CN105093971B - Power supply system, linear control module and control method of switch element - Google Patents

Abstract

A power supply system, a linear control module and a control method for a switch element, wherein the linear control module is electrically connected to a power supply device, the power supply device comprises an AC/DC power conversion module, a switch element, a control signal output terminal, a main power output terminal and a standby power output terminal, the AC/DC power conversion module has a power output terminal, the switch element is electrically connected to the power output terminal and the main power output terminal of the AC/DC power conversion module, the standby power output terminal is electrically connected to the power output terminal of the AC/DC power conversion module, the linear control module comprises a control switch, a first resistor, a capacitor and a second resistor, the control switch is electrically connected to the control signal output terminal, the first resistor is electrically connected to the control switch, the capacitor is electrically connected to the power output terminal and the first resistor of the AC/DC power conversion module, and the second resistor is electrically connected to the switch element, the first resistor and the capacitor.

Description

Power supply system, linear control module and control method for switching elements

technical field

The present invention relates to a power supply system, and in particular to a power supply system with low standby power consumption.

Background technique

Referring to FIG. 1 , it is a circuit diagram of an existing switch control circuit. The switch control circuit 1 is electrically connected between a DC power VDC and a switch element 10 , and the switch control circuit 1 is used to control the switch element 10 to be turned on or off, and then determine whether the DC power VDC is connected to an electronic system PS. Wherein, the electronic system PS is electrically connected to the drain of the switch element 10 through the output resistors Ro1 and Ro2, and the terminals connected between the electronic system PS and the output resistors Ro1 and Ro2 are defined as power output terminals Vo1 and Vo2.

The switch control circuit 1 includes a sense resistor RS, a control switch Q, a resistor R and a capacitor C. One end of the sensing resistor RS is electrically connected to the DC power source VDC and the source of the switching element 10 , and the other end of the sensing resistor RS is electrically connected to the drain of the control switch Q and the gate of the switching element 10 . The source of the control switch Q is electrically connected to the ground terminal, and the gate of the control switch Q is electrically connected to a control signal output terminal Sin. One end of the resistor R and the capacitor C is electrically connected to the gate of the control switch Q, and the other end of the resistor R and the capacitor C is electrically connected to the ground. In other words, the resistor R and the capacitor C are connected in parallel, It is used to filter the noise of the signal output from the control signal output terminal Sin.

When the electronic system PS starts up, the control signal output terminal Sin sends a control signal to the control switch Q to drive the control switch Q to conduct. At the same time, the switching element 10 will also be turned on. In other words, when the switch control circuit 1 receives the control signal, the control switch Q and the switching element 10 will be turned on almost at the same time. However, this makes the DC power supply VDC The voltage drops suddenly, as shown in Figure 2.

Contents of the invention

The object of the present invention is to provide a linear control module, the linear control module is electrically connected to a power supply device for supplying DC power, to solve the problem of DC power generation when the electronic system electrically connected to the power supply device is started. slump problem.

In one embodiment of this technical aspect, a linear control module is provided, which is electrically connected to a power supply device, and the power supply device includes an AC/DC power conversion module, a switching element, a control signal output terminal, and a main power supply output terminal and a standby power output terminal, the AC/DC power conversion module has a power output terminal, the switching element is electrically connected to the power output terminal of the AC/DC power conversion module and the main power output terminal, and the standby power output terminal is electrically connected to the AC /The power output end of the DC power conversion module. The linear control module includes a control switch, a first resistor, a capacitor and a second resistor, the control switch is electrically connected to the control signal output end; the first resistor is electrically connected to the control switch; the capacitor is electrically connected to the AC/DC The power output terminal of the power conversion module and the first resistor; the second resistor is electrically connected to the power output terminal of the AC/DC power conversion module, the switch element, the first resistor and the capacitor.

In this way, the switching element can be linearly turned on, and the voltage value output from the power output terminal is prevented from suddenly dropping at the moment when an electronic system connected to the power supply device starts up.

In other implementations of this technical aspect, the linear control module further includes a discharge circuit electrically connected to the power output terminal, the control signal output terminal, the capacitor, the first resistor and the second resistor of the AC/DC power conversion module . The discharge circuit includes a switching element and a third resistor, the switching element is electrically connected to the power output end of the AC/DC power conversion module and the control signal output end, and the third resistor is electrically connected to the switching element, the first resistor, capacitor and second resistor. The switching element may eg be a metal oxide semiconductor field effect transistor. The discharge circuit can provide a capacitor to accelerate the discharge time of the capacitor, so as to avoid the problem of a sudden drop in the output voltage of the power output terminal when the electronic system is repeatedly started in a short period of time.

In another embodiment of this technical aspect, the linear control module further includes a protection switch electrically connected to the power output end, the switching element and the capacitor of the AC/DC power conversion module; the protection switch can be, for example, a diode. The protection switch is to allow the capacitor to discharge when the electronic system is short-circuited. Therefore, when the short-circuit problem of the electronic system is eliminated and restarted, the output voltage of the power output terminal will not cause a sudden drop.

Another technical aspect of the disclosed content of the present invention is to provide a power supply system, which provides power to an electronic system, and the power supply system can avoid the voltage output from the power output terminal of the electronic system at the moment of startup. Problems with dips.

In one embodiment of this technical aspect, a power supply system is provided, which is electrically connected to an AC power supply and an electronic system. The power supply system includes: an AC/DC power conversion module, a switching element, and a power management device, a controller, a main power output terminal, a standby power output terminal and a linear control module. The AC/DC power conversion module is electrically connected to the AC power supply, and the AC/DC power conversion module includes a power output end; the switching element is electrically connected to the power output end; the power manager is electrically connected to the electronic system and the switching element, the power manager It includes a control signal output end; the controller is electrically connected to the power manager and the AC/DC power conversion module; the main power output end is electrically connected to the switching element and the electronic system; the standby power output end is electrically connected to the power output end and the electronic system. The linear control module includes a control switch, a first resistor, a capacitor and a second resistor, the control switch is electrically connected to the control signal output end; the first resistor is electrically connected to the control switch; the capacitor is electrically connected to the AC/DC The power output terminal of the power conversion module and the first resistor; the second resistor is electrically connected to the power output terminal of the AC/DC power conversion module, the switch element, the first resistor and the capacitor.

In this way, the switching element can be linearly turned on, and the voltage value output from the power output terminal is prevented from dropping suddenly when the power supply system starts up the electronic system.

In other implementations of this technical aspect, the linear control module further includes a discharge circuit electrically connected to the power output terminal, the control signal output terminal, the capacitor, the first resistor and the second resistor of the AC/DC power conversion module . The discharge circuit includes a switching element and a third resistor. The switching element is electrically connected to the power output end and the control signal output end of the AC/DC power conversion module. The switching element can be, for example, a MOSFET. The third resistor is electrically connected to the switching element, the first resistor, the capacitor and the second resistor. The discharge circuit can provide a capacitor to accelerate the discharge time of the capacitor, so as to avoid the problem of a sudden drop in the output voltage of the power output terminal when the electronic system is repeatedly started in a short period of time.

In another embodiment of this technical aspect, the linear control module further includes a protection switch electrically connected to the power output end, the switching element and the capacitor of the AC/DC power conversion module; the protection switch can be, for example, a diode. The protection switch allows the capacitor to discharge when the electronic system is short-circuited. Therefore, when the short-circuit problem of the electronic system is eliminated and restarted, the output voltage of the circuit output terminal will not cause a sudden drop.

In addition, the power supply system further includes an isolation unit electrically connected to the power manager and the controller. The AC/DC power conversion module includes an electromagnetic interference filter, a rectifier and a DC/DC power converter, the electromagnetic interference filter is electrically connected to the AC power supply; the rectifier is electrically connected to the electromagnetic interference filter; DC/DC power conversion The device is electrically connected to the rectifier, and the DC/DC power converter includes a power output terminal.

Another technical aspect of the disclosed content of the present invention is to provide a method for controlling a switching element, so as to make the switching element conduct linearly.

In one embodiment of the present technology, the control method of the switching element is used to make a switching element conduct linearly, and the switching element is electrically connected to the secondary side of an AC/DC power conversion module. The AC/DC power conversion module has a power output terminal, the power output terminal is electrically connected to a standby power supply output terminal, the switching element is electrically connected to the power output terminal and a main power supply output terminal, the switching element determines whether the power output from the power output terminal is transmitted to the mains output. The control method of the switching element includes: providing a driving voltage; providing a plurality of pulse width modulation signals in sequence; switching the duty cycle of the pulse width modulation signal so that the duty cycle of the pulse width modulation signal is increased from 0% to 100 in sequence %, wherein the pulse width modulation signal makes the switching element conduct linearly. The duty cycle of the PWM signal increases from 0% to 100% in 20 milliseconds.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

Figure 1 shows a circuit block diagram of an existing power supply system;

Fig. 2 is a waveform diagram corresponding to the DC power supply of Fig. 1 and the voltage at the output end of the power supply;

FIG. 3 shows a circuit block diagram of the power supply system of the present invention;

FIG. 4 is a circuit diagram of a linear control module according to the first embodiment of the present invention;

5 shows a circuit diagram of a linear control module according to a second embodiment of the present invention;

Fig. 6 corresponds to the waveform diagram of the voltage output from the power output terminal and the output terminal of the main power supply shown in Fig. 4 and Fig. 5;

FIG. 7 illustrates linear control signals of switching elements.

Among them, reference signs

1 switch control circuit

3 Power supply system

5 Power supply unit

50 AC/DC power conversion module

500 EMI filter

502 rectifier

503 power factor correction circuit

504 power converter

506 power manager

52 controller

54 switching element

56 Power Manager

58 Isolation unit 7, 7a linear control module

70 discharge circuit

ACP AC Power Supply Unit

C, C1 capacitor

D protection switch

PS electronic system

Q, Q1 control switch

R resistor

Ro1, Ro2 Main power output resistors

Ro3 Standby power output resistor

R1 first resistor

RS second resistor

R3 third resistor

VDC DC power supply

Vdc power output terminal

Vo1, Vo2 power output

V1, V2 main power output

Vsb Standby power output terminal

Detailed ways

The above and additional objects, features and advantages of the disclosure of the present invention will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the disclosure with reference to the accompanying drawings.

Referring to FIG. 3 , it is a circuit block diagram of the power supply system of the present invention. The power supply system 3 includes a power supply device 5 and a linear control module 7 . The linear control module 7 is used to control the working state of a switch element 54 of the power supply device 5 .

The power supply device 5 is electrically connected between an AC power supply ACP and an electronic system PS for receiving the AC power output by the AC power supply ACP, and converting the AC power to the electronic system PS.

The power supply device 5 includes an AC/DC power conversion module 50, a controller 52, a switch element 54, a power manager 56, an isolation unit 58, a plurality of main power output resistors Ro1 and Ro2, at least one main power output terminal, a standby power output resistor Ro3 and a standby power output terminal Vsb. In this embodiment, the power supply device 5 includes two main power output terminals V1 and V2 as an example for illustration.

The AC/DC power conversion module 50 includes an EMI filter 500 , a rectifier 502 and a power converter 504 . The EMI filter 500 is electrically connected to the AC power supply ACP, the rectifier 502 is electrically connected to the EMI filter 500 and the controller 52 , and the power converter 504 is electrically connected to the rectifier 502 and the controller 52 . The EMI filter 500 receives the AC power output by the AC power supply ACP, and filters out the EMI components present in the AC power. The rectifier 502 converts the AC power passing through the EMI filter 500 and filtering out the EMI components into DC power. The rectifier 502 may include a power factor correction circuit 503 for reducing the output current.

The power converter 504 is a DC/DC power converter 504. The power converter 504 receives the DC power passing through the rectifier 502, and changes the voltage value of the power output from the power output terminal Vdc according to the control of the controller 52, such as boosting the power output terminal. The voltage value of the power output by Vdc (boost) or reduce the voltage value of the power output terminal Vdc (step down). The power converter 504 can be, for example (but not limited to), an LLC resonant power converter, a dual forward converter (Dual Forward Converter) or a single forward converter (Single Forward Converter).

The switch element 54 is electrically connected to the power output terminal Vdc of the AC/DC power conversion module 50 . The main power output resistors Ro1 and Ro2 are electrically connected to the switch element 54 and the main power output terminals V1 and V2 respectively, the main power output terminals V1 and V2 are electrically connected to the electronic system PS, and the standby power output resistor Ro3 is electrically connected to the AC/DC The power output terminal Vdc and the standby power output terminal Vsb of the power converter module 50 .

In addition, it should be noted that the power supply system 3 of the present invention can not only include two main power output terminals V1 and V2. In actual implementation, users can increase the number of main power output terminals according to actual needs. Correspondingly increase the number of mains output resistors connected to the output of the mains.

In this embodiment, the voltage level of the power output from the output terminal Vsb of the standby power supply may be the same as the voltage level of the power output from the output terminals V1 and V2 of the main power supply, or the voltage level of the power output from the output terminal Vsb of the standby power supply may be different. It is the same as the power voltage level output from the output terminals V1 and V2 of the main power supply. When the voltage level of the power output from the output terminal Vsb of the standby power supply is different from the voltage level of the power output from the output terminals V1 and V2 of the main power supply, there can be a connection between the AC/DC power conversion module 50 and the output resistor Ro3 of the standby power supply. A step-up circuit or a step-down circuit is provided to increase or decrease the voltage level of the power output from the output terminal Vsb of the standby power supply.

The power manager 56 is electrically connected to the AC/DC power conversion module 50 , the electronic system PS and the isolation unit 58 . The power manager 56 includes a signal output terminal PG, a signal input terminal PS_on and a control signal output terminal Sin, the signal output terminal PG and the signal input terminal PS_on are respectively electrically connected to the electronic system PS, and the control signal output terminal Sin is electrically connected to the linear control module7. The signal output terminal PG is used to transmit the signal output by the power manager 56 to the electronic system PS, and the signal input terminal PS_on is used to receive the signal from the electronic system PS.

The linear control module 7 is electrically connected to the switch element 54 and the power manager 56 . The linear control module 7 receives a control signal output by the control signal output terminal Sin of the power manager 56, and selects to close or open the switching element 54 according to the control signal, and then cuts off or conducts the output from the main power supply output terminals V1 and V2 to Electricity of the electronic system PS.

The isolation unit 58 is electrically connected to the power manager 56 and the controller 52, and is used to transmit the signal sent by the power manager 56 to the controller 52 in isolation. In addition, the isolation unit 58 can also transmit the signal sent by the controller 52 in isolation. to Power Manager 56 .

In actual operation, when the switch element 54 is turned off, the DC power output by the power output terminal Vdc of the AC/DC power conversion module 50 cannot be transmitted to the electronic system PS through the output terminals V1 and V2 of the main power supply; otherwise, when the switch element When 54 is turned on, the DC power output by the power output terminal Vdc of the AC/DC power conversion module 50 can be transmitted to the electronic system PS through the main power output terminals V1 and V2. In addition, no matter whether the switch element 54 is turned on or off, the standby power output terminal Vsb will output power to the electronic system PS.

Referring to FIG. 4 , it is a circuit diagram of the linear control module according to the first embodiment of the present invention. For the convenience of illustration, FIG. 4 also shows the switch element 54 , the main power output resistors Ro1 and Ro2 , the main power output terminals V1 and V2 , the standby power output terminal Vsb and the standby power output resistor Ro3 . Meanwhile, FIG. 4 also shows the power output terminal Vdc of the AC/DC power conversion module 50 and the control signal output terminal Sin of the power manager 56 . In this embodiment, the switch element 54 is illustrated by using a P-type Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) as an example, and it is not limited to this in actual implementation.

The linear control module 7 includes a control switch Q1, a first resistor R1, a capacitor C1 and a second resistor RS, the control switch Q1 is electrically connected to the control signal output terminal Sin, and the first resistor R1 is electrically connected to the control switch Q1, the capacitor C1 is electrically connected to the power output terminal Vdc of the AC/DC power conversion module 50 and the switching element 54, the second resistor RS is electrically connected to the capacitor C1, the first resistor R1 and the switching element 54, and is connected in parallel to the capacitor C1 .

In this embodiment, the control switch Q1 is an NMOS field effect transistor, and the gate of the control switch Q1 is electrically connected to the control signal output terminal Sin, and the drain of the control switch Q1 is electrically connected to the first resistor R1 , the source of the control switch Q1 is electrically connected to the ground terminal. In actual implementation, the control switch Q1 may also be other electronic components with a switching function.

Referring to FIG. 3 and FIG. 4 together, when the electronic system PS is started, the signal input terminal PS_On of the power manager 56 will receive the start signal sent by the electronic system PS. Afterwards, the control signal output terminal Sin of the power manager 56 sends a control signal to the control switch Q1 of the linear control module 7 to drive the control switch Q1 to conduct. When the control switch Q1 is turned on, the capacitor C1 starts to charge, and the voltage between the gate and the source of the switching element 54 rises. Secondly, when the control switch Q1 is turned on, the first resistor R1 and the second resistor R2 form a voltage divider circuit, so by properly configuring the resistance values of the first resistor R1 and the second resistor RS, it is possible to control The voltage difference between the gate and the source of the switching element 54 is used to control the switching element 54 to be turned on, and at the same time prevent the switching element 54 from being damaged due to excessive voltage. When the switch element 54 is turned on, the main power output terminals V1 and V2 output power to the electronic system PS.

By using the capacitor C1, the first resistor R1 and the second resistor RS, the voltage difference between the source and the gate of the switching element 54 can be increased gently and linearly, so as to prevent the switching element 54 from being activated in the electronic system PS Instantaneous conduction, so that the voltage value output by the power output terminal Vdc can be prevented from suddenly dropping suddenly when the electronic system PS is started.

Referring to FIG. 6 , the solid line shows the voltage corresponding to the power output terminal Vdc in FIG. 3 , and the dotted line shows the voltage corresponding to the main power output terminals V1 and V2 in FIG. 3 . Compared with Fig. 2, the voltage output by the power output terminal Vdc shown in Fig. 6 does not have the problem of instantaneous sudden drop at the moment when the electronic system PS is started, which can provide the stability of the power supply system 3 and avoid the power supply system 3 due to Malfunction due to voltage drop. Therefore, the linear control module 7 of the present invention can effectively avoid the sudden sudden drop of the voltage value output by the power output terminal Vdc when the electronic system PS is started.

Conversely, when the electronic system PS is not activated (that is, the electronic system PS is operating in a standby state), the power manager 56 controls the signal output terminal Sin to send a control signal to the control signal input terminal Sin of the linear control module 7 . The linear control module 7 receives the aforementioned control signal, and drives the control switch Q1 to be turned off. When the control switch Q1 is turned off, the switch element 54 is turned off, and the main power output terminals V1 and V2 have no power output; otherwise, only the standby power output terminal Vsb outputs power to the electronic system PS.

Thus, when the electronic system PS is not activated, the main power supply output terminals V1 and V2 will not provide power to the electronic system PS, and only the standby power supply output terminal Vsb supplies the power of the electronic system PS when it is in a standby state. In this way, Can effectively achieve energy saving effect.

Referring to FIG. 5 , it is a circuit diagram of the linear control module according to the second embodiment of the present invention. For the convenience of illustration, FIG. 5 also shows the switch element 54 , the main power output resistors Ro1 and Ro2 , the main power output terminals V1 and V2 , the standby power output terminal Vsb and the standby power output resistor Ro3 . Meanwhile, FIG. 5 also shows the power output terminal Vdc of the AC/DC power conversion module 50 and the control signal output terminal Sin of the power manager 56 .

In addition, the linear control module 7 a of this embodiment is similar to the linear control module 7 of the first embodiment, and the same components are marked with the same symbols. The difference between the linear control module 7 a of this embodiment and the linear control module 7 of the first embodiment is that the control module 7 a of this embodiment further includes a discharge circuit 70 .

The discharge circuit 70 is electrically connected to the power output terminal Vdc, the control signal output terminal Sin, the capacitor C1 and the first resistor R1 of the AC/DC power conversion module 50 , and the discharge circuit 70 serves as a discharge path for the capacitor C1 .

The discharge circuit 70 includes a switching element Q2 and a third resistor R3, the switching element Q2 is electrically connected to the power output terminal Vdc of the AC/DC power conversion module 50, the control signal output terminal Sin and the control switch Q1, and the third resistor R3 It is electrically connected to the control switch Q1, the first resistor R1, the second resistor RS and the capacitor C1. In this embodiment, the switching element Q2 is a metal oxide field effect transistor, the gate of the switching element Q2 is electrically connected to the control signal output terminal Sin and the control switch Q1, and the source of the switching element Q2 is electrically connected to the AC/DC power conversion The power output terminal Vdc of the module 50 and the drain of the switching element Q2 are electrically connected to the third resistor R3.

The discharge circuit 70 provides a discharge path for the charge stored in the capacitor C1 to accelerate the discharge of the capacitor C1. In this way, when the power supply system 3 is restarted within a short time after the electronic system PS is turned off, the switching element 54 cannot be linearly turned on due to the capacitor C1 not being fully discharged, resulting in a voltage output from the power output terminal Vdc occurring. Instantly plummeted.

In addition, the linear control module 7 a further includes a protection switch D electrically connected to the power output terminal Vdc of the AC/DC power conversion module 50 , the switching element Q2 and the capacitor C1 . In this embodiment, the protection switch D is, for example (but not limited to) a diode, and the anode of the protection switch D2 is electrically connected to the power output terminal Vdc, and the cathode of the protection switch D is electrically connected to the switching element Q2 and the capacitor C1. When the electronic system PS is short-circuited, the power output terminal Vdc generates a large current output, and the protection switch D2 can prevent the capacitor C1 from being effectively discharged when the electronic system PS is short-circuited and the power output terminal Vdc outputs a large current, which means protection The switch D2 can allow the capacitor C1 to still discharge through the discharge circuit 70 when the electronic system PS is short-circuited. Therefore, when the short-circuit of the electronic system PS is eliminated and restarted, the switching element 54 will be linearly turned on to avoid power output. The voltage value output by the terminal Vdc suddenly drops suddenly at the moment when the electronic system PS is started.

In addition, the present invention further provides a control method of the switch element, which is suitable for the circuit structure of the linear control module shown in FIG. 4 and FIG. 5 . The switching element control method is used to control the switching element electrically connected to the secondary side of the AC/DC power conversion module. The AC/DC power conversion module 50 has a power output terminal on the secondary side, as shown in FIG. 3 .

The switching element receives the power output from the power output terminal, and when the electronic system PS is started, the main power supply output terminal outputs the aforementioned power to the electronic system PS to supply the operating power of the electronic system PS in the starting state; and in the electronic system PS When operating in the standby state, stop outputting power from the output terminal of the main power supply to the electronic system PS.

The control method of the switching element is used to control the switching state of the switching element 54, so that the switching element 54 is turned on linearly, so that the switching element 54 operates in a safe operating area, thereby preventing the switching element 54 from being damaged due to overheating. The control method of the switching element 54 firstly provides a driving voltage, and provides a plurality of pulse width modulation (PWM) control signals to the switching element 54 in sequence. Switching the duty cycle of these pulse width modulation signals, so that the duty cycle of the pulse width modulation signal is increased from 0% to 100% in sequence, as shown in Figure 7, so that the driving voltage increases linearly, so as to drive the switching element 54 is turned on linearly. In this embodiment, the time for the duty cycle of the control signal to increase from 0% to 100% is about 20 milliseconds (ms).

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention.

Claims (11)

1. A linear control module electrically connected to a power supply device, the power supply device comprising: an AC/DC power conversion module, a switching element, a control signal output terminal, a main power output terminal and a standby power output terminal, the AC/DC power conversion module has a power output terminal, the switching element is electrically connected to the power output terminal of the AC/DC power conversion module and the main power output terminal, and the standby power output terminal is electrically connected to the AC/DC power supply output terminal. The power output terminal of the DC power conversion module is characterized in that the linear control module includes: A control switch electrically connected to the control signal output end; a first resistor electrically connected to the control switch; a capacitor electrically connected to the power output terminal of the AC/DC power conversion module and the first resistor; and A second resistor is electrically connected to the power output terminal of the AC/DC power conversion module, the switch element, the first resistor and the capacitor. 2. The linear control module according to claim 1, further comprising a discharge circuit electrically connected to the power output terminal, the control signal output terminal, the capacitor, and the first AC/DC power conversion module. A resistor and the second resistor. 3. The linear control module according to claim 2, wherein the discharge circuit comprises: a switching element electrically connected to the power output end and the control signal output end of the AC/DC power conversion module; and A third resistor electrically connected to the switching element, the first resistor, the capacitor and the second resistor. 4. The linear control module according to claim 3, wherein the switching element is a MOSFET. 5 . The linear control module according to claim 4 , further comprising a protection switch electrically connected to the power output end, the switching element and the capacitor of the AC/DC power conversion module. 6. The linear control module according to claim 5, wherein the protection switch is a diode. 7. A power supply system, comprising the linear control module according to any one of claims 1 to 6, electrically connected to an AC power supply and an electronic system, characterized in that the power supply system comprises: An AC/DC power conversion module electrically connected to the AC power supply, the AC/DC power conversion module includes a power output terminal; a switching element electrically connected to the power output end; A power manager, electrically connected to the electronic system and the switch element, the power manager includes a control signal output terminal; a controller electrically connected to the power manager and the AC/DC power conversion module; a main power output terminal electrically connected to the switching element and the electronic system; and A standby power output terminal is electrically connected to the power output terminal and the electronic system. 8. The power supply system according to claim 7, further comprising an isolation unit electrically connected to the power manager and the controller, for transmitting the signal sent by the power manager to the controller in isolation controller and transmits signals from the controller to the power manager in isolation. 9. The power supply system according to claim 8, wherein the AC/DC power conversion module comprises: an electromagnetic interference filter electrically connected to the AC power supply; a rectifier electrically connected to the EMI filter; and A DC/DC power converter is electrically connected to the rectifier, and the DC/DC power converter includes the power output terminal. 10. A control method for a switch element, used to make a switch element conduct linearly, the switch element is electrically connected to the secondary side of an AC/DC power conversion module, and the AC/DC power conversion module has a power output end, the power output end is electrically connected to a standby power output end, the switch element is electrically connected to the power output end and a main power output end, and the switch element determines whether the power output from the power output end is transmitted to the main power output end , characterized in that the control method of the switching element includes: providing a driving voltage; providing multiple pulse width modulated signals in sequence; and switching the duty cycle of the plurality of pulse width modulation signals, so that the duty cycle of the plurality of pulse width modulation signals increases from 0% to 100% in sequence, Wherein, the plurality of pulse width modulation signals make the switch element conduct linearly. 11. The control method of the switch element according to claim 10, wherein the time for the duty cycle of the PWM signal to increase from 0% to 100% is 20 milliseconds.