阅读说明：本技术 开关电源及其控制电路 (Switching power supply and control circuit thereof ) 是由 陈伟栋 李骞 王慧 于 2019-07-08 设计创作，主要内容包括：本发明提供了开关电源控制电路,其特征在于,控制电路包括输入滤波模块、整流控制模块、输出模块；输入滤波模块包括火线引脚、零线引脚、稳压元件Z1、电容C1、电容C2、第一电阻组、第一共模电感LF1、第二共模电感LF2,火线引脚、零线引脚分别与稳压元件Z1的两端引脚相连,第一电阻组、电容C1、第一共模电感LF1、第二共模电感LF2、电容C2依次与稳压元件Z1并联,电容C2的两端还设有火线输出引脚、零线输出引脚；所述整流控制模块分别与火线输出引脚、零线输出引脚相连,所述整流控制模块包括正极输出端、负极输出端；所述输出模块包括电阻R24、开关控制器U3、电容C37、电容C17、光耦合器OP2、电感T1。本发明控制电路可进行长时间稳定输出。(the invention provides a switching power supply control circuit which is characterized by comprising an input filtering module, a rectification control module and an output module; the input filtering module comprises a live wire pin, a zero line pin, a voltage stabilizing element Z1, a capacitor C1, a capacitor C2, a first resistor group, a first common mode inductor LF1 and a second common mode inductor LF2, wherein the live wire pin and the zero line pin are respectively connected with pins at two ends of the voltage stabilizing element Z1, the first resistor group, the capacitor C1, the first common mode inductor LF1, the second common mode inductor LF2 and the capacitor C2 are sequentially connected in parallel with the voltage stabilizing element Z1, and a live wire output pin and a zero line output pin are further arranged at two ends of the capacitor C2; the rectification control module is respectively connected with the live wire output pin and the zero line output pin and comprises a positive electrode output end and a negative electrode output end; the output module comprises a resistor R24, a switch controller U3, a capacitor C37, a capacitor C17, an optical coupler OP2 and an inductor T1. The control circuit of the invention can stably output for a long time.)

1. The switching power supply control circuit is characterized by comprising an input filtering module, a rectification control module and an output module;

The input filtering module comprises a live wire pin, a zero wire pin, a voltage stabilizing element Z1, a capacitor C1, a capacitor C2, a first resistor group, a first common-mode inductor LF1 and a second common-mode inductor LF2, wherein the live wire pin and the zero wire pin are respectively connected with pins at two ends of the voltage stabilizing element Z1, the first resistor group, the capacitor C1, the first common-mode inductor LF1, the second common-mode inductor LF2 and the capacitor C2 are sequentially connected in parallel with the voltage stabilizing element Z1, and a live wire output pin and a zero wire output pin are further arranged at two ends of the capacitor C2;

The rectification control module comprises a bridge rectifier, a control chip U1, a first capacitor bank, a PNP type triode, a capacitor C5 and a diode D1; the bridge rectifier is respectively connected with a live wire output pin and a zero wire output pin, the bridge rectifier further comprises an output end and an input end, the first capacitor bank comprises an anode output end and a cathode output end, the output end is connected with the anode output end of the first capacitor bank through a diode D1, and the input end is connected with the cathode output end of the first capacitor bank; the control chip U1 further comprises a GND pin, a VM pin, a CS pin, a BO pin, a V pin, an FB pin, a VCC pin and a DRV pin, the input end of the control chip U1 is connected with the CS pin, the output end of the control chip U1 is connected with the BO pin, the FB pin of the control chip U1 is connected with the positive electrode output end of the first capacitor bank, the DRV pin of the control chip U1 is connected with the B electrode of the PNP type triode, the C electrode of the PNP type triode is connected with the input end of the bridge rectifier, and the E electrode of the PNP type triode is connected with the output end of the bridge rectifier; the input filtering module further comprises a second capacitor bank connected in parallel between the first common-mode inductor LF1 and the second common-mode inductor LF2, the second capacitor bank is formed by connecting a third capacitor C3 and a fourth capacitor C4 in series, and a ground wire pin is arranged between the third capacitor C3 and the fourth capacitor C4;

the output module comprises a resistor R24, a switch controller U3, a capacitor C37, a capacitor C17, an optical coupler OP2 and an inductor T1, the switch controller U3 is provided with a plurality of D pins, a plurality of S pins, a VCC pin and an FB pin, the inductor T1 comprises an input part T1A and an output part T2C, an anode output end of the rectification control module is connected with the D pins through the resistor R24 and the input part T1A of the inductor T1 in sequence, an output part T2C of the inductor T1 forms a 12V power output end, the resistor R24 is connected with the S pin through the capacitor C37, the S pin is connected with a cathode output end of the rectification control module, the S pin is connected with the FB pin through the capacitor C17, the optical coupler OP2 comprises a diode OP2B and a light-emitting diode OP2A, the S pin is connected with the FB pin through a light-receiving diode OP2B, and the light-emitting diode OP2A comprises a light-emitting diode OP2 input end OP, And the output part T2C of the inductor T1 comprises a 12V positive output end and a negative output end, the input end of the light-emitting secondary tube end OP2A is connected with the 12V positive output end, and the output end of the light-emitting secondary tube end OP2A is connected with the ground wire.

2. The control circuit of claim 1, wherein the output module further comprises a diode D6 and a capacitor C60, the capacitor C60 is installed in an output portion T2C of the inductor L1, a positive terminal of the output portion T2C of the inductor T1 is connected to one terminal of the capacitor C60 through the diode D6, and a negative terminal of the output portion T2C of the inductor T1 is connected to the other terminal of the capacitor C60.

3. The control circuit of claim 1, wherein the output module further comprises a capacitor C30, a diode D11, a resistor R80 and a resistor R81, the resistor R24 is connected to the D pin of the switch controller U3 through a capacitor C30 and a diode D11 in sequence, the resistor R80 is connected in parallel to a capacitor C30, the resistor R81 is connected in parallel to a capacitor C30, the input terminal of the diode D11 is connected to the D pin, and the output terminal of the diode D11 is connected to the capacitor C30.

4. The control circuit of claim 1, wherein the inductor T1 further comprises an input portion T1B, and the S pin of the switch controller U3 is connected to the VCC pin of the switch controller U3 through the input portion T1B.

5. The control circuit of claim 4, wherein the output module further comprises a diode D4, a diode D5 and a resistor R82, the input part T1B is connected with the switch controller U3 through a diode D5, a resistor R82 and a diode D4 in sequence, the input end of the diode D5 is connected with the input part T1B, and the input end of the diode D4 is connected with the resistor R82.

6. The control circuit according to claim 5, wherein the output module further comprises a zener diode ZD1, the FB pin of the switch controller U3 is connected to an input terminal of a zener diode ZD1, an output terminal of the zener diode ZD1 is connected to an input terminal of a diode D4, and an output terminal of the zener diode ZD1 is further connected to a light receiving diode OP 2B.

7. the control circuit of claim 6, wherein the output module further comprises a capacitor C17, and the FB pin of the switch controller U3 is connected to the S pin of the switch controller U3 through a capacitor C17.

8. The control circuit of claim 6, wherein the output module further comprises a capacitor C15, a capacitor C16, a capacitor C61, and a resistor R83, two ends of the capacitor C16 are respectively connected with a VCC pin and an S pin of the switch controller U3, one end of the capacitor C15 is connected to the output end of the zener diode ZD1 and the input end of the diode D4 respectively, the other end of the capacitor C15 is connected with an S pin of a switch controller U3, the capacitor C61 is connected with a light receiving diode end OP2B in parallel, the output module also comprises a PNP type triode Q2, the triode Q2 comprises a C end, a B end and an E end, the triode Q2 comprises a C end, a B end and an E end, the E end of the triode Q2 is connected with the output end of the zener diode ZD1, the B end of the triode Q2 is connected with the S end of the switch controller U3, and the C end of the triode Q2 is connected with the VCC pin of the control chip U1. .

Technical Field

The present invention relates to a control circuit, and more particularly, to a switching power supply control circuit.

background

With the progress of the second industrial revolution, electric power has been widely popularized, and electric appliances have been advanced into various industries. The voltage of a public power grid in China is 220V, but the electric appliances have different power and different required driving voltages, so that the electric appliances cannot be directly connected into the public power grid, and the voltage of the public power grid needs to be adjusted to the driving voltage of the electric appliances by using a switching power supply, so that the electric appliances can work safely and stably. However, when the switching power supply works for a long time, the voltage output changes due to various reasons, so that the voltage output is unstable, and the use safety of the switching power supply is affected.

disclosure of Invention

The invention provides a switching power supply and a control circuit thereof, which can ensure the long-time stable output of the switching power supply.

The invention provides a switching power supply control circuit, which comprises an input filtering module, a rectification control module and an output module;

The input filtering module comprises a live wire pin, a zero wire pin, a voltage stabilizing element Z1, a capacitor C1, a capacitor C2, a first resistor group, a first common-mode inductor LF1 and a second common-mode inductor LF2, wherein the live wire pin and the zero wire pin are respectively connected with pins at two ends of the voltage stabilizing element Z1, the first resistor group, the capacitor C1, the first common-mode inductor LF1, the second common-mode inductor LF2 and the capacitor C2 are sequentially connected in parallel with the voltage stabilizing element Z1, and a live wire output pin and a zero wire output pin are further arranged at two ends of the capacitor C2;

the rectification control module is respectively connected with the live wire output pin and the zero line output pin and comprises a positive electrode output end and a negative electrode output end;

The output module comprises a resistor R24, a switch controller U3, a capacitor C37, a capacitor C17, an optical coupler OP2 and an inductor T1, the switch controller U3 is provided with a plurality of D pins, a plurality of S pins, a VCC pin and an FB pin, the inductor T1 comprises an input part T1A and an output part T2C, an anode output end of the rectification control module is connected with the D pins through the resistor R24 and the input part T1A of the inductor T1 in sequence, an output part T2C of the inductor T1 forms a 12V power output end, the resistor R24 is connected with the S pin through the capacitor C37, the S pin is connected with a cathode output end of the rectification control module, the S pin is connected with the FB pin through the capacitor C17, the optical coupler OP2 comprises a diode OP2B and a light-emitting diode OP2A, the S pin is connected with the FB pin through a light-receiving diode OP2B, and the light-emitting diode OP2A comprises a light-emitting diode OP2 input end OP, And the output part T2C of the inductor T1 comprises a 12V positive output end and a negative output end, the input end of the light-emitting secondary tube end OP2A is connected with the 12V positive output end, and the output end of the light-emitting secondary tube end OP2A is connected with the ground wire.

Further, the rectification control module comprises a bridge rectifier, a control chip U1, a first capacitor group, a PNP type triode, a capacitor C5 and a diode D1; the bridge rectifier is respectively connected with a live wire output pin and a zero wire output pin, the bridge rectifier further comprises an output end and an input end, the first capacitor bank comprises an anode output end and a cathode output end, the output end is connected with the anode output end of the first capacitor bank through a diode D1, and the input end is connected with the cathode output end of the first capacitor bank; the control chip U1 further comprises a GND pin, a VM pin, a CS pin, a BO pin, a V pin, an FB pin, a VCC pin and a DRV pin, the input end of the control chip U1 is connected with the CS pin, the output end of the control chip U1 is connected with the BO pin, the FB pin of the control chip U1 is connected with the positive electrode output end of the first capacitor bank, the DRV pin of the control chip U1 is connected with the B electrode of the PNP type triode, the C electrode of the PNP type triode is connected with the input end of the bridge rectifier, and the E electrode of the PNP type triode is connected with the output end of the bridge rectifier; the input filtering module further comprises a second capacitor bank connected in parallel between the first common-mode inductor LF1 and the second common-mode inductor LF2, the second capacitor bank is composed of a third capacitor C3 and a fourth capacitor C4 in series, and a ground wire pin is arranged between the third capacitor C3 and the fourth capacitor C4.

Furthermore, the output module further comprises a diode D6 and a capacitor C60, the capacitor C60 is mounted on the output portion T2C of the inductor L1, the positive terminal of the output portion T2C of the inductor T1 is connected to one terminal of the capacitor C60 through the diode D6, and the negative terminal of the output portion T2C of the inductor T1 is connected to the other terminal of the capacitor C60.

furthermore, the output module further includes a capacitor C30, a diode D11, a resistor R80, and a resistor R81, the resistor R24 is connected to the D pin of the switch controller U3 sequentially through a capacitor C30 and a diode D11, the resistor R80 is connected in parallel to the capacitor C30, the resistor R81 is connected in parallel to the capacitor C30, the input terminal of the diode D11 is connected to the D pin, and the output terminal of the diode D11 is connected to the capacitor C30.

Further, the inductor T1 further includes an input portion T1B, and the S pin of the switch controller U3 is connected to the VCC pin of the switch controller U3 through the input portion T1B.

Furthermore, the output module further comprises a diode D4, a diode D5 and a resistor R82, the input part T1B is connected with the switch controller U3 through the diode D5, the resistor R82 and the diode D4 in sequence, the input end of the diode D5 is connected with the input part T1B, and the input end of the diode D4 is connected with the resistor R82.

Furthermore, the output module further includes a zener diode ZD1, the FB pin of the switch controller U3 is connected through an input terminal of a zener diode ZD1, an output terminal of the zener diode ZD1 is connected to an input terminal of a diode D4, and an output terminal of the zener diode ZD1 is further connected to a light receiving diode terminal OP 2B.

Furthermore, the output module further includes a capacitor C17, and the FB pin of the switch controller U3 is connected to the S pin of the switch controller U3 through a capacitor C17.

Furthermore, the output module further includes a capacitor C15, a capacitor C16, a capacitor C61, and a resistor R83, two ends of the capacitor C16 are respectively connected to a VCC pin and an S pin of the switch controller U3, one end of the capacitor C15 is respectively connected to an output end of the zener diode ZD1 and an input end of the diode D4, the other end of the capacitor C15 is connected to the S pin of the switch controller U3, and the capacitor C61 is connected in parallel to the light-receiving diode OP 2B.

Furthermore, the output module further includes a PNP type triode Q2, the triode Q2 includes a C terminal, a B terminal, and an E terminal, the triode Q2 includes a C terminal, a B terminal, and an E terminal, the E terminal of the triode Q2 is connected to the output terminal of the zener diode ZD1, the B terminal of the triode Q2 is connected to the S terminal of the switch controller U3, the C terminal of the triode Q2 is connected to the VCC pin of the control chip U1.

Further, the input filter module further includes a second capacitor bank connected in parallel between the first common-mode inductor LF1 and the second common-mode inductor LF2, the second capacitor bank is formed by connecting a third capacitor C3 and a fourth capacitor C4 in series, and a ground wire pin is arranged between the third capacitor C3 and the fourth capacitor C4.

Further, an inductor L5 is further disposed between the live line output end of the input filtering module and the second capacitor C2.

further, the first capacitor bank is formed by connecting a capacitor C11, a capacitor C12, a capacitor C13 and a capacitor C33 in parallel, and the capacitor C11, the capacitor C12 and the capacitor C13 are all large-capacity capacitors.

Further, a first N-channel insulated gate field effect transistor Q1 is further included between the E-pole of the PNP triode and the output end of the bridge rectifier, the D-pole of the first N-channel insulated gate field effect transistor Q1 is connected to the output end of the bridge rectifier, the G-pole of the first N-channel insulated gate field effect transistor Q1 is connected to the E-pole of the PNP triode, and the S-pole of the first N-channel insulated gate field effect transistor Q1 is connected to the C-pole of the PNP triode.

Furthermore, the rectification control module further includes a second N-channel insulated gate field effect transistor Q1A, the second N-channel insulated gate field effect transistor Q1A is connected in parallel with the first N-channel insulated gate field effect transistor Q1, a D-pole of the second N-channel insulated gate field effect transistor Q1A is connected to the output end of the bridge rectifier, a G-pole of the second N-channel insulated gate field effect transistor Q1A is connected to an E-pole of the PNP type triode, and an S-pole of the second N-channel insulated gate field effect transistor Q1A is connected to a C-pole of the PNP type triode.

Further, the rectification control module further comprises a thermistor N1, and the thermistor N1 is installed between the diode D1 and the positive output end of the first capacitor bank.

Further, the first resistor group comprises a resistor R1, a resistor R1A, a resistor R2 and a resistor R2A, wherein the resistor R1 is connected in series with the resistor R2, the resistor R1A is connected in parallel with the resistor R1, and the resistor R2A is connected in parallel with the resistor R2.

Further, an inductor L1A is also arranged between the pole E of the PNP transistor and the output terminal of the bridge rectifier.

Further, the rectification control module further comprises a second resistor group, the second resistor group is formed by connecting a resistor R9, a resistor R10 and a resistor R10A in parallel, and the second resistor group is installed between the C pole of the PNP type triode and the input end of the bridge rectifier.

The invention also relates to a switching power supply with the control circuit.

Compared with the prior art, the invention realizes effective control of output voltage by adopting the optical coupler OP2 and the switch controller U3, and can control the working state of the switch controller U3 through the optical coupler OP2 when the voltage is overhigh, thereby ensuring the output stability of the control circuit and improving the use safety of the control circuit.

Drawings

FIG. 1 is a schematic circuit diagram of an input filter module according to an embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of a rectification control module according to an embodiment of the present invention;

Fig. 3 is a schematic circuit diagram of an output module according to an embodiment of the invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described implementations are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

The embodiment of the invention discloses a switching power supply, and a control circuit thereof comprises an input filtering module, a rectification control module and an output module, as shown in figures 1-3;

The input filtering module comprises a live wire pin, a zero wire pin, a voltage stabilizing element Z1, a capacitor C1, a capacitor C2, a first resistor group, a first common-mode inductor LF1 and a second common-mode inductor LF2, wherein the live wire pin and the zero wire pin are respectively connected with pins at two ends of the voltage stabilizing element Z1, the first resistor group, the capacitor C1, the first common-mode inductor LF1, the second common-mode inductor LF2 and the capacitor C2 are sequentially connected in parallel with the voltage stabilizing element Z1, and a live wire output pin and a zero wire output pin are further arranged at two ends of the capacitor C2;

The rectification control module is respectively connected with the live wire output pin and the zero line output pin and comprises a positive electrode output end and a negative electrode output end;

The output module comprises a resistor R24, a switch controller U3, a capacitor C37, a capacitor C17, an optical coupler OP2 and an inductor T1, the switch controller U3 is provided with a plurality of D pins, a plurality of S pins, a VCC pin and an FB pin, the inductor T1 comprises an input part T1A and an output part T2C, an anode output end of the rectification control module is connected with the D pins through the resistor R24 and the input part T1A of the inductor T1 in sequence, an output part T2C of the inductor T1 forms a 12V power output end, the resistor R24 is connected with the S pin through the capacitor C37, the S pin is connected with a cathode output end of the rectification control module, the S pin is connected with the FB pin through the capacitor C17, the optical coupler OP2 comprises a diode OP2B and a light-emitting diode OP2A, the S pin is connected with the FB pin through a light-receiving diode OP2B, and the light-emitting diode OP2A comprises a light-emitting diode OP2 input end OP, And the output part T2C of the inductor T1 comprises a 12V positive output end and a negative output end, the input end of the light-emitting secondary tube end OP2A is connected with the 12V positive output end, and the output end of the light-emitting secondary tube end OP2A is connected with the ground wire. The switch power supply is provided with three-hole power supply output ends, the positive terminal of each three-hole power supply output end is connected with the 12V positive terminal output end, and the negative terminal of each three-hole power supply output end is connected with the negative terminal output end of the output part T2C.

Optionally, the rectification control module includes a bridge rectifier, a control chip U1, a first capacitor bank, a PNP type triode, a capacitor C5, and a diode D1; the bridge rectifier is respectively connected with a live wire output pin and a zero wire output pin, the bridge rectifier further comprises an output end and an input end, the first capacitor bank comprises an anode output end and a cathode output end, the output end is connected with the anode output end of the first capacitor bank through a diode D1, and the input end is connected with the cathode output end of the first capacitor bank; the control chip U1 further comprises a GND pin, a VM pin, a CS pin, a BO pin, a V pin, an FB pin, a VCC pin and a DRV pin, the input end of the control chip U1 is connected with the CS pin, the output end of the control chip U1 is connected with the BO pin, the FB pin of the control chip U1 is connected with the positive electrode output end of the first capacitor bank, the DRV pin of the control chip U1 is connected with the B electrode of the PNP type triode, the C electrode of the PNP type triode is connected with the input end of the bridge rectifier, and the E electrode of the PNP type triode is connected with the output end of the bridge rectifier; the input filtering module further comprises a second capacitor bank connected in parallel between the first common-mode inductor LF1 and the second common-mode inductor LF2, the second capacitor bank is composed of a third capacitor C3 and a fourth capacitor C4 in series, and a ground wire pin is arranged between the third capacitor C3 and the fourth capacitor C4.

In particular, the output module further comprises a diode D6 and a capacitor C60, the capacitor C60 is mounted on an output portion T2C of the inductor L1, the positive terminal of the output portion T2C of the inductor T1 is connected to one terminal of the capacitor C60 through the diode D6, and the negative terminal of the output portion T2C of the inductor T1 is connected to the other terminal of the capacitor C60.

Particularly, the output module further includes a capacitor C30, a diode D11, a resistor R80, and a resistor R81, the resistor R24 is connected to a pin D of the switch controller U3 sequentially through a capacitor C30 and a diode D11, the resistor R80 is connected in parallel to the capacitor C30, the resistor R81 is connected in parallel to the capacitor C30, an input terminal of the diode D11 is connected to the pin D, and an output terminal of the diode D11 is connected to the capacitor C30.

In particular, the inductor T1 further includes an input portion T1B, and the S pin of the switch controller U3 is connected to the VCC pin of the switch controller U3 through the input portion T1B.

Specifically, the output module further includes a diode D4, a diode D5, and a resistor R82, the input portion T1B is connected to the switch controller U3 through the diode D5, the resistor R82, and the diode D4 in sequence, the input end of the diode D5 is connected to the input portion T1B, and the input end of the diode D4 is connected to the resistor R82.

In particular, the output module further includes a zener diode ZD1, the FB pin of the switch controller U3 is connected through an input terminal of a zener diode ZD1, an output terminal of the zener diode ZD1 is connected to an input terminal of a diode D4, and an output terminal of the zener diode ZD1 is further connected to a light receiving diode terminal OP 2B.

In particular, the output module further includes a capacitor C17, and the FB pin of the switch controller U3 is connected to the S pin of the switch controller U3 through a capacitor C17.

Specifically, the output module further includes a capacitor C15, a capacitor C16, a capacitor C61, and a resistor R83, two ends of the capacitor C16 are respectively connected to a VCC pin and an S pin of the switch controller U3, one end of the capacitor C15 is respectively connected to an output end of the zener diode ZD1 and an input end of the diode D4, the other end of the capacitor C15 is connected to the S pin of the switch controller U3, and the capacitor C61 is connected in parallel to the light-receiving diode OP 2B.

Particularly, the output module further includes a PNP type triode Q2, the triode Q2 includes a C terminal, a B terminal, and an E terminal, the triode Q2 includes a C terminal, a B terminal, and an E terminal, the E terminal of the triode Q2 is connected to the output terminal of the zener diode ZD1, the B terminal of the triode Q2 is connected to the S terminal of the switch controller U3, the C terminal of the triode Q2 is connected to the VCC pin of the control chip U1.

the output module is provided with a transformer structure, so that the output voltage of the output module is matched with the working voltage of the electric equipment, and the electric equipment can work normally. The output end and the input end of the bridge rectifier are further connected with a capacitor C5, the input end is connected with a CS pin of a control chip U1 through a resistor R7, a resistor R3 and a resistor R4 which are connected in series are arranged between the output end and a BO pin of the control chip U1, the BO pin is further connected with a resistor R5, the resistor R5 is connected with one end of the capacitor C19, the other end of the capacitor C19 is connected with a ground wire, the resistor R8 and the capacitor C6 are connected with the resistor R5 in parallel, a V pin of the control chip U1 is connected with a circuit structure between the capacitor C19 and the resistor R5 through the resistor R6 and the capacitor C8 in sequence, and the circuit structure between the capacitor C9 and the resistor R6 and the capacitor C8. The resistor R19 and the resistor R18 which are connected in series with the FB pin of the control chip U1 are connected with the anode output end of the first capacitor bank, the FB pin of the control chip U1 is also connected with the capacitor C19 through the capacitor C10, and the resistor R20 is connected with the capacitor C10 in parallel. The DRV pin is connected with the B pole of the PNP type triode through a resistor R13, the GND pin is connected with a capacitor C19, and the VM pin is connected with a capacitor C19 through a capacitor C7 and a resistor R23 which are connected in parallel. The B pole of the PNP type triode is also connected with the C pole through a diode D3, and the current flow direction of the diode D3 is from the B pole to the E pole.

According to the embodiment of the invention, the optical coupler OP2 and the switch controller U3 are adopted to realize effective control of the output voltage, and when the voltage is too high, the working state of the switch controller U3 can be controlled through the optical coupler OP2, so that the output stability of the control circuit is ensured, and the use safety of the control circuit is improved.

Optionally, as shown in fig. 1 and fig. 2, the input filter module further includes a second capacitor bank connected in parallel between the first common-mode inductor LF1 and the second common-mode inductor LF2, where the second capacitor bank is formed by connecting a third capacitor C3 and a fourth capacitor C4 in series, and a ground wire pin is disposed between the third capacitor C3 and the fourth capacitor C4.

Optionally, as shown in fig. 1 and fig. 2, an inductor L5 is further disposed between the live output terminal of the input filtering module and the second capacitor C2.

Optionally, as shown in fig. 1 and fig. 2, the first capacitor bank is formed by connecting a capacitor C11, a capacitor C12, a capacitor C13, and a capacitor C33 in parallel, and the capacitor C11, the capacitor C12, and the capacitor C13 are all large-capacity capacitors.

optionally, as shown in fig. 1 and fig. 2, a first N-channel insulated gate field effect transistor Q1 is further included between the E-pole of the PNP type triode and the output end of the bridge rectifier, the D-pole of the first N-channel insulated gate field effect transistor Q1 is connected to the output end of the bridge rectifier, the G-pole of the first N-channel insulated gate field effect transistor Q1 is connected to the E-pole of the PNP type triode, and the S-pole of the first N-channel insulated gate field effect transistor Q1 is connected to the C-pole of the PNP type triode.

As shown in fig. 2, the D pole of the first N-channel insulated gate field effect transistor Q1 is further connected to the positive output end of the first capacitor bank through a resistor R25 and a capacitor C18 that are sequentially connected in series, the resistor R25A is connected in parallel to the resistor R25, the G pole of the first N-channel insulated gate field effect transistor Q1 is connected to the E pole of the PNP triode through a resistor R11, and the G pole of the first N-channel insulated gate field effect transistor Q1 is further connected to the C pole of the PNP triode through a resistor R12.

specifically, the rectification control module further includes a second N-channel insulated gate field effect transistor Q1A, the second N-channel insulated gate field effect transistor Q1A is connected in parallel with the first N-channel insulated gate field effect transistor Q1, a D-pole of the second N-channel insulated gate field effect transistor Q1A is connected to the output end of the bridge rectifier, a G-pole of the second N-channel insulated gate field effect transistor Q1A is connected to an E-pole of the PNP type triode, and an S-pole of the second N-channel insulated gate field effect transistor Q1A is connected to a C-pole of the PNP type triode.

The D pole of the second N-channel insulated gate field effect transistor Q1A is further connected to the positive output end of the first capacitor bank through a diode D2, the G pole of the second N-channel insulated gate field effect transistor Q1A is connected to the E pole of the PNP type triode through a resistor R11A, the G pole of the second N-channel insulated gate field effect transistor Q1A is further connected to the C pole of the PNP type triode through a resistor R12A, the D pole of the second N-channel insulated gate field effect transistor Q1A is further connected to the C pole of the PNP type triode through a capacitor C29, and the diode D2 is connected to the C pole of the PNP type triode through a capacitor C45.

Optionally, the rectification control module further includes a thermistor N1, and the thermistor N1 is installed between the diode D1 and the positive output terminal of the first capacitor bank.

Optionally, the first resistor group includes a resistor R1, a resistor R1A, a resistor R2, and a resistor R2A, the resistor R1 is connected in series with the resistor R2, the resistor R1A is connected in parallel with the resistor R1, and the resistor R2A is connected in parallel with the resistor R2.

Optionally, an inductor L1A is further disposed between the E-pole of the PNP transistor and the output end of the bridge rectifier.

Optionally, the rectification control module further includes a second resistor group, the second resistor group is formed by connecting a resistor R9, a resistor R10, and a resistor R10A in parallel, and the second resistor group is installed between the C-pole of the PNP type triode and the input end of the bridge rectifier.

According to the invention, the first common mode inductor LF1 and the second common mode inductor LF2 are adopted to filter the input voltage and ensure the stability of the input alternating voltage. Meanwhile, the first capacitor group is adopted in the embodiment of the invention, so that the rectifying control module has stronger electric energy holding capacity, and can effectively play a role in voltage stabilization under the condition of unstable input voltage, and the control circuit can still keep a constant voltage effect under the condition of high-power work.

Finally, it should be noted that the above-mentioned embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that the modifications and equivalents of the specific embodiments of the present invention can be made by those skilled in the art after reading the present specification, but these modifications and variations do not depart from the scope of the claims of the present application.