CN114448271A

CN114448271A - Power supply circuit

Info

Publication number: CN114448271A
Application number: CN202210131937.7A
Authority: CN
Inventors: 徐磊; 张小兵; 廖光朝
Original assignee: Shenzhen Yuntong Technology Co ltd
Current assignee: Shenzhen Yuntong Technology Co ltd
Priority date: 2022-02-14
Filing date: 2022-02-14
Publication date: 2022-05-06

Abstract

The invention discloses a power supply circuit. The power supply circuit includes: the device comprises a rectifying module, a voltage stabilizing module, an MOS tube module, a filtering module and a main control chip. The rectification module rectifies the input alternating current and outputs direct current; the input end of the voltage stabilizing module is electrically connected with the output end of the rectifying module and is used for dividing and stabilizing the direct current to obtain a voltage reduction signal and outputting the voltage reduction signal from the output end of the voltage stabilizing module; the control end of the MOS tube module is electrically connected with the output end of the voltage stabilizing module, the input end of the MOS tube module is connected with direct current, and the output end of the MOS tube module outputs controllable low voltage; the input end of the filtering module is electrically connected with the output end of the MOS tube module; the power supply end of the main control chip is electrically connected with the output end of the filtering module. According to the technical scheme of the embodiment of the invention, the MOS tube is adopted to reduce the voltage, so that the adjustable and stable low-voltage direct current is obtained to supply power to the main control chip, the occupied volume of the power circuit on the main board is reduced, and the power supply circuit is applicable to the application field with smaller power.

Description

Power supply circuit

Technical Field

The invention relates to the technical field of power supplies, in particular to a power supply circuit.

Background

In a main board used for products such as electric appliances and industrial equipment, an input voltage is required to be a direct current low voltage, for example: 24V, 12V, etc.

In the prior art, the low-voltage dc power supply reduces ac mains supply into low-voltage ac power through a transformer, and then converts the low-voltage ac power into pulse dc power through a rectifier bridge. After being filtered by the electrolytic capacitor, the Low Dropout Regulator (LDO) is connected to obtain a stable Low-voltage direct current power supply. However, in the application with smaller power, the power supply provided by the prior art has the problem of occupying large volume.

Disclosure of Invention

The invention provides a power supply circuit, which aims to solve the problem that a power supply occupies a large volume in application with low power.

According to an aspect of the present invention, a power supply circuit is provided. The power supply circuit includes:

the rectification module rectifies the input alternating current and outputs direct current;

the input end of the voltage stabilizing module is electrically connected with the output end of the rectifying module and is used for dividing and stabilizing the direct current to obtain a voltage reduction signal and outputting the voltage reduction signal from the output end of the voltage stabilizing module;

the control end of the MOS tube module is electrically connected with the output end of the voltage stabilizing module, the input end of the MOS tube module is connected with direct current, and the output end of the MOS tube module outputs controllable low voltage;

the input end of the filtering module is electrically connected with the output end of the MOS tube module;

and the power supply end of the main control chip is electrically connected with the output end of the filtering module.

Optionally, the MOS transistor module includes:

the grid electrode of the MOS tube is electrically connected with the control end of the MOS tube module, the source electrode of the MOS tube is electrically connected with the output end of the MOS tube module, and the drain electrode of the MOS tube is electrically connected with the input end of the MOS tube module.

Optionally, the MOS transistor is packaged in a patch manner.

Optionally, the MOS transistor module further includes:

and the anode of the first diode is electrically connected with the output end of the MOS tube module, and the cathode of the first diode is electrically connected with the control end of the MOS tube module.

Optionally, the MOS transistor module further includes:

and the positive end of the filter capacitor is electrically connected with the output end of the MOS tube module, and the negative end of the filter capacitor is grounded.

Optionally, the power circuit further includes:

and the first end of the piezoresistor is electrically connected with the output end of the rectifying module, and the second end of the piezoresistor is grounded.

Optionally, the voltage stabilizing module includes:

the first end of the first resistor at the head end is electrically connected with the input end of the voltage stabilizing module, and the second end of the first resistor at the tail end is electrically connected with the output end of the voltage stabilizing module;

the cathode of the voltage stabilizing diode is electrically connected with the output end of the voltage stabilizing module, and the anode of the voltage stabilizing diode is grounded;

the first end of the second resistor is electrically connected with the output end of the voltage stabilizing module;

and the first end of the first capacitor is electrically connected with the second end of the second resistor, and the second end of the first capacitor is grounded.

Optionally, the filtering module includes:

the anode of the second diode is electrically connected with the output end of the MOS tube module;

a first end of the third resistor is electrically connected with the cathode of the second diode, and a second end of the third resistor is electrically connected with a power supply end of the main control chip;

and the first end of the second capacitor is electrically connected with the cathode of the second diode, and the second end of the second capacitor is grounded.

Optionally, the power circuit further includes:

the input end of the optical coupling module is connected with an external control voltage, the first output end of the optical coupling module is electrically connected with the power supply end of the main control chip, and the second output end of the optical coupling module is electrically connected with the regulating end of the main control chip;

and the fourth resistor at the head end is electrically connected with the output end of the MOS tube module, and the fourth resistor at the tail end is electrically connected with the input end of the main control chip.

Optionally, the optical coupling module includes:

the optical coupler comprises an input end, a first grounding end, an output end and a second grounding end, the input end of the optical coupler is electrically connected with the input end of the optical coupling module, and the second grounding end of the optical coupler is electrically connected with the second output end of the optical coupling module;

a first end of the fifth resistor is electrically connected with the first grounding end of the optical coupler;

a first end of the third capacitor is electrically connected with a second end of the fifth resistor, and a second end of the third capacitor is grounded;

a first end of the sixth resistor is electrically connected with the output end of the optical coupler, and a second end of the sixth resistor is electrically connected with the first output end of the optical coupling module;

and a first end of the seventh resistor is electrically connected with the second grounding end of the optical coupler, and a second end of the seventh resistor is grounded.

The technical scheme provided by the embodiment of the invention comprises a rectifying module, a voltage stabilizing module, an MOS tube module, a filtering module and a main control chip, wherein direct current is obtained after rectifying alternating current input into an external power circuit, the direct current is subjected to voltage reduction and voltage stabilization through the voltage stabilizing module and the MOS tube module, controllable low voltage can be output from the output end of the MOS tube module, and the controllable low voltage is output to the main control chip after being subjected to filtering processing through the filtering module to supply power for the main control chip. The power supply circuit provided by the embodiment adopts the voltage stabilizing module and the MOS tube module to realize the voltage reduction effect, and obtains controllable low-voltage direct current. Compared with the scheme of utilizing the LDO voltage reduction chip to realize the power circuit in the prior art, the embodiment does not need to adopt a transformer and a large device with the same volume, so that the volume occupied by the power circuit on the main board can be reduced, and the LDO voltage reduction chip is effectively suitable for application with small power.

It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present invention, nor do they necessarily limit the scope of the invention. Other features of the present invention will become apparent from the following description.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a power supply circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a power supply circuit according to another embodiment of the present invention;

fig. 3 is a schematic structural diagram of another power supply circuit provided in accordance with an embodiment of the present 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 embodiments 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. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in other sequences than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The embodiment of the invention provides a power supply circuit. Fig. 1 is a schematic structural diagram of a power supply circuit according to an embodiment of the present invention, and as shown in fig. 1, the power supply circuit includes: the circuit comprises a rectifying module 10, a voltage stabilizing module 20, a MOS tube module 30, a filtering module 40 and a main control chip 50.

The rectifying module 10 rectifies the input alternating current and outputs direct current;

the input end of the voltage stabilizing module 20 is electrically connected with the output end of the rectifying module 10, and is used for dividing and stabilizing the direct current to obtain a voltage reduction signal and outputting the voltage reduction signal from the output end of the voltage stabilizing module;

the control end of the MOS transistor module 30 is electrically connected with the output end of the voltage stabilizing module 20, the input end of the MOS transistor module 30 is connected with direct current, and the output end of the MOS transistor module 30 outputs controllable low voltage;

the input end of the filtering module 40 is electrically connected with the output end of the MOS tube module 30;

the power supply end of the main control chip 50 is electrically connected with the output end of the filtering module 40.

Specifically, the external ac power is input to the power circuit, processed and then input to the main control chip 50 to supply power to the main control chip 50. Illustratively, the externally input ac power may be 220V ac mains power. The rectifying module 10 rectifies the input ac power to obtain a dc power, and the dc power is output from the output terminal of the rectifying module 10 to the input terminal of the voltage stabilizing module 20. The input end of the voltage stabilizing module 20 is electrically connected to the output end of the rectifying module 10, and the rectified dc power is input into the voltage stabilizing module 20 to reduce the dc power, and the voltage stabilizing module can stabilize the voltage at a predetermined voltage and output the voltage to the input end of the MOS transistor module 30. For example, the preset voltage is a voltage value of power required by the main control chip 50 to normally operate, and the preset voltage value may be determined according to voltages required by different application devices. For applications with less power, the preset voltage is lower than the voltage value of the externally input alternating current. The direct current outputs a divided voltage signal after being divided and stepped down by the voltage stabilizing module 20, and the direct current outputs a direct current with controllable voltage after being stabilized by the voltage stabilizing module 20. The control end of the MOS transistor module 30 is electrically connected to the output end of the voltage regulation module 20, so that the divided voltage signal output by the output end of the voltage regulation module 20 is output to the control end of the MOS transistor module 30, and the conduction or the cut-off of the MOS transistor module 30 is controlled by the level of the voltage signal. The input end of the MOS transistor module 30 is connected to the direct current obtained through rectification. When the control end of the MOS transistor module 30 receives a divided voltage signal to control the conduction of the MOS transistor module 30, the output end of the MOS transistor module 30 can output a controllable low voltage after the direct current input to the MOS transistor module 30 is subjected to voltage stabilization. Then, the controllable low voltage is input to the filtering module 40 from the input end of the filtering module 40, and the filtering module 40 performs filtering processing on the controllable low voltage output by the MOS transistor module 30 to filter out the specific band frequency. The filtered electric energy is output from the output terminal of the filtering module 40 to the power supply terminal of the main control chip 50, so as to meet the requirement of the main control chip 50 for normal operation.

The technical scheme that this embodiment provided includes rectifier module 10, voltage regulator module 20, MOS pipe module 30, filtering module 40 and main control chip 50, after the alternating current through to external input power supply circuit carries out the rectification processing, obtain the direct current, after voltage regulator module 20 and MOS pipe module 30 step down and the steady voltage to the direct current, can be by the controllable low-voltage of MOS pipe module 30's output, controllable low-voltage carries out the filtering processing back through filtering module 40, output to main control chip 50, for main control chip 50 power supply. The power supply circuit provided by the embodiment adopts the voltage stabilizing module 20 and the MOS transistor module 30 to realize the voltage reduction effect, and obtains controllable low-voltage direct current. Compared with the scheme of utilizing the LDO voltage reduction chip to realize the power circuit in the prior art, the embodiment does not need to adopt a transformer and a large device with the same volume, so that the volume occupied by the power circuit on the main board can be reduced, and the LDO voltage reduction chip is effectively suitable for application with small power.

Optionally, fig. 2 is a schematic structural diagram of another power circuit provided in an embodiment of the present invention, and this embodiment is a refinement of a specific structure of the MOS transistor module in the foregoing embodiment. As shown in fig. 2, the MOS transistor module 30 includes:

at least one MOS pipe, the grid of MOS pipe and MOS pipe module 30's control end electricity are connected, and the source electrode of MOS pipe is connected with MOS pipe module 30's output electricity, and the drain electrode of MOS pipe is connected with MOS pipe module 30's input electricity.

Illustratively, the number of MOS transistors may be 2, for example: a first MOS transistor Q1 and a second MOS transistor Q2. The MOS tube can be an N-channel enhancement type MOS tube.

The gates of the first MOS transistor Q1 and the second MOS transistor Q2 are electrically connected to the control electrode of the MOS transistor module 30. After the control electrode of the MOS transistor module 30 receives the divided voltage signal output by the voltage stabilizing module 20, the divided voltage signal is transmitted to the gates of the first MOS transistor Q1 and the second MOS transistor Q2, and the first MOS transistor Q1 and the second MOS transistor Q2 are controlled to be turned on or off. The drains of the first MOS transistor Q1 and the second MOS transistor Q2 are used for accessing the direct current rectified by the rectifier module 10, and the sources of the first MOS transistor Q1 and the second MOS transistor Q2 are used for outputting a controllable direct current low voltage, so that the electric energy requirement of the main control chip 50 is met. When the control electrode of the MOS transistor module 30 receives a high level signal, the high level signal is input to the gates of the first MOS transistor Q1 and the second MOS transistor Q2, and the first MOS transistor Q1 and the second MOS transistor Q2 are controlled to be turned on, the rectified dc signal is input from the drains of the first MOS transistor Q1 and the second MOS transistor Q2. Through the regulation and control of the voltage stabilizing module 20, the source electrodes of the first MOS transistor Q1 and the second MOS transistor Q2 output controllable direct current low voltage, and provide electric energy required by the normal operation of the main control chip 50.

Optionally, the MOS transistor is packaged in a patch manner. In particular, the package type of the MOS transistor may include a plug-in type and a patch type. Compared with an insertion type packaging form, the MOS transistor in this embodiment adopts a patch type packaging form, and is directly soldered on a Printed Circuit Board (PCB). Because the area of the pins of the MOS tube packaged in a surface mount manner is large, the heat dissipation effect can be effectively enhanced by means of PCB heat dissipation.

Optionally, with continuing reference to fig. 2, the MOS transistor module further includes: the first diode D1.

The anode of the first diode D1 is electrically connected to the output terminal of the MOS transistor module 30, and the cathode of the first diode D1 is electrically connected to the control terminal of the MOS transistor module 30.

Specifically, the first diode D1 is connected between the output terminal and the control terminal of the MOS transistor module 30, and is used for preventing the current generated by the voltage regulation module 20 after voltage regulation processing from directly flowing out from the output terminal of the MOS transistor module 30. Illustratively, the anode of the first diode D1 is electrically connected to the output terminal of the MOS transistor module 30, and the cathode is electrically connected to the control terminal of the MOS transistor module 30.

Optionally, with continued reference to fig. 2, the MOS transistor module further includes: a filter capacitor C1.

The positive terminal of the filter capacitor C1 is electrically connected with the output terminal of the MOS transistor module 30, and the negative terminal of the filter capacitor C1 is grounded.

Specifically, when the voltage of the voltage regulator module 20 is adjusted, the voltage at the filter capacitor C1 changes linearly, so that the dc signal output by the MOS transistor in the MOS transistor module 30 is regulated and controlled, and a controllable dc low-voltage signal is output.

Optionally, fig. 3 is a schematic structural diagram of another power supply circuit provided in the embodiment of the present invention. As shown in fig. 3, the power supply circuit further includes:

the first end of the piezoresistor RV1 and the first end of the piezoresistor RV1 are electrically connected with the output end of the rectifier module 10, and the second end of the piezoresistor RV1 is grounded.

Specifically, the voltage dependent resistor RV1 is used as a voltage limiting device, plays a role in voltage protection in a power supply circuit, and can receive the magnitude of a voltage change value in the circuit. When the circuit works normally, the voltage dependent resistor RV1 has large impedance, which is equivalent to an open circuit state; when the voltage in the circuit changes greatly, the resistance value of the voltage dependent resistor RV1 is reduced instantly, and the current flows to the voltage dependent resistor RV1, so that the effect of protecting the circuit is achieved. In the embodiment, a first end of the piezoresistor RV1 is electrically connected with the output end of the rectifier module 10, and a second end of the piezoresistor RV1 is grounded. When the voltage value output by the rectifier module 10 changes greatly, the resistance value of the voltage dependent resistor RV1 decreases instantly, so that the current with a large voltage change value flows to the first end of the voltage dependent resistor RV1 and flows to the ground end from the second end of the voltage dependent resistor RV1, thereby realizing the effect of protecting the voltage stabilizing module 20 and the MOS transistor module 30.

Optionally, with continued reference to fig. 3, the voltage stabilization module 20 includes:

at least one first resistor R1 connected in series, wherein a first end of the first resistor R1 at the head end is electrically connected with the input end of the voltage stabilizing module 20, and a second end of the first resistor R1 at the tail end is electrically connected with the output end of the voltage stabilizing module 20;

a voltage stabilizing diode D2, wherein the cathode of the voltage stabilizing diode D2 is electrically connected with the output end of the voltage stabilizing module 20, and the anode of the voltage stabilizing diode D2 is grounded;

a second resistor R2, wherein a first end of the second resistor R2 is electrically connected with the output end of the voltage stabilizing module 20;

a first end of the first capacitor C2 is electrically connected to a second end of the second resistor R2, and a second end of the first capacitor C2 is grounded.

Exemplarily, the following steps are carried out: the first resistor R1 may include 4. Each first resistor R1 is connected in series and has a voltage dividing function. The first end of the first resistor R1 at the head end is electrically connected to the input terminal of the voltage regulator module 20, and the second end of the first resistor R1 at the tail end is electrically connected to the output terminal of the voltage regulator module 20. The dc power output by the rectifying module 10 is input to the input terminal of the voltage stabilizing module 20, the dc power obtained by the rectifying process is divided by the first resistors R1 connected in series, and the second terminal of the first resistor R1 outputs a level signal of the divided voltage to the output terminal of the voltage stabilizing module 20. The output end of the voltage stabilizing module 20 is electrically connected to the control electrode of the MOS transistor module 30, and the output end of the voltage stabilizing module 20 outputs a level signal of the divided voltage to the control electrode of the MOS transistor module 30, and then transmits the level signal to the gate electrode of each MOS transistor in the MOS transistor module 30, so as to control the conduction or the turn-off of the MOS transistor. And the direct current without voltage division by the first resistor R1 connected in series is directly output to the drain of each MOS transistor in the MOS transistor module 30.

The cathode of the zener diode D2 is electrically connected to the output terminal of the zener module 20, and the anode of the zener diode D2 is grounded. By adjusting the voltage parameter of the zener diode D2, the voltage at the filter capacitor C1 in the MOS transistor module 30 can be linearly changed, so that the source of the MOS transistor can output low-voltage direct current. And the parameters of the zener diode D2 can be adjusted according to the voltage value of the electric energy required by the main control chip 50, so that the source of each MOS transistor in the MOS transistor module 30 outputs a controllable low-voltage direct current, thereby supplying power for applications with low power. The voltage stabilizing module 20 further includes a second resistor R2 and a first capacitor C2, a first end of the second resistor R2 is electrically connected to the output end of the voltage stabilizing module 20, a first end of the first capacitor C2 is electrically connected to a second end of the second resistor R2, and a second end of the first capacitor C2 is grounded.

Optionally, with continued reference to fig. 3, the filtering module 40 includes: a second diode D3, a third resistor R3, and a second capacitor C3.

The anode of the second diode D3 is electrically connected with the output end of the MOS transistor module 30;

a first end of the third resistor R3 is electrically connected to the cathode of the second diode D3, and a second end of the third resistor R3 is electrically connected to the power supply terminal 8 of the main control chip 50;

the first terminal of the second capacitor C3 is electrically connected to the cathode of the second diode D3, and the second terminal of the second capacitor C3 is grounded.

Specifically, the controllable low-voltage direct current output by the output terminal of the MOS transistor module 30 is input to the filtering module 40 by the anode of the second diode D3, and is output by the cathode of the second diode D3 and then transmitted to the power supply terminal 8 of the main control chip 50 through the third resistor R3, so that power is supplied to the main control chip 50, and electric energy with different voltages required by the main control chip 50 adapted to different application devices can be output.

Optionally, with continued reference to fig. 3, the power circuit further comprises: the optocoupler module 60 and at least one fourth resistor R4 connected in series.

An input end of the optical coupling module 60 is connected with an external control voltage, a first output end of the optical coupling module 60 is electrically connected with a power supply end 8 of the main control chip 50, and a second output end of the optical coupling module 60 is electrically connected with an adjusting end 1 of the main control chip 50;

at least one fourth resistor R4 connected in series, the fourth resistor R4 located at the head end is electrically connected with the output end of the MOS transistor module 30, and the fourth resistor R4 located at the tail end is electrically connected with the input end 5 of the main control chip 50.

Specifically, the power circuit further includes an optical coupler module 60, an input end of the optical coupler module 60 is connected to the interface P2, and the interface P2 is used for receiving an external control voltage. The external control voltage is a small voltage signal, and the voltage value is lower than that of the alternating current accessed by the interface P1. For example: the voltage value of the external control voltage connected to the interface P2 may be 3.3V. After the external control voltage is input by the input end of the optical coupling module 60, the optical coupling module 60 emits light according to the received electrical signal, generates photocurrent, and is output to the adjusting end 1 of the main control chip 50 by the second output end of the optical coupling module 60, so that the voltage waveform of the filter capacitor C1 in the MOS transistor module 30 is adjusted, and the voltage waveform of the filter capacitor C1 is the same as and synchronous with the waveform of the external control voltage input by the input end 5 of the main control chip 50 and the interface P2. In addition, in the power supply circuit, at least one fourth resistor R4 is connected in series between the output terminal of the MOS transistor module 30 and the input terminal 5 of the main control chip 50. Illustratively, the number of the fourth resistors R4 may be 2. At least one fourth resistor R4 connected in series has a current limiting function to protect the MOS transistor in the input terminal 5 of the main control chip 50 from being burned by the current output by the MOS transistor module 30, so that the main control chip 50 can operate normally.

Optionally, with continued reference to fig. 3, the optocoupler module 60 includes: the circuit comprises an optical coupler 61, a fifth resistor R5, a third capacitor C4, a sixth resistor R6 and a seventh resistor R7.

The optical coupler 61 comprises an input end, a first grounding end, an output end and a second grounding end, the input end of the optical coupler 61 is electrically connected with the input end of the optical coupling module 60, and the second grounding end of the optical coupler 61 is electrically connected with the second output end of the optical coupling module 60;

a first end of the fifth resistor R5 is electrically connected to the first ground terminal of the optical coupler 61;

a first end of the third capacitor C4 is electrically connected with a second end of the fifth resistor R5, and a second end of the third capacitor C4 is grounded;

a first end of the sixth resistor R6 is electrically connected with the output end of the optical coupler 61, and a second end of the sixth resistor R6 is electrically connected with the first output end of the optical coupler module 60;

a first end of the seventh resistor R7 is electrically connected to the second ground terminal of the optocoupler 61, and a second end of the seventh resistor R7 is grounded.

Specifically, an input end of the optical coupler 61 in the optical coupler module 60 is electrically connected to an input end of the optical coupler module 60, and a second ground end of the optical coupler 61 is electrically connected to a second output end of the optical coupler module 60. The optical coupler 61 can emit light according to an external control voltage accessed by the input end, and generate photocurrent to realize 'electro-optic-electrical' conversion, so that the input end and the output end of the optical coupler 61 are insulated, and the anti-interference capability is strong. The first ground terminal of the optical coupler 61 is electrically connected to the first terminal of the fifth resistor R5, the second terminal of the fifth resistor R5 is electrically connected to the first terminal of the third capacitor C4, and the second terminal of the third capacitor C4 is grounded. An output end of the optical coupler 61 is electrically connected to a first end of the sixth resistor R6, and a second end of the sixth resistor R6 is electrically connected to a first output end of the optical coupling module 60. The second ground terminal of the optocoupler 61 is electrically connected to the first terminal of the seventh resistor R7, and the second terminal of the seventh resistor R7 is grounded. The optical coupling module 60 can transmit the low-voltage signal carrier accessed by the interface P2 to the high-voltage signal accessed by the interface P1, so as to realize signal transmission.

The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power supply circuit, comprising:

the rectifier module rectifies input alternating current and outputs direct current;

the control end of the MOS tube module is electrically connected with the output end of the voltage stabilizing module, the input end of the MOS tube module is connected with the direct current, and the output end of the MOS tube module outputs controllable low voltage;

2. The power supply circuit of claim 1, wherein the MOS transistor module comprises:

at least one MOS pipe, the grid of MOS pipe with the control end electricity of MOS pipe module is connected, the source electrode of MOS pipe with the output electricity of MOS pipe module is connected, the drain electrode of MOS pipe with the input electricity of MOS pipe module is connected.

3. The power circuit of claim 2, wherein the MOS transistor is packaged in a patch manner.

4. The power supply circuit of claim 2, wherein the MOS transistor module further comprises:

5. The power supply circuit of claim 2, wherein the MOS transistor module further comprises:

6. The power supply circuit according to claim 1, further comprising:

7. The power supply circuit of claim 1, wherein the voltage regulation module comprises:

and a first end of the first capacitor is electrically connected with a second end of the second resistor, and a second end of the first capacitor is grounded.

8. The power supply circuit of claim 1, wherein the filtering module comprises:

and a first end of the second capacitor is electrically connected with the cathode of the second diode, and a second end of the second capacitor is grounded.

9. The power supply circuit according to claim 1, further comprising:

the input end of the optical coupling module is connected with an external control voltage, the first output end of the optical coupling module is electrically connected with the power supply end of the main control chip, and the second output end of the optical coupling module is electrically connected with the adjusting end of the main control chip;

and at least one fourth resistor connected in series is positioned at the head end, electrically connected with the output end of the MOS tube module and electrically connected with the input end of the main control chip.

10. The power supply circuit of claim 9, wherein the optocoupler module comprises:

a first end of the sixth resistor is electrically connected with the output end of the optical coupler, and a second end of the sixth resistor is electrically connected with the first output end of the optical coupler module;