CN213544754U

CN213544754U - Relay switch state monitoring circuit and air conditioner

Info

Publication number: CN213544754U
Application number: CN202022286217.7U
Authority: CN
Inventors: 党培育; 姜颖异; 黄猛; 徐志国; 郭泳颖
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-10-14
Filing date: 2020-10-14
Publication date: 2021-06-25
Anticipated expiration: 2030-10-14

Abstract

The utility model discloses a relay on-off state monitoring circuit and air conditioner, wherein relay on-off state monitoring circuit includes DC power supply DC, relay K, the load that establishes ties in proper order, concatenate monitoring module between relay K and the load, monitoring module monitoring relay K feeds back switch state signal to the controller, the controller judges whether relay K switch is normal, and control relay K's break-make; the utility model can detect whether the relay has mechanical failure in time, and can try to recover the normal work of the relay when the relay has mechanical failure; the reliability of the equipment is greatly improved, and the device has the advantages of reliable operation, simple structure and low cost.

Description

Relay switch state monitoring circuit and air conditioner

Technical Field

The utility model relates to an electrical equipment especially relates to a relay on-off state monitoring circuit and air conditioner.

Background

The relay has a certain mechanical service life, and when the relay has a mechanical fault, the circuit abnormity caused by the relay fault cannot be detected in time. Therefore, the state of the relay is monitored very necessarily, so that circuit abnormity caused by mechanical damage of the relay can be solved in time, and the stability and reliability of hardware circuit work are improved.

The existing relay detection circuit has the defects of complex circuit and high cost, so how to design a relay switch state monitoring circuit and an air conditioner is a technical problem to be solved urgently in the industry.

SUMMERY OF THE UTILITY MODEL

In order to solve the defect that the circuit is complicated and has high cost among the prior art, the utility model provides a relay on-off state monitoring circuit and air conditioner.

The utility model discloses a technical scheme design a relay on-off state monitoring circuit, including DC power supply DC, relay K, the load of establishing ties in proper order, monitoring module concatenates between relay K and the load, monitoring module monitoring relay K feeds on-off state signal back to the controller, the controller judges whether relay K switch is normal, and control relay K's break-make.

The monitoring module comprises a monitoring resistor R1 and an isolation feedback module connected in parallel with the monitoring resistor R1; one end of the monitoring resistor R1 is connected with the relay K, and the other end is grounded; the isolation feedback module feeds back a switch state signal to the controller.

The isolation feedback module comprises an optical coupler U, wherein the anode of the input side of the optical coupler U is connected with the relay K through a second resistor R2, the cathode of the input side of the optical coupler U is grounded with the emitter of the output side of the optical coupler U, the collector of the output side of the optical coupler U is connected with a control power supply Vcc through a fourth resistor R4, and the collector is also connected with a signal acquisition point A to feed back a level signal representing a switch state signal to the controller.

And a coil of the relay K is connected between the control power supply Vcc and a terminal B in series, the coil of the relay K is connected with a freewheeling diode D2 in parallel, and the terminal B is connected with the controller.

The coil of the relay K is connected with a third resistor R3 in parallel.

The control power Vcc is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the anode of the DC power DC.

The voltage of the direct current power supply DC is higher than the control power supply Vcc.

The utility model also designs an air conditioner, air conditioner adopts foretell relay on-off state monitoring circuit.

The utility model provides a technical scheme's beneficial effect is:

the utility model can detect whether the relay has mechanical failure in time, and can try to recover the normal work of the relay when the relay has mechanical failure; the reliability of the equipment is greatly improved, and the device has the advantages of reliable operation, simple structure and low cost.

Drawings

The invention is explained in more detail below with reference to exemplary embodiments and the accompanying drawings, in which:

FIG. 1 is a circuit diagram of a preferred embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The utility model discloses a relay on-off state monitoring circuit, including DC power supply DC, relay K, the load of establishing ties in proper order, monitoring module concatenates between relay K and the load, monitoring module monitoring relay K feeds back switch state signal to the controller, the controller judges whether relay K switch is normal, and control relay K's break-make. The utility model discloses can solve following technical problem: when the controller does not send a control instruction, the load controlled by the relay (normally open) works. The controller has no effective control over the relay.

Referring to the circuit diagram of the preferred embodiment shown in fig. 1, the monitoring module includes a monitoring resistor R1 and an isolated feedback module connected in parallel therewith; one end of the monitoring resistor R1 is connected with the relay K, and the other end of the monitoring resistor R1 is grounded (the monitoring resistor R1 is simultaneously used as a pull-down resistor of the optocoupler U); the isolation feedback module feeds back a switch state signal to the controller. The isolation feedback module comprises an optocoupler U, wherein an anode on an input side of the optocoupler U is connected with the relay K through a second resistor R2, a cathode on the input side of the optocoupler U is grounded with an emitter on an output side of the optocoupler U, a collector on an output side of the optocoupler U is connected with a control power supply Vcc through a fourth resistor R4 (a monitoring resistor R1 and a second resistor R2 are current-limiting resistors, and a fourth resistor R4 is a pull-up resistor), and the collector is also connected with a signal acquisition point A to feed back a level signal representing a switching state signal to the controller. And a coil of the relay K is connected between the control power supply Vcc and a terminal B in series, the coil of the relay K is connected with a freewheeling diode D2 in parallel, and the terminal B is connected with the controller. The coil of the relay K is connected with a third resistor R3 in parallel, and the third resistor R3 is a current-limiting resistor. The control power Vcc is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the anode of the DC power DC. The voltage of the direct current power supply DC is higher than the control power supply Vcc. It should be noted that, in the determination of the preferred embodiment, the DC power supply DC is turned off, and the power supply Vcc needs to be controlled to supply power to the optocoupler. Vcc is always present and the first diode D1 is added only to serve as isolation of the two sources when the load is running.

The working principle of the present invention will be described in detail below with reference to fig. 1 (DI is the relay switch state feedback interface; DO is the relay control interface):

when the circuit works, the point B is a low potential, the relay K is closed, the D1 is in a cut-off state, the load power supply DC and the control power supply Vcc are isolated, and the DC supplies power to the load. At this time point a remains low. When the load stops running, the B sends out high potential, the relay is disconnected, at the moment, the R1 pulls the upper end of the optical coupler input into low potential, the U stops working, and the point A is pulled up to high potential by the R4. That is, when the load is operating, the potential at point a is kept low, and when the load is not operating, the potential at point a is kept high.

When the relay is damaged mechanically, the judgment is divided into two conditions:

(1) after the coil of the relay K is electrified, namely DO is a low potential, the contact of the relay K cannot be closed, the point A still keeps a high potential, the logic is judged, the point B is a low potential, the point A is a high potential, and the abnormal condition that the relay K cannot be closed is judged.

(2) After the coil of the relay K is powered off, namely DO is high potential, the contact of the relay K cannot be disconnected, the point A still keeps low potential at the moment, the judgment logic is that the point B is high potential and the point A is low potential, and the abnormity that the relay K cannot be disconnected is judged at the moment.

When the relay K is judged to have a fault, a truth table can be stored in the controller in advance, and the controller can check the truth table to quickly judge whether the relay K has a mechanical fault.

The truth table may take the form:

it should be noted that the truth table may be data stored in a memory unit of the controller, or may be a logic circuit constructed by logic components. The logic relation is simple, and whether the relay K has a fault or not can be judged by arranging a simple logic circuit on the controller. The utility model discloses do not rely on software can normally work. For a normally closed relay, the truth table judgment logic is opposite.

After judging that the relay K has a mechanical fault, in order to judge whether the relay K is completely damaged or is blocked due to respective times, the controller sends a recovery pulse to the relay K (point B). The recovery pulse is composed of a pulse string with a certain period, and aims to enable the relay to be repeatedly switched on and off, see whether the fault can be eliminated, if the fault can be eliminated, the fault indicates that the on and off of the relay is abnormal only occasionally, and the controller records the event times. If the failure can not be eliminated, the irreversible damage of the relay is generated, the controller feeds back the fault information of the relay, and the damage of the relay is prompted, and the relay needs to be replaced.

The utility model also discloses an air conditioner, air conditioner adopts foretell relay on-off state monitoring circuit.

The foregoing examples are illustrative only and are not intended to be limiting. Any equivalent modifications or variations without departing from the spirit and scope of the present application should be included in the claims of the present application.

Claims

1. The utility model provides a relay on-off state monitoring circuit, is including direct current power supply DC, relay K, the load that establishes ties in proper order, its characterized in that, concatenate monitoring module between relay K and the load, monitoring module monitoring relay K feeds back switch state signal to the controller, the controller judges whether relay K switch is normal, and control relay K's break-make.

2. The relay switch state monitoring circuit of claim 1, wherein the monitoring module comprises a monitoring resistor R1 and an isolated feedback module connected in parallel therewith; one end of the monitoring resistor R1 is connected with the relay K, and the other end is grounded; the isolation feedback module feeds back a switch state signal to the controller.

3. The relay switch state monitoring circuit according to claim 2, wherein the isolation feedback module comprises an optocoupler U, an anode at an input side of the optocoupler U is connected with the relay K through a second resistor R2, a cathode at the input side of the optocoupler U is connected with an emitter at an output side of the optocoupler U, the cathode at the input side of the optocoupler U is connected with the emitter at the output side of the optocoupler U, a collector at the output side of the optocoupler U is connected with a control power supply Vcc through a fourth resistor R4, and the collector is further connected with a signal acquisition point A.

4. The relay switch state monitoring circuit of claim 3, wherein the coil of the relay K is connected in series between the control power supply Vcc and a terminal B, the coil of the relay K is connected in parallel with a freewheeling diode D2, and the terminal B is connected to the controller.

5. The relay switch state monitoring circuit of claim 4, wherein the relay K coil is connected in parallel with a third resistor R3.

6. The relay switch state monitoring circuit according to any one of claims 3 to 5, wherein the control power source Vcc is connected to an anode of a first diode D1, and a cathode of a first diode D1 is connected to an anode of the DC power source DC.

7. The relay switch state monitoring circuit according to claim 6, wherein the voltage of the direct current power supply DC is higher than the control power supply Vcc.

8. An air conditioner characterized in that the air conditioner employs the relay switch state monitoring circuit according to any one of claims 1 to 7.