CN-122000830-A - Protection circuit, method, relay and electric equipment

Abstract

The invention discloses a protection circuit, a method, a relay and electric equipment, wherein the protection circuit comprises a first switching tube, a second switching tube, an over-temperature protection module and an over-current protection module, wherein the input end and the control end of the first switching tube are connected with the output end of a driving signal of the relay, the input end of the second switching tube is connected with the output end of the first switching tube, the output end of the second switching tube is connected with the first end of a coil of the relay, the second end of the coil is grounded, the first input end of the over-temperature protection module inputs first voltage, the second input end of the over-temperature protection module inputs second voltage, the output end of the over-temperature protection module is connected with the control end of the second switching tube, the first input end of the over-current protection module inputs third voltage, the second input end of the over-current protection module is connected with a main loop where the first static contact and the second static contact of the relay are located, and the output end of the over-temperature protection module is connected with the control end of the second switching tube. According to the invention, when the overcurrent condition occurs, the control relay is disconnected in time, so that the safety is improved, and the maintenance cost is reduced.

Inventors

• YAO XIN
• XIONG ZHEN
• YANG FAN

Assignees

• 珠海格力电器股份有限公司

Dates

Publication Date

20260508

Application Date

20260122

Claims (12)

1. 1. A protection circuit for a relay, the relay comprising a coil, a first stationary contact, a second stationary contact, a first movable contact, a second movable contact, a third stationary contact and a fourth stationary contact, the protection circuit comprising: The input end and the control end of the first switching tube are connected with the output end of the driving signal of the relay; the input end of the second switching tube is connected with the output end of the first switching tube, the output end of the second switching tube is connected with the first end of the coil of the relay, and the second end of the coil is grounded; the first input end of the over-temperature protection module inputs a first voltage, the second input end of the over-temperature protection module inputs a second voltage, and the output end of the over-temperature protection module is connected with the control end of the second switching tube; And the first input end of the overcurrent protection module inputs a third voltage, the second input end of the overcurrent protection module is connected with a main loop where the first static contact and the second static contact of the relay are positioned, and the output end of the overcurrent protection module is connected with the control end of the second switching tube.
2. 2. The protection circuit of claim 1, wherein the over-temperature protection module comprises: a thermistor having a first end to which a first voltage is input; The first end of the first voltage dividing resistor is connected with the second end of the thermistor, and the second end of the first voltage dividing resistor is grounded; The second voltage dividing resistor is connected in series with the third voltage dividing resistor, the second voltage dividing resistor inputs second voltage, and the third voltage dividing resistor is grounded; and the non-inverting input end of the first comparator is connected between the second voltage dividing resistor and the third voltage dividing resistor, the inverting input end of the first comparator is connected between the thermistor and the first voltage dividing resistor, and the output end of the first comparator is connected with the control end of the second switching tube.
3. 3. The protection circuit of claim 1, wherein the over-current protection module comprises: A current sensor disposed on a line between the first stationary contact of the relay and an input of the main circuit or on a line between the second stationary contact and an output of the main circuit; the fourth voltage dividing resistor is connected in series with the fifth voltage dividing resistor, the third voltage is input into the fourth voltage dividing resistor, and the fifth voltage dividing resistor is grounded; And the inverting input end of the second comparator is connected with the output end of the current sensor, the non-inverting input end of the second comparator is connected between the fourth voltage dividing resistor and the fifth voltage dividing resistor, and the output end of the second comparator is connected with the control end of the second switching tube.
4. 4. The protection circuit according to claim 1, the protection circuit is characterized by further comprising: And the first input end of the main control unit is connected with the output end of the over-temperature protection module, the second input end of the main control unit is connected with the output end of the over-current protection module, the output end of the main control unit is connected with the control end of the first switch tube, and the main control unit is used for controlling whether the main control unit outputs the driving signal according to the signals output by the over-temperature protection module and/or the over-current protection module.
5. 5. The protection circuit according to claim 1, the protection circuit is characterized by further comprising: the first end of the fault indicator is connected between the second end of the coil and the ground, the second end of the fault indicator is connected with the third static contact, and the fault indicator is used for being lightened when the coil is powered on but the relay is disconnected.
6. 6. The protection circuit according to claim 1, the protection circuit is characterized by further comprising: And the input end of the voltage conversion module is connected with the output end of the driving signal, and the output end of the voltage conversion module outputs the first voltage, the second voltage and the third voltage respectively.
7. 7. A protection method applied to the protection circuit of any one of claims 1 to 6, characterized in that the protection method comprises: acquiring signals output by the over-temperature protection module and/or the over-current protection module; And controlling whether to output the driving signal according to the signal output by the over-temperature protection module and/or the over-current protection module.
8. 8. The protection method according to claim 7, wherein controlling whether to output the driving signal according to the signal output by the over-temperature protection module and/or the over-current protection module comprises: Outputting the driving signal if the signals output by the over-temperature protection module and the over-current protection module are high-level signals; and if the output of the over-temperature protection module and/or the over-current protection module is a low-level signal, the driving signal is not output any more.
9. 9. A relay comprising the protection circuit according to any one of claims 1 to 6.
10. 10. A powered device comprising the relay of claim 9.
11. 11. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the protection method according to claim 7 or 8.
12. 12. An electronic device, comprising: One or more processors; Storage means for storing one or more programs that, when executed by the one or more processors, cause the one or more processors to implement the protection method of claim 7 or 8.

Description

Protection circuit, method, relay and electric equipment Technical Field The invention relates to the technical field of electronic power, in particular to a protection circuit, a protection method, a relay and electric equipment. Background The conventional normally open relay is only a simple structure of a simple coil, an armature, an iron core, a contact and the like, and is commonly used for a high-voltage circuit so as to prevent personnel from directly contacting high-voltage power. Since the relay is applied to a high-voltage circuit, the relay and the main circuit are likely to be impacted by a strong overcurrent or the like due to a fluctuation of an input current, an input voltage, or a load. Aiming at the situation, the existing relay is generally provided with single overcurrent protection or overtemperature protection, but once a protection circuit fails, the protection effect is lost, so that the relay is burnt out, the safety is reduced, and the maintenance cost is increased. Aiming at the problems that the relay in the prior art adopts a single overcurrent protection or overtemperature protection mode, once a protection circuit fails, the protection effect is lost, the relay is burnt out, the safety is reduced, and the maintenance cost is increased, and no effective solution is proposed at present. Disclosure of Invention The embodiment of the invention provides a protection circuit, a protection method, a relay and electric equipment, which are used for solving the problems that the relay in the prior art adopts a single overcurrent protection or overtemperature protection mode, and once the protection circuit fails, the protection effect is lost, so that the relay is burnt, the safety is reduced and the maintenance cost is increased. In order to solve the technical problem, the present invention provides a protection circuit, which is applied to a relay, wherein the relay comprises a coil, a first stationary contact, a second stationary contact, a first movable contact, a second movable contact, a third stationary contact and a fourth stationary contact, and the protection circuit comprises: The input end and the control end of the first switching tube are connected with the output end of the driving signal of the relay; the input end of the second switching tube is connected with the output end of the first switching tube, the output end of the second switching tube is connected with the first end of the coil of the relay, and the second end of the coil is grounded; the first input end of the over-temperature protection module inputs a first voltage, the second input end of the over-temperature protection module inputs a second voltage, and the output end of the over-temperature protection module is connected with the control end of the second switching tube; And the first input end of the overcurrent protection module inputs a third voltage, the second input end of the overcurrent protection module is connected with a main loop where the first static contact and the second static contact of the relay are positioned, and the output end of the overcurrent protection module is connected with the control end of the second switching tube. Further, the over-temperature protection module includes: a thermistor having a first end to which a first voltage is input; The first end of the first voltage dividing resistor is connected with the second end of the thermistor, and the second end of the first voltage dividing resistor is grounded; The second voltage dividing resistor is connected in series with the third voltage dividing resistor, the second voltage dividing resistor inputs second voltage, and the third voltage dividing resistor is grounded; and the non-inverting input end of the first comparator is connected between the second voltage dividing resistor and the third voltage dividing resistor, the inverting input end of the first comparator is connected between the thermistor and the first voltage dividing resistor, and the output end of the first comparator is connected with the control end of the second switching tube. Further, the overcurrent protection module includes: A current sensor disposed on a line between the first stationary contact of the relay and an input of the main circuit or on a line between the second stationary contact and an output of the main circuit; the fourth voltage dividing resistor is connected in series with the fifth voltage dividing resistor, the third voltage is input into the fourth voltage dividing resistor, and the fifth voltage dividing resistor is grounded; And the inverting input end of the second comparator is connected with the output end of the current sensor, the non-inverting input end of the second comparator is connected between the fourth voltage dividing resistor and the fifth voltage dividing resistor, and the output end of the second comparator is connected with the control end of the second switching tube. Further, the protection circuit