CN217545567U

CN217545567U - Overvoltage protection device

Info

Publication number: CN217545567U
Application number: CN202221021506.7U
Authority: CN
Inventors: 孔凡峰; 刘康乐
Original assignee: Xi'an Qiantuo Electronic Technology Co ltd; Suzhou Qiantuo Electronic Technology Co ltd
Current assignee: Xi'an Qiantuo Electronic Technology Co ltd; Suzhou Qiantuo Electronic Technology Co ltd
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-10-04
Anticipated expiration: 2032-04-29

Abstract

The utility model discloses an overvoltage protector, including sampling circuit, detection circuitry and control circuit, sampling circuit electric connection has the positive link, detection circuitry includes zener diode, first detection piece, second detection piece and negative pole link, zener diode and sampling circuit electric connection, first detection piece respectively with sampling circuit, zener diode, negative pole link electric connection, the second detection piece respectively with control circuit, first detection piece, negative pole link electric connection, control circuit and sampling circuit electric connection. The utility model discloses the beneficial effect who gains: the voltage that can effectively avoid inserting motor controller is too big, plays the effect that improves the reliability. The motor controller does not need to be provided with a power supply chip with an overhigh voltage withstanding specification, and the manufacturing cost of the motor controller is effectively reduced. The advantages of low cost and high reliability are achieved.

Description

Overvoltage protection device

Technical Field

The utility model relates to an overvoltage protector's technical field, concretely relates to overvoltage protector.

Background

Overvoltage protection refers to a protection mode that disconnects the power supply or reduces the voltage of the controlled device when the protected line voltage exceeds a predetermined maximum value. The electric forklift controller controls the motor to work according to the set direction, speed, angle and response time through the active work of the integrated circuit. The motor has the advantages of wider application range, higher output efficiency, lower noise and the like. However, the motor controller may also be in failure, which causes the failure of the motor controller mainly because the instantaneous voltage of the electric forklift is too high during operation, and the internal control power supply of the motor controller is burned out.

In the traditional controller, only a power supply with higher voltage-resistant specification can be selected, so that the controller is prevented from generating high voltage exceeding the load capacity during operation. However, this method can only work below the DCDC nominal power supply, and a higher voltage-withstanding chip is required, which will greatly increase the cost and is unreliable. Therefore, the problems of high cost and poor reliability exist in the prior art.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, an object of the utility model is to provide an overvoltage protector, it includes sampling circuit, detection circuitry and control circuit, and this overvoltage protector has the advantage that the cost is lower, the reliability is higher.

In order to realize the purpose of the utility model, the utility model adopts the following technical scheme:

the utility model provides an overvoltage protector, includes sampling circuit, detection circuitry and control circuit, sampling circuit electric connection has the positive pole link, detection circuitry includes zener diode, first detection piece, second detection piece and negative pole link, zener diode and sampling circuit electric connection, first detection piece respectively with sampling circuit, zener diode, negative pole link electric connection, the second detection piece respectively with control circuit, first detection piece, negative pole link electric connection, control circuit and sampling circuit electric connection. By such an arrangement: the voltage that can effectively avoid inserting motor controller is too big, avoids motor controller to burn out, effectively protects motor controller, plays the effect that improves the reliability. The motor controller does not need to be provided with a power supply chip with an over-high voltage-resistant specification, and the manufacturing cost of the motor controller is effectively reduced. The advantages of low cost and high reliability are achieved.

Preferably, the first detection element is a first triode, a collector, a base and an emitter of the first triode are respectively and electrically connected with the sampling circuit, the zener diode and the negative connection end, the second detection element is a second triode, and the collector, the base and the emitter of the second triode are respectively and electrically connected with the control circuit, the first triode and the negative connection end. By such an arrangement: the current of the control circuit can be changed by the detection circuit when the input voltage is higher than the voltage protection point.

Preferably, the control circuit comprises a field effect transistor, a drain of the field effect transistor is electrically connected with the sampling circuit, and a gate of the field effect transistor is electrically connected with a collector of the second triode. By such an arrangement: the function of controlling the on-off of the motor controller and the power supply is realized.

Preferably, a first resistor is arranged between the collector of the second triode and the control circuit. By such an arrangement: and the function of protecting the circuit is realized.

Preferably, a second resistor is arranged between the zener diode and the first triode. By such an arrangement: and the function of protecting the circuit is realized.

Preferably, a third resistor is arranged between the collector of the first triode and the sampling circuit. By such an arrangement: and the function of protecting the circuit is realized.

Preferably, a fourth resistor is disposed between the collector of the first triode and the negative connection terminal. By such an arrangement: the effect of conveniently detecting faults is achieved, and the effect of conveniently maintaining is achieved.

Preferably, a fifth resistor is arranged between the voltage stabilizing diode and the negative electrode connecting end. By such an arrangement: the effect of conveniently detecting faults is achieved, and the effect of conveniently maintaining is achieved.

Preferably, the control circuit is provided with an output end, and a capacitor is arranged between the output end and the negative electrode connecting end. By such an arrangement: the capacitor supplies power to the motor controller when the field effect tube is disconnected, and the advantage of high stability is achieved.

Compared with the prior art, the utility model discloses profitable technological effect has been obtained:

1. whether it is higher than the protection voltage point to detect input voltage through detection circuitry, change control circuit's electric current to make control circuit can control the switch-on and the disconnection of machine controller and anodal link according to the change of electric current, and then can effectively avoid the voltage of inserting machine controller too big, avoid machine controller to burn out, effectively protect machine controller, play the effect that improves the reliability. The motor controller does not need to be provided with a power supply chip with an over-high voltage-resistant specification, and the manufacturing cost of the motor controller is effectively reduced. The advantages of low cost and high reliability are achieved.

2. The capacitor supplies power to the motor controller when the field effect tube is disconnected, so that the motor controller can stably operate, the effect of improving the operation stability of the motor controller is achieved, and the advantage of high stability is achieved.

Drawings

Fig. 1 is a schematic diagram of a circuit connection structure of an overvoltage protection device according to an embodiment of the present invention.

Wherein, the technical characteristics that each reference numeral refers to are as follows:

11. a sampling circuit; 12. a positive electrode connecting end; 21. a voltage regulator diode; 22. a negative electrode connecting end; 23. a first triode; 24. a second triode; 31. a field effect transistor; 32. an output end; 33. a capacitor; 41. a first resistor; 42. a second resistor; 43. a third resistor; 44. a fourth resistor; 45. and a fifth resistor.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the following embodiments, but the scope of the present invention is not limited to the following embodiments.

Referring to fig. 1, an overvoltage protection device includes a sampling circuit 11, a detection circuit and a control circuit, the sampling circuit 11 is electrically connected to an anode connection end 12, and the anode connection end 12 is connected to an anode of a power supply. The detection circuit comprises a voltage stabilizing diode 21, a first detection piece, a second detection piece and a negative connecting end 22, the negative connecting end 22 is connected with the negative electrode of the power supply, the voltage stabilizing diode 21 is electrically connected with the sampling circuit 11, the first detection piece is respectively electrically connected with the sampling circuit 11, the voltage stabilizing diode 21 and the negative connecting end 22, the second detection piece is respectively electrically connected with the control circuit, the first detection piece and the negative connecting end 22, and the control circuit is electrically connected with the sampling circuit 11. The first detection part is a first triode 23, the collector, the base and the emitter of the first triode 23 are respectively and electrically connected with the sampling circuit 11, the zener diode 21 and the negative connecting end 22, the second detection part is a second triode 24, and the collector, the base and the emitter of the second triode 24 are respectively and electrically connected with the control circuit, the first triode 23 and the negative connecting end 22.

The control circuit comprises a field effect transistor 31, the drain of the field effect transistor 31 is electrically connected with the sampling circuit 11, and the gate of the field effect transistor 31 is electrically connected with the collector of the second triode 24. The control circuit is provided with an output end 32 electrically connected with the field effect transistor 31, and a capacitor 33 is arranged between the output end 32 and the negative electrode connecting end 22. The drain and the source of the field effect transistor 31 are electrically connected to the sampling circuit 11 and the output terminal 32, respectively, the output terminal 32 is electrically connected to the motor controller for outputting voltage to the motor controller, and a DC-DC power supply module electrically connected to the output terminal 32 is disposed inside the motor controller.

A first resistor 41 is arranged between the collector of the second triode 24 and the control circuit, a second resistor 42 is arranged between the zener diode 21 and the first triode 23, a third resistor 43 is arranged between the collector of the first triode 23 and the sampling circuit 11, a fourth resistor 44 is arranged between the collector of the first triode 23 and the negative connection end 22, and a fifth resistor 45 is arranged between the zener diode 21 and the negative connection end 22.

The zener diode 21 is preset with a protection voltage point, when the zener diode 21 is connected with a voltage higher than the protection voltage point, the zener diode 21 is conducted, and when the zener diode 21 is connected with a voltage lower than the protection voltage point, the zener diode 21 is not conducted.

The specific working process is as follows:

when the input voltage is lower than the protection voltage point of the zener diode 21, the zener diode 21 is not conducted, the base of the first triode 23 is in a state of not being connected with the power supply, so that the first triode 23 is not conducted, the base of the second triode 24 is connected with the power supply, so that the second triode 24 is conducted, and thus the current of the positive connecting terminal 12 is conducted to the negative connecting terminal 22 through the sampling circuit 11, the field effect transistor 31 and the second triode 24. When the input voltage is higher than the protection voltage point of the zener diode 21, the base of the first triode 23 is connected to the power supply, so that the first triode 23 is conducted, the base of the second triode 24 is connected to the negative electrode of the power supply by the first triode 23, and at this time, the second triode 24 is not conducted, so that the current of the positive electrode connecting terminal 12 cannot be conducted to the negative electrode connecting terminal 22 through the sampling circuit 11, the field effect transistor 31 and the second triode 24. The field effect tube 31 detects whether current passes between the sampling circuit 11 and the second triode 24, if the current passes, the current of the power supply connecting end is communicated to the motor controller through the sampling circuit 11, the field effect tube 31 and the output end 32, and the capacitor 33 is charged normally; if no current passes through the field effect transistor 31, the output end 32 is disconnected from the positive connecting end 12, so that the positive connecting end 12 is disconnected from a DC-DC power supply module of a rear-stage motor controller when the input voltage is higher than a protection voltage point, the motor controller is supplied with power by the capacitor 33, and the stable operation of the motor controller is ensured.

The embodiment has the following advantages:

whether the input voltage is higher than the protection voltage point or not is detected through the detection circuit, and the current of the control circuit is changed, so that the control circuit can control the connection and disconnection of the motor controller and the anode connecting end 12 according to the change of the current, the voltage which can be effectively prevented from being connected into the motor controller is too large, the motor controller is prevented from being burnt out, the motor controller is effectively protected, and the effect of improving the reliability is achieved. The motor controller does not need to be provided with a power supply chip with an over-high voltage-resistant specification, and the manufacturing cost of the motor controller is effectively reduced. The advantages of low cost and high reliability are achieved.

Through the setting of first triode 23 and second triode 24, the function that second triode 24 switches off when having realized first triode 23 switch-on, second triode 24 switches on when first triode 23 switches off to can change control circuit's electric current when the input voltage is higher than the voltage protection point through detection circuitry, make control circuit can detect the change of electric current.

Through the setting of the field effect transistor 31, the connection and disconnection between the output end 32 and the positive connecting end 12 can be controlled according to the connection and disconnection of the on-off control output end 32 of the second triode 24, so that the function of controlling the connection and disconnection between the motor controller and the positive connecting end 12 is realized.

By providing the first resistor 41 between the second transistor 24 and the control circuit, the circuit overload is avoided when the second transistor 24 is turned on, and the circuit is protected.

By arranging the second resistor 42 between the zener diode 21 and the first transistor 23, the circuit overload is avoided when the zener diode 21 is switched on, and the circuit is protected.

By arranging the third resistor 43 between the first triode 23 and the sampling circuit 11, the circuit overload is avoided when the sampling circuit 11 is connected with the negative pole of the power supply through the first triode 23, and the function of protecting the circuit is achieved.

Through detecting the voltage at the two ends of the fourth resistor 44 and the fifth resistor 45, whether the first triode 23 and the second triode 24 have voltage access or not is conveniently judged, the effect of conveniently detecting faults is achieved, and the effect of conveniently maintaining is achieved.

The capacitor 33 supplies power to the motor controller when the field effect tube 31 is disconnected, so that the motor controller can stably operate, the effect of improving the operation stability of the motor controller is achieved, and the advantage of high stability is achieved.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, in light of the above teachings and teachings. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should fall within the protection scope of the claims of the present invention. In addition, although specific terms are used in the specification, the terms are used for convenience of description and do not limit the utility model in any way.

Claims

1. An overvoltage protection device, characterized by: including sampling circuit (11), detection circuitry and control circuit, sampling circuit (11) electric connection has anodal link (12), detection circuitry includes zener diode (21), first detection piece, second detection piece and negative pole link (22), zener diode (21) and sampling circuit (11) electric connection, first detection piece respectively with sampling circuit (11), zener diode (21), negative pole link (22) electric connection, the second detection piece respectively with control circuit, first detection piece, negative pole link (22) electric connection, control circuit and sampling circuit (11) electric connection.

2. The overvoltage protection device of claim 1, wherein: the first detection piece is first triode (23), the collecting electrode, the base, the projecting pole of first triode (23) respectively with sampling circuit (11), zener diode (21), negative pole link (22) electric connection, the second detection piece is second triode (24), the collecting electrode, the base, the projecting pole of second triode (24) respectively with control circuit, first triode (23), negative pole link (22) electric connection.

3. The overvoltage protection device of claim 2, wherein: the control circuit comprises a field effect tube (31), the drain electrode of the field effect tube (31) is electrically connected with the sampling circuit (11), and the grid electrode of the field effect tube (31) is electrically connected with the collector electrode of the second triode (24).

4. The overvoltage protection device of claim 3, wherein: and a first resistor (41) is arranged between the collector of the second triode (24) and the control circuit.

5. The overvoltage protection device of claim 2, wherein: and a second resistor (42) is arranged between the voltage stabilizing diode (21) and the first triode (23).

6. The overvoltage protection device of claim 2, wherein: and a third resistor (43) is arranged between the collector of the first triode (23) and the sampling circuit (11).

7. The overvoltage protection device of claim 2, wherein: and a fourth resistor (44) is arranged between the collector of the first triode (23) and the negative electrode connecting end (22).

8. The overvoltage protection device of claim 1, wherein: and a fifth resistor (45) is arranged between the voltage stabilizing diode (21) and the negative electrode connecting end (22).

9. The overvoltage protection device of claim 1, wherein: the control circuit is provided with an output end (32), and a capacitor (33) is arranged between the output end (32) and the negative connecting end (22).