the second end of the secondary winding Terminal 4 is respectively connected to the second feedback terminal of the switching power supply circuit module 101 and ground, for detecting and feeding back the primary currents of the first flyback driving module 103 and the second flyback driving module 104 to the switching power supply circuit module 101;

an inductor L1 connected between the output end of the secondary rectification and filtering module 105 and the input end of the LED load 300; and

The capacitor C1 is connected between the input end of the LED load 300 and the loop end of the secondary rectification and filtering module 105 .

In the embodiment of the present invention, the switching power supply circuit module 101 includes a commonly used switching power supply control IC, IC power supply circuit and IC start-up circuit; the transformer T1 can realize the primary The current is detected and combined with the electrical parameter detection and feedback module 106 to realize real-time current and voltage detection on the primary and secondary sides of the entire LED drive circuit, so that the switching power supply circuit module 101 can more accurately adjust the output pulse duty cycle, improve the constant current control capability of the entire LED drive circuit; inductance L1 and capacitor C1 form an output stage LC filter circuit to filter the direct current output by the secondary rectification filter module 105, so that the direct current output to the LED load 300 The waveform is more pure and without interference, thereby ensuring that the LED load 300 can work more stably.

Figure 2 shows an example circuit structure of the LED driving circuit provided by the embodiment of the present invention. For the convenience of description, only the parts related to the embodiment of the present invention are shown, and the details are as follows:

As an embodiment of the present invention, the voltage dividing filter module 102 includes:

Resistor R1, resistor R2, capacitor C2, resistor R3, resistor R4 and capacitor C3;

The first end of the resistor R1 is the input end of the voltage divider filter module 102, the first end of the capacitor C2 is the first output end of the voltage divider filter module 102 and is connected to the first end of the resistor R1, and the first end of the resistor R2 is connected to The second end of the resistor R1, the second end of the resistor R2 and the second end of the capacitor C2 are connected to the first end of the resistor R3, the first end of the capacitor C3 is the second output end of the voltage divider filter module 102 and is connected to the resistor The first terminal of R3 is connected, the first terminal of resistor R4 is connected to the second terminal of resistor R3, and the second terminal of resistor R4 and the second terminal of capacitor C3 are both connected to ground.

As an embodiment of the present invention, the first flyback drive module 103 includes:

Capacitor C4, resistor R5, diode D1, transformer T2, diode D2, capacitor C5, capacitor C6, resistor R6, resistor R7, diode D3, diode D4, resistor R8, PNP transistor Q1, resistor R9, resistor R10 and NMOS tube Q2 ;

The first end of the capacitor C4 and the first end of the resistor R5 are jointly connected to the first end 1 of the primary winding of the transformer T2, and the first end 1 of the primary winding of the transformer T1 is the input end of the first flyback drive module 103, The second end of the capacitor C4 and the second end of the resistor R5 are connected to the cathode of the diode D1, the anode of the diode D1 is connected to the second end 2 of the primary winding of the transformer T2, and the first end 3 of the secondary winding of the transformer T2 is connected to the diode The anode of D2, the cathode of diode D2 and the second terminal 4 of the secondary winding of transformer T2 are respectively the output terminal and the loop terminal of the first flyback drive module 103, and the first terminal of the capacitor C5 is the first flyback drive module 103 The control signal terminal of the capacitor C5, the first terminal of the capacitor C6 and the first terminal of the resistor R7 are connected to the anode of the diode D4, and the second terminal of the capacitor C6 and the first terminal of the resistor R6 are connected to the PNP The base of the type transistor Q1, the cathode of the diode D3 is connected to the second end of the resistor R7, the second end of the resistor R6 is the loop end of the first flyback drive module 103 and is connected to the PNP type transistor Q1 with the anode of the diode D3 The collector, the resistor R8 is connected between the cathode of the diode D4 and the emitter of the PNP transistor Q1, the first end of the resistor R9 and the first end of the resistor R10 are connected to the emitter of the PNP transistor Q1, and the first end of the resistor R9 The two terminals and the collector of the PNP transistor Q1 are jointly connected to the source of the NMOS transistor Q2. The source of the NMOS transistor Q2 is the return terminal of the first flyback drive module 103. The drain and gate of the NMOS transistor Q2 are respectively connected to the transformer T2. The second end 2 of the primary winding is connected to the second end of the resistor R10. Among them, the sub-circuit composed of capacitor C4, resistor R5 and diode D1 can absorb the leakage inductance voltage peak of the primary winding of the transformer T2, so that the direct current obtained by the first end 1 of the primary winding of the transformer T2 has no interference, ensuring that the transformer T2 In addition, the PNP transistor Q1 is used to quickly charge or discharge the parasitic capacitance of the NMOS transistor Q2 when the capacitor C5 receives a high-level pulse or a low-level pulse to trigger the NMOS transistor Q2 to be turned on or off, thereby shortening the The turn-on and turn-off time of the NMOS transistor Q2 achieves the purpose of quickly driving the NMOS transistor Q2.

As an embodiment of the present invention, the second flyback driving module 104 includes:

Capacitor C7, resistor R11, diode D5, transformer T3, diode D6, capacitor C8, capacitor C9, resistor R12, resistor R13, diode D6, diode D7, resistor R14, PNP transistor Q3, resistor R15, resistor R16 and NMOS transistor Q4 ;

The first end of the capacitor C7 and the first end of the resistor R11 are jointly connected to the first end 1 of the primary winding of the transformer T3, and the first end 1 of the primary winding of the transformer T3 is the input end of the second flyback drive module 104, The second end of the capacitor C7 and the second end of the resistor R11 are connected to the cathode of the diode D5, the anode of the diode D5 is connected to the second end 2 of the primary winding of the transformer T3, and the first end 3 of the secondary winding of the transformer T3 is connected to the diode The anode of D6, the cathode of diode D6 and the second terminal 4 of the secondary winding of transformer T3 are respectively the output terminal and the loop terminal of the second flyback drive module 104, and the first terminal of the capacitor C8 is the second flyback drive module 104 The control signal terminal of the capacitor C8, the first terminal of the capacitor C9 and the first terminal of the resistor R13 are connected to the anode of the diode D7, and the second terminal of the capacitor C9 and the first terminal of the resistor R12 are connected to the PNP The base of the type transistor Q3, the cathode of the diode D6 is connected to the second end of the resistor R13, the second end of the resistor R12 is the loop end of the second flyback drive module 104 and is connected with the anode of the diode D6 to the PNP type transistor Q3 The collector, the resistor R14 is connected between the cathode of the diode D7 and the emitter of the PNP transistor Q3, the first end of the resistor R15 and the first end of the resistor R16 are connected to the emitter of the PNP transistor Q3, and the first end of the resistor R15 The two terminals and the collector of the PNP transistor Q3 are commonly connected to the source of the NMOS transistor Q4, the source of the NMOS transistor Q4 is the return terminal of the second flyback drive module 104 and connected to the ground, and the drain and gate of the NMOS transistor Q4 They are respectively connected to the second end 2 of the primary winding of the transformer T3 and the second end of the resistor R16. Among them, the sub-circuit composed of capacitor C7, resistor R11 and diode D5 can absorb the leakage inductance voltage peak of the primary winding of the transformer T3, so that the direct current obtained by the first end 1 of the primary winding of the transformer T3 has no interference, ensuring that the transformer T3 In addition, the PNP transistor Q3 is used to quickly charge or discharge the parasitic capacitance of the NMOS transistor Q4 when the capacitor C8 obtains a high-level pulse or a low-level pulse to trigger the NMOS transistor Q4 to be turned on or off, thereby shortening the The turn-on and turn-off time of the NMOS transistor Q4 achieves the purpose of quickly driving the NMOS transistor Q4.

As an embodiment of the present invention, the secondary rectification and filtering module 105 includes:

Transformer T4, Schottky diode D8, capacitor C10, resistor R17, energy storage capacitor C11, inductor L2, energy storage capacitor C12 and resistor R18;

The first terminal 1 of the first primary winding of the transformer T4 and the first terminal 3 of the second primary winding are respectively the first input terminal and the second input terminal of the secondary rectification and filtering module 105, and the first terminal 3 of the first primary winding of the transformer T4 is The two terminals 2 and the second terminal 4 of the second primary winding are respectively the third input terminal and the fourth input terminal of the secondary rectification filter module 105, and the first terminal 5 of the secondary winding of the transformer T4 is connected with the first terminal of the capacitor C10 at the same time. terminal and the anode of the Schottky diode D8, the resistor R17 is connected between the capacitor C10 and the cathode of the Schottky diode D8, the positive electrode of the energy storage capacitor C11 and the first end of the inductor L2 are connected to the Schottky diode D8 The cathode of the inductance L2 is the output end of the secondary rectification filter module 105 and is connected to the positive pole of the energy storage capacitor C12, the negative pole of the energy storage capacitor C11, the second end 6 of the secondary winding of the transformer T4 and the energy storage The negative pole of the capacitor C12 is connected to the equipotential ground, the first terminal of the resistor R18 is connected to the negative pole of the energy storage capacitor C12, and the second terminal of the resistor R18 is the loop terminal of the secondary rectifying and filtering module 105 .

As an embodiment of the present invention, the electrical parameter detection and feedback module 106 includes:

Resistor R19, resistor R20, capacitor C13, capacitor C14, resistor R21, capacitor C15, capacitor C16, resistor R22, resistor R23, capacitor C17, resistor R24, resistor R25, resistor R26, resistor R27, capacitor C18, capacitor C19, resistor R28 , capacitor C20, capacitor C21, diode D9, diode D10, TSM103 constant current chip U1 and optocoupler U2;

The first end of the resistor R19 is the first detection end of the electrical parameter detection and feedback module 106, and is simultaneously connected with the first end of the resistor R24, the first end of the resistor R25, the first end of the capacitor C14, and the TSM103 constant current chip U1. The power supply pin VCC+ is connected, the second end of the resistor R19 is connected with the first end of the resistor R22, the first end of the capacitor C17 and the first inverting input pin I1 of the TSM103 constant current chip U1, and the second end of the resistor R24 Connect to the first non-inverting input pin NI1 of the TSM103 constant current chip U1, the second terminal of the resistor R25 is connected to the anode of the light-emitting diode in the optocoupler U2, the second terminal of the capacitor C14 is connected to the equipotential ground, and the second terminal of the resistor R22 is connected to the resistor The first end of R23, the second end of the resistor R23 and the second end of the capacitor C17 are connected to the equipotential ground, the first end of the resistor R20 is the second detection end of the electrical parameter detection and feedback module 106, and the second end of the resistor R20 The two ends are connected to the first end of capacitor C13, the first end of capacitor C15, the first end of capacitor C16 and the second inverting input pin I2 of TSM103 constant current chip U1, and the second end of capacitor C13 is connected to the equipotential ground, the second end of capacitor C15 is connected to the first end of resistor R21, the second end of resistor R21, the cathode of diode D9 and the second end of capacitor C16 are connected to the second output pin OUT2 of TSM constant current chip U1, and the diode The anode of D9 and the anode of diode D10 are connected to the cathode of the light-emitting diode in optocoupler U2, and the cathode of diode D10 is simultaneously connected to the first end of resistor R28, the first end of capacitor C21 and the first output pin of TSM103 constant current chip U1 OUT1 is connected, the second end of the resistor R28 is connected to the first end of the capacitor C20, the second end of the capacitor C20 and the second end of the capacitor C21 are connected to the first inverting input pin I1 of the TSM103 constant current chip U1, and the resistor R26 The first end and the first end of the capacitor C19 are connected to the first non-inverting input pin NI1 of the TSM103 constant current chip U1, the second end of the resistor R26, the first end of the resistor R27 and the first end of the capacitor C18 The second non-inverting input pin NI2 of the TSM103 constant current chip U1, the second end of the capacitor C19, the second end of the resistor R27 and the second end of the capacitor C18 are connected to the equipotential ground, and the ground terminal VCC of the TSM103 constant current chip U1 - connected to the equipotential ground, the collector of the phototransistor in the optocoupler U2 is the output terminal of the electrical parameter detection and feedback module 106, and the emitter of the phototransistor in the optocoupler U2 is grounded.

As an embodiment of the present invention, the isolation transmission module 107 includes a capacitor C22, a diode D11 and a transformer T5, the first end of the capacitor C22 is the input end of the isolation transmission module 107, the cathode of the diode D11 is connected to the first end of the capacitor C22, and the diode D11 The anode and the second end of the capacitor C22 are connected to the first end 1 of the primary winding T5-A of the transformer T5, the second end 2 of the primary winding T5-A of the transformer T5 is grounded, and the first secondary winding T5 of the transformer T5 - The first terminal 3 and the second terminal 4 of B are respectively the first drive signal terminal and the first loop terminal of the isolated transmission module 107, and the first terminal 5 and the second terminal of the second secondary winding T5-C of the transformer T5 6 are the second drive signal terminal and the second loop terminal of the isolation transmission module 107, respectively. Among them, the sub-circuit composed of the capacitor C22 and the diode D11 is used to absorb the leakage inductance voltage peak generated by the primary winding of the transformer T5, so as to ensure that the transformer T5 can output the pulse signal of the switching power supply circuit module 101 without interference. Make an isolated transfer.

The LED driving circuit 100 will be further described in combination with the working principle as follows:

The LED drive circuit 100 starts to work by obtaining DC power from the output terminal of the DC power supply 200, and divides the DC power output by the DC power supply 200 into two circuits with equal voltages by the resistors R1, R2, R3 and R4 in the voltage divider filter module 102. The direct current is filtered by the capacitor C2 and the capacitor C3 respectively, and then output to the input terminal of the first flyback drive module 103 and the input terminal of the second flyback drive module 104, and then the two voltages are converted by the transformer T2 and the transformer T3 The equal direct current is subjected to voltage conversion, rectified by diode D2 and diode D6, and then output to the secondary rectification and filtering module 105, and the direct current output from diode D2 and diode D6 is coupled and superimposed by transformer T4, and passed by Schottky The rectifier sub-circuit composed of diode D8, capacitor C10 and resistor R17 performs rectification processing, and the filter sub-circuit composed of energy storage capacitor C11, inductor L2 and energy storage capacitor C12 performs filtering and output, and then the inductor L1 and capacitor C1 convert the direct current After filtering again, the output is used to drive the LED load 300 to work.

In the LED drive circuit 100, the electrical parameter detection and feedback module 106 detects the current and voltage of the output terminal and the loop terminal of the secondary rectification filter module 105, and the secondary current of the LED drive circuit 100 is controlled by the TSM103 constant current chip U1. After real-time comparison and amplification processing with the voltage, the voltage drop across the two poles of the light-emitting diode of the optocoupler U2 is correspondingly controlled, so that the collector of the phototransistor of the optocoupler U2 correspondingly generates a voltage as a feedback signal and outputs it to the switching power supply circuit module 101, and then The switching power supply circuit module 101 adjusts the duty cycle of its output pulse accordingly according to the feedback signal, and the pulse signal output by the switching power supply circuit module 101 is isolated by the transformer T5 and sent to the control signal terminal of the first flyback drive module 103 (capacitor C5 The first end of the first end) and the control signal end of the second flyback drive module 104 (the first end of the capacitor C7) to control the switching duty ratio of the NMOS transistor Q2 and the NMOS transistor Q3, thereby adjusting the output of the transformer T2 and the transformer T3 The coupling voltage is used to achieve the purpose of negative feedback closed-loop control on the output current of the LED driving circuit 100, so that the direct current output by the secondary side of the LED driving circuit 100 is constant within a current value range, so that the LED load 300 can be stably driven to work .

In the embodiment of the present invention, the LED load 300 can be a series LED light group or a parallel LED light group, and the DC power supply 200 with different output current values is selected according to the electrical connection mode of the LED light group in the LED load 300 and the rated operating current of the LED. .

The embodiment of the present invention also provides an LED lamp comprising the above-mentioned LED driving circuit.

In the embodiment of the present invention, by adopting a voltage divider filter module, a first flyback drive module, a second flyback drive module, a secondary rectification filter module, an electrical parameter detection and feedback module, an isolation transmission module and a switching power supply circuit module The LED drive circuit consists of two series-connected flyback drive modules that undertake the same voltage and power output respectively, and can provide sufficient power drive for high-power LED loads without the need for high-power transformers, with low power loss. The electric energy utilization rate is high and the circuit cost is low, thus solving the problems of low electric energy utilization efficiency, large power consumption and high cost existing in the prior art.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (8)

1. A kind of LED driving circuit, comprises switching power supply circuit module, is connected with DC power supply and LED load, is characterized in that, described LED driving circuit also comprises: The voltage dividing filter module has a first output terminal and a second output terminal, and the input terminal is connected to the output terminal of the DC power supply, and is used to divide the DC power output by the DC power supply, and then output the DC power from the first output terminal respectively. The output terminal and the second output terminal output two direct currents with equal voltages; The first flyback drive module, the input terminal is connected to the first output terminal of the voltage dividing filter module, and is used to perform voltage conversion and rectification processing on the direct current output by the first output terminal of the voltage dividing filter module and output it; The second flyback drive module, the input terminal is connected to the second output terminal of the voltage dividing filter module, and is used to perform voltage conversion and rectification processing on the direct current output by the second output terminal of the voltage dividing filter module and output it; The secondary rectification and filtering module, the first input end and the second input end are respectively connected to the output end of the first flyback drive module and the output end of the second flyback drive module, and the third input end and the fourth input end are connected to the output end of the second flyback drive module The input end is respectively connected to the loop end of the first flyback drive module and the loop end of the second flyback drive module, and the output end and the loop end are respectively connected to the input end and the output end of the LED load. superimposing and rectifying and filtering the DC coupling outputted by the first flyback drive module and the second flyback drive module; Electrical parameter detection and feedback module, the first detection terminal and the second detection terminal are respectively connected to the output terminal and the loop terminal of the secondary rectification and filtering module, and the output terminal is connected to the first feedback terminal of the switching power supply module for Perform voltage and current detection on the direct current output by the secondary rectification and filtering module, and output a feedback signal to the switching power supply circuit module accordingly; An isolated transmission module, the input terminal is connected to the output terminal of the switching power supply circuit module, and the first drive signal terminal and the second drive signal terminal are respectively connected to the control signal terminal of the first flyback drive module and the second flyback drive The control signal terminals of the modules are connected, and the first loop terminal and the second loop terminal are respectively connected to the loop terminal of the first flyback drive module and the loop terminal of the second flyback drive module, for connecting the switching power supply The driving control signal output by the circuit module is isolated and transmitted to the first flyback driving module and the second flyback driving module. 2. The LED drive circuit according to claim 1, wherein the voltage dividing filter module comprises: Resistor R1, resistor R2, capacitor C2, resistor R3, resistor R4 and capacitor C3; The first end of the resistor R1 is the input end of the voltage divider filter module, the first end of the capacitor C2 is the first output end of the voltage divider filter module and is connected to the first end of the resistor R1 , the first end of the resistor R2 is connected to the second end of the resistor R1, the second end of the resistor R2 and the second end of the capacitor C2 are connected to the first end of the resistor R3, the The first end of the capacitor C3 is the second output end of the voltage dividing filter module and is connected to the first end of the resistor R3, the first end of the resistor R4 is connected to the second end of the resistor R3, and the first end of the resistor R4 is connected to the second end of the resistor R3. The second end of the resistor R4 and the second end of the capacitor C3 are commonly connected to the ground. 3. The LED drive circuit according to claim 1, wherein the first flyback drive module comprises: Capacitor C4, resistor R5, diode D1, transformer T2, diode D2, capacitor C5, capacitor C6, resistor R6, resistor R7, diode D3, diode D4, resistor R8, PNP transistor Q1, resistor R9, resistor R10 and NMOS tube Q2 ; The first end of the capacitor C4 and the first end of the resistor R5 are commonly connected to the first end of the primary winding of the transformer T2, and the first end of the primary winding of the transformer T1 is the first flyback drive The input end of the module, the second end of the capacitor C4 and the second end of the resistor R5 are connected to the cathode of the diode D1, and the anode of the diode D1 is connected to the second end of the primary winding of the transformer T2 , the first end of the secondary winding of the transformer T2 is connected to the anode of the diode D2, the cathode of the diode D2 and the second end of the secondary winding of the transformer T2 are respectively the first flyback drive module The output terminal and the loop terminal of the capacitor C5, the first terminal of the capacitor C5 is the control signal terminal of the first flyback drive module, the second terminal of the capacitor C5, the first terminal of the capacitor C6 and the resistor The first terminal of R7 is commonly connected to the anode of the diode D4, the second terminal of the capacitor C6 and the first terminal of the resistor R6 are commonly connected to the base of the PNP transistor Q1, and the diode D3 The cathode is connected to the second end of the resistor R7, and the second end of the resistor R6 is the loop end of the first flyback drive module and is connected to the collector of the PNP transistor Q1 together with the anode of the diode D3. electrode, the resistor R8 is connected between the cathode of the diode D4 and the emitter of the PNP transistor Q1, the first end of the resistor R9 and the first end of the resistor R10 are connected to the PNP The emitter of the NMOS transistor Q1, the second end of the resistor R9 and the collector of the PNP transistor Q1 are connected to the source of the NMOS transistor Q2, and the source of the NMOS transistor Q2 is the first inverter. The drain and gate of the NMOS transistor Q2 are respectively connected to the second end of the primary winding of the transformer T2 and the second end of the resistor R10. 4. The LED drive circuit according to claim 1, wherein the second flyback drive module comprises: Capacitor C7, resistor R11, diode D5, transformer T3, diode D6, capacitor C8, capacitor C9, resistor R12, resistor R13, diode D6, diode D7, resistor R14, PNP transistor Q3, resistor R15, resistor R16 and NMOS tube Q4 ; The first end of the capacitor C7 and the first end of the resistor R11 are commonly connected to the first end of the primary winding of the transformer T3, and the first end of the primary winding of the transformer T3 is the second inverter The input terminal of the excitation drive module, the second terminal of the capacitor C7 and the second terminal of the resistor R11 are connected to the cathode of the diode D5, and the anode of the diode D5 is connected to the first terminal of the primary winding of the transformer T3. Two terminals, the first terminal of the secondary winding of the transformer T3 is connected to the anode of the diode D6, the cathode of the diode D6 and the second terminal of the secondary winding of the transformer T3 are respectively the second flyback The output end and the loop end of the drive module, the first end of the capacitor C8 is the control signal end of the second flyback drive module, the second end of the capacitor C8, the first end of the capacitor C9 and the The first end of the resistor R13 is commonly connected to the anode of the diode D7, the second end of the capacitor C9 and the first end of the resistor R12 are commonly connected to the base of the PNP transistor Q3, and the diode The cathode of D6 is connected to the second end of the resistor R13, the second end of the resistor R12 is the loop end of the second flyback drive module and is connected to the PNP transistor Q3 in common with the anode of the diode D6 The collector of the resistor R14 is connected between the cathode of the diode D7 and the emitter of the PNP transistor Q3, and the first end of the resistor R15 and the first end of the resistor R16 are connected to the The emitter of the PNP transistor Q3, the second end of the resistor R15 and the collector of the PNP transistor Q3 are connected to the source of the NMOS transistor Q4, and the source of the NMOS transistor Q4 is the first The return terminals of the two flyback drive modules are connected to the ground, and the drain and gate of the NMOS transistor Q4 are respectively connected to the second end of the primary winding of the transformer T3 and the second end of the resistor R16. 5. The LED drive circuit according to claim 1, wherein the secondary rectification and filtering module comprises: Transformer T4, Schottky diode D8, capacitor C10, resistor R17, energy storage capacitor C11, inductor L2, energy storage capacitor C12 and resistor R18; The first end of the first primary winding of the transformer T4 and the first end of the second primary winding are respectively the first input end and the second input end of the secondary rectification filter module, and the first primary end of the transformer T4 The second end of the winding and the second end of the second primary winding are respectively the third input end and the fourth input end of the secondary rectification and filtering module, and the first end of the secondary winding of the transformer T4 is simultaneously connected with the The first end of the capacitor C10 is connected to the anode of the Schottky diode D8, the resistor R17 is connected between the capacitor C10 and the cathode of the Schottky diode D8, and the positive electrode of the energy storage capacitor C11 The first end of the inductance L2 is commonly connected to the cathode of the Schottky diode D8, the second end of the inductance L2 is the output end of the secondary rectification and filtering module and is connected to the energy storage capacitor C12 positive connection, the negative pole of the energy storage capacitor C11, the second end of the secondary winding of the transformer T4 and the negative pole of the energy storage capacitor C12 are connected to the equipotential ground, and the first end of the resistor R18 is connected to the The negative pole of the energy storage capacitor C12, and the second end of the resistor R18 is the loop end of the secondary rectification and filtering module. 6. The LED drive circuit according to claim 1, wherein the electrical parameter detection and feedback module comprises: Resistor R19, resistor R20, capacitor C13, capacitor C14, resistor R21, capacitor C15, capacitor C16, resistor R22, resistor R23, capacitor C17, resistor R24, resistor R25, resistor R26, resistor R27, capacitor C18, capacitor C19, resistor R28 , capacitor C20, capacitor C21, diode D9, diode D10, TSM103 constant current chip U1 and optocoupler U2; The first end of the resistor R19 is the first detection end of the electrical parameter detection and feedback module, and is simultaneously connected to the first end of the resistor R24, the first end of the resistor R25, and the first end of the capacitor C14. One end is connected to the power supply pin of the TSM103 constant current chip U1, and the second end of the resistor R19 is simultaneously connected to the first end of the resistor R22, the first end of the capacitor C17 and the TSM103 constant current chip The first inverting input pin of U1 is connected, the second terminal of the resistor R24 is connected to the first non-inverting input pin of the TSM103 constant current chip U1, and the second terminal of the resistor R25 is connected to the optocoupler U2 The anode of the light-emitting diode, the second end of the capacitor C14 is connected to the equipotential ground, the second end of the resistor R22 is connected to the first end of the resistor R23, the second end of the resistor R23 is connected to the capacitor C17 The second end is connected to the equipotential ground, the first end of the resistor R20 is the second detection end of the electrical parameter detection and feedback module, and the second end of the resistor R20 is connected to the first end of the capacitor C13 at the same time. end, the first end of the capacitor C15, the first end of the capacitor C16 and the second inverting input pin of the TSM103 constant current chip U1 are connected, the second end of the capacitor C13 is connected to an equipotential ground, The second end of the capacitor C15 is connected to the first end of the resistor R21, the second end of the resistor R21, the cathode of the diode D9 and the second end of the capacitor C16 are connected to the TSM constant current The second output pin of the chip U1, the anode of the diode D9 and the anode of the diode D10 are connected to the cathode of the light-emitting diode in the optocoupler U2, and the cathode of the diode D10 is connected to the first of the resistor R28 at the same time. end, the first end of the capacitor C21 and the first output pin of the TSM103 constant current chip U1 are connected, the second end of the resistor R28 is connected to the first end of the capacitor C20, and the first end of the capacitor C20 The two ends and the second end of the capacitor C21 are connected to the first inverting input pin of the TSM103 constant current chip U1, and the first end of the resistor R26 is connected to the first end of the capacitor C19. The first non-inverting input pin of the TSM103 constant current chip U1, the second end of the resistor R26, the first end of the resistor R27 and the first end of the capacitor C18 are connected to the TSM103 constant current chip U1 The second non-inverting input pin of the capacitor C19, the second end of the resistor R27 and the second end of the capacitor C18 are connected to the equipotential ground, and the ground terminal of the TSM103 constant current chip U1 Connected to equipotential ground, the collector of the phototransistor in the optocoupler U2 is the output terminal of the electrical parameter detection and feedback module, and the emitter of the phototransistor in the optocoupler U2 is grounded. 7. The LED drive circuit according to claim 1, wherein the isolation transmission module comprises a capacitor C22, a diode D11 and a transformer T5, the first end of the capacitor C22 is the input end of the isolation transmission module, The cathode of the diode D11 is connected to the first end of the capacitor C22, the anode of the diode D11 and the second end of the capacitor C22 are connected to the first end of the primary winding of the transformer T5, and the transformer T5 The second end of the primary winding of the transformer T5 is grounded, the first end and the second end of the first secondary winding of the transformer T5 are respectively the first drive signal end and the first loop end of the isolated transmission module, and the transformer T5 The first end and the second end of the second secondary winding are respectively the second drive signal end and the second loop end of the isolated transmission module. 8. An LED lamp, characterized in that the LED lamp comprises the LED drive circuit according to any one of claims 1-7.

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