Elevator relay loop monitoring device

Abstract

The utility model discloses an elevator relay loop monitoring device which comprises a voltage detection terminal, a first analog switch module, a single chip microcomputer, a voltage detection module, a timer and a GSM communication module, and the output end of a normally open loop of a relay of an elevator control loop and the positive electrode of a coil are connected with the input end of the voltage detection terminal. The input end of the first analog switch module is connected with the output end of the voltage detection terminal, the input end of the voltage detection module is connected with the output end of the first analog switch module, the output end of the voltage detection module is connected with the single-chip microcomputer, and the control end of the first analog switch module and the GSM communication module are connected with the single-chip microcomputer. According to the utility model, the voltage of the normally open loop and the coil of the relay of the elevator control loop is monitored in real time through the voltage detection module, the action time of the relay is recorded through the timer, and an alarm short message is sent through the GSM communication module, so that the working state of the relay of the elevator control loop is monitored in real time.

Description

Technical Field

[0001] This utility model belongs to the field of elevator safety technology, and specifically relates to an elevator relay circuit monitoring device. Background Technology

[0002] Relays are key components in elevator control systems, playing a crucial role in transmitting signals and outputting control signals. Different types of relays enable functions such as elevator up / down control, door opening / closing control, brake control, and alarm output.

[0003] During elevator operation, common relay faults in elevator control systems include contact adhesion, oxidation, wear, coil breakage and short circuit, and mechanical faults in the armature or spring. Once a relay in the elevator control system fails, the control of the circuit containing the faulty relay will fail. For example, if the door lock relay contacts stick together, the elevator controller will fail to detect the closure of the door lock circuit. That is, regardless of whether the door lock circuit switch is closed, the controller will judge that the elevator door lock is closed and the elevator can run, which can easily cause shearing or crushing accidents. If the brake relay in the elevator braking control circuit fails, it will cause the elevator brake to fail, resulting in elevator overshooting or slippage.

[0004] The inventors discovered during their work that the current methods for testing relays in elevator control systems involve maintenance personnel using a multimeter to measure the relay coil resistance, check for contact adhesion, and identify short circuits in the coil during elevator maintenance. They also visually inspect the relay contacts for burnt-out and check the relay indicator lights to see if the relay starts normally. This method is inherently lagging, and considering the potential for negligence by maintenance personnel during relay inspections, it is difficult to detect potential relay malfunctions in the elevator control system in a timely manner. Once a relay in the elevator control system malfunctions during elevator operation, it can easily lead to elevator accidents.

[0005] Therefore, this utility model proposes an elevator relay circuit monitoring device to solve the above-mentioned technical problems. Utility Model Content

[0006] The purpose of this utility model is to provide an elevator relay circuit monitoring device to solve the technical problem in the prior art that manual detection of relays in elevator control systems is subject to lag and human negligence, and cannot effectively monitor relays in elevator control systems in real time and promptly detect potential relay failures.

[0007] To achieve the above objectives, this utility model provides an elevator relay circuit monitoring device, comprising:

[0008] The detection terminal includes a voltage detection terminal, and the output terminal of the normally open circuit of the relay of the elevator control circuit and the positive terminal of the coil are respectively connected to the input terminal of the voltage detection terminal.

[0009] A first analog switch module, wherein the input terminal of the first analog switch module is connected to the output terminal of the voltage detection terminal;

[0010] A voltage detection module, wherein the input terminal of the voltage detection module is connected to the output terminal of the first analog switch module;

[0011] The system includes a microcontroller, a serial opto-isolator, and a timer. The output of the voltage detection module and the timer are connected to the microcontroller. The control terminal of the first analog switch module and the output of the serial opto-isolator are connected to the microcontroller. The input of the serial opto-isolator is connected to the serial port of the elevator main control board.

[0012] Preferably, in the above technical solution, the voltage detection module includes a first comparator module, a step-down module, and a second comparator module. The input terminal of the step-down module is connected to the output terminal of the first analog switch module, and its output terminal is connected to one input terminal of the first comparator module. The other input terminal of the first comparator module is connected to a first reference voltage, and the output terminal of the first comparator module is connected to the microcontroller. One input terminal of the second comparator module is connected to the output terminal of the first analog switch module, and its other input terminal is connected to a second reference voltage. The output terminal of the second comparator module is connected to the microcontroller.

[0013] Preferably, the voltage detection module further includes an optocoupler module, the input terminal of which is connected to the output terminal of the first analog switch module, and the output terminal of which is connected to the microcontroller.

[0014] Preferably, the above technical solution further includes a current detection module and a second analog switch module, wherein the output terminal of the second analog switch module is connected to the input terminal of the current detection module, and the control terminal of the second analog switch module and the output terminal of the current detection module are connected to the microcontroller.

[0015] The detection terminal also includes a current detection terminal, the input terminal of which is connected in series with the output terminal of the normally open circuit of the relay in the elevator control circuit, and the output terminal of which is connected to the input terminal of the second analog switch module.

[0016] Preferably, in the above technical solution, the current detection module includes a current detector and a third comparator module. The input terminal of the current detector is connected to the output terminal of the second analog switch module, and the output terminal is connected to one input terminal of the third comparator module. The other input terminal of the third comparator module is connected to a third reference voltage, and the output terminal of the third comparator module is connected to the microcontroller.

[0017] Preferably, in the above technical solution, the first analog switch module includes a first switch circuit and a second switch circuit. The input terminals of the first switch circuit and the second switch circuit are connected to the output terminal of the voltage detection terminal. The output terminal of the first switch circuit is connected to the input terminal of the voltage detection module, and the output terminal of the second switch circuit is connected to one input terminal of the second comparator module.

[0018] Preferably, in the above technical solution, the current detection module further includes a current limiting circuit. The input terminal of the current limiting circuit is connected to the output terminal of the second analog switch module, and the output terminal is connected to the current detector. The current limiting circuit includes a third analog switch module and a current limiting resistor. The input terminal of the third analog switch module is connected to the output terminal of the second analog switch module. One output terminal of the third analog switch module is connected to one end of the current limiting resistor, and the other end of the current limiting resistor is connected to the current detector and another output terminal of the third analog switch module.

[0019] Preferably, in the above technical solution, the voltage detection module further includes a demagnetizing circuit, which includes a MOSFET, a thermistor, and an inductor. The output terminal of the MOSFET, the inductor, and the thermistor are connected in sequence. The input terminal of the MOSFET is connected to the output terminal of the second switching circuit. The control terminal of the MOSFET is connected to the microcontroller. The output terminal of the thermistor is connected to the negative terminal of the relay coil of the elevator control circuit.

[0020] Preferably, the above technical solution further includes a GSM communication module, a display, and a button module, which are respectively connected to the microcontroller.

[0021] Compared with existing technologies, this utility model has the following beneficial effects:

[0022] 1. This utility model uses a voltage detection module to detect the voltage at the output terminal and positive terminal of the normally open circuit of the relay in the elevator control circuit. When the voltage at the output terminal and positive terminal of the normally open circuit of the relay under test is lower than a user-defined threshold, a low-level signal is output to the microcontroller. The microcontroller judges whether the voltage at the normally open circuit or coil of the relay is abnormal by judging the output level signal of the voltage detection module. After the relay coil loses voltage, the microcontroller records the closing and opening times of the normally open circuit of the relay through a timer to judge whether the contact action of the normally open circuit of the relay is normal, whether there is sticking, short circuit, or other faults. The microcontroller reads the elevator's operating status through a serial port opto-isolator, and then closes the first analog switch module to connect the voltage detection module with the relay to be tested, realizing real-time monitoring of the relays in the elevator control circuit.

[0023] 2. This utility model uses a current detection module to detect the current in the normally open circuit of the relay in the elevator control circuit. When the current detection module detects that the current in the normally open circuit of the relay is greater than the user-set threshold, the current detection module outputs a low level to the microcontroller. The microcontroller controls the relay module to connect the current-limiting resistor in series with the normally open circuit of the relay, thereby protecting the contacts of the normally open circuit of the relay and preventing excessive current from burning out the contacts of the normally open circuit of the relay.

[0024] 3. This utility model demagnetizes the coil of the relay in the elevator control circuit under test through a demagnetizing circuit. When the microcontroller reads through the serial port opto-isolator that the main control board of the elevator has de-energized the coil of the relay under test, it detects whether there is still voltage in the coil of the relay under test through the voltage detection module. Then, the microcontroller activates the demagnetizing circuit to demagnetize the coil of the relay under test, causing the coil of the relay under test to lose voltage and causing the normally open circuit of the relay under test to trip, thus ensuring the accuracy of the control signal of the elevator control circuit.

[0025] 4. When this utility model detects a fault in the relay of the elevator control circuit, it sends an alarm SMS to the mobile phone of the back-end management personnel via the GSM communication module to remind the back-end management personnel to maintain or replace the faulty relay in a timely manner, so as to prevent the elevator fault from further expanding and endangering the life and property safety of passengers. Attached Figure Description

[0026] Figure 1 This is a block diagram of the overall circuit principle of the elevator relay circuit monitoring device of this utility model.

[0027] Figure 2 This is a circuit diagram of the voltage detection module of this utility model.

[0028] Figure 3This is the circuit diagram of the current detection module of this utility model.

[0029] In the diagram: 100—Microcontroller, 101—Voltage detection module, 102—Current detection module, 103—First analog switch module, 104—Second analog switch module, 105—GSM communication module, 106—Display, 107—Button module, 108—Serial port opto-isolator, 109—Step-down module, 110—Timer, 111—Current limiting circuit, 112—Demagnetizing circuit, 113—Optical coupler module, 1031—First switching circuit, 1032—Second switching circuit, K2—Third analog switch module, U1.1—First comparator module, U2.1—Second comparator module, U3.1—Third comparator module, U4—Current detector, H1—Voltage detection terminal, H2—Current detection terminal. Detailed Implementation

[0030] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. However, it should be understood that the scope of protection of this utility model is not limited to the specific embodiments.

[0031] refer to Figure 1 An elevator relay circuit monitoring device includes detection terminals, a first analog switch module 103, a voltage detection module 101, a microcontroller 100, a serial port opto-isolator 108, a timer 110, and a GSM communication module 105. The detection terminals include a voltage detection terminal H1. The input terminal of the first analog switch module 103 is connected to the output terminal of the voltage detection terminal H1, and the output terminal of the first analog switch module 103 is connected to the input terminal of the voltage detection module 101. The output terminal of the voltage detection module 101 is connected to the microcontroller 100. The control terminal of the first analog switch module 103 and the output terminal of the serial port opto-isolator 108 are respectively connected to the microcontroller 100. The input terminal of the serial port opto-isolator 108 is connected to the serial port of the elevator main control board. The GSM communication module 105 is connected to the microcontroller 100. In this embodiment, the microcontroller 100 is an STC12C5A60S2 chip, and the GSM communication module 105 is a SIM800L communication module.

[0032] refer to Figure 2The voltage detection module 101 includes a first comparator module U1.1, a step-down module 109, a second comparator module U2.1, and an optocoupler module 113. The input terminal of the step-down module 109 is connected to the output terminal of the first analog switch module 103, and its output terminal is connected to the non-inverting terminal of the first comparator module U1.1. The inverting terminal of the first comparator module U1.1 is connected to a first reference voltage VREF1, and its output terminal is connected to a microcontroller 100. The non-inverting terminal of the second comparator module U2.1 is connected to the output terminal of the first analog switch module 103, and its inverting terminal is connected to a second reference voltage VREF2. The output terminal of the second comparator module U2.1 is connected to the microcontroller 100. The input terminal of the optocoupler module 113 is connected to the output terminal of the first analog switch module 103, and its output terminal is connected to the microcontroller 100.

[0033] The first analog switch module 103 includes a first switch circuit 1031 and a second switch circuit 1032. The input terminals of the first switch circuit 1031 and the second switch circuit 1032 are connected to the output terminal of the voltage detection terminal H1. The output terminal of the first switch circuit 1031 is connected to the input terminals of the step-down module 109 and the optocoupler module 113, respectively. The output terminal of the second switch circuit 1032 is connected to the non-inverting terminal of the second comparator module U2.1. In this embodiment, the first switch circuit 1031 and the second switch circuit 1032 are composed of multiple relay modules.

[0034] In specific implementation, taking relay K1 of the brake circuit in the elevator control circuit as an example, the input terminal of the normally open circuit of relay K1 is connected to a DC 110V voltage. The positive terminal of the coil of relay K1 is connected to the input terminal of the voltage detection terminal H1, and the negative terminal of the coil is connected to the elevator main control board. When the microcontroller 100 reads the command issued by the elevator main control board to close the normally open circuit of relay K1 to brake the elevator through the serial port opto-isolator 108, the microcontroller 100 controls the relay module j11 of the first switching circuit 1031 to close the normally open circuit. The normally open circuit of relay K1 is connected to the input terminal of the step-down module 109. The DC 110V voltage from the normally open circuit of relay K1 is stepped down by the step-down module 109 to become a DC 5V voltage, which is input to the non-inverting terminal of the first comparator module U1.1. The step-down ratio of the step-down module 109 is: According to the national standard GB / T 12325-2008 "Power Quality - Permissible Deviation of Supply Voltage", the supply voltage of the elevator brake should fluctuate within ±7% of the rated voltage. The voltage value of the first reference voltage VREF1 connected to the inverting terminal of the first comparator module U1.1 is... (V) When the voltage at the non-inverting input of the first comparator module U1.1 is less than the voltage at the inverting input, that is, when the voltage in the normally open circuit of relay K1 is lower than... When (V), the output terminal of the first comparator module U1.1 outputs a low-level signal to the microcontroller 100. The microcontroller 100 determines that the voltage of the normally open circuit of the relay K1 is too low. The microcontroller 100 drives the GSM module 105 to send an alarm SMS message "The voltage of the normally open circuit of the brake relay K1 is too low" to the mobile phone of the background administrator.

[0035] When the microcontroller 100 reads the command issued by the elevator main control board to trip the normally open circuit of relay K1 through the serial port opto-isolator 108, causing the brake to stop, if the microcontroller 100 detects that the output of the optocoupler module 113 is at a high level, it indicates that the normally open circuit of relay K1 has not tripped normally, and the contacts of the normally open circuit of relay K1 have a fault of sticking or being short-circuited. The microcontroller 100 drives the GSM communication module 105 to send an alarm SMS message "The normally open circuit of the brake relay K1 has not tripped normally" to the mobile phone of the back-end administrator.

[0036] The microcontroller 100 controls the relay module j21 of the second switching circuit 1032 to close the normally open circuit, so that the positive terminal of the coil of relay K1 is connected to the non-inverting terminal of the second comparator module U2.1. The voltage value of the second reference voltage VREF2 connected to the inverting terminal of the second comparator module U2.1 is 4V. When the voltage of the positive terminal of the coil of relay K1 is lower than 4V, the output terminal of the second comparator module U2.1 outputs a low-level signal to the microcontroller 100. The microcontroller 100 determines that the coil driving voltage of relay K1 is too low. The microcontroller 100 drives the GSM module 105 to send an alarm SMS message "The coil driving voltage of the brake relay K1 is too low" to the mobile phone of the background administrator. In this embodiment, the step-down module 109 is a DC-DC high-power step-down power supply module DC-DC converter, and the first comparator module U1.1 and the second comparator module U2.1 are LM393 comparator modules.

[0037] Furthermore, the microcontroller 100 records the closing and reopening times of the normally open circuit of relay K1 through timer 110. When the closing time or reopening time of the normally open circuit exceeds the set threshold, that is, the coil of relay K1 may have faults such as poor wiring, low coil voltage, or excessive wear of the contacts of the normally open circuit, the microcontroller 100 drives the GSM module 105 to send an alarm SMS message "abnormal operation time of relay K1 of the brake".

[0038] Furthermore, the voltage detection module 101 also includes a demagnetizing circuit 112, which includes a MOSFET Q1, a thermistor R2, and an inductor L1. The output terminal of the MOSFET Q1, the inductor L1, and the thermistor R2 are connected in sequence. The input terminal of the MOSFET Q1 is connected to the output terminal of the second switching circuit 1032, and the output terminal of the thermistor R2 is connected to the negative terminal of the relay coil of the elevator control circuit. Specifically, when the microcontroller 100 detects the coil voltage signal of the disconnected relay K1 through the serial port opto-isolator 108, and the output of the second comparator module U2.1 is high, the microcontroller 100 determines that there is residual magnetism in the coil of relay K1, causing the normally open circuit of relay K1 to fail to open normally. The microcontroller 100 controls the MOSFET Q1 to close, so that the thermistor R2 and the inductor L1 are connected in parallel across the coil of relay K1. The current in the coil of relay K1 flows through the inductor L1 and the thermistor R2. Before the coil is turned on, the resistance of the thermistor R2 is very small, resulting in a large current flowing through the coil. This causes the temperature of the thermistor R2 to rise rapidly, and its resistance to increase sharply, thereby rapidly reducing the current flowing through the coil. This change in current generates an alternating magnetic field from large to small through the inductor L1. After several cycles, the magnetic field strength decreases with the current, the residual magnetism of the iron components of the coil of relay K1 is eliminated, and the normally open circuit of relay K1 opens, ensuring the accuracy of the braking control signal of the elevator control circuit.

[0039] refer to Figure 3 The elevator relay circuit monitoring device also includes a current detection module 102 and a second analog switch module 104. The output terminal of the second analog switch module 104 is connected to the input terminal of the current detection module 102. The control terminal of the second analog switch module 104 and the output terminal of the current detection module 102 are connected to the microcontroller 100. The detection terminal also includes a current detection terminal H2. The input terminal of the current detection terminal H2 is connected in series with the output terminal of the normally open circuit of the relay in the elevator control circuit. The output terminal of the current detection terminal H2 is connected to the input terminal of the second analog switch module 104.

[0040] refer to Figure 3Furthermore, the current detection module 102 includes a current detector U4, a current limiting circuit 111, and a third comparator module U3.1. The input terminal of the current limiting circuit 111 is connected to the output terminal of the second analog switch module 104, and the output terminal is connected to the input terminal of the current detector U4. The output terminal of the current detector U4 is connected to the inverting terminal of the third comparator module U3.1. The non-inverting terminal of the third comparator module U3.1 is connected to a third reference voltage VREF3. The output terminal of the third comparator module U3.1 is connected to the microcontroller 100. In this embodiment, the second analog switch module 104 is composed of multiple relay modules. The current detector U4 is a Hall current detection chip of model ACS712ELCTR 20A, and the third comparator module U3.1 is an operational amplifier chip of model LMV7235.

[0041] Specifically, the current limiting circuit 111 includes a third analog switch module K2 and a current limiting resistor R3. The input terminal of the third analog switch module K2 is connected to the output terminal of the second analog switch module 104. One output terminal of the third analog switch module K2 is connected to one end of the current limiting resistor R3. The other end of the current limiting resistor R3 is connected to the current detector U4 and another output terminal of the third analog switch module K2. The control terminal of the third analog switch module K2 is connected to a microcontroller. In a specific implementation, the third analog switch module K2 can be a relay module. The contact 2 of the relay module is connected to the output terminal of the second analog switch module 104, the normally open contact 3 is connected to one end of the current limiting resistor R3, and the normally closed contact 1 is connected to the other end of the current limiting resistor R3.

[0042] Taking relay K1 in the brake circuit of the elevator control circuit as an example, the microcontroller 100 controls the relay module j31 of the second analog switch module 104 to close the normally open circuit, making the normally open circuit of relay K1 connected to the input terminal IP+ of the current detector U4. The current detector U4 converts the current in the normally open circuit of relay K1, i.e., the braking current of the brake, into a voltage signal and outputs it to the non-inverting input of the third comparator module U3.1. The formula for calculating the output voltage of the current detector U4 is: In the formula, The operating voltage of the current detector U4 is 5V. The braking current of the brake is assumed to be 15A. Therefore, the maximum output voltage of the current detector U4 is 4V, and the third reference voltage VREF3 is selected to be between 4V and 4.5V. When the third comparator module U3.1 detects that the voltage at the inverting input is greater than that at the non-inverting input, it outputs a low-level signal to the microcontroller 100. The microcontroller 100 then determines that the braking current of the brake is too high, posing a risk of burning out the normally open contacts of the relay K1.

[0043] When the current detection module 102 detects that the rated braking current of the brake is greater than the user-set threshold, the microcontroller 100 controls the relay of the third analog switch module K2 to open the normally closed contact 1 and close the normally open contact 3, so that the current limiting resistor R3 is connected in series into the normally open circuit after the relay K1 is closed until the normally open circuit of the relay K1 trips, thereby achieving the function of limiting the current of the normally open circuit of the relay K1.

Claims

1. An elevator relay circuit monitoring device, characterized in that, include: The detection terminal includes a voltage detection terminal, and the output terminal of the normally open circuit of the relay of the elevator control circuit and the positive terminal of the coil are respectively connected to the input terminal of the voltage detection terminal. A first analog switch module, wherein the input terminal of the first analog switch module is connected to the output terminal of the voltage detection terminal; A voltage detection module, wherein the input terminal of the voltage detection module is connected to the output terminal of the first analog switch module; The system includes a microcontroller, a serial opto-isolator, and a timer. The output of the voltage detection module and the timer are connected to the microcontroller. The control terminal of the first analog switch module and the output of the serial opto-isolator are connected to the microcontroller. The input of the serial opto-isolator is connected to the serial port of the elevator main control board.

2. The elevator relay circuit monitoring device according to claim 1, characterized by The voltage detection module includes a first comparator module, a step-down module, and a second comparator module. The input terminal of the step-down module is connected to the output terminal of the first analog switch module, and its output terminal is connected to one input terminal of the first comparator module. The other input terminal of the first comparator module is connected to a first reference voltage, and the output terminal of the first comparator module is connected to the microcontroller. One input terminal of the second comparator module is connected to the output terminal of the first analog switch module, and its other input terminal is connected to a second reference voltage. The output terminal of the second comparator module is connected to the microcontroller.

3. The elevator relay circuit monitoring device according to claim 2, characterized in that, The voltage detection module also includes an optocoupler module, the input of which is connected to the output of the first analog switch module, and the output of which is connected to the microcontroller.

4. The elevator relay circuit monitoring device according to claim 1, characterized by It also includes a current detection module and a second analog switch module. The output terminal of the second analog switch module is connected to the input terminal of the current detection module. The control terminal of the second analog switch module and the output terminal of the current detection module are connected to the microcontroller. The detection terminal also includes a current detection terminal. The input terminal of the current detection terminal is connected to the normally open circuit output terminal of the relay in the elevator control circuit. The output terminal of the current detection terminal is connected to the input terminal of the second analog switch module.

5. The elevator relay circuit monitoring device according to claim 4, characterized in that, The current detection module includes a current detector and a third comparator module. The input terminal of the current detector is connected to the output terminal of the second analog switch module, and the output terminal is connected to one input terminal of the third comparator module. The other input terminal of the third comparator module is connected to a third reference voltage, and the output terminal of the third comparator module is connected to the microcontroller.

6. The elevator relay circuit monitoring device according to claim 2, characterized by The first analog switch module includes a first switch circuit and a second switch circuit. The input terminals of the first switch circuit and the second switch circuit are connected to the output terminal of the voltage detection terminal. The output terminal of the first switch circuit is connected to the input terminal of the voltage detection module, and the output terminal of the second switch circuit is connected to one input terminal of the second comparator module.

7. The elevator relay circuit monitoring device according to claim 5, characterized in that, The current detection module further includes a current limiting circuit. The input terminal of the current limiting circuit is connected to the output terminal of the second analog switch module, and the output terminal is connected to the input terminal of the current detector. The current limiting circuit includes a third analog switch module and a current limiting resistor. The input terminal of the third analog switch module is connected to the output terminal of the second analog switch module. One output terminal of the third analog switch module is connected to one end of the current limiting resistor. The other end of the current limiting resistor is connected to the current detector and another output terminal of the third analog switch module. The control terminal of the third analog switch module is connected to the microcontroller.

8. The elevator relay circuit monitoring device according to claim 6, characterized in that, The voltage detection module also includes a demagnetizing circuit, which includes a MOSFET, a thermistor, and an inductor. The output terminal of the MOSFET, the inductor, and the thermistor are connected in sequence. The input terminal of the MOSFET is connected to the output terminal of the second switching circuit. The control terminal of the MOSFET is connected to the microcontroller. The output terminal of the thermistor is connected to the negative terminal of the relay coil in the elevator control circuit.

9. The elevator relay circuit monitoring device according to claim 1, characterized by It also includes a GSM communication module, a display, and a button module, which are respectively connected to the microcontroller.

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