Electromagnetic switch service life detection circuit

Abstract

The utility model discloses a service life detection circuit for an electromagnetic switch. The service life detection circuit comprises a control module, a square wave identification module, a first control type switch module, a second control type switch module, a switch action position detection module and a power supply, the output end of the control module outputs a square wave signal, the output end of the control module is connected to the input end of the square wave recognition module, and the first output end of the square wave recognition module is used for outputting a high level when the square wave signal is a high level and outputting a low level when the square wave signal is a low level. The second output end of the square wave recognition module is used for outputting low level when the square wave signal is high level and outputting high level when the square wave signal is low level, and the first output end of the square wave recognition module is connected to the control end of the first control type switch module. The electromagnetic switch service life detection circuit solves the problem that in the prior art, a square wave signal cannot control operation of a plurality of contactors.

Description

Technical Field

[0001] This utility model relates to the field of switch life testing, specifically to an electromagnetic switch life testing circuit. Background Technology

[0002] Electromagnetic switches include relays and contactors. Electromagnetic switches contain an electromagnetic coil and an actuating switch. When the electromagnetic coil is energized, it controls the actuating switch to close through the principle of magnetic attraction.

[0003] Chinese patent discloses an elevator contactor life verification device with application number CN202510378861.1. This device includes: a detection power supply circuit, a first detection execution circuit, a second detection execution circuit, a first control drive circuit, a second control drive circuit, a control circuit, and a display screen. The input terminal of the detection power supply circuit is used to connect to external AC mains power. The detection power supply circuit converts AC mains power into 110V DC, 24V DC, and 5V DC. The first output terminal of the detection power supply circuit outputs 110V DC, the second output terminal outputs 24V DC, and the third output terminal outputs 5V DC. The first output terminal of the detection power supply circuit supplies power to the input terminal of the high-voltage contactor JC1, and the output terminal of the high-voltage contactor JC1 is connected to the input terminal of the first detection execution circuit.

[0004] Although this elevator contactor life verification device can solve the problem of not being able to perform life verification testing on elevator contactors, it still has a drawback: it cannot control the operation of multiple coils after outputting a square wave signal, which requires the use of multiple square wave signal recognition modules to control the operation of multiple contactors, thus increasing the cost of the square wave signal recognition modules. Utility Model Content

[0005] This invention provides an electromagnetic switch life detection circuit to solve the problem in the prior art that it is impossible to control the operation of multiple contactors with a single square wave signal.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This utility model discloses an electromagnetic switch life detection circuit, comprising: a control module, a square wave recognition module, a first controllable switch module, a second controllable switch module, a switch actuation detection module, and a power supply; the output terminal of the control module outputs a square wave signal, and the output terminal of the control module is connected to the input terminal of the square wave recognition module; the first output terminal of the square wave recognition module is used to output a high level when the square wave signal is high and output a low level when the square wave signal is low; the second output terminal of the square wave recognition module is used to output a low level when the square wave signal is high and output a high level when the square wave signal is low; the first output terminal of the square wave recognition module is connected to the first controllable switch module. The control terminal of the standard switch module and the second output terminal of the square wave recognition module are connected to the control terminal of the second controllable switch module; the first output terminal of the power supply powers the square wave recognition module, the second output terminal of the power supply powers the coil of at least one electromagnetic switch under test through the first controllable switch module, and the second output terminal of the power supply powers the coil of another electromagnetic switch under test through the second controllable switch module; the third output terminal of the power supply powers the first terminal of the action switch in the electromagnetic switch under test, the input terminal of the switch action detection module is connected to the second terminal of the action switch in the electromagnetic switch under test, and the output terminal of the switch action detection module is connected to the input terminal of the control module.

[0008] Preferably, both the first and second controllable switch modules include: a resistor R1 and an NMOS transistor Q1. The first terminal of the resistor R1 is the control terminal of either the first or second controllable switch module. The resistor R1 is connected to the gate of the NMOS transistor Q1. The source of the NMOS transistor Q1 is connected to the positive terminal of the coil in the electromagnetic switch under test. The negative terminal of the coil in the electromagnetic switch under test is grounded. The drain of the NMOS transistor Q1 is connected to the second output terminal of the power supply.

[0009] Preferably, both the first controllable switch module and the second controllable switch module further include: a diode D2, the anode of the diode D2 being connected to the source of the NMOS transistor Q1, and the cathode of the diode D2 being connected to the drain of the NMOS transistor Q1.

[0010] Preferably, the first control switch module supplies power to the coils of the two electromagnetic switches to be tested, and the second control switch module supplies power to the coils of the other two electromagnetic switches to be tested.

[0011] Preferably, the square wave recognition module uses a driver U1, which is an IR2104, IR2106, or IR2109 chip.

[0012] Preferably, the square wave recognition module includes: electrolytic capacitor C1, electrolytic capacitor C2, capacitor C3, and diode D1. The positive terminals of capacitor C3, electrolytic capacitor C2, and diode D1 are all connected to the first output terminal of the power supply. The first output terminal of the power supply is connected to the VCC and SD pins of driver U1. The negative terminals of capacitor C3 and electrolytic capacitor C2 are grounded. The COM pin of driver U1 is grounded. The IN pin of driver U1 is the input terminal of the square wave recognition module. The cathode of diode D1 is connected to the VB pin of driver U1. The cathode of diode D1 is connected to the positive terminal of electrolytic capacitor C1. The negative terminal of electrolytic capacitor C1 is connected to the COM pin of driver U1. The HO pin of driver U1 is the first output terminal of the square wave recognition module, and the LO pin of driver U1 is the second output terminal of the square wave recognition module.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] In this application, a square wave recognition module is set up to control the operation of the first and second controllable switch modules after the control module outputs a square wave signal. When the square wave signal is high, the square wave recognition module controls the first controllable switch module to close, energizing the coil of the electromagnetic switch under test powered by the first controllable switch module. The coil then actuates once. When the square wave signal becomes high again, the coil actuates again, thus controlling the electromagnetic switch under test powered by the first controllable switch module. Similarly, when the square wave signal is low, the square wave recognition module controls the second controllable switch module to close, energizing the coil of the electromagnetic switch under test powered by the second controllable switch module. The coil actuates once, and so on, achieving control of the electromagnetic switch under test powered by the second controllable switch module. If a single square wave signal can simultaneously control both the first and second control switch modules, thereby increasing the number of electromagnetic switches under test that can be controlled (since at least 10 types of electromagnetic switches need to be measured), this design reduces the number of output terminals required in the control module, thus lowering its cost. Furthermore, the square wave recognition module, composed of drivers such as the IR2104, ensures more stable and reliable operation. Although both the first and second control switch modules can control the energization of coils in multiple electromagnetic switches under test, parallel connection of these coils would lead to excessive current in both modules, potentially causing damage. Therefore, the optimal connection between the first and second control switch modules and the coils in the electromagnetic switches under test is crucial. By setting both modules to operate under the control of a single square wave recognition module, the need for a dedicated driver is reduced, allowing a single square wave signal to control both modules.

[0015] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0016] Figure 1 This is a circuit diagram of the square wave identification module, the first control switch module, and the second control switch module in an electromagnetic switch life detection circuit.

[0017] Figure 2 This is a circuit diagram of the detection module at the switch action point in an electromagnetic switch life detection circuit.

[0018] Figure 3 The circuit diagram for the power supply.

[0019] Figure 4 This is the circuit diagram for the control module. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] like Figures 1 to 4 As shown, this utility model discloses an electromagnetic switch life detection circuit, including: a control module, a square wave recognition module, a first controllable switch module, a second controllable switch module, a switch action detection module, and a power supply; the output terminal of the control module outputs a square wave signal, and the output terminal of the control module is connected to the input terminal of the square wave recognition module. The first output terminal of the square wave recognition module is used to output a high level when the square wave signal is high and to output a low level when the square wave signal is low. The second output terminal of the square wave recognition module is used to output a low level when the square wave signal is high and to output a high level when the square wave signal is low. The first output terminal of the square wave recognition module is connected to the first controllable switch module. The control terminal of the controllable switch module and the second output terminal of the square wave recognition module are connected to the control terminal of the second controllable switch module. The first output terminal of the power supply powers the square wave recognition module, and the second output terminal of the power supply powers the coil of at least one electromagnetic switch under test through the first controllable switch module. The second output terminal of the power supply powers the coil of another electromagnetic switch under test through the second controllable switch module. The third output terminal of the power supply powers the first terminal of the actuated switch in the electromagnetic switch under test. The input terminal of the switch actuation detection module is connected to the second terminal of the actuated switch in the electromagnetic switch under test, and the output terminal of the switch actuation detection module is connected to the input terminal of the control module. The coil of the external electromagnetic switch under test is... Figure 1 Center coil L1.

[0022] like Figure 3As shown, the power supply includes: an AC-DC conversion module, a first step-down module, and a second step-down module. The input terminal of the AC-DC conversion module is connected to the AC 220V AC mains voltage. The rectifier bridge BR1 in the AC-DC conversion module performs AC-DC conversion, and the transformer TR1 in the AC-DC conversion module transforms the voltage. The AC-DC conversion module converts the AC 220V AC voltage to DC 110V DC voltage and outputs it. The output terminal of the AC-DC conversion module is the third output terminal of the power supply. The output terminal of the AC-DC conversion module is connected to the first step-down module. The first step-down module is equipped with a step-down chip U4, which can be a sample MK9016 chip. The step-down chip U4 converts the DC voltage of 110V to 24V. The output terminal of the first step-down module is the second output terminal of the power supply. The output terminal of the first step-down module is connected to the input terminal of the second step-down module. The second step-down module is equipped with a step-down chip U3, which can be an LM338 chip. The step-down chip U3 converts the DC voltage of 24V to 5V. The output terminal of the second step-down module is the first output terminal of the power supply.

[0023] The power supply outputs 5V from its first output terminal, 24V from its second output terminal, and 110V from its third output terminal (this voltage is required for elevator safety brakes, elevator safety circuits, etc.). The voltage output from the first output terminal meets the operating requirements of the square wave recognition module, while the voltage from the second output terminal meets the operating requirements of the coil in the electromagnetic switch under test.

[0024] like Figure 1 As shown, preferably, both the first and second controllable switch modules include: a resistor R1 and an NMOS transistor Q1. The first terminal of resistor R1 is the control terminal of either the first or second controllable switch module. Resistor R1 is connected to the gate of NMOS transistor Q1. The source of NMOS transistor Q1 is connected to the positive terminal of the coil in the electromagnetic switch under test. The negative terminal of the coil in the electromagnetic switch under test is grounded. The drain of NMOS transistor Q1 is connected to the second output terminal of the power supply. When the gate of NMOS transistor Q1 is high, NMOS transistor Q1 is closed; when the gate of NMOS transistor Q1 is low, NMOS transistor Q1 is closed. Resistor R1 serves a voltage stabilizing function.

[0025] In this application, both the first and second controlled switching modules further include a diode D2, with the anode of diode D2 connected to the source of NMOS transistor Q1 and the cathode of diode D2 connected to the drain of NMOS transistor Q1. Diode D2 serves as a voltage regulator.

[0026] In this application, the first control switch module supplies power to the coils of two electromagnetic switches under test, and the second control switch module supplies power to the coils of two other electromagnetic switches under test. Since the more coils of the electromagnetic switches under test controlled by the first and second control switch modules, the greater the current flowing through them, excessive current can easily damage both modules.

[0027] In this application, the square wave recognition module uses a driver U1, which is an IR2104, IR2106, or IR2109 chip.

[0028] The square wave recognition module includes: electrolytic capacitor C1, electrolytic capacitor C2, capacitor C3, and diode D1. The positive terminals of capacitor C3, electrolytic capacitor C2, and diode D1 are all connected to the first output terminal of the power supply. The first output terminal of the power supply is connected to the VCC and SD pins of driver U1. The negative terminals of capacitor C3 and electrolytic capacitor C2 are grounded. The COM pin of driver U1 is grounded. The IN pin of driver U1 is the input terminal of the square wave recognition module. The cathode of diode D1 is connected to the VB pin of driver U1. The cathode of diode D1 is connected to the positive terminal of electrolytic capacitor C1. The negative terminal of electrolytic capacitor C1 is connected to the COM pin of driver U1. The HO pin of driver U1 is the first output terminal of the square wave recognition module, and the LO pin of driver U1 is the second output terminal of the square wave recognition module. The LO pin of driver U1 outputs a high level when the square wave signal is low, and the LO pin of driver U1 outputs a low level when the square wave signal is high. The HO pin of driver U1 outputs a high level when the square wave signal is high, and the HO pin of driver U1 outputs a low level when the square wave signal is low. This ensures that the first control switch module is closed only when the square wave signal is high, and the second control switch module is closed only when the square wave signal is low.

[0029] like Figure 2As shown, the switch action detection module includes an optocoupler U2, resistors R2, R3, and R4. The anode of the LED in optocoupler U2 is the input terminal of the switch action detection module, and the cathode of the LED in optocoupler U2 is grounded through resistor R2. The collector of the transistor in optocoupler U2 is connected to the first output terminal of the power supply, and the emitter of the transistor in optocoupler U2 is connected to the first terminal of resistor R3. The second terminal of resistor R3 is grounded through resistor R4, and the second terminal of resistor R3 is the output terminal of the switch action detection module. Since the voltage at the third output terminal of the power supply connected to the operating switch in the electromagnetic switch under test is relatively high, optocoupler U2 is used to isolate the circuit containing resistor R2 from the circuit containing resistor R3. This ensures that when the operating switch in the electromagnetic switch under test is normally closed, the LED in optocoupler U2 illuminates, and there is a voltage output at the second terminal of resistor R3. The output voltage at the second terminal of resistor R3 is relatively small and can be connected to the input terminal of the control module. When the operating switch in the electromagnetic switch under test is open, the LED in optocoupler U2 does not illuminate, and there is no voltage output at the second terminal of resistor R3. This allows the control module to control the electromagnetic switch under test to operate multiple times, and then detect whether the operating switch in the electromagnetic switch under test can be controlled to close.

[0030] like Figure 4 As shown, the control module is equipped with a control chip U5, which can be an STM32 series chip.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An electromagnetic switch life detection circuit, characterized in that, include: The system includes a control module, a square wave recognition module, a first control switch module, a second control switch module, a switch action detection module, and a power supply. The control module outputs a square wave signal, which is connected to the input of the square wave recognition module. The first output of the square wave recognition module is used to output a high level when the square wave signal is high and a low level when the square wave signal is low. The second output of the square wave recognition module is used to output a low level when the square wave signal is high and a high level when the square wave signal is low. The first output of the square wave recognition module is connected to the control terminal of the first control switch module, and the second output of the square wave recognition module is connected to the control terminal of the second control switch module. The first output terminal of the power supply powers the square wave recognition module, and the second output terminal of the power supply powers the coil of at least one electromagnetic switch to be tested through the first control switch module. The second output terminal of the power supply powers the coil of another electromagnetic switch to be tested through the second control switch module. The third output terminal of the power supply supplies power to the first terminal of the operating switch in the electromagnetic switch under test. The input terminal of the switch operation detection module is connected to the second terminal of the operating switch in the electromagnetic switch under test, and the output terminal of the switch operation detection module is connected to the input terminal of the control module.

2. The electromagnetic switch life detection circuit according to claim 1, characterized in that, Both the first and second controllable switch modules include: a resistor R1 and an NMOS transistor Q1. The first terminal of the resistor R1 is the control terminal of either the first or second controllable switch module. The resistor R1 is connected to the gate of the NMOS transistor Q1. The source of the NMOS transistor Q1 is connected to the positive terminal of the coil in the electromagnetic switch under test. The negative terminal of the coil in the electromagnetic switch under test is grounded. The drain of the NMOS transistor Q1 is connected to the second output terminal of the power supply.

3. The electromagnetic switch life detection circuit according to claim 2, characterized in that, Both the first and second controllable switching modules further include a diode D2, with the anode of diode D2 connected to the source of NMOS transistor Q1 and the cathode of diode D2 connected to the drain of NMOS transistor Q1.

4. The electromagnetic switch life detection circuit according to any one of claims 1 to 3, characterized in that, The first control switch module supplies power to the coils of two electromagnetic switches to be tested, and the second control switch module supplies power to the coils of another two electromagnetic switches to be tested.

5. The electromagnetic switch life detection circuit according to claim 4, characterized in that, The square wave recognition module uses driver U1, which is an IR2104, IR2106, or IR2109 chip.

6. The electromagnetic switch life detection circuit according to claim 5, characterized in that, The square wave recognition module includes: electrolytic capacitor C1, electrolytic capacitor C2, capacitor C3, and diode D1. The positive terminals of capacitor C3, electrolytic capacitor C2, and diode D1 are all connected to the first output terminal of the power supply. The first output terminal of the power supply is connected to the VCC and SD pins of driver U1. The negative terminals of capacitor C3 and electrolytic capacitor C2 are grounded. The COM pin of driver U1 is grounded. The IN pin of driver U1 is the input terminal of the square wave recognition module. The cathode of diode D1 is connected to the VB pin of driver U1. The cathode of diode D1 is connected to the positive terminal of electrolytic capacitor C1. The negative terminal of electrolytic capacitor C1 is connected to the COM pin of driver U1. The HO pin of driver U1 is the first output terminal of the square wave recognition module, and the LO pin of driver U1 is the second output terminal of the square wave recognition module.

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