Remaining electricity rapid discharge circuit and switch thereof

Abstract

The utility model relates to the technical field of switch power supply circuits, in particular to a residual electricity rapid discharge circuit and a switch thereof. The relay RL1 is used for controlling on and off of a power supply; the bleeder circuit comprises a triode Q1, and a base electrode of the triode Q1 is connected to the control circuit and used for controlling conduction of the bleeder circuit; the control circuit comprises an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) Q2, and a grid electrode of the MOSFET Q2 is connected with an external MCU (Microprogrammed Control Unit) and is used for controlling the conduction state of the triode Q1 during power failure; and the load circuit is connected with the power supply input end VCC-IN and the bleeder circuit, and the load circuit comprises an electrolytic capacitor U1. According to the utility model, through controlling the conduction of the triode Q1, the rapid discharge of residual electricity is realized, the abnormal reset starting problem caused by incomplete power failure when the circuit is connected with the power supply again is avoided, the circuit design is simple and reliable, the realization is easy, and the stability and reliability of the circuit are improved.

Description

Technical Field

[0001] This utility model relates to the field of power supply circuit technology for switches, and in particular to a residual power fast discharge circuit and a switch thereof. Background Technology

[0002] In power management systems of electronic devices (such as switches and servers), a problem arises in scenarios requiring rapid and repeated power switching and where the load circuit contains large-capacity capacitors: the voltage drop on the load circuit is slow after a power outage. This can cause the load circuit to re-energize before it has completely lost power when the power switch is turned on again, preventing the circuit from resetting and starting properly, leading to abnormal circuit operation and issues such as system crashes during startup. Summary of the Invention

[0003] This utility model addresses the problems of existing technologies by providing a residual power rapid discharge circuit and its switch. By controlling the conduction of transistor Q1, the residual power is rapidly discharged, avoiding the abnormal reset and startup problem caused by incomplete power-off when the circuit is reconnected. The circuit design is simple, reliable, and easy to implement, improving the stability and reliability of the circuit.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] This utility model provides a residual current rapid discharge circuit, which includes:

[0006] Power input terminal VCC-IN;

[0007] Relay RL1 is used to control the on / off state of the power supply;

[0008] The discharge circuit includes a transistor Q1, the base of which is connected to a control circuit to control the conduction of the discharge circuit.

[0009] The control circuit includes a MOSFET Q2, the gate of which is connected to an external MCU and is used to control the conduction state of transistor Q1 when power is off.

[0010] A load circuit is connected to the power input terminal VCC-IN and the discharge circuit. The load circuit includes an electrolytic capacitor U1. The power input terminal VCC-IN is connected to the load circuit and one end of the electrolytic capacitor U1 via a diode D1. The other end of the electrolytic capacitor U1 is grounded.

[0011] During normal power supply, relay RL1 is closed, and the power input terminal VCC-IN supplies power to the load through the relay and diode D1, while simultaneously charging the electrolytic capacitor U1. Transistor Q1 is not conducting. During power failure, relay RL1 is open, and the external MCU controls MOSFET Q2 to conduct, causing the base voltage of transistor Q1 to rise and conduct, thus rapidly discharging the residual charge on electrolytic capacitor U1.

[0012] The discharge circuit further includes resistors R1 and R2. Resistor R1 is connected between the base of transistor Q1 and ground, and resistor R2 is connected between the emitter of transistor Q1 and ground.

[0013] Preferably, the transistor Q1 is a PNP transistor, and the model of the transistor Q1 is PMBT3906.

[0014] Preferably, the MOSFET Q2 is a DPSS84.

[0015] This utility model also provides a switch, which includes the aforementioned residual power rapid discharge circuit.

[0016] The beneficial effects of this utility model are:

[0017] In normal power supply, relay RL1 is closed, and power supply VCC-IN supplies power to the load through the relay and diode D1, while simultaneously charging the electrolytic capacitor. At this time, the base of transistor Q1 is grounded through resistor R1, maintaining a low level, so transistor Q1 is not conducting and the discharge circuit does not work. When power is off, relay RL1 is open, and power supply VCC-IN is cut off, but there is still residual charge on the electrolytic capacitor. The external MCU controls the gate voltage of MOSFET Q2 to turn it on. At this time, the source voltage of MOSFET Q2 drops, causing the base voltage of transistor Q1 to rise, and transistor Q1 turns on. After transistor Q1 turns on, the electrolytic capacitor is quickly discharged to ground through transistor Q1 and resistor R2, achieving rapid discharge. This invention achieves rapid discharge of residual charge by controlling the conduction of transistor Q1, avoiding abnormal reset and startup problems caused by incomplete power-off when the circuit is reconnected. The circuit design is simple, reliable, and easy to implement, improving the stability and reliability of the circuit. Attached Figure Description

[0018] Figure 1 This is a circuit diagram of a residual current rapid discharge circuit according to the present invention. Detailed Implementation

[0019] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention. The present invention will be described in detail below with reference to the accompanying drawings.

[0020] Example 1

[0021] Embodiment 1 of this application provides a residual current rapid discharge circuit, such as... Figure 1 As shown, it includes: a power input terminal VCC-IN; a relay RL1 for controlling the power supply; a bleeder circuit including a transistor Q1, the base of which is connected to a control circuit to control the conduction of the bleeder circuit; a control circuit including a MOSFET Q2, the gate of which is connected to an external MCU to control the conduction state of the transistor Q1 when power is off; a load circuit connected to the power input terminal VCC-IN and the bleeder circuit, the load circuit including an electrolytic capacitor U1; the power input terminal VCC-IN is connected to the load circuit and one end of the electrolytic capacitor U1 via a diode D1, and the other end of the electrolytic capacitor U1 is grounded; wherein, under normal power supply, the relay RL1 is closed, the power input terminal VCC-IN supplies power to the load through the relay and diode D1, and simultaneously charges the electrolytic capacitor U1, while the transistor Q1 is not conducting; when power is off, the relay RL1 is open, and the external MCU controls the MOSFET When transistor Q2 is turned on, the base voltage of transistor Q1 rises and turns on, allowing the residual charge on electrolytic capacitor U1 to be discharged quickly. The discharge circuit also includes resistors R1 and R2. Resistor R1 is connected between the base of transistor Q1 and ground, and resistor R2 is connected between the emitter of transistor Q1 and ground.

[0022] Specifically, under normal power supply conditions, relay RL1 is closed, and power supply VCC-IN supplies power to the load through the relay and diode D1, while simultaneously charging the electrolytic capacitor. At this time, the base of transistor Q1 is grounded through resistor R1, maintaining a low level, so transistor Q1 is not conducting and the discharge circuit does not work. When the power is off, relay RL1 is open, and power supply VCC-IN is cut off, but there is still residual charge on the electrolytic capacitor. The external MCU controls the gate voltage of MOSFET Q2 to turn it on. At this time, the source voltage of MOSFET Q2 drops, causing the base voltage of transistor Q1 to rise, and transistor Q1 turns on. After transistor Q1 turns on, the electrolytic capacitor is quickly discharged to ground through transistor Q1 and resistor R2, achieving rapid discharge. This invention achieves rapid discharge of residual charge by controlling the conduction of transistor Q1, avoiding abnormal reset and startup problems caused by incomplete power-off when the circuit is reconnected. The circuit design is simple, reliable, and easy to implement, improving the stability and reliability of the circuit.

[0023] In Embodiment 1 of this application, the transistor Q1 is a PNP transistor, and the model of the transistor Q1 is PMBT3906; the model of the MOSFET Q2 is DPSS84.

[0024] Example 2

[0025] Embodiment 2 of this application also provides a switch, which includes the aforementioned residual power rapid discharge circuit. Specifically, with the setting of this residual power rapid discharge circuit, the problem of slow voltage drop on the load circuit after power failure is solved in the power management system of the switch in scenarios where rapid and repeated power switching is required and the load circuit contains a large-capacity capacitor.

[0026] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present utility model without departing from the scope of the present utility model shall fall within the scope of the present utility model.

Claims

1. A residual current rapid discharge circuit, characterized in that, include: Power input terminal VCC-IN; Relay RL1 is used to control the on / off state of the power supply; The discharge circuit includes a transistor Q1, the base of which is connected to a control circuit to control the conduction of the discharge circuit. The control circuit includes a MOSFET Q2, the gate of which is connected to an external MCU and is used to control the conduction state of transistor Q1 when power is off. A load circuit is connected to the power input terminal VCC-IN and the discharge circuit. The load circuit includes an electrolytic capacitor U1. The power input terminal VCC-IN is connected to the load circuit and one end of the electrolytic capacitor U1 via a diode D1. The other end of the electrolytic capacitor U1 is grounded. During normal power supply, relay RL1 is closed, and the power input terminal VCC-IN supplies power to the load through the relay and diode D1, while simultaneously charging the electrolytic capacitor U1. Transistor Q1 is not conducting. During power failure, relay RL1 is open, and the external MCU controls MOSFET Q2 to conduct, causing the base voltage of transistor Q1 to rise and conduct, thus rapidly discharging the residual charge on electrolytic capacitor U1.

2. The residual current rapid discharge circuit according to claim 1, characterized in that: The discharge circuit also includes resistors R1 and R2. Resistor R1 is connected between the base of transistor Q1 and ground, and resistor R2 is connected between the emitter of transistor Q1 and ground.

3. The residual current rapid discharge circuit according to claim 1, characterized in that: The transistor Q1 is a PNP transistor, and the model number of transistor Q1 is PMBT3906.

4. The residual current rapid discharge circuit according to claim 1, characterized in that: The MOSFET Q2 is a DPSS84.

5. A switch, characterized in that: Includes the residual power rapid discharge circuit as described in any one of claims 1-4.

Images