Coil control circuit and contactor

Abstract

The utility model provides a coil control circuit and a contactor. The coil control circuit comprises a main control module, a power supply module, a PLC control module, a PLC enabling module and a coil circuit module, wherein the main control module has a local control mode and a remote control mode; the power supply module is electrically connected to the input end of the main control module; the PLC control module is electrically connected to the input end of the main control module; the PLC enabling module is electrically connected to the output end of the power supply module and the input end of the main control module and is used for controlling the main control module to be switched between a local control mode and a remote control mode; the coil circuit module is electrically connected to the output end of the main control module and the output end of the power supply module. According to the coil control circuit, the PLC control module and the PLC enabling module are introduced into the main control module, remote control of the coil is achieved through the PLC control module, and switching between local control and remote control is achieved through the PLC enabling module.

Description

Technical Field

[0001] This application relates to the technical field of low-voltage electrical appliances, and particularly to a coil control circuit and a contactor. Background Art

[0002] In the related art, a contactor is connected to a control circuit, and the switching between the release and suction states of the contactor is realized by using the control circuit. However, the control of the contactor by the control circuit is limited to local control, and the applicable range is relatively narrow, which cannot meet the need of remote control. Summary of the Utility Model

[0003] In view of this, this application provides a coil control circuit and a contactor to improve the problem that the contactor can only achieve local control and cannot achieve remote control.

[0004] The technical solutions adopted by this application to solve the above technical problems are as follows:

[0005] In a first aspect, an embodiment of this application provides a coil control circuit, including:

[0006] A main control module, which has a local control mode and a remote control mode;

[0007] A power supply module, electrically connected to the input end of the main control module;

[0008] A PLC control module, electrically connected to the input end of the main control module;

[0009] A PLC enabling module, electrically connected to the output end of the power supply module and the input end of the main control module, and is used to control the main control module to switch between the local control mode and the remote control mode;

[0010] A coil circuit module, electrically connected to the output end of the main control module and electrically connected to the output end of the power supply module.

[0011] In some embodiments of this application, when the main control module is in the local control mode, the PLC enabling module is in an open state, the power supply module supplies power to the coil circuit module, and the main control module sends an action signal to the coil circuit module;

[0012] When the main control module is in the remote control mode, the PLC enabling module is in a closed state, the power supply module supplies power to the coil circuit module, and the main control module receives the control signal of the PLC control module and sends an action signal to the coil circuit module.

[0013] In some embodiments of the present application, the PLC control module includes a suppression diode, a first voltage-dividing resistor, a second voltage-dividing resistor, a first optocoupler, a first pull-up resistor, a second pull-up resistor, and a first capacitor. The two ends of the first voltage-dividing resistor are electrically connected to the power supply module and the first pin of the first optocoupler respectively. The two ends of the second voltage-dividing resistor are electrically connected to the power supply module and the second pin of the first optocoupler respectively. A first node is provided between the first voltage-dividing resistor and the power supply module, and a second node is provided between the second voltage-dividing resistor and the power supply module. The first voltage-dividing resistor and the second voltage-dividing resistor are connected in parallel. The two ends of the suppression diode are respectively connected to the first node and the second node. The third pin of the first optocoupler is connected to a third node, and the fourth pin of the first optocoupler is connected to a fourth node. The two ends of the first pull-up resistor are respectively connected to the fourth node and a fifth node. The two ends of the first capacitor are respectively connected to the third node and the fifth node. The two ends of the second pull-up resistor are respectively connected to the power supply module and the fourth node.

[0014] In some embodiments of the present application, the PLC enabling module includes a first diode, a current-limiting resistor, a second optocoupler, a third pull-up resistor, a fourth pull-up resistor, a second capacitor, and a control switch. The first diode includes an anode electrically connected to the output end of the power supply module and a cathode electrically connected to the first pin of the second optocoupler. The two ends of the current-limiting resistor are electrically connected to the second pin of the second optocoupler and the control switch respectively. The two ends of the third pull-up resistor are electrically connected to a sixth node and a PLC signal line respectively. The two ends of the fourth pull-up resistor are electrically connected to the power supply module and the first node respectively. The fourth pin of the second optocoupler is connected to the sixth node. The two ends of the second capacitor are electrically connected to a seventh node and an eighth node. The seventh node is located between the third pull-up resistor and the PLC signal line, and the eighth node is located between the third pin of the second optocoupler and a first ground wire.

[0015] In some embodiments of the present application, the coil circuit module includes two coil circuits. Both of the two coil circuits are electrically connected to the power supply module and the main control module, and the two coil circuits are connected in parallel or in series.

[0016] In some embodiments of the present application, the coil circuit includes a drive circuit, a temperature measurement circuit, a current sampling circuit, and a coil. The input end of the drive circuit is electrically connected to the output end of the main control module, the output end of the drive circuit is connected to the input end of the coil, the input end of the coil is also electrically connected to the power supply module, the output end of the coil is electrically connected to the temperature measurement circuit and the current sampling circuit, and the output ends of the temperature measurement circuit and the current sampling circuit are both electrically connected to the receiving end of the main control module.

[0017] In some embodiments of the present application, the coil circuit further includes a quick release circuit, and both ends of the quick release circuit are respectively electrically connected to the output end of the main control module and the input end of the coil.

[0018] In some embodiments of the present application, the power supply module includes a main power supply, an EMC circuit, a first voltage sampling circuit, a switching power supply, and a linear power supply. The main power supply is electrically connected to both the input end of the EMC circuit and the input end of the first voltage sampling circuit. The output end of the EMC circuit is electrically connected to the input end of the switching power supply. The output end of the switching power supply is electrically connected to the input end of the linear power supply. The output end of the linear power supply is electrically connected to both the PLC enabling module and the main control module.

[0019] In some embodiments of the present application, a second voltage sampling circuit is electrically connected to the output end of the PLC control module, and the output end of the second voltage sampling circuit is electrically connected to the input end of the main control module.

[0020] In a second aspect, the present application provides a contactor, including the coil control circuit as described in the first aspect.

[0021] In summary, due to the adoption of the above technical solutions, the present application has at least the following beneficial effects:

[0022] The embodiments of the present application provide a coil control circuit and a contactor. By introducing a PLC control module and a PLC enabling module into the main control module in the coil control circuit, the remote control of the coil is realized by using the PLC control module, and the switching between local control and remote control is realized by using the PLC enabling module. Specifically, first, the power supply module, the PLC control module, and the PLC enabling module are all connected to the main control module, and the coil circuit module is connected to both the output end of the main control module and the output end of the power supply module, so that the power supply module can supply power to the coil circuit module, and the main control module can switch between local control and remote control of the coil circuit module according to the action of the PLC enabling module. And in the remote control mode, the main control module realizes the remote control of the coil circuit module according to the control signal of the PLC control module, effectively improving the applicable range of the control circuit and meeting the requirements of the remote control of the contactor. Description of the Drawings

[0023] Figure 1 A circuit block diagram of a coil control circuit provided for an embodiment of the present application;

[0024] Figure 2 A circuit diagram of a main control module in a coil control circuit provided for an embodiment of the present application;

[0025] Figure 3 A circuit diagram of an EMC circuit in a power supply module provided for an embodiment of the present application;

[0026] Figure 4 A circuit diagram of a first voltage sampling circuit in a power supply module provided for an embodiment of the present application;

[0027] Figure 5 A circuit diagram of a PLC control module in a coil control circuit provided for an embodiment of the present application;

[0028] Figure 6 A circuit diagram of a PLC enabling module in a coil control circuit provided for an embodiment of the present application;

[0029] Figure 7 A circuit diagram of a first drive circuit in a coil circuit module provided for an embodiment of the present application;

[0030] Figure 8 A circuit diagram of a first temperature measurement circuit in a coil circuit module provided for an embodiment of the present application;

[0031] Figure 9 A circuit diagram of a first current sampling circuit in a coil circuit module provided for an embodiment of the present application;

[0032] Figure 10 A circuit diagram of a first fast release circuit in a coil circuit module provided for an embodiment of the present application. Detailed Description of the Embodiments

[0033] Next, the technical solutions in the embodiments of the present application will be described with reference to the drawings in the embodiments of the present application.

[0034] In the description of the present application, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0035] In this application, the term "exemplary" is used to mean "serving as an example, illustration, or instance". Any embodiment described as "exemplary" in this application is not necessarily to be construed as more preferred or advantageous than other embodiments.

[0036] Please refer to Figure 1 and Figure 2 , embodiments of the present application provide a coil control circuit, including a main control module, a power supply module, a PLC control module, a PLC enable module, and a coil circuit module. Among them, the main control module has a local control mode and a remote control mode. The power supply module is electrically connected to the input end of the main control module and is used to supply power to the main control module to ensure the normal operation of the main control module. The PLC control module is electrically connected to the input end of the main control module and is used to input a control signal to the main control module, only when the control circuit is in the remote control mode. The PLC enable module is electrically connected to the output end of the power supply module and the input end of the main control module. The electrical connection between the power supply module and the PLC enable module is mainly used to supply power to the PLC enable module so that the PLC enable module can perform corresponding actions. The PLC enable module is connected to the input end of the main control module, mainly to input a signal for mode switching to the main control module. The coil circuit module is electrically connected to the output end of the main control module. The main control module is used to control the suction and release of the coil circuit module, and the coil circuit module is also electrically connected to the output end of the power supply module. The power supply module is used to supply power to the coil circuit module to ensure the normal operation of the coil circuit module. Whether in the local control mode or the remote control mode, the power supply module is required to supply power to the coil circuit module.

[0037] The technical solution provided by the present application is to introduce a PLC control module and a PLC enable module into the main control module, use the PLC control module to achieve remote control of the coil, and use the PLC enable module to achieve the switching between local control and remote control. Specifically, first, the power supply module, the PLC control module, and the PLC enable module are all connected to the main control module, and the coil circuit module is connected to the output end of the main control module and the output end of the power supply module, so that the power supply module can supply power to the coil circuit module, and the main control module can switch between local control and remote control of the coil circuit module according to the action of the PLC enable module. In the remote control mode, the main control module realizes remote control of the coil circuit module according to the control signal of the PLC control module, effectively improving the applicable range of the control circuit and meeting the requirements of remote control of the contactor.

[0038] In this embodiment, the PLC control module is connected to the input end of the main control module and is used to receive control signals from the PLC. When the remote control mode is enabled, the PLC control module receives instructions from the remote PLC and transmits them to the main control module to control the suction and release of the coil. The PLC enable module is connected to the output end of the power supply module and the input end of the main control module. It is used to control the switching of the main control module between the local control mode and the remote control mode. Specifically, when the PLC enable module is enabled, the main control module switches to the remote control mode and receives and executes control signals from the PLC control module.

[0039] For the coil control circuit provided in this application, since it has two modes of local control and remote control, it can adapt to various scenarios. For example, in a large industrial production line, contactors are used to control the operation of various equipment such as motors, pumps, and conveyor belts. On-site operators can directly control the contactors in case of an emergency to immediately stop the equipment operation and ensure the safety of personnel and equipment. The central control room can automatically start and stop the equipment through the remote control system, optimize the production line efficiency, and adjust the operation status of the equipment according to needs during the production process. In high-rise buildings, contactors are used to control the power supply of key systems such as floor lighting, water supply pumps, and elevators. These devices require both daily maintenance and management, as well as remote monitoring and control. Building managers or electricians need to manually start and stop the equipment through local control during equipment maintenance or emergency repair to ensure the smooth progress of maintenance work. The building automation system manages the power equipment in the building through remote control, such as automatically controlling the start and stop of the water supply pump and automatically controlling the switch of the lighting system according to the preset time, to save energy and improve management efficiency. In petrochemical plants, contactors are widely used to control various pumping stations, such as pumping stations for transporting crude oil, natural gas, or chemical raw materials. The operation of these pumping stations requires both on-site manual operation and automated management through the remote monitoring system. During equipment maintenance and repair, on-site operators need to manually start or stop the pumping station equipment through local control to ensure the safety and accuracy of the operation. The central control system remotely monitors the pumping stations, remotely starts and stops the pumping stations based on the requirements of the process flow, monitors the operation status of the equipment, and responds quickly in case of abnormalities.

[0040] In some embodiments, when the main control module is in the local control mode, the PLC enable module is in the off state, blocking the input of remote control signals. At this time, the power supply module supplies power to the coil circuit module, and the main control module directly controls the working state of the coil circuit to achieve the suction and release of the contactor. In this mode, the system operates completely relying on the local circuit and is not interfered by remote signals.

[0041] When the main control module is in the remote control mode, the PLC enabling module is in the closed state, enabling the remote control signal to enter the main control module. At this time, the power supply module still powers the coil circuit module, but the main control module receives the control signal from the PLC control module, thereby controlling the working state of the coil circuit module to achieve remote control of the contactor. In the remote mode, the operation of the system is controlled by the remote signal, which is suitable for scenarios that require remote monitoring and operation.

[0042] By controlling the on / off of the PLC enabling module, the system can flexibly switch the working mode to meet the diverse requirements of operations. In the local control mode, the system does not rely on external signals and directly controls the contactor through the main control module. This method can ensure that the operation of the contactor is not affected in case of network failure or unavailable remote control, improving the reliability of the system. In the remote control mode, the system receives and executes the control signal from the PLC, enabling remote operation and management of the contactor. This mode is suitable for scenarios that require remote monitoring and operation in industrial automation, greatly increasing the flexibility of operations.

[0043] In some embodiments, please refer to Figure 5, the PLC control module includes a suppression diode D12, a first voltage-dividing resistor R37, a second voltage-dividing resistor R41, a first optocoupler U9, a first pull-up resistor R38, a second pull-up resistor R36, and a first capacitor C23. The two ends of the first voltage-dividing resistor R37 are respectively connected to the power supply module and the first pin of the first optocoupler U9. The two ends of the second voltage-dividing resistor R41 are respectively connected to the power supply module and the second pin of the first optocoupler U9. The two resistors are connected in parallel to form a voltage-dividing network, which plays a role in voltage division to ensure that the voltage applied to the input end of the optocoupler is within its safe operating range. The two ends of the suppression diode D12 are respectively connected to the nodes (the first node and the second node) between the first voltage-dividing resistor R37 and the second voltage-dividing resistor R41, and are used to protect the circuit and prevent transient voltage or reverse current from damaging other components in the circuit. The third pin of the first optocoupler U9 is connected to the third node, and the fourth pin is connected to the fourth node. The signal after being divided by the voltage-dividing resistors enters the first optocoupler U9. The optocoupler emits light through its internal LED and activates the photosensitive transistor to achieve electrical isolation between the input end and the output end during the signal transmission process. The two ends of the first pull-up resistor R38 are respectively connected to the fourth node and the PLC signal line, and are used to stabilize the signal level. The two ends of the second pull-up resistor R36 are respectively connected to the power supply module and the fourth node to further enhance the signal stability. The pull-up resistor ensures that the level of the optocoupler output end is in the high-level state to prevent the signal from floating. The first capacitor C23 is connected between the third node and the fifth node and is used to filter out high-frequency noise in the signal to ensure the stability of signal transmission. The first optocoupler U9 is used to achieve electrical isolation of the signal and transmit the PLC control signal to the next part of the circuit through photoelectric conversion. Its input end is connected to the output ends of the first voltage-dividing resistor R37 and the second voltage-dividing resistor R41, and the output end is connected to the PLC signal line through the pull-up resistor.

[0044] In some embodiments, please refer to Figure 6, the PLC enabling module includes a first diode D10, a current-limiting resistor R40, a second optocoupler U8, a third pull-up resistor R35, a fourth pull-up resistor R34, a second capacitor C22, and a control switch. The first diode D10 includes an anode electrically connected to the output terminal of the power supply module and a cathode electrically connected to the first pin of the second optocoupler U8, which is used to prevent reverse current from damaging the circuit and protect subsequent components. The two ends of the current-limiting resistor R40 are respectively electrically connected to the second pin of the second optocoupler U8 and the control switch, which is used to limit the current flowing through the input terminal of the optocoupler to ensure that the current is within a safe range and protect the LED of the optocoupler. The second optocoupler U8 is used to achieve electrical isolation of the control signal and transmit the input PLC enabling signal to the output terminal through an optical signal. The two ends of the third pull-up resistor R35 are respectively electrically connected to the sixth node and the PLC signal line, and the two ends of the fourth pull-up resistor R34 are respectively electrically connected to the power supply module and the sixth node, which are used to stabilize the signal level at the output terminal of the second optocoupler U8 and prevent the signal from floating or being in an unstable state. The fourth pin of the second optocoupler U8 is connected to the sixth node, and the two ends of the second capacitor C22 are electrically connected to the seventh node and the eighth node. The seventh node is located between the third pull-up resistor R35 and the PLC signal line, and the eighth node is located between the third pin of the second optocoupler U8 and the first ground wire. The second capacitor C22 is used to filter out high-frequency noise, smooth the output signal, and ensure the stability of the signal. The control switch is used to manually switch the state of the PLC enabling module and determine whether the system is in the local control mode or the remote control mode. When the switch is closed, the PLC enabling module is activated and the system switches to the remote control mode.

[0045] In some embodiments, please refer to Figure 1 , the coil circuit module includes two coil circuits operating in parallel. The two coil circuits can be in a series relationship or a parallel relationship. These two coil circuits include a first coil circuit and a second coil circuit. Each coil circuit is connected to the power supply module and the main control module and has the same circuit structure. Through such a design, the coil control circuit can control the two coils simultaneously or independently when needed, ensuring the redundancy and reliability of the system. Also, two coils are provided in the coil control circuit. Through the synergistic effect of the two coils, a greater electromagnetic force can be generated, improving the action speed and accuracy of the contactor. The design of the dual coils makes the magnetic field distribution more uniform, reduces unnecessary mechanical stress inside the contactor, reduces the wear of the moving contact and the static contact, and extends the service life of the contactor. Also, by sharing the current load, the heat generation of a single coil is reduced, which helps with thermal management, avoids aging or failure caused by overheating of the coil, and thus extends the life and reliability of the circuit.

[0046] The first coil circuit consists of a coil and its driving circuit, and its circuit structure is exactly the same as that of the second coil circuit. Its input terminal is connected to the output terminal of the main control module and is powered by the power supply module. When the main control module issues a control signal, the first coil circuit performs corresponding operations according to this signal, such as the suction or release of the contactor. The structure of the second coil circuit is the same as that of the first coil circuit, and it also consists of a coil and its driving circuit. Its input terminal is connected to the output terminal of the main control module and is powered by the power supply module. The second coil circuit works in parallel with the first coil circuit to ensure that the system can still maintain normal operation through the second coil circuit when the first coil circuit fails.

[0047] Further, please refer to Figure 1 , the first coil circuit includes a first driving circuit, a first temperature measurement circuit, a first current sampling circuit, and a first coil. The input terminal of the first driving circuit is electrically connected to the output terminal of the main control module, the output terminal of the first driving circuit is connected to the input terminal of the first coil, the input terminal of the first coil is also electrically connected to the power supply module, the output terminal of the first coil is electrically connected to the first temperature measurement circuit and the first current sampling circuit, and the output terminals of the first temperature measurement circuit and the first current sampling circuit are both electrically connected to the receiving terminal of the main control module. The first driving circuit is used to control the on / off of the coil and is directly connected to the output terminal of the main control module. According to the control signal issued by the main control module, the driving circuit adjusts the energization state of the coil, thereby controlling the suction or release of the contactor. The first temperature measurement circuit is used to monitor the temperature state of the coil and detect the temperature rise generated by the coil during operation. The output terminal of the temperature measurement circuit is connected to the receiving terminal of the main control module, and the temperature information is fed back to the main control module in real time to determine whether the coil is within the safe operating temperature range. The first current sampling circuit is used to detect the magnitude of the current passing through the coil and is connected between the output terminal of the coil and the receiving terminal of the main control module. By monitoring the current, it can be judged whether the operating state of the coil is normal and fed back to the main control module in time for adjustment or protection. The first coil is the key component for controlling the mechanical action of the contactor. Its input terminal is connected to the output terminal of the driving circuit and the power supply module, and its output terminal is connected to the temperature measurement circuit and the current sampling circuit. When the coil is energized, a magnetic field is generated, thereby driving the moving contact of the contactor to achieve suction or release.

[0048] When the main control module issues a control signal, the drive circuit adjusts the current of the coil according to this signal, causing the coil to generate a corresponding magnetic field to drive the moving contact of the contactor to complete the closing or releasing action. During the operation of the coil, the temperature measurement circuit monitors the temperature of the coil in real time. If the temperature exceeds the safe range, the temperature measurement circuit feeds this information back to the main control module so as to take appropriate protection measures, such as reducing the current or stopping the power supply to the coil, to prevent the coil from being damaged due to overheating. The current sampling circuit monitors the magnitude of the current passing through the coil and feeds the current data back to the main control module. The main control module judges the working state of the coil according to the feedback current information, such as whether there is overcurrent or abnormal current, so as to adjust the working state of the coil in time or issue a fault alarm. Under high load or complex environment, the coil is prone to malfunction or even damage due to overheating or abnormal current. In order to ensure the normal operation of the coil and the safety of the system, it is necessary to monitor the temperature and current of the coil in real time and make dynamic adjustments or protections according to these parameters.

[0049] Please refer to Figure 7, for the first driving circuit, it includes a first inductor L5, a second inductor L6, a first capacitor CE3, a second capacitor CE4, a fifth capacitor CE2, a sixth capacitor CE7, a third capacitor C6, a fourth capacitor C7, and a first integrated circuit U2. One end of the second inductor L6 is connected to the input voltage, and the other end is connected to the test point TP18, which is used to block the passage of high-frequency signals and only allow direct current and alternating current with relatively low frequencies to pass through, thereby reducing the high-frequency noise in the input voltage. Both ends of the first inductor L5 are respectively connected to the test point TP18 and the test point TP19, which is used to continue filtering the noise that has not been completely removed in the previous stage (the filtering circuit composed of L6 and CE3). It also plays a buffering role for the change of the load to stabilize the voltage input to the voltage regulator U2. One end of the first capacitor CE3 is connected to the test point TP18, and the other end is grounded. The first capacitor CE3 and the second inductor L6 together form an LC filter. The function of the first capacitor CE3 is to filter the voltage, further smooth the input voltage, and reduce the ripple noise. The second capacitor CE4 is connected in parallel with the first inductor L5, between the test point TP19 and the ground wire, which is used for filtering again to ensure that the voltage input to the first integrated circuit U2 is more stable. The first integrated circuit U2 is a DC conversion chip, which is responsible for converting the input stable voltage into the required positive and negative output voltages. The first pin of the first integrated circuit U2 is connected to the test point TP19, and the voltage is input through the first inductor L5. The second pin of the first integrated circuit U2 is grounded. The output voltages of the first integrated circuit U2 are +15V and -8V respectively, and are output through the seventh pin and the sixth pin respectively. The fifth capacitor CE2 is connected in parallel with the +15V output terminal, between the test point TP17 and the ground wire, which is used to smooth the +15V output voltage. The sixth capacitor is connected in parallel with the -8V output terminal, between the test point TP26 and the ground wire, which is used to smooth the -8V output voltage. The third capacitor C6 and the fourth capacitor C7 are respectively connected in parallel with the fifth capacitor CE2 and the sixth capacitor CE7, further filtering to reduce the high-frequency noise interference.

[0050] For the second driving circuit, its structure and function are the same as those of the first driving circuit, and will not be elaborated here.

[0051] Please refer to Figure 8, for the first temperature measurement circuit, it includes a first thermistor RT1, a fifth capacitor C29, a first resistor R56, a second resistor R58, and a sixth capacitor C30. One side of this temperature measurement circuit is connected to a 3.3V power supply. The first thermistor RT1 is a negative temperature coefficient thermistor, which is connected between the 3.3V voltage and the test point TP73. The resistance value of the first thermistor RT1 will decrease as the temperature increases. In this way, when the temperature rises, the voltage drop across the first thermistor RT1 becomes smaller, while the voltage at the test point TP73 increases; conversely, when the temperature drops, the voltage at the test point TP73 decreases. The fifth capacitor C29 is connected in parallel across the first thermistor RT1, between the 3.3V voltage and the test point TP73, and is used to filter out high-frequency noise, ensuring that the voltage interference received by the first thermistor RT1 during temperature measurement is as small as possible and improving the measurement accuracy. The first resistor R56 is connected between the test point TP73 and the test point TP74. The first resistor R56 and the first thermistor RT1 together form a voltage divider through voltage division, which is used to convert the voltage change across the first thermistor RT1 into the voltage output at the test point TP74. The second resistor is connected between the test point TP73 and the ground wire, and is used to provide a stable bias current for the first thermistor RT1 and the first resistor R56, ensuring the stable operation of the circuit at different temperatures. The sixth capacitor C30 is connected in parallel with the second resistor R58, specifically between the test point TP74 and the ground wire, and is used for filtering to eliminate high-frequency noise in the voltage signal. One side of the test point TP74 is connected to the output terminal TA_ADC. The signal voltage changes with the temperature and is converted into a digital signal through an ADC (analog-to-digital converter) to achieve temperature measurement and monitoring. This output terminal is correspondingly connected to the pin TA_ADC in the main control module.

[0052] It should be noted that the structure and function of the second temperature measurement circuit in the second coil circuit are exactly the same as those of the first temperature measurement circuit, and will not be elaborated here.

[0053] Please refer to Figure 9, for the first current sampling circuit, it includes a third resistor R44, a fourth resistor R45, a fifth resistor R24, a sixth resistor R3, a seventh capacitor C25, an eighth capacitor C26, a ninth capacitor C28, a tenth capacitor C33, and an operational amplifier U11. The input end of the first current sampling circuit inputs a current signal I_A. The current signal I_A passes through two series-connected third resistor R44 and fourth resistor R45. These two resistors convert the input current into a voltage signal through voltage division. The eighth capacitor C26 is connected in parallel between the fourth resistor R45 and the input end (pin 3) of the operational amplifier U11, and one end of the ninth capacitor C28 is connected between the third resistor R44 and the fourth resistor R45, and the other end is connected between the operational amplifier U11 and the output end I_ADC of the sampling circuit. The operational amplifier U11 is an operational amplifier of model TP5551-TR, its pin 3 is connected to the node of the fourth resistor R45 and the eighth capacitor C26, as the inverting input end of the input signal, and pin 4 is connected to one end of the sixth resistor R3. The non-inverting input end (pin 2) of the operational amplifier is grounded, and it is configured as an inverting amplifier to amplify the voltage converted from the input current signal. The fifth resistor R24 is connected in parallel with a seventh capacitor C25, and forms a feedback loop with pin 4 and pin 1 of the operational amplifier. The tenth capacitor C33 is connected in series between the power supply pin of the operational amplifier and the ground wire, which plays a decoupling role to reduce the influence of power supply noise. The amplified voltage signal of the output signal I_ADC passes through the sixth resistor R3 and the tenth capacitor C33 for filtering from pin 4 of the operational amplifier, and is used as the output signal I_ADC and transmitted to the subsequent analog-to-digital converter.

[0054] It should be noted that the structure and function of the second current sampling circuit in the second coil circuit are exactly the same as those of the first current sampling circuit, and will not be elaborated here.

[0055] Please refer to Figure 10 , in some embodiments, the first coil circuit further includes a first fast release circuit. The two ends of the first fast release circuit are respectively electrically connected to the output end of the main control module and the input end of the first coil, and are used to quickly cut off the current of the coil and quickly eliminate the magnetic field when the main control module issues a fast power-off instruction, so that the coil can be quickly released.

[0056] The structure of the second coil circuit is the same as that of the first coil circuit. Therefore, the structure and function of the second fast release circuit in the second coil circuit are the same as those of the first fast release circuit. Please refer to Figure 10, regarding the first quick release circuit, it includes a third rectifier diode D5, a zener diode ZD1, a resistor R14, a resistor R15, a resistor R23, a resistor R25, a bias resistor R18, a field effect transistor Q2, an optocoupler U5, a current limiting resistor R20, a current limiting resistor R21, a current limiting resistor R22, a field effect transistor Q3, a suppression diode D7, a suppression diode D8, a suppression diode D9, a zener diode D6, and a capacitor C14.

[0057] Among them, B1 is the power input terminal. The resistor R14 and the resistor R15 are connected in series between the power input terminal B1 and the main circuit. The anode of the third rectifier diode is connected to the resistor R15, and the cathode is connected to the main circuit. The zener diode D6 is connected between the main circuit and the ground, playing a role in reverse connection protection to prevent damage to the circuit when the power supply polarity is reversed. The source of the field effect transistor Q2 is connected to the main circuit, the drain is connected to the cathode of the suppression diode D7, and the gate is connected to the test point TP38. When the voltage is too high, the field effect transistor Q2 conducts, and the excessive voltage is clamped through the suppression diode D7. The cathode of the suppression diode D7 is connected to the drain of the field effect transistor Q2, and the anode of the suppression diode D7 is grounded. The pin 3 of the optocoupler U5 is connected to the main circuit, the pin 4 is grounded, and the pin 1 is connected to the current limiting resistor R20, the test point TP39, and the positive electrode of the capacitor C15, for providing a stable voltage output. The current limiting resistor R20, the current limiting resistor R21, and the current limiting resistor R22 together constitute a voltage dividing resistor network. The current limiting resistor R20 is connected to the output of the optocoupler U5 and the current limiting resistor R21, the current limiting resistor R21 is connected to the current limiting resistor R22, and the current limiting resistor R22 is grounded. The positive electrode of the capacitor C15 is connected to the output of the optocoupler U5, and the negative electrode is grounded, playing a role in filtering, smoothing the output voltage, and reducing ripple. The drain of the field effect transistor Q3 is connected to the intersection of the cathode of the suppression diode D8 and the anode of the suppression diode D9, the source is grounded, and the gate is connected to the test point TP45 through the resistor R23. The anode of the suppression diode D8 is connected to the test point TP47, and the cathode of the suppression diode D9 is connected to the main circuit. The suppression diodes D8 and D9 are mainly used to protect the field effect transistor Q3 from being damaged by high voltage in the case of overcurrent. The capacitor C14 is connected in parallel between the main circuit and the ground, serving as a decoupling capacitor, for filtering high-frequency noise on the power line and providing circuit stability. The bias resistor R18 is connected in parallel between the main circuit and the ground, providing a high-resistance discharge path to prevent residual charge from existing in the capacitor after power-off.

[0058] In some embodiments, please refer to Figure 1, the power supply module includes a main power supply, an EMC circuit, a first voltage sampling circuit, a switching power supply, and a linear power supply. The main power supply is electrically connected to both the input end of the EMC circuit and the input end of the first voltage sampling circuit. The output end of the EMC circuit is electrically connected to the input end of the switching power supply. The output end of the switching power supply is electrically connected to the input end of the linear power supply. The output end of the linear power supply is electrically connected to both the PLC enabling module and the main control module. Among them, the main power supply is the electrical energy input port of the entire power supply module, used to receive external alternating current and supply electrical energy input to the EMC circuit and the first voltage sampling circuit. The EMC circuit is connected between the main power supply and the switching power supply, used to filter out electromagnetic interference and radio frequency interference in the input power supply, ensuring the stability of the current and voltage entering the switching power supply. The first voltage sampling circuit is used to monitor the input voltage of the main power supply to ensure it is within the specified range. The switching power supply is used to convert the power regulated by the EMC circuit into stable low-voltage direct current for use by other parts of the coil control circuit. The linear power supply is used for further voltage regulation to provide a more stable direct current power supply, ensuring that the PLC enabling module and the main control module can obtain the best power supply and reducing the impact on the system caused by voltage fluctuations.

[0059] Please refer to Figure 3, Regarding the EMC circuit, it includes a varistor RV1, an iron core inductor L2, a seventh capacitor CX1, a first voltage-sharing resistor R4, a second voltage-sharing resistor R9, a third voltage-sharing resistor R10, a rectifier BR1, an electrolytic capacitor C4, a relay RV2, and a power transformer L3. Among them, the EMC circuit has a first input terminal A1 and a second input terminal A2, and the main power supply inputs alternating current to the two input terminals of the EMC circuit. The two ends of the varistor RV1 are respectively connected to the test point TP5 of the first input terminal A1 and the test point TP13 of the second input terminal A2, and are used to provide overvoltage protection. When the input voltage exceeds the safe range, the varistor RV1 will quickly conduct and absorb the overvoltage energy, thereby protecting the circuit from damage by high-voltage impacts. The two ends of the iron core inductor L2 are respectively connected to the test point TP5 and the test point TP7, and are used to suppress high-frequency noise in the circuit. The seventh capacitor CX1, multiple voltage-sharing resistors, and the varistor RV1 are all connected in parallel. One end of the seventh capacitor CX1 is connected to the test point TP7, and the other end is connected between the test point TP13 and the voltage-sharing resistor. The first voltage-sharing resistor R4, the second voltage-sharing resistor R9, and the third voltage-sharing resistor R10 in the voltage-sharing resistors are connected in series with each other. The power transformer L3 is used to isolate and convert the power supply voltage, and its primary winding is connected between the iron core inductor L2 and the relay RV2, and the secondary winding is connected to the rectifier BR1 through the test point TP8. The relay RV2 is in a closed state by default, enabling current to flow through the power transformer L3. The relay RV2 is connected in series with the power transformer L3 and plays a role in circuit protection. When overcurrent or abnormality is detected, the circuit can be disconnected. The input terminal of the rectifier BR1 is connected to the output terminal of the secondary winding of the power transformer L3. The positive output terminal of the rectifier BR1 is connected to the electrolytic capacitor C4, and the negative output terminal is grounded, and is used to convert the alternating voltage provided by the power transformer L3 into a direct current voltage. The electrolytic capacitor C4 is a filter capacitor and is connected between the output terminal of the rectifier BR1 and the ground wire, and is used to smooth the rectified direct current voltage. And, in the EMC circuit, there are multiple nodes grounded, and the single-point grounding method is used to reduce the noise and interference of the ground loop.

[0060] Please refer to Figure 4, Regarding the first voltage sampling circuit, it includes a first rectifying diode D14, a second rectifying diode D15, a resistor network, a first voltage stabilizing diode D13, a seventh resistor R51, an eighth resistor R55, and an eleventh capacitor C27. The first rectifying diode D14 and the second rectifying diode D15 are two rectifying diodes connected in reverse parallel, which are used to rectify the input AC voltage. The anodes of the first rectifying diode D14 and the second rectifying diode D15 are respectively connected to the live wire L and the neutral wire N of the power supply, and the cathodes are commonly connected to the test point TP60, which is used to convert the AC voltage into a unidirectional pulsating DC voltage. The first resistor network includes multiple resistors connected in series. In this embodiment, the resistor network includes four resistors connected in series, which are used to divide the voltage of the rectified pulsating DC voltage to reduce the voltage input amplitude of the subsequent circuit. The two ends of the first resistor network are respectively connected between the test point TP60 and the test point TP64. The first voltage stabilizing diode D13 is a bipolar first voltage stabilizing diode, and its function is to clamp the voltage to 3.3V to protect the subsequent analog-to-digital converter from being damaged by high voltage. Specifically, one end of the first voltage stabilizing diode D13 is connected to the test point TP65, and the other end is grounded. The seventh resistor is connected between the test point TP65 and the test point TP66, which is used to cooperate with the first voltage stabilizing diode D13 to limit the current flowing through the diode and provide a stable input voltage for the analog-to-digital converter. The eighth resistor R55 is connected between the test point TP72 and the ground wire, which is used to adjust the voltage signal and further modulate the voltage signal into a range suitable for sampling by the analog-to-digital converter. The eleventh capacitor C27 is connected between the test point TP66 and the ground wire, which is used for filtering.

[0061] In some embodiments, the output end of the PLC control module is electrically connected to a second voltage sampling circuit, and the output end of the second voltage sampling circuit is electrically connected to the input end of the main control module. The PLC control module is used to receive remote control signals and generate corresponding control outputs according to the instructions of the signals. The second voltage sampling circuit is connected between the output end of the PLC control module and the input end of the main control module, and is responsible for monitoring the voltage level output by the PLC control module in real time. The voltage sampling circuit realizes voltage monitoring through components such as sampling resistors and voltage dividing circuits, converts the detected voltage signal into a voltage value suitable for processing by the main control module, and transmits it to the input end of the main control module. The main control module judges whether the output of the PLC control module is normal according to the voltage signal received from the second voltage sampling circuit. The specific structure of the second voltage sampling circuit is the same as that of the first voltage sampling circuit. The specific structure of the first voltage sampling circuit has been described in the previous embodiments, and the specific structure of the second voltage sampling circuit will not be elaborated here.

[0062] Meanwhile, the present application uses specific terms to describe the embodiments of the present application. For example, "an embodiment", "one embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "an embodiment" or "one embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the present application can be appropriately combined.

[0063] Similarly, it should be noted that, in order to simplify the description of the present application and thus help the understanding of one or more embodiments of the application, in the foregoing description of the embodiments of the present application, sometimes multiple features are grouped into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the subject matter of the present application are more than those mentioned in the claims. In fact, the features of the embodiment are fewer than all the features of the single embodiment disclosed above.

Claims

1. A coil control circuit, characterized in that: include: Main control module, with local control mode and remote control mode; A power module, electrically connected to the input terminal of the main control module; A PLC control module, electrically connected to the input end of the main control module; A PLC enabling module, electrically connected to the output end of the power module and the input end of the main control module, and used to control the main control module to switch between the local control mode and the remote control mode; The coil circuit module is electrically connected to the output end of the main control module and the output end of the power module.

2. The coil control circuit according to claim 1, characterized in that: When the main control module is in the local control mode, the PLC enabling module is in a disconnected state, the power supply module supplies power to the coil circuit module, and the main control module sends an action signal to the coil circuit module; When the main control module is in the remote control mode, the PLC enabling module is in a closed state, the power supply module supplies power to the coil circuit module, and the main control module receives the control signal of the PLC control module and sends an action signal to the coil circuit module.

3. The coil control circuit according to claim 1, characterized in that: The PLC control module includes a suppression diode, a first voltage-dividing resistor, a second voltage-dividing resistor, a first optical coupler, a first pull-up resistor, a second pull-up resistor, and a first capacitor, wherein two ends of the first voltage-dividing resistor are electrically connected to the power module and the first pin of the first optical coupler, respectively, and two ends of the second voltage-dividing resistor are electrically connected to the power module and the second pin of the first optical coupler, respectively, a first node is provided between the first voltage-dividing resistor and the power module, a second node is provided between the second voltage-dividing resistor and the power module, and the first voltage-dividing resistor is connected in parallel with the second voltage-dividing resistor, two ends of the suppression diode are connected to the first node and the second node, respectively, a third pin of the first optical coupler is connected to the third node, a fourth pin of the first optical coupler is connected to the fourth node, two ends of the first pull-up resistor are connected to the fourth node and the fifth node, respectively, two ends of the first capacitor are connected to the third node and the fifth node, and two ends of the second pull-up resistor are connected to the power module and the fourth node, respectively.

4. The coil control circuit according to claim 1, characterized in that: The PLC enabling module includes a first diode, a current limiting resistor, a second optical coupler, a third pull-up resistor, a fourth pull-up resistor, a second capacitor and a control switch, wherein the first diode includes an anode electrically connected to the output end of the power module and a cathode electrically connected to the first pin of the second optical coupler, two ends of the current limiting resistor are electrically connected to the second pin of the second optical coupler and the control switch, two ends of the third pull-up resistor are electrically connected to the sixth node and the PLC signal line, two ends of the fourth pull-up resistor are electrically connected to the power module and the sixth node, a fourth pin of the second optical coupler is connected to the sixth node, two ends of the second capacitor are electrically connected to the seventh node and the eighth node, the seventh node is located between the third pull-up resistor and the PLC signal line, and the eighth node is located between the third pin of the second optical coupler and the first ground line.

5. The coil control circuit according to claim 1, characterized in that: The coil circuit module includes two coil circuits, both of which are electrically connected to the power module and the main control module, and the two coil circuits are connected in parallel or in series.

6. The coil control circuit according to claim 5, characterized in that: The coil circuit includes a drive circuit, a temperature measurement circuit, a current sampling circuit and a coil. The input end of the drive circuit is electrically connected to the output end of the main control module, the output end of the drive circuit is connected to the input end of the coil, the input end of the coil is also electrically connected to the power supply module, the output end of the coil is electrically connected to the temperature measurement circuit and the current sampling circuit, and the output end of the temperature measurement circuit and the output end of the current sampling circuit are both electrically connected to the receiving end of the main control module.

7. The coil control circuit according to claim 6, characterized in that: The coil circuit also includes a quick release circuit, and two ends of the quick release circuit are electrically connected to the output end of the main control module and the input end of the coil respectively.

8. The coil control circuit according to claim 1, characterized in that: The power supply module includes a main power supply, an EMC circuit, a first voltage sampling circuit, a switching power supply and a linear power supply. The main power supply is electrically connected to an input end of the EMC circuit and an input end of the first voltage sampling circuit. The output end of the EMC circuit is electrically connected to an input end of the switching power supply. The output end of the switching power supply is electrically connected to an input end of the linear power supply. The output end of the linear power supply is electrically connected to both the PLC enabling module and the main control module.

9. The coil control circuit according to claim 1, characterized in that: The output end of the PLC control module is electrically connected to a second voltage sampling circuit, and the output end of the second voltage sampling circuit is electrically connected to the input end of the main control module.

10. A contactor, characterized in that: The invention comprises a coil control circuit as claimed in any one of claims 1 to 9.

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