CN216699484U - Overvoltage protection circuit and device - Google Patents

Abstract

The utility model provides an overvoltage protection circuit and device. The overvoltage protection circuit includes: a power supply control circuit, an overvoltage release circuit, and a power supply circuit; The voltage is released, and the overvoltage signal is output to the power supply control circuit; when the power supply control circuit receives the overvoltage signal, it outputs a cutoff signal to the power supply circuit; when the power supply circuit receives the cutoff signal, it disconnects the power supply and the power supply. The connection between the charging base station and the charging device. The utility model releases the abnormal power supply voltage output by the power supply through the overvoltage release circuit, and disconnects the connection between the power supply, the charging base station and the charging equipment, and effectively avoids the impact of the overvoltage on the charging base station and the charging equipment. .

Description

Overvoltage protection circuit and device

technical field

The utility model relates to the technical field of power supplies, in particular to an overvoltage protection circuit and a device.

Background technique

During the charging process of the electrical equipment, the charging base station and the charging equipment are usually connected through an adapter. When the adapter is faulty and damaged, it is easy to cause an impact between the charging base station and the charging equipment caused by overvoltage or power grid surge, which will cause the components in the charging circuit to fail to work normally, and even lead to power consumption. Components in the circuit burned out. Therefore, in order to ensure the performance and service life of the components in the charging circuit, it is very important to protect the charging circuit from overvoltage.

The above content is only used to assist the understanding of the technical solutions of the present invention, and does not mean that the above content is the prior art.

Utility model content

The main purpose of the utility model is to provide an overvoltage protection circuit and device, which aims to solve the technical problem of the impact between the overvoltage charging base station and the charging equipment in the prior art.

In order to achieve the above purpose, the present utility model proposes an overvoltage protection circuit, the overvoltage protection circuit includes: a power supply control circuit, an overvoltage release circuit and a power supply circuit;

The overvoltage release circuit is respectively connected with a power supply and the power supply control circuit, the power supply circuit is respectively connected with the power supply control circuit and the power supply, and the power supply control circuit is connected with the power supply;

The overvoltage release circuit is configured to release the abnormal power supply voltage when the power supply outputs an abnormal power supply voltage, and output an overvoltage signal to the power supply control circuit;

the power supply control circuit, for outputting a cutoff signal to the power supply circuit when receiving the overvoltage signal;

The power supply circuit is used for disconnecting the connection between the power supply source, the charging base station and the charging device when the cut-off signal is received.

Optionally, the power supply control circuit is further configured to output a conduction signal to the power supply circuit when the power supply outputs a normal power supply voltage;

The power supply circuit is further configured to conduct the connection between the power supply source, the charging base station and the charging device when the on-signal is received.

Optionally, the overvoltage protection circuit further includes: a filter circuit;

Wherein, the filter circuit is respectively connected with the power supply, the power supply control circuit and the overvoltage release circuit;

the filter circuit, configured to filter the abnormal power supply voltage output by the power supply to obtain the abnormal filter voltage, and output the abnormal filter voltage to the overvoltage release circuit;

The overvoltage release circuit is further configured to release the abnormal filter voltage when receiving the abnormal filter voltage, and output a cutoff signal to the power supply control circuit.

Optionally, the filter circuit is further configured to filter the normal power supply voltage output by the power supply to obtain a normal filtered voltage, and output the normal filtered voltage to the power supply control circuit;

The power supply control circuit is further configured to output the conduction signal to the power supply circuit when receiving the normal filter voltage.

Optionally, the overvoltage release circuit includes: a first diode, first to second resistors, a first capacitor and a first transistor;

Wherein, the first end of the first diode is connected to the filter circuit, the second end of the first diode is connected to the base of the first triode, the second end of the first capacitor One end is connected to the first end of the first resistor, the first end of the second resistor is connected to the first end of the first diode, the filter circuit and the power supply circuit, the second resistor The second end of the first transistor is connected to the collector of the first transistor and the power supply control circuit, the second end of the first capacitor, the second end of the first resistor and the first transistor The emitter is grounded.

Optionally, the overvoltage including circuit further includes: a step-down circuit;

Wherein, the step-down circuit is respectively connected with the second end of the first diode and the base of the first triode;

The step-down circuit is configured to step down the normal filter voltage when the normal filter voltage breaks down the first diode, so that the first transistor is in an off state.

Optionally, the step-down circuit includes: third to fourth resistors;

The first end of the third resistor is connected to the second end of the first diode, and the second end of the third resistor is respectively connected to the first end of the first capacitor and the second end of the first resistor. The first end is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the base of the first triode.

Optionally, the power supply control circuit includes fifth to eighth resistors, second to third capacitors and a second transistor;

Wherein, the first end of the fifth resistor is respectively connected with the second end of the second resistor, the collector of the first triode and the first end of the second capacitor, and the second end of the fifth resistor are respectively connected to the first end of the sixth resistor and the base of the second triode, and the first end of the seventh resistor is respectively connected to the filter circuit, the first end of the first diode, the The first end of the second resistor, the first end of the third capacitor and the power supply circuit are connected, and the second end of the seventh resistor is respectively connected to the second end of the third capacitor and the eighth resistor The first end of the second capacitor is connected to the power supply circuit, the second end of the eighth resistor is connected to the collector of the second transistor, the second end of the second capacitor, the second end of the sixth resistor The two terminals and the emitter of the second triode are grounded.

Optionally, the power supply circuit includes: a switch tube triggered by a low level;

Wherein, the control end of the switch tube is respectively connected with the second end of the seventh resistor, the second end of the third capacitor and the first end of the eighth resistor, and the input end of the switch tube is respectively connected to the filter circuit, the first end of the first diode, the first end of the second resistor, the first end of the seventh resistor and the first end of the third capacitor, so The output end of the switch tube is connected to the charging base station and the charging equipment.

Optionally, the switch tube is a PMOS tube;

The gate of the PMOS transistor is respectively connected to the second end of the seventh resistor, the second end of the third capacitor and the first end of the eighth resistor, and the source of the PMOS transistor is respectively connected to the filter circuit, the first end of the first diode, the first end of the second resistor, the first end of the seventh resistor and the first end of the third capacitor, so The drain of the PMOS transistor is connected to the charging base station and the charging device.

Optionally, the overvoltage protection circuit further includes: a self-recovery fuse;

One end of the self-recovery fuse is connected to the power supply, and the other end of the self-recovery fuse is connected to the filter circuit.

Optionally, the filter circuit includes: a second diode and a fourth capacitor;

Wherein, the first end of the second diode is respectively connected with the other end of the resettable fuse, the first end of the fourth capacitor, the first end of the first diode, the second end of the second The first end of the resistor, the first end of the seventh resistor, the first end of the third capacitor and the input end of the PMOS transistor are connected, and the second end of the second diode is connected to the first end of the third capacitor. The second terminal of the quad capacitor is grounded.

Optionally, the overvoltage protection circuit further includes: a voltage regulator circuit; the voltage regulator circuit includes: a ninth resistor, fifth to seventh capacitors, and a voltage regulator chip;

The first end of the ninth resistor is connected to the drain of the PMOS transistor, the second end of the ninth resistor is connected to the first end of the fifth capacitor, the first end of the sixth capacitor, and the first end of the seventh capacitor One end is connected to the input end of the voltage regulator chip, and the output end of the voltage regulator chip is connected to the charging device; the second end of the fifth capacitor, the second end of the sixth capacitor and the seventh The second terminal of the capacitor is grounded.

Optionally, the drain of the PMOS transistor is also connected to a power supply socket to provide a socket voltage for the power supply socket.

In order to achieve the above purpose, the present invention also provides an overvoltage protection device, the overvoltage protection device includes the above-mentioned overvoltage protection circuit.

The utility model provides an overvoltage protection circuit and a device. The overvoltage protection circuit includes: a power supply control circuit, an overvoltage release circuit and a power supply circuit; The voltage is released, and the overvoltage signal is output to the power supply control circuit; when the power supply control circuit receives the overvoltage signal, it outputs a cutoff signal to the power supply circuit; when the power supply circuit receives the cutoff signal, it disconnects the power supply and the power supply. The connection between the charging base station and the charging device. The utility model releases the abnormal power supply voltage output by the power supply through the overvoltage release circuit, and disconnects the connection between the power supply, the charging base station and the charging equipment, and effectively avoids the impact of the overvoltage on the charging base station and the charging equipment. .

Description of drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are just some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained based on the structures shown in these drawings without any creative effort.

1 is a schematic structural diagram of a first embodiment of an overvoltage protection circuit proposed by an embodiment of the utility model;

2 is a first circuit schematic diagram of the second embodiment of the overvoltage protection circuit proposed by the embodiment of the utility model;

FIG. 3 is a circuit diagram of the second circuit principle of the second embodiment of the overvoltage protection circuit proposed by the embodiment of the utility model.

Description of reference numbers:

label name label name 10 Power supply control circuit R1～R9 The first to ninth resistors 20 Overvoltage release circuit C1～C9 The first to ninth capacitors 30 power supply circuit Z1～Z2 first to second diodes 40 filter circuit Q1～Q2 first to second transistors 50 Buck circuit P PMOS tube 60 Regulator circuit QN QN103 chip 70 power socket DC Power supply S resettable fuse GND ground

The realization, functional characteristics and advantages of the purpose of the present utility model will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not intended to limit the present invention.

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, not all of them. Example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the difference between the various components under a certain posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly.

In addition, the descriptions involving "first", "second", etc. in the present invention are only for description purposes, and should not be understood as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exists, and is not within the protection scope required by the present utility model.

Referring to FIG. 1 , FIG. 1 is a schematic structural diagram of a first embodiment of an overvoltage protection circuit proposed by the utility model. Based on FIG. 1 , a first embodiment of the overvoltage protection circuit of the present invention is proposed.

In this embodiment, the overvoltage protection circuit includes: a power supply control circuit 10, an overvoltage release circuit 20, and a power supply circuit 30;

The overvoltage release circuit 20 is respectively connected with the power supply DC and the power supply control circuit 10, the power supply circuit 30 is respectively connected with the power supply control circuit 10 and the power supply DC, and the power supply control circuit 10 is connected with the power supply control circuit 10 and the power supply control circuit 10 respectively. The power supply DC connection described above.

It should be noted that the power supply control circuit 10 can be used to control whether the charging base station and the charging device are powered. The power supply control circuit 10 can control the power supply of the charging base station and the charging equipment by outputting a high-level signal or a low-level signal to control the related switch components in the power supply circuit to be turned on or off. The overvoltage release circuit 20 is a circuit for releasing abnormal power supply voltage. The overvoltage release circuit 20 can be turned on or off according to the specific value of the power supply voltage provided by the power supply DC. When the power supply voltage provided by the power supply DC is an abnormal power supply voltage with an excessively high voltage value, the overvoltage release circuit 20 is turned on to release the abnormal power supply voltage; and when the power supply voltage provided by the power supply DC is a normal power supply voltage, the The voltage release circuit 20 is turned off to avoid releasing the normal power supply voltage. The charging device may be a recyclable charging device such as a sweeper. The power supply DC may be a direct current power supply DC.

In a specific implementation, when the power supply DC outputs an abnormal power supply voltage, the overvoltage release circuit 20 forms a complete loop to release the abnormal power supply voltage, and outputs an overvoltage signal to the The power supply control circuit 10; the power supply control circuit 10 can output a cutoff signal to the power supply circuit 30 when receiving the overvoltage signal; the power supply circuit 30 can cut off all the power supply when receiving the cutoff signal The connection between the power supply DC, the charging base station and the charging equipment is described. For example, when the overvoltage release circuit receives a power supply voltage with an excessively high voltage value, a certain component in the overvoltage release circuit 20 will be broken down by the high voltage to form a complete release loop to release the abnormal power supply voltage. In order to avoid the influence of the abnormal power supply voltage on the charging base station and the charging equipment, it is necessary to disconnect the power supply DC from the charging base station and the charging equipment. In the embodiment of this city, the abnormal power supply voltage refers to a voltage with an excessively high voltage value.

The overvoltage signal may be used to indicate that the power supply voltage provided by the power supply DC is an abnormal power supply voltage with an excessively high voltage value. The cut-off signal can be used to control the switching components in the power supply circuit 30 to cut off, so that the abnormal power supply voltage output by the power supply DC cannot be input to the charging base station or charging equipment.

In this embodiment, an overvoltage protection circuit is provided. The overvoltage protection circuit includes: a power supply control circuit, an overvoltage release circuit, and a power supply circuit; release, and output an overvoltage signal to the power supply control circuit; when the power supply control circuit receives the overvoltage signal, it outputs a cutoff signal to the power supply circuit; when the power supply circuit receives the cutoff signal, it disconnects the power supply and charging The connection between the base station and the charging device. In this embodiment, the abnormal power supply voltage output by the power supply is released through the overvoltage release circuit, and the connection between the power supply and the charging base station and the charging equipment is disconnected, which effectively avoids the impact of the overvoltage on the charging base station and the charging equipment. .

Based on the above-mentioned first embodiment of the overvoltage protection circuit, a second embodiment of the overvoltage protection circuit of the present invention is proposed.

In this embodiment, the power supply control circuit 10 may output a conduction signal to the power supply circuit when the power supply DC outputs a normal power supply voltage; the power supply circuit 30 may receive the conduction signal when the power supply circuit 30 receives the conduction signal. The internal switch components are turned on, thereby turning on the connection between the power supply DC, the charging base station and the charging equipment, and the power supply DC can supply power to the charging base station and the charging equipment through the power supply circuit 30 .

In this embodiment, the overvoltage protection circuit further includes: a filter circuit 40;

Wherein, the filter circuit 40 is respectively connected with the power supply DC, the power supply control circuit 10 and the overvoltage release circuit 20 .

It should be noted that the filter circuit 40 can filter the noise in the power supply voltage output by the power supply DC. In this embodiment, the filter circuit 40 can filter the abnormal power supply voltage output by the power supply DC to obtain an abnormal filter voltage without noise interference, and output the abnormal filter voltage to the overvoltage release circuit 20 ; The overvoltage release circuit 20 can release the abnormal filter voltage when receiving the abnormal filter voltage, and output a cut-off signal to the power supply control circuit 10, thereby controlling the power supply DC and the charging base station and charging connections between devices. In addition, in this embodiment, the filter circuit 40 can also filter the normal power supply voltage output by the power supply DC to obtain a normal filtered voltage without noise interference, and output the normal filtered voltage to the power supply control Circuit 10; the power supply control circuit 10 can output the on-signal to the power supply circuit 30 when receiving the normal filtered voltage, so as to realize normal power supply of the related loads of the charging base station and the charging equipment.

In this embodiment, the overvoltage release circuit 20 includes: a first diode Z1, first to second resistors, a first capacitor C1 and a first transistor Q1;

Wherein, the first end of the first diode Z1 is connected to the filter circuit 40, the second end of the first diode Z1 is connected to the base of the first transistor Q1, the The first end of a capacitor C1 is connected to the first end of the first resistor R1, the first end of the second resistor R2 is connected to the first end of the first diode Z1, the filter circuit 40 and the The power supply circuit 30 is connected, the second end of the second resistor R2 is connected to the collector of the first transistor Q1 and the power supply control circuit 10, the second end of the first capacitor C1, the first The second end of a resistor R1 and the emitter of the first transistor Q1 are grounded to GND.

It should be noted that, in this embodiment, the first diode Z1 is a Zener diode. When the power supply voltage provided by the power supply DC exceeds a certain value, the first diode Z1 will be broken down. The first transistor Q1 is an NPN type transistor.

In the specific implementation, when the abnormal power supply voltage of the power supply DC output voltage value is too high, the first diode Z1 will be broken down, so as to provide a high-level voltage for the base of the first transistor Q1 to make the first transistor Q1 Q1 is turned on. When the first transistor Q1 is turned on, the abnormal power supply voltage provided by the power supply DC will flow into the collector of the first transistor Q1 through the second resistor R2, and flow to the collector of the first transistor Q1 through the emitter of the first transistor Q1. Ground GND to realize the release of abnormal power supply voltage. The first capacitor C1 is a filter capacitor.

In this embodiment, the overvoltage including circuit further includes: a step-down circuit 50;

The step-down circuit 50 is respectively connected to the second end of the first diode Z1 and the base of the first transistor Q1.

It should be noted that in this embodiment, the first diode Z1 may have a normal voltage breakdown. For example, the normal power supply voltage output by the power supply DCDC is 24V, while the breakdown voltage of the first diode Z1 At this time, the normal power supply voltage can provide a high level signal to the base of the first transistor Q1 through the first diode Z1, so that the first transistor Q1 is turned on and the normal power supply voltage is released. In order to avoid the above situation, a step-down circuit 50 can be arranged between the first diode Z1 and the first transistor Q1. When the first diode Z1 is broken down by the normal power supply voltage, the voltage will flow into the first transistor Q1. The voltage of the base electrode of Q1 is stepped down, so that the first transistor Q1 is kept in an off state to prevent the normal power supply voltage output by the power supply DC from being released.

In this embodiment, the step-down circuit includes: third to fourth resistors;

The first end of the third resistor R3 is connected to the second end of the first diode Z1, and the second end of the third resistor 33 is connected to the first end of the first capacitor C1, the second end of the The first end of the first resistor R1 and the first end of the fourth resistor R4 are connected, and the second end of the fourth resistor R4 is connected to the base of the first transistor Q1.

It should be noted that, in this embodiment, the third resistor R3 and the fourth resistor R4 are both step-down resistors. When the first diode Z1 is broken down by the normal power supply voltage, the voltage value flowing into the first triode Q1 can be reduced by the step-down action of the third resistor R3 and the fourth resistor R4, which is the first triode Tube Q1 is in a cut-off state.

In this embodiment, the power supply control circuit includes fifth to eighth resistors R8, second to third capacitors C3, and a second transistor Q2;

The first end of the fifth resistor R5 is respectively connected to the second end of the second resistor R2, the collector of the first transistor Q1 and the first end of the second capacitor C2, and the fifth resistor The second end of R5 is respectively connected to the first end of the sixth resistor R6 and the base of the second transistor Q2, and the first end of the seventh resistor R7 is respectively connected to the filter circuit 40, the first two The first end of the pole tube Z1, the first end of the second resistor R2, the first end of the third capacitor C3 and the power supply circuit 30 are connected, and the second end of the seventh resistor R7 is respectively connected to the power supply circuit 30. The second end of the third capacitor C3, the first end of the eighth resistor R8 and the power supply circuit 30 are connected, and the second end of the eighth resistor R8 is connected to the collector of the second transistor Q2 For connection, the second end of the second capacitor C2, the second end of the sixth resistor R6 and the emitter of the second transistor Q2 are grounded to GND.

It should be noted that, in this embodiment, the second transistor Q2 is also an NPN transistor. The second capacitor C2 and the third capacitor C3 are both filter capacitors.

In a specific implementation, when the power supply DC outputs an abnormal power supply voltage to turn on the first transistor Q1, the power supply DC cannot provide a high-level signal for the base of the second transistor Q2, and the second transistor Q1 is turned on by the power supply DC. The transistor Q2 is turned off. At this time, the power supply DC can provide a high-level signal for the switching components in the power supply circuit 30 through the seventh resistor R7, so that the switching components are in the off state, and the power supply DC cannot convert the abnormal power supply voltage. Output to the charging base station and charging equipment. Among them, the switch component is a switch component with the control terminal being turned on at a low level and turned off at a high level. When the power supply DC outputs a normal power supply voltage to turn off the first transistor Q1, the power supply DC can provide a high-level signal for the base of the second transistor Q2, so that the second transistor Q2 conducts. At this time, the power supply DC can output the normal power supply voltage provided by the power supply DC to the ground terminal GND through the seventh resistor R7, the eighth resistor R8 and the second transistor Q2, so as to provide the switching element in the power supply circuit. The device provides a low-level signal to make the switching components in a conducting state, and the power supply DC can output the normal power supply voltage to the charging base station and related loads in the charging equipment.

In this embodiment, the power supply circuit includes: a switch tube triggered by a low level;

Wherein, the control end of the switch tube is respectively connected with the second end of the seventh resistor R7, the second end of the third capacitor C3 and the first end of the eighth resistor R8, and the switch tube The input terminal is respectively connected with the filter circuit 40, the first terminal of the first diode Z1, the first terminal of the second resistor R2, the first terminal of the seventh resistor R7 and the third capacitor The first end of C3 is connected, and the output end of the switch tube is connected to the charging base station and the charging device. In this embodiment, the switch transistor is a PMOS transistor P; correspondingly, the gate of the PMOS transistor P is respectively connected with the second end of the seventh resistor R7, the second end of the third capacitor C3 and the The first end of the eighth resistor R8 is connected, and the source of the PMOS transistor P is connected to the filter circuit 40, the first end of the first diode Z1, the first end of the second resistor R2, The first end of the seventh resistor R7 and the first end of the third capacitor C3 are connected, and the drain of the PMOS transistor P is connected to the charging base station and the charging device. In this embodiment, the switch tube may also be a QN103 chip QN. A PMOS tube is set in the QN103 chip QN to allow a large current to pass through. Determined according to the current value of the load connected to the back end, in the case of low current output, the switch tube can choose PMSO tube P, and in the case of high current output, the switch tube can choose QN103 chip QN.

In this embodiment, the overvoltage protection circuit further includes: a self-recovery fuse S;

One end of the resettable fuse S is connected to the power supply DC, and the other end of the resettable fuse S is connected to the filter circuit 40 .

It should be noted that the resettable fuse S is an overcurrent protection component. When the current in the overvoltage protection circuit is too large, the self-recovery fuse S is automatically disconnected, so that the excessive current will not flow into the overvoltage protection circuit to prevent the components in the overvoltage protection circuit from being damaged. When the current in the overvoltage protection circuit is in the normal use range of the overvoltage protection circuit, the self-recovery fuse S automatically recovers, so as to continue to control the current in the overvoltage protection circuit.

In this embodiment, the filter circuit 40 includes: a second diode Z2 and a fourth capacitor C4;

Wherein, the first end of the second diode Z2 is respectively connected with the other end of the resettable fuse S, the first end of the fourth capacitor C4, the first end of the first diode Z1, The first end of the second resistor R2, the first end of the seventh resistor R7, the first end of the third capacitor C3 and the input end of the PMOS transistor P are connected, and the second diode The second terminal of Z2 and the second terminal of the fourth capacitor C4 are grounded.

It should be noted that, in this embodiment, the fourth capacitor C4 is an electrolytic capacitor. In the specific implementation process, the charging and discharging characteristics of the fourth capacitor C4 can be used to filter the abnormal power supply voltage or the normal power supply voltage provided by the power supply DC, and filter out the noise interference in the abnormal power supply voltage or the normal power supply voltage.

In this embodiment, the overvoltage protection circuit further includes: a voltage stabilization circuit 60; the voltage stabilization circuit includes: a ninth resistor R9, fifth to seventh capacitors, and a voltage stabilization chip U;

The first end of the ninth resistor R9 is connected to the drain of the PMOS transistor P, the second end of the ninth resistor R9 is connected to the first end of the fifth capacitor C5, the first end of the sixth capacitor C6, The first end of the seventh capacitor C7 is connected to the input end of the voltage stabilization chip U, and the output end of the voltage stabilization chip U is connected to the relevant load of the charging device or the charging base station; the second end of the fifth capacitor C5 , the second end of the sixth capacitor C6 and the second end of the seventh capacitor C7 are grounded.

It should be noted that the voltage stabilization circuit 60 can be used to stabilize the normal power supply voltage to obtain a power supply voltage with a stable voltage value. The voltage stabilizing circuit 60 can also be connected to the load in the charging base station to provide a stable power supply voltage for the load in the charging base station. Wherein, the voltage stabilization chip U in the voltage stabilization circuit can realize voltage stabilization of the normal power supply voltage, and the fifth to seventh capacitors are all filter capacitors, which can be used to stabilize the noise generated by other components in the overvoltage protection circuit. filter out. After the normal power supply voltage provided by the power supply DC is stabilized, the normal power supply voltage can also be converted into the voltage required by the load connected to the voltage stabilizer circuit. For example, the normal power supply voltage of 24V output by the power supply DC can be converted into 5V. The voltage can be used to supply power to loads such as MCU and infrared transmitters.

In this embodiment, the drain of the PMOS transistor P is also connected to the power supply socket 70 to provide a socket voltage for the power supply socket 70 .

It should be noted that some loads in the charging base station may require power supply sockets for power supply. In this embodiment, the power supply socket can be connected to a plug of a partial load in the charging base station to provide a working voltage for the load of the charging base station. The power socket 70 can be connected with the control board in the charging base station.

In this embodiment, the overvoltage protection circuit further includes an eighth capacitor C8 and a ninth capacitor C9, wherein the first end of the eighth capacitor C8 and the first end of the second diode Z2, the The first end of the fourth capacitor C4, the first end of the ninth capacitor C9, the first end of the second resistor R2, the first end of the seventh resistor R7, the first end of the third capacitor C3 One end and the source of the PMOS transistor P are connected. The eighth capacitor C8 and the ninth capacitor C9 are both filter capacitors.

This embodiment provides an overvoltage protection circuit, the overvoltage protection circuit includes: a power supply control circuit, an overvoltage release circuit and a power supply circuit; the overvoltage release circuit releases the abnormal power supply voltage when the power supply outputs an abnormal power supply voltage, And output the overvoltage signal to the power supply control circuit; when the power supply control circuit receives the overvoltage signal, it outputs a cutoff signal to the power supply circuit; when the power supply circuit receives the cutoff signal, it disconnects the power supply from the charging base station and charging connections between devices. In this embodiment, the release of the abnormal power supply voltage is controlled by the breakdown of the first diode, and the PMOS transistor or QN103 chip connected between the power supply and the charging base station and charging equipment is controlled by the turn-on or off-state of the second transistor. It is turned on or off, so that the abnormal power supply voltage cannot be output to the charging base station and the charging equipment, which effectively avoids the impact of the overvoltage abnormal power supply voltage on the charging base station and the charging equipment.

In order to achieve the above purpose, the present invention also provides an overvoltage protection device, the overvoltage protection device includes the above-mentioned overvoltage protection circuit. The specific structure of the overvoltage protection circuit refers to the above-mentioned embodiments. Since the overvoltage protection device adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments. Repeat them one by one.

The above are only the preferred embodiments of the present utility model, and are not intended to limit the scope of the present utility model patent. Any equivalent structure or equivalent process transformation made by using the contents of the present utility model description and accompanying drawings, or directly or indirectly applied to other related The technical fields of the present invention are similarly included in the scope of patent protection of the present invention.

Claims (15)

1. An overvoltage protection circuit, characterized in that the overvoltage protection circuit comprises: a power supply control circuit, an overvoltage release circuit and a power supply circuit; The overvoltage release circuit is respectively connected with a power supply and the power supply control circuit, the power supply circuit is respectively connected with the power supply control circuit and the power supply, and the power supply control circuit is connected with the power supply; The overvoltage release circuit is configured to release the abnormal power supply voltage when the power supply outputs an abnormal power supply voltage, and output an overvoltage signal to the power supply control circuit; the power supply control circuit, for outputting a cutoff signal to the power supply circuit when receiving the overvoltage signal; The power supply circuit is used for disconnecting the connection between the power supply source, the charging base station and the charging device when the cut-off signal is received. 2. The overvoltage protection circuit according to claim 1, wherein the power supply control circuit is further configured to output a conduction signal to the power supply circuit when the power supply outputs a normal power supply voltage; The power supply circuit is further configured to conduct the connection between the power supply source, the charging base station and the charging device when the on-signal is received. 3. The overvoltage protection circuit according to claim 2, wherein the overvoltage protection circuit further comprises: a filter circuit; Wherein, the filter circuit is respectively connected with the power supply, the power supply control circuit and the overvoltage release circuit; the filter circuit, configured to filter the abnormal power supply voltage output by the power supply to obtain the abnormal filter voltage, and output the abnormal filter voltage to the overvoltage release circuit; The overvoltage release circuit is further configured to release the abnormal filter voltage when receiving the abnormal filter voltage, and output a cutoff signal to the power supply control circuit. 4. The overvoltage protection circuit according to claim 3, wherein the filter circuit is further configured to filter the normal power supply voltage output by the power supply to obtain a normal filter voltage, and to filter the normal filter voltage. output to the power supply control circuit; The power supply control circuit is further configured to output the conduction signal to the power supply circuit when receiving the normal filter voltage. 5. The overvoltage protection circuit of claim 4, wherein the overvoltage release circuit comprises: a first diode, a first to a second resistor, a first capacitor and a first transistor; Wherein, the first end of the first diode is connected to the filter circuit, the second end of the first diode is connected to the base of the first triode, the second end of the first capacitor One end is connected to the first end of the first resistor, the first end of the second resistor is connected to the first end of the first diode, the filter circuit and the power supply circuit, the second resistor The second end of the first transistor is connected to the collector of the first transistor and the power supply control circuit, the second end of the first capacitor, the second end of the first resistor and the first transistor The emitter is grounded. 6 . The overvoltage protection circuit according to claim 5 , wherein the overvoltage protection circuit further comprises: a step-down circuit; 6 . Wherein, the step-down circuit is respectively connected with the second end of the first diode and the base of the first triode; The step-down circuit is configured to step down the normal filter voltage when the normal filter voltage breaks down the first diode, so that the first transistor is in an off state. 7. The overvoltage protection circuit of claim 6, wherein the step-down circuit comprises: third to fourth resistors; The first end of the third resistor is connected to the second end of the first diode, and the second end of the third resistor is respectively connected to the first end of the first capacitor and the second end of the first resistor. The first end is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the base of the first triode. 8. The overvoltage protection circuit of claim 7, wherein the power supply control circuit comprises fifth to eighth resistors, second to third capacitors and a second transistor; Wherein, the first end of the fifth resistor is respectively connected with the second end of the second resistor, the collector of the first triode and the first end of the second capacitor, and the second end of the fifth resistor are respectively connected to the first end of the sixth resistor and the base of the second triode, and the first end of the seventh resistor is respectively connected to the filter circuit, the first end of the first diode, the The first end of the second resistor, the first end of the third capacitor and the power supply circuit are connected, and the second end of the seventh resistor is respectively connected to the second end of the third capacitor and the eighth resistor The first end of the second capacitor is connected to the power supply circuit, the second end of the eighth resistor is connected to the collector of the second transistor, the second end of the second capacitor, the second end of the sixth resistor The two terminals and the emitter of the second triode are grounded. 9 . The overvoltage protection circuit according to claim 8 , wherein the power supply circuit comprises: a switch tube triggered by a low level; 10 . Wherein, the control end of the switch tube is respectively connected with the second end of the seventh resistor, the second end of the third capacitor and the first end of the eighth resistor, and the input end of the switch tube is respectively connected to the filter circuit, the first end of the first diode, the first end of the second resistor, the first end of the seventh resistor and the first end of the third capacitor, so The output end of the switch tube is connected with the charging base station and the charging equipment. 10. The overvoltage protection circuit of claim 9, wherein the switch tube is a PMOS tube; The gate of the PMOS transistor is respectively connected to the second end of the seventh resistor, the second end of the third capacitor and the first end of the eighth resistor, and the source of the PMOS transistor is respectively connected to the filter circuit, the first end of the first diode, the first end of the second resistor, the first end of the seventh resistor and the first end of the third capacitor, so The drain of the PMOS transistor is connected to the charging base station and the charging device. 11. The overvoltage protection circuit of claim 10, wherein the overvoltage protection circuit further comprises: a self-recovery fuse; One end of the self-recovery fuse is connected to the power supply, and the other end of the self-recovery fuse is connected to the filter circuit. 12. The overvoltage protection circuit of claim 11, wherein the filter circuit comprises: a second diode and a fourth capacitor; Wherein, the first end of the second diode is respectively connected with the other end of the resettable fuse, the first end of the fourth capacitor, the first end of the first diode, the second end of the second The first end of the resistor, the first end of the seventh resistor, the first end of the third capacitor and the input end of the PMOS transistor are connected, and the second end of the second diode is connected to the first end of the third capacitor. The second terminal of the quad capacitor is grounded. 13. The overvoltage protection circuit of claim 12, wherein the overvoltage protection circuit further comprises: a voltage regulator circuit; the voltage regulator circuit comprises: a ninth resistor, fifth to seventh capacitors, and a voltage regulator. pressure chip; The first end of the ninth resistor is connected to the drain of the PMOS transistor, the second end of the ninth resistor is connected to the first end of the fifth capacitor, the first end of the sixth capacitor, and the first end of the seventh capacitor One end is connected to the input end of the voltage regulator chip, and the output end of the voltage regulator chip is connected to the charging device; the second end of the fifth capacitor, the second end of the sixth capacitor and the seventh The second terminal of the capacitor is grounded. 14 . The overvoltage protection circuit according to claim 13 , wherein the drain of the PMOS transistor is further connected to a power supply socket to provide a socket voltage for the power supply socket. 15 . 15. An overvoltage protection device, characterized in that the overvoltage protection device comprises the overvoltage protection circuit of any one of claims 1-14.

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