Control circuit for contactor and contactor

Abstract

The present application relates to the field of electronic technology, and in particular to a control circuit and a contactor for a contactor. The control circuit includes a first power supply circuit, a first protection circuit, a first control unit, a first power supply and a first coil drive circuit; the input end of the first power supply circuit is used to connect to the main contact of the contactor; the first power supply circuit is used to supply power to the first coil unit and the first power supply after taking power from the main contact of the contactor; the output end of the first power supply circuit is used to connect to the first power supply end of the first coil unit through the first protection circuit; the first protection circuit is used to suppress the instantaneous high voltage generated on the first power supply circuit, so that the first power supply circuit outputs to the downstream first power supply, the first control unit and the first coil drive circuit to avoid being damaged by high voltage shock, thereby ensuring the working life of the downstream first power supply, the first control unit and the first coil drive circuit.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a control circuit for a contactor and a contactor. Background Art

[0002] Contactors are common electronic devices that are widely used in various control circuit scenarios. In related technologies, the power supply terminal of the load is generally connected to the main contact of the coil unit in the contactor. When the main contact of the contactor is closed, the load is connected to the circuit and turned on.

[0003] Generally, the control circuit of the contactor also draws power from the main contact of the contactor. For example, the power supply end of the control circuit is connected to the incoming line end of the main contact to draw power. When the main contact is closed, high voltage is usually generated, that is, surge phenomenon occurs, and it will last for 1 to 2ms. The instantaneous high voltage will have a strong impact on the coil control system downstream of the control circuit, causing damage to the coil control system or shortening the service life of the coil control system. Utility Model Content

[0004] The present application provides a control circuit and a contactor for a contactor, so as to solve the technical problem in the related art that instantaneous high voltage damages the service life of a downstream coil control system.

[0005] In a first aspect, the present application provides a control circuit for a contactor, the contactor comprising a first coil unit, the control circuit being used to control the first coil unit to be powered on or off, thereby controlling the contactor to be closed or released; the control circuit comprising a first power supply circuit, a first protection circuit, a first control unit, a first power supply, and a first coil drive circuit;

[0006] The input end of the first power circuit is used to connect to the main contact of the contactor, and the output end of the first power circuit is used to connect to the first power supply end of the first coil unit through the first protection circuit; the second power supply end of the first coil unit is connected to the power supply input end of the first power supply;

[0007] The first power circuit is used to supply power to the first coil unit and the first power supply after taking power from the main contact of the contactor; the first protection circuit is used to suppress the instantaneous high voltage generated on the first power circuit;

[0008] The power supply output end of the first power supply is connected to the power supply end of the first coil drive circuit and the first control unit respectively; the first power supply is used to supply power to the first control unit and the first coil drive circuit;

[0009] The first control unit is used to output a control signal to the first coil driving circuit;

[0010] The output end of the first coil driving circuit is connected to the second power supply end of the first coil unit; the first coil driving circuit is used to generate a corresponding driving signal according to the control signal, and the driving signal is used to control the first coil unit to power on or off.

[0011] In some embodiments, the control circuit further includes a second protection circuit;

[0012] The first end of the second protection circuit is connected to the second power supply end of the first coil unit, and the second power supply end of the first coil unit is also connected to the power supply input end of the first power supply through the second protection circuit;

[0013] The second protection circuit is used to suppress the instantaneous high voltage output by the second power supply end of the first coil unit.

[0014] In some embodiments, the first protection circuit includes a first diode, at least one capacitor, and at least one resistor;

[0015] The at least one capacitor and the at least one resistor are connected in series to form a voltage absorption circuit;

[0016] The anode of the first diode is connected to the output end of the first power extraction circuit, and the cathode of the first diode is connected to the input end of the voltage absorption circuit.

[0017] In some embodiments, the first protection circuit includes a first capacitor, a second capacitor, a first resistor, and a second resistor;

[0018] A first end of the first capacitor is connected to the cathode of the first diode, a second end of the first capacitor is connected to the first end of the second capacitor, and a second end of the second capacitor is grounded;

[0019] The first resistor is connected in parallel with the first capacitor, and the second resistor is connected in parallel with the second capacitor.

[0020] In some embodiments, the second protection circuit includes a second diode, a third capacitor, a fourth capacitor, a first voltage zener diode and a second voltage zener diode;

[0021] The anode of the second diode is connected to the second power supply end of the first coil unit, the cathode of the second diode is connected to the first end of the third capacitor, the second end of the third capacitor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is grounded;

[0022] The first Zener diode is connected in parallel with the third capacitor, and the anode of the first Zener diode is connected to the second end of the third capacitor; the second Zener diode is connected in parallel with the fourth capacitor, and the anode of the second Zener diode is connected to the second end of the fourth capacitor.

[0023] In some embodiments, the first power extraction circuit includes an inverter circuit and at least one EMC protection circuit;

[0024] The input end of the inverter circuit is the input end of the first power-taking circuit, and the output end of the inverter circuit is the output end of the first power-taking circuit; the at least one EMC protection circuit is arranged at the input end or the output end of the inverter circuit;

[0025] The inverter circuit is used to convert the input alternating current into direct current; and the at least one EMC protection circuit is used to perform electromagnetic compatibility processing on the input alternating current.

[0026] In some embodiments, the first power extraction circuit includes a first EMC protection circuit and a second EMC protection circuit;

[0027] The input end of the first EMC protection circuit is the input end of the first power-taking circuit and is connected to the main contact of the contactor. The output end of the first EMC protection circuit is connected to the input end of the inverter circuit. The output end of the inverter circuit is connected to the input end of the second EMC protection circuit. The output end of the second EMC protection circuit is the output end of the first power-taking circuit.

[0028] In some embodiments, it further includes a first voltage sampling circuit;

[0029] The sampling end of the first voltage sampling circuit is connected to the first power taking circuit, and the output end of the first voltage sampling circuit is connected to the first control unit;

[0030] The first voltage sampling circuit is used to collect the voltage value input to the busbar of the first power-taking circuit, and input the collected voltage value to the first control unit.

[0031] In some embodiments, the first voltage sampling circuit includes a third diode, a fourth diode and at least two resistors;

[0032] The at least two resistors are connected in series to form a series voltage divider circuit;

[0033] The positive electrode of the third diode is connected to the first busbar of the inverter circuit input end, and the positive electrode of the fourth diode is connected to the second busbar of the inverter circuit input end; the cathode of the third diode and the cathode of the fourth diode are short-circuited; and the cathode of the third diode and the cathode of the fourth diode are connected to the first end of the series voltage divider circuit, and the second end of the series voltage divider circuit is grounded; one end of a resistor in the series voltage divider circuit is the output end of the first voltage sampling circuit, and is connected to the first control unit.

[0034] In a second aspect, the present application provides a contactor, which includes the control circuit for the contactor as described above.

[0035] The control circuit for the contactor provided by the above-mentioned first aspect includes a first power supply circuit, a first protection circuit, a first control unit, a first power supply and a first coil drive circuit; the input end of the first power supply circuit is used to connect to the main contact of the contactor, and the second power supply end of the first coil unit is connected to the power supply input end of the first power supply; the first power supply circuit is used to supply power to the first coil unit and the first power supply after drawing power from the main contact of the contactor; wherein the output end of the first power supply circuit is used to connect to the first power supply end of the first coil unit through the first protection circuit; the first protection circuit is used to suppress the instantaneous high voltage generated on the first power supply circuit, so that the first power supply circuit outputs to the downstream first power supply, the first control unit and the first coil drive circuit to avoid them being damaged by high voltage shock, thereby ensuring the working life of the downstream first power supply, the first control unit and the first coil drive circuit.

[0036] The beneficial effects provided in the above-mentioned second aspect and various possible designs of the above-mentioned second aspect can refer to the beneficial effects brought about by the above-mentioned first aspect and various possible implementation methods of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0038] Figure 1 A schematic diagram of a contactor control circuit structure provided in the related art;

[0039] Figure 2 One of the schematic diagrams of the control circuit structure for a contactor provided in an embodiment of the present application;

[0040] Figure 3 A schematic diagram of the first protection circuit structure provided in an embodiment of the present application;

[0041] Figure 4 The second schematic diagram of the control circuit structure for the contactor provided in the embodiment of the present application;

[0042] Figure 5 A schematic diagram of the structure of a second protection circuit provided in an embodiment of the present application;

[0043] Figure 6 The third schematic diagram of the control circuit structure for a contactor provided in an embodiment of the present application.

[0044] Figure numerals: 101-second coil unit, 102-second power supply, 103-second control unit, 104-second coil drive circuit, 105-second power supply circuit, 106-second voltage sampling circuit; 201-first coil unit, 202-first power supply, 203-first control unit, 204-first coil drive circuit, 205-first power supply circuit, 206-first protection circuit, 207-second protection circuit, 208-first voltage sampling circuit, 205 1-first EMC protection circuit, 2052-second EMC protection circuit, 2053-inverter circuit, D1-first diode, D2-second diode, D3-third diode, D4-fourth diode, C1-first capacitor, C2-second capacitor, C3-third capacitor, C4-fourth capacitor, R1-first resistor, R2-second resistor, R3-third resistor, R4-fourth resistor, R5-fifth resistor, TVS1-first voltage-stabilizing diode, TVS2-second voltage-stabilizing diode. DETAILED DESCRIPTION

[0045] In this application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c alone can represent: a, b, c, a and b, a and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0046] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0047] The terms "connected" and "connected" should be understood in a broad sense. For example, the "connected" or "connected" of a circuit structure can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] Figure 1 This is a schematic diagram of a contactor control circuit structure provided in the related technology, please refer to Figure 1 As shown, the contactor control circuit includes a second coil unit 101 , a second power supply 102 , a second control unit 103 , a second coil drive circuit 104 , a second power supply circuit 105 and a second voltage sampling circuit 106 .

[0049] The input terminals IN1 and IN2 of the second power supply circuit 105 are connected to the main contacts of the contactor, and are used to supply power to the second coil unit 101 and the second power supply 102 after taking power from the main contacts. The power supply output terminal of the second power supply 102 is respectively connected to the power supply terminal of the second coil drive circuit 104 and the second control unit 103; the second power supply 102 is used to supply power to the second control unit 103 and the second coil drive circuit 104. The second voltage sampling circuit 106 is used to collect the voltage value on the bus in the second power supply circuit 105, so as to determine whether the current input power is normally powered off or the power supply voltage drops according to the voltage on the bus. The second control unit 103 is used to output a control signal to the second coil drive circuit 104; the output terminal of the second coil drive circuit 104 is connected to the second coil unit 101; wherein the second coil unit 101 includes a coil for generating a magnetic field and related peripheral circuits. The second coil driving circuit 104 is used to generate a corresponding driving signal according to the control signal; the driving signal is used to control the second coil unit 101 to be powered on or off, thereby controlling the main contacts of the contactor to be attracted or released.

[0050] In the related art, low-power electronic contactors are widely used in new energy fields such as charging piles and energy storage. For example, in the field of charging piles, the control circuit for the contactor usually draws power from the main contacts of the contactor. After the charging gun is connected, a high voltage will be generated on the main contacts at the moment the main contacts of the contactor are energized. The instantaneously generated high voltage will produce a strong voltage impact on the second control unit 103, the second power supply 102 and the second coil drive circuit 104 in the coil control system downstream of the control circuit. Specifically, it mainly impacts the transistors in the second control unit 103, the second power supply 102 and the second coil drive circuit 104, thereby shortening the working life of the second control unit 103, the second power supply 102 and the second coil drive circuit 104. In severe cases, it may even cause the second control unit 103, the second power supply 102 and the second coil drive circuit 104 to be damaged on the spot.

[0051] In order to overcome the defects in the above-mentioned related technologies, the present application provides a control circuit for a contactor, in which a first protection circuit is arranged between the second power supply circuit 105 and the second coil unit 101, and the first protection circuit is used to suppress the instantaneous high voltage generated on the second power supply circuit 105; in other words, the first protection circuit can absorb the instantaneous high voltage generated when the main contacts are closed, thereby preventing the instantaneous high voltage from damaging the downstream second control unit 103, the second power supply 102 and the second coil drive circuit 104.

[0052] Figure 2 One of the control circuit structure diagrams for the contactor provided in the embodiment of the present application is shown in FIG. Figure 2 As shown, the control circuit includes a first coil unit 201 , a first power supply 202 , a first control unit 203 , a first coil driving circuit 204 , a first power supply circuit 205 , and a first protection circuit 206 .

[0053] Among them, the input terminals L1 and L2 of the first power supply circuit 205 are used to connect to the main contacts of the contactor, and the output terminal of the first power supply circuit 205 is used to connect to the first power supply terminal of the first coil unit 201 through the first protection circuit 206; the second power supply terminal of the first coil unit 201 is connected to the power supply input terminal of the first power supply 202.

[0054] The first power circuit 205 is used to supply power to the first coil unit 201 and the first power supply 202 after drawing power from the main contact of the contactor; the first protection circuit 206 is used to suppress the instantaneous high voltage generated on the first power circuit 205 to absorb the instantaneous peak voltage.

[0055] The power supply output end of the first power supply 202 is connected to the power supply end of the first coil drive circuit 204 and the first control unit 203 respectively; the first power supply 202 is used to supply power to the first control unit 203 and the first coil drive circuit 204. It can be understood that the first power supply 202 may include a voltage conversion circuit, which converts the received voltage, specifically, it can be converted into the power supply voltage required by the first coil drive circuit 204 and the first control unit 203, and then outputs the power supply voltage to supply power to the first coil drive circuit 204 and the first control unit 203.

[0056] The first control unit is used to output a control signal to the first coil drive circuit 204; the output end of the first coil drive circuit 204 is connected to the second power supply end of the first coil unit 201; the first coil drive circuit 204 is used to generate a corresponding drive signal according to the control signal, and the drive signal is used to control the first coil unit to power on or off. In other words, the drive signal is used to control the first coil unit to be turned on or off to realize the main contact to be attracted or released.

[0057] It can be seen that in this embodiment, a first protection circuit 206 is arranged between the first power supply circuit 205 and the first coil unit 201. The first protection circuit 206 is used to absorb the instantaneous peak voltage, which is equivalent to suppressing the instantaneous high voltage generated on the first power supply circuit 205, so as to avoid the instantaneous high voltage flowing into the first coil unit 201, the first power supply 202, the first control unit 203 and the first coil drive circuit 204, so as to damage the first coil unit 201, the first power supply 202, the first control unit 203 and the first coil drive circuit 204, thereby ensuring the working life of the first power supply 202, the first control unit 203 and the first coil drive circuit 204.

[0058] Furthermore, in the present embodiment, the input end of the first power supply 202 is moved from point A to point B in the related art, that is, from the first power supply end of the first coil unit 201 to the second power supply end, so that the coil in the first coil unit 201 will also have a certain inhibitory effect on the instantaneous high voltage and surge, and further protect the downstream first power supply 202, the first control unit 203 and the first coil drive circuit 204.

[0059] In some embodiments, the first control unit 203 may be a microcontroller unit (MCU).

[0060] In some embodiments, the first protection circuit 206 may include at least one capacitor, which may absorb the instantaneously generated high voltage to a certain extent, so as to achieve the purpose of absorbing the instantaneously generated peak voltage.

[0061] In addition, during the operation of the contactor, the release time of the contactor is one of the key factors affecting the working life of the contactor. Therefore, when the input power is off, it is necessary to detect the information of the input power off in a timely manner. After the first control unit 203 detects the information of the input power off, it immediately controls the first coil drive circuit 204 to output a corresponding drive signal to power off the first coil unit 201 (that is, the circuit is disconnected). Only in this way can the service life of each circuit unit in the contactor control circuit be guaranteed.

[0062] In some embodiments, if only a high-power capacitor is used to absorb the instantaneous peak voltage, the control circuit of the contactor will lose power more slowly. In this way, when the input power is cut off, the voltage on the first power supply circuit 205 will slowly decrease. The first voltage sampling circuit cannot determine whether the current state is that the input power is cut off or the input power voltage is reduced, which will affect the efficiency of detecting the input power cut information, and then affect the release speed of the contactor, which will also lead to the service life of each circuit unit in the contactor control circuit.

[0063] In order to overcome the above-mentioned defect that the use of capacitors to absorb peak voltage will also affect the service life of each circuit unit in the contactor control circuit, a first protection circuit is further provided in this embodiment, which includes a first diode, at least one capacitor and at least one resistor; at least one capacitor and at least one resistor are connected in series to form a voltage absorption circuit; the positive electrode of the first diode is connected to the output end of the first power supply circuit, and the negative electrode of the first diode is connected to the input end of the voltage absorption circuit.

[0064] According to the first protection circuit provided in the above embodiment, when the main contact of the contactor is closed and generates instantaneous high voltage, the instantaneous high voltage will charge the voltage absorption circuit through the first diode, thereby absorbing the energy of the instantaneous high voltage (i.e., the peak voltage) to achieve the purpose of suppressing the instantaneous high voltage, so as to protect the downstream first coil unit 201, the first power supply 202, the first control unit 203 and the first coil drive circuit 204. When the instantaneous high voltage stops, the capacitor in the voltage absorption circuit will discharge the resistor, which is equivalent to being released through the resistor in the voltage absorption circuit, waiting for the next instantaneous high voltage to come, thereby protecting the control circuit.

[0065] When the input power supply voltage loses power, due to the reverse cutoff effect of the first diode, the capacitor in the voltage absorption circuit cannot discharge the first coil unit 201, causing the current in the first coil unit 201 to drop rapidly, thereby causing the voltage on the bus in the first power supply circuit 205 to drop rapidly. The first voltage sampling circuit can quickly determine that the current state is that the input power is off, and the first control unit 203 outputs a corresponding control signal to control the first coil drive circuit 204 to drive the main contact in the first coil unit 201 to release, thereby protecting the working life of the contactor.

[0066] The present application further provides a first protection circuit, Figure 3 For a schematic diagram of the first protection circuit structure provided in the embodiment of the present application, please refer to Figure 3 As shown, the first protection circuit 206 includes a first diode D1, a first capacitor C1, a second capacitor C2, a first resistor R1 and a second resistor R2. The first end of the first capacitor C1 is connected to the cathode of the first diode D1, the second end of the first capacitor C1 is connected to the first end of the second capacitor C2, and the second end of the second capacitor C2 is grounded; the first resistor R1 is connected in parallel with the first capacitor C1, and the second resistor R2 is connected in parallel with the second capacitor C2.

[0067] It can be seen that when the main contact of the contactor is closed to generate instantaneous high voltage, the instantaneous high voltage will charge the first capacitor C1 and the second capacitor C2 through the first diode D1, thereby absorbing the energy of the instantaneous high voltage to achieve the purpose of suppressing the instantaneous high voltage. When the input power supply voltage is powered off, due to the reverse cutoff effect of the first diode D1, the first capacitor C1 and the second capacitor C2 cannot discharge the first coil unit 201, resulting in a rapid decrease in the current in the first coil unit 201, thereby causing the voltage on the bus in the first power circuit 205 to drop rapidly, and then the first voltage sampling circuit can quickly determine that the current state is that the input power supply is powered off, and then the first control unit 203 outputs a corresponding control signal to control the first coil drive circuit 204 to drive the main contact in the first coil unit 201 to release, thereby achieving the purpose of protecting the working life of the contactor.

[0068] It is understandable that, in other embodiments, the resistor in the first protection circuit 206 may be replaced by a voltage regulator diode or a transient voltage suppressor diode TVS (Transient Voltage Suppressor), and the above technical effect may also be achieved.

[0069] Figure 4 For the second schematic diagram of the control circuit structure for the contactor provided in the embodiment of the present application, please refer to Figure 4As shown, in some embodiments, the control circuit further includes a second protection circuit 207; a first end of the second protection circuit 207 is connected to the second power supply end of the first coil unit 201, and the second power supply end of the first coil unit 201 is also connected to the power supply input end of the first power supply 202 through the second protection circuit. The second protection circuit 207 is used to suppress the instantaneous high voltage output by the second power supply end of the first coil unit, and further protects the first power supply 202, the first control unit 203 and the first coil drive circuit 204.

[0070] Figure 5 For a schematic diagram of the structure of the second protection circuit provided in the embodiment of the present application, see Figure 5 As shown, the second protection circuit includes a second diode D2, a third capacitor C3, a fourth capacitor C4, a first voltage zener diode TVS1 and a second voltage zener diode TVS2. The anode of the second diode D2 is connected to the second power supply end of the first coil unit 201, the cathode of the second diode D2 is connected to the first end of the third capacitor C3, the second end of the third capacitor C3 is connected to the first end of the fourth capacitor C4, and the second end of the fourth capacitor C4 is grounded. The first voltage zener diode TVS1 is connected in parallel with the third capacitor C3, and the anode of the first voltage zener diode TVS1 is connected to the second end of the third capacitor C3; the second voltage zener diode TVS2 is connected in parallel with the fourth capacitor C4, and the anode of the second voltage zener diode TVS2 is connected to the second end of the fourth capacitor C4.

[0071] It should be noted that, generally, when the first coil driving circuit 204 drives the first coil unit 201 to be electrically turned on, it is mainly achieved by lowering the voltage of the second power supply end of the first coil unit 201 .

[0072] It can be seen that when a spike voltage is generated, the third capacitor C3 and the fourth capacitor C4 will also absorb the generated spike voltage, further preventing the spike voltage from damaging the first power supply 202, the first control unit 203 and the first coil drive circuit 204.

[0073] Through the second protection circuit provided in this embodiment, due to the directional cutoff effect of the second diode D2, when the first coil driving circuit 204 controls the first coil unit 201 to be turned on, it can be avoided that the first coil driving circuit 204 simultaneously lowers the input voltage of the first power supply 202 when lowering the voltage of the second power supply end of the first coil unit 201, causing the first power supply 202 to lose power.

[0074] When the main contact of the contactor is in the energized state, the first coil drive circuit 204 is generally required to output a certain holding current to maintain the conduction of the first coil unit 201. When the second protection circuit provided in this embodiment is adopted, the third capacitor C3, the fourth capacitor C4, the first voltage zener diode TVS1 and the second voltage zener diode TVS2 in the second protection circuit 207 will form a current loop, so that the current in the current loop can also serve the purpose of maintaining the conduction of the first coil unit 201, thereby reducing the magnitude of the holding current output by the first coil drive circuit 204 and saving the electric energy of the control circuit. At the same time, the transistor in the first coil drive circuit 204 does not need to flow through a larger holding circuit, which also ensures the working life of the first coil drive circuit 204.

[0075] When releasing the contactor, the purpose of quickly releasing the contactor is generally achieved by changing the loop impedance of the first coil unit 201. At this time, the first coil unit 201 will generate a reverse electromotive force at the output end of the first coil drive circuit 204. At this time, the third capacitor C3 and the fourth capacitor C4 have a good absorption effect on the reverse electromotive force generated by the first coil unit 201, thereby avoiding damage to the first coil drive circuit 204 caused by the reverse electromotive force generated by the first coil unit 201.

[0076] It is understandable that, in other embodiments, the voltage-stabilizing diode in the second protection circuit 207 may be replaced by a resistor or a transient voltage suppressor diode TVS (Transient Voltage Suppressor), and the above technical effects may also be achieved.

[0077] In one embodiment, in order to prevent the voltage input to the first power supply 202 from being too high to damage it, a sixth resistor R6 can be connected in series between the cathode of the second diode D2 and the input end of the first power supply 202, and the sixth resistor R6 plays a role of voltage division. The resistance value of the sixth resistor R6 can be selected according to actual circuit requirements.

[0078] In some embodiments, the first power supply circuit 205 includes an inverter circuit and at least one EMC protection circuit; the input end of the inverter circuit is the input end of the first power supply circuit, and the output end of the inverter circuit is the output end of the first power supply circuit; at least one EMC protection circuit is arranged on the input end or the output end of the inverter circuit; the inverter circuit is used to convert the input alternating current into direct current; and at least one EMC protection circuit is used to perform electromagnetic compatibility processing on the input alternating current.

[0079] Figure 6 For the third schematic diagram of the control circuit structure for the contactor provided in the embodiment of the present application, please refer to Figure 6As shown, in some embodiments, the first power supply circuit 205 includes a first EMC protection circuit 2051, a second EMC protection circuit 2052 and an inverter circuit 2053; the input end of the first EMC protection circuit 2051 is the input end of the first power supply circuit 205 and is connected to the main contact of the contactor, and the output end of the first EMC protection circuit 2051 is connected to the input end of the inverter circuit 2053; the output end of the inverter circuit 2053 is connected to the input end of the second EMC protection circuit 2052, and the output end of the second EMC protection circuit 2052 is the output end of the first power supply circuit 205.

[0080] Among them, the first EMC protection circuit 2051 is used to perform electromagnetic compatibility processing on the alternating current before being input into the inverter circuit 2053, and the second EMC protection circuit 2052 is used to perform electromagnetic compatibility processing on the direct current output by the inverter circuit 2053, so as to ensure that the stability of the direct current output by the second EMC protection circuit 2052 is better.

[0081] In some embodiments, the control circuit also includes a first voltage sampling circuit; the sampling end of the first voltage sampling circuit is connected to the first power supply circuit, and the output end of the first voltage sampling circuit is connected to the first control unit; the first voltage sampling circuit is used to collect the voltage value input on the bus of the first power supply circuit, and input the collected voltage value to the first control unit 203, so that the first control unit 203 can determine the state of the input power supply voltage on the first power supply circuit 205 according to the collected voltage value.

[0082] Specifically, the state of the input power voltage on the first power circuit 205 includes two states: the input power is off or the input power voltage is reduced. When the input power is off, the contactor needs to be released.

[0083] In some embodiments, the control circuit also includes a first voltage sampling circuit 208; the first voltage sampling circuit 208 includes a third diode D3, a fourth diode D4 and at least two resistors; at least two resistors are connected in series to form a series voltage divider circuit, and one end of a resistor in the series voltage divider circuit is the output end of the first voltage sampling circuit and is connected to the first control unit 103.

[0084] Please continue to refer to Figure 6As shown, the first voltage sampling circuit 208 includes a third diode D3, a fourth diode D4, a third resistor R3, a fourth resistor R4 and a fifth resistor R5. The third resistor R3, the fourth resistor R4 and the fifth resistor R5 are connected in series to form a series voltage divider circuit. Among them, the positive electrode of the third diode D3 is connected to the first bus L1 at the input end of the inverter circuit 2053, and the positive electrode of the fourth diode D4 is connected to the second bus L2 at the input end of the inverter circuit 2054; the cathode of the third diode D3 and the cathode of the fourth diode D4 are short-circuited; and the cathode of the third diode D3 and the cathode of the fourth diode D4 are connected to the first end of the series voltage divider circuit, and the second end of the series voltage divider circuit is grounded; the first end of the fifth resistor R5 is the output end of the first voltage sampling circuit, and is connected to the first control unit 103.

[0085] The embodiment of the present application further provides a contactor, which includes the control circuit for the contactor as described above. The functions and technical effects of the contactor can refer to the control circuit described above, and will not be described in detail here.

[0086] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A control circuit for a contactor, the contactor comprising a first coil unit, the control circuit being used to control the first coil unit to be powered on or off, thereby controlling the contactor to be closed or released; characterized in that: The control circuit includes a first power supply circuit, a first protection circuit, a first control unit, a first power supply and a first coil driving circuit; The input end of the first power circuit is used to connect to the main contact of the contactor, and the output end of the first power circuit is used to connect to the first power supply end of the first coil unit through the first protection circuit; the second power supply end of the first coil unit is connected to the power supply input end of the first power supply; The first power supply circuit is used to supply power to the first coil unit and the first power supply after taking power from the main contact of the contactor; The first protection circuit is used to suppress the instantaneous high voltage generated on the first power taking circuit; The power supply output end of the first power supply is connected to the power supply end of the first coil drive circuit and the first control unit respectively; the first power supply is used to supply power to the first control unit and the first coil drive circuit; The first control unit is used to output a control signal to the first coil driving circuit; The output end of the first coil driving circuit is connected to the second power supply end of the first coil unit; the first coil driving circuit is used to generate a corresponding driving signal according to the control signal, and the driving signal is used to control the first coil unit to power on or off.

2. The control circuit according to claim 1, characterized in that: Also comprising a second protection circuit; The first end of the second protection circuit is connected to the second power supply end of the first coil unit, and the second power supply end of the first coil unit is also connected to the power supply input end of the first power supply through the second protection circuit; The second protection circuit is used to suppress the instantaneous high voltage output by the second power supply end of the first coil unit.

3. The control circuit according to claim 1 or 2, characterized in that: The first protection circuit includes a first diode, at least one capacitor and at least one resistor; The at least one capacitor and the at least one resistor are connected in series to form a voltage absorption circuit; The anode of the first diode is connected to the output end of the first power extraction circuit, and the cathode of the first diode is connected to the input end of the voltage absorption circuit.

4. The control circuit according to claim 3, characterized in that: The first protection circuit includes a first capacitor, a second capacitor, a first resistor and a second resistor; A first end of the first capacitor is connected to the cathode of the first diode, a second end of the first capacitor is connected to the first end of the second capacitor, and a second end of the second capacitor is grounded; The first resistor is connected in parallel with the first capacitor, and the second resistor is connected in parallel with the second capacitor.

5. The control circuit according to claim 2, characterized in that: The second protection circuit includes a second diode, a third capacitor, a fourth capacitor, a first voltage stabilizing diode and a second voltage stabilizing diode; The anode of the second diode is connected to the second power supply end of the first coil unit, the cathode of the second diode is connected to the first end of the third capacitor, the second end of the third capacitor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is grounded; The first Zener diode is connected in parallel with the third capacitor, and the anode of the first Zener diode is connected to the second end of the third capacitor; the second Zener diode is connected in parallel with the fourth capacitor, and the anode of the second Zener diode is connected to the second end of the fourth capacitor.

6. The control circuit according to claim 1 or 2, characterized in that: The first power supply circuit includes an inverter circuit and at least one EMC protection circuit; The input end of the inverter circuit is the input end of the first power-taking circuit, and the output end of the inverter circuit is the output end of the first power-taking circuit; the at least one EMC protection circuit is arranged at the input end or the output end of the inverter circuit; The inverter circuit is used to convert the input alternating current into direct current; and the at least one EMC protection circuit is used to perform electromagnetic compatibility processing on the input alternating current.

7. The control circuit according to claim 6, characterized in that: The first power supply circuit includes a first EMC protection circuit and a second EMC protection circuit; The input end of the first EMC protection circuit is the input end of the first power-taking circuit and is connected to the main contact of the contactor. The output end of the first EMC protection circuit is connected to the input end of the inverter circuit. The output end of the inverter circuit is connected to the input end of the second EMC protection circuit. The output end of the second EMC protection circuit is the output end of the first power-taking circuit.

8. The control circuit according to claim 7, characterized in that: Also includes a first voltage sampling circuit; The sampling end of the first voltage sampling circuit is connected to the first power taking circuit, and the output end of the first voltage sampling circuit is connected to the first control unit; The first voltage sampling circuit is used to collect the voltage value input to the busbar of the first power-taking circuit, and input the collected voltage value to the first control unit.

9. The control circuit according to claim 8, characterized in that: The first voltage sampling circuit includes a third diode, a fourth diode and at least two resistors; The at least two resistors are connected in series to form a series voltage divider circuit; The positive electrode of the third diode is connected to the first busbar of the inverter circuit input end, and the positive electrode of the fourth diode is connected to the second busbar of the inverter circuit input end; the cathode of the third diode and the cathode of the fourth diode are short-circuited; and the cathode of the third diode and the cathode of the fourth diode are connected to the first end of the series voltage divider circuit, and the second end of the series voltage divider circuit is grounded; one end of a resistor in the series voltage divider circuit is the output end of the first voltage sampling circuit, and is connected to the first control unit.

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

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