CN-121984333-A - Up-down residual voltage clearing circuit and power supply equipment

CN121984333ACN 121984333 ACN121984333 ACN 121984333ACN-121984333-A

Abstract

The embodiment of the application discloses a power-on and power-off residual voltage clearing circuit and power supply equipment. According to the technical scheme provided by the embodiment of the application, the residual voltage clearing circuit formed by the control module, the bleeder module and the load capacitor is introduced, so that the circuit can automatically control the bleeder module to be conducted at the moment of power-on and power-off of the power supply, and the residual voltage in the load capacitor is rapidly and automatically discharged. Compared with the prior art requiring an additional controller and a special discharging control circuit, the application does not need the intervention of an external controller and complex software, reduces the hardware cost and the software complexity of the system, improves the reliability and the system integration level of the power-on and power-off process, and meets the operation and maintenance requirements of a power supply system on high reliability, low cost and quick power-on and power-off.

Inventors

BAI JINLONG
LIU GUILIN
ZHANG PENG
CHEN WEI

Assignees

广州立功电子科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251225

Claims (10)

1. The power-on and power-off residual voltage clearing circuit is characterized by comprising a power output end, a control module, a discharging module and a load capacitor; The power supply output end is connected with the first end of the control module and the input end of the load circuit, the second end of the control module is connected with the first end of the discharge module, the second end of the discharge module is connected with the positive electrode of the load capacitor, the third end of the discharge module is grounded, the positive electrode of the load capacitor is also connected with the input end of the load circuit, and the negative electrode of the load capacitor is grounded; The control module is used for controlling the conduction between the bleeder module and the load capacitor under the condition that the power supply output end is electrified or electrified so as to remove residual voltage on the load capacitor.
2. The power-on-power-off residual voltage removal circuit of claim 1, wherein the bleed module includes a discharge resistor and a switching device; the first end of the switching device is connected with the first end of the discharging resistor, the second end of the switching device is grounded, the controlled end of the switching device is connected with the second end of the control module, and the second end of the discharging resistor is connected with the anode of the load capacitor.
3. The power-on and power-off residual voltage removal circuit of claim 2, wherein the switching device is a first NMOS transistor; The grid electrode of the first NMOS tube is connected with the second end of the control module, the source electrode of the first NMOS tube is grounded, and the drain electrode of the first NMOS tube is connected with the first end of the discharge resistor.
4. The power-on-off residual voltage removal circuit of claim 1, further comprising a switch module, a first end of the switch module being connected to the power output, a second end of the switch module being connected to the load circuit input, a controlled end of the switch module being connected to the second end of the control module; the control module is also used for controlling the switch module to conduct the power output end and the load circuit input end after clearing residual voltage on the load capacitor.
5. The power-on and power-off residual voltage removal circuit of claim 4, wherein the switch module comprises a PMOS transistor, a first capacitor, a first resistor and a second resistor; The source electrode of the PMOS tube is connected with the power output end, the first end of the first capacitor and the first end of the first resistor, the grid electrode of the PMOS tube is connected with the second end of the first capacitor, the second end of the first resistor, the second end of the control module and the first end of the second resistor, the drain electrode of the PMOS tube is connected with the input end of the load circuit, and the second end of the second resistor is grounded.
6. The power-on and power-off residual voltage removal circuit according to claim 1, wherein the control module comprises a delay control unit and a driving unit; The delay control unit is connected with the power output end and is used for detecting the power-on and power-off states of the power output end and generating corresponding state signals; The driving unit is connected with the discharging module and used for controlling the on-off of the discharging module and the load capacitor according to the state signal.
7. The power-on and power-off residual voltage removal circuit of claim 6, wherein said delay control unit includes an RC delay circuit; The first end of the RC delay circuit is connected with the power output end, the second end of the RC delay circuit is grounded, and the third end of the RC delay circuit is connected with the driving unit.
8. The power-on/power-off residual voltage clearing circuit according to claim 7, wherein the driving unit comprises a second NMOS tube, the RC delay circuit comprises a third resistor, a fourth resistor, a second capacitor and a diode, the grid electrode of the second NMOS tube is connected with the first end of the fourth resistor and the first end of the second capacitor, the source electrode of the second NMOS tube is grounded, the drain electrode of the second NMOS tube serves as the second end of the control module, the first end of the third resistor is connected with the power output end and the cathode of the diode, the second end of the third resistor is connected with the first end of the fourth resistor and the first end of the second capacitor, the second end of the second capacitor is grounded, and the anode of the diode is connected with the first end of the second capacitor.
9. The power-on and power-off residual voltage removal circuit according to claim 1, further comprising an energy storage capacitor, wherein an anode of the energy storage capacitor is connected to the power output terminal, and a cathode of the energy storage capacitor is grounded.
10. A power supply apparatus comprising a power-on-power-off residual voltage removal circuit, the power-on-power-off residual voltage removal circuit being the power-on-power-off residual voltage removal circuit according to any one of claims 1 to 9.

Description

Up-down residual voltage clearing circuit and power supply equipment Technical Field The embodiment of the application relates to the technical field of power supply circuits, in particular to a power-on and power-off residual voltage clearing circuit and power supply equipment. Background At present, in a power supply circuit system comprising a large-capacity energy storage capacitor, the system has the condition of slow voltage change in the power-on and power-off stages due to the inherent characteristics of the capacitor charging and discharging processes. This situation can lead to the load device being in an unstable operating state for a long period of time when it is started and shut down, affecting the reliability of the system. Particularly, in the application scene of quick power-on and power-off test or system frequency restarting, the residual voltage in the energy storage capacitor cannot be timely discharged, the initial potential of the load can be lifted when the power is on again, and faults such as device latching, abnormal starting and the like are easily caused. For this reason, a dedicated rapid discharge module is usually added in the power supply path, and is controlled by a general input/output pin of a Microcontroller (MCU) to avoid the residual voltage affecting the operation of the circuit. However, by adding a special rapid discharging module in the power supply circuit, not only are additional control chips, peripheral circuits and corresponding software drivers added, so that the hardware cost and the software complexity of the system are obviously increased, but also additional control delay and power consumption are introduced, and the overall efficiency and the integration level of the system are reduced. Thereby influencing the operation reliability of the power supply circuit and increasing the operation and maintenance cost of the circuit. Disclosure of Invention The embodiment of the application provides a circuit for clearing residual voltage of power on and power off and power supply equipment, which can automatically control the conduction of a discharging module at the moment of power on and power off, realize the rapid and automatic discharging of the residual voltage in a load capacitor and solve the technical problems of device latch and abnormal starting caused by slow power on and power off and residual voltage in a power supply system with a large capacitor. In a first aspect, an embodiment of the present application provides a power-on/power-off residual voltage removal circuit, including: The power supply comprises a power supply output end, a control module, a discharging module and a load capacitor; The power supply output end is connected with the first end of the control module and the input end of the load circuit, the second end of the control module is connected with the first end of the discharge module, the second end of the discharge module is connected with the positive electrode of the load capacitor, the third end of the discharge module is grounded, the positive electrode of the load capacitor is also connected with the input end of the load circuit, and the negative electrode of the load capacitor is grounded; The control module is used for controlling the conduction between the bleeder module and the load capacitor under the condition that the power output end is electrified or electrified so as to remove the residual voltage on the load capacitor. Further, the bleeder module comprises a discharge resistor and a switching device; the first end of the switching device is connected with the first end of the discharging resistor, the second end of the switching device is grounded, the controlled end of the switching device is connected with the second end of the control module, and the second end of the discharging resistor is connected with the anode of the load capacitor. Further, the switching device is a first NMOS tube; the grid electrode of the first NMOS tube is connected with the second end of the control module, the source electrode of the first NMOS tube is grounded, and the drain electrode of the first NMOS tube is connected with the first end of the discharge resistor. Further, the circuit further comprises a switch module, a first end of the switch module is connected with the power supply output end, a second end of the switch module is connected with the input end of the load circuit, and a controlled end of the switch module is connected with the second end of the control module; The control module is also used for controlling the switch module to conduct the power supply output end and the load circuit input end after the residual voltage on the load capacitor is cleared. Further, the switch module comprises a PMOS tube, a first capacitor, a first resistor and a second resistor; The source electrode of the PMOS tube is connected with the power supply output end, the first end of the first capacitor and the first end of the firs