Voltage doubler switch drive circuit and electromagnetic switch device

Abstract

The utility model discloses a kind of voltage-doubler switch drive circuit and electromagnetic switch device, it is related to the technical field of magnetron type switch circuit.Electromagnetic switch device includes electromagnetic switch assembly and control circuit, voltage-doubler switch drive circuit includes: power input end;Voltage-doubler circuit, with power input end electricity is connected, for output first voltage and second voltage;Drive circuit, the first input end of drive circuit and the first output end of voltage-doubler circuit electricity is connected, second input end and the second output end of voltage-doubler circuit electricity is connected, controlled end and control circuit electricity is connected, for receiving first voltage or second voltage, and when receiving the first drive control signal or the second drive control signal input by control circuit, electromagnetic switch assembly is driven to close or open gate.The utility model aims at not affecting the service life and abnormal bounce of electromagnetic switch assembly in electromagnetic switch device, to improve the total rate of electromagnetic switch assembly closing and opening gate.

Description

Technical Field

[0001] This utility model relates to the field of magnetically controlled switch circuit technology, and in particular to a voltage multiplier switch drive circuit and an electromagnetic switch device. Background Technology

[0002] With the rapid development of my country's economy and new energy sources, power users have increasingly higher requirements for power quality, including various requirements for resistance to voltage dips and low-voltage ride-through, necessitating improved power supply quality and rapid electromagnetic decoupling. Research has found that voltage drops in power quality issues mostly originate from short-circuit faults in medium-voltage distribution networks. Simultaneously, with the deepening integration of primary and secondary circuits in the medium-voltage distribution network sector, the operating speed of medium-voltage circuit breakers is required to be increasingly faster. Among these, magnetically controlled switches based on shape memory alloy semi-hard magnets have received significant attention and application.

[0003] In existing technologies, the drive circuits for magnetically controlled switches are all composed of H-bridges, with the same coil controlling the opening and closing. Therefore, the rate of change of the coil's current is related to the response time of excitation and demagnetization. Thus, a core principle for fast driving of magnetically controlled switches is to increase the rate of change of current. However, an excessively large rate of change of current will affect the closing bounce and lifespan, thus creating a contradiction in the drive power supply. Utility Model Content

[0004] The main purpose of this invention is to provide a voltage multiplier switch drive circuit and an electromagnetic switch device, which aims to improve the overall opening and closing rate of the electromagnetic switch assembly without affecting the service life of the electromagnetic switch assembly or abnormal bouncing in the electromagnetic switch device.

[0005] To achieve the above objectives, this utility model proposes a voltage multiplier switch driving circuit for use in an electromagnetic switching device. The electromagnetic switching device includes an electromagnetic switch assembly and a control circuit. The voltage multiplier switch driving circuit includes: Power input terminal, used to connect to external AC power; A voltage multiplier circuit, wherein the input terminal of the voltage multiplier circuit is electrically connected to the power input terminal; the voltage multiplier circuit is used to output a first voltage and a second voltage; The driving circuit has a first input terminal electrically connected to the first output terminal of the voltage multiplier circuit, a second input terminal electrically connected to the second output terminal of the voltage multiplier circuit, and a controlled terminal electrically connected to the control circuit. The driving circuit is configured to receive the first voltage and, upon receiving a first driving control signal input from the control circuit, drive the electromagnetic switch assembly to close; it is also configured to receive the second voltage and, upon receiving a second driving control signal input from the control circuit, drive the electromagnetic switch assembly to open. Wherein, the second voltage is an odd multiple of the first voltage, and the odd multiple is not 1.

[0006] In one embodiment, the voltage multiplier circuit is a triple voltage multiplier circuit.

[0007] In one embodiment, the tripler circuit includes a first diode, a second diode, a third diode, a first capacitor, a second capacitor, and a third capacitor; Wherein, the anode of the first diode is electrically connected to the first terminal of the second capacitor and the first terminal of the power input terminal; the cathode of the first diode is electrically connected to the second terminal of the first capacitor, the first input terminal of the driving circuit, the anode of the second diode, and the first terminal of the third capacitor; the second terminal of the second capacitor is electrically connected to the cathode of the second diode and the anode of the third diode; the first terminal of the first capacitor is electrically connected to the second input terminal of the power input terminal; and the second terminal of the third capacitor is electrically connected to the cathode of the third diode and the second input terminal of the driving circuit.

[0008] In one embodiment, the first capacitor is an electrolytic capacitor.

[0009] In one embodiment, the second capacitor and the third capacitor are thin-film capacitors.

[0010] In one embodiment, the first output terminal of the voltage multiplier circuit is electrically connected to the second terminal of the first capacitor, the cathode of the first diode, the anode of the second diode, and the first terminal of the third capacitor; the second output terminal of the voltage multiplier circuit is electrically connected to the first terminal of the third capacitor and the cathode of the third diode.

[0011] In one embodiment, the driving circuit includes a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, and an inductor; Wherein, the first terminal of the first switching transistor is electrically connected to the first output terminal of the voltage multiplier circuit; the second terminal of the first switching transistor is electrically connected to the first terminal of the inductor and the first terminal of the second switching transistor; and the controlled terminal of the first switching transistor is electrically connected to the control circuit. The second terminal of the second switching transistor is electrically connected to the second terminal of the third switching transistor and the ground terminal; and the controlled terminal of the second switching transistor is electrically connected to the control circuit. The first terminal of the third switching transistor is electrically connected to the second terminal of the inductor and the second terminal of the fourth switching transistor; and the controlled terminal of the third switching transistor is electrically connected to the control circuit. The first terminal of the fourth switching transistor is electrically connected to the second output terminal of the voltage multiplier circuit; and the controlled terminal of the fourth switching transistor is electrically connected to the control circuit.

[0012] In one embodiment, the first switch, the second switch, the third switch, and the fourth switch are all NMOS transistors.

[0013] This utility model also proposes an electromagnetic switch device, wherein the electromagnetic switch includes an electromagnetic switch assembly and a voltage multiplier switch drive circuit as described in any of the above claims.

[0014] This invention employs a voltage multiplier switch drive circuit for electromagnetic switching devices, effectively increasing the overall opening and closing speed of the electromagnetic switch components without affecting their lifespan or causing abnormal bouncing. The voltage multiplier switch drive circuit includes a power input terminal for connecting to external AC power, a voltage multiplier circuit for outputting a first voltage and a second voltage, and a drive circuit for driving the electromagnetic switch components to open and close. It is important to note that the second voltage used to open the electromagnetic switch components is an odd multiple of the first voltage used to close them. This odd multiple is not equal to 1. This method effectively increases the opening speed of the electromagnetic switch components, thereby improving the overall opening and closing speed. Since the closing speed remains constant, the problem of reduced lifespan and abnormal bouncing of the electromagnetic switch components due to excessively fast closing speeds is avoided. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the voltage multiplier switch drive circuit of this utility model; Figure 2 This is a circuit diagram of one embodiment of the voltage multiplier switch drive circuit of this utility model.

[0017] Explanation of icon numbers: 10. Electromagnetic switch assembly; 20. Control circuit; 30. Voltage multiplier circuit; 40. Drive circuit; D1-D3, first diode-third diode; C1-C3, first capacitor-third capacitor; Q1-Q4, first switching transistor-fourth switching transistor; L, inductor.

[0018] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0021] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0022] With the rapid development of my country's economy and new energy sources, power users have increasingly higher requirements for power quality, including various requirements for resistance to voltage dips and low-voltage ride-through, necessitating improved power supply quality and rapid electromagnetic decoupling. Research has found that voltage drops in power quality issues mostly originate from short-circuit faults in medium-voltage distribution networks. Simultaneously, with the deepening integration of primary and secondary circuits in the medium-voltage distribution network sector, the operating speed of medium-voltage circuit breakers is required to be increasingly faster. Among these, magnetically controlled switches based on shape memory alloy semi-hard magnets have received significant attention and application.

[0023] In existing technologies, the drive circuits for magnetically controlled switches are all composed of H-bridges, with the same coil controlling the opening and closing. Therefore, the rate of change of the coil's current is related to the response time of excitation and demagnetization. Thus, a core principle for fast driving of magnetically controlled switches is to increase the rate of change of current. However, an excessively large rate of change of current will affect the closing bounce and lifespan, thus creating a contradiction in the drive power supply.

[0024] To solve the above problems, refer to Figure 1 This utility model proposes a voltage multiplier switch driving circuit for use in an electromagnetic switching device. The electromagnetic switching device includes an electromagnetic switch assembly 10 and a control circuit 20. The voltage multiplier switch driving circuit includes: Power input terminal, used to connect to external AC power; A voltage multiplier circuit 30, the input terminal of which is electrically connected to the power input terminal; the voltage multiplier circuit 30 is used to output a first voltage and a second voltage; A drive circuit 40 is provided, wherein its first input terminal is electrically connected to the first output terminal of the voltage multiplier circuit 30, its second input terminal is electrically connected to the second output terminal of the voltage multiplier circuit 30, and its controlled terminal is electrically connected to the control circuit 20. The drive circuit 40 is configured to receive the first voltage and, upon receiving a first drive control signal input from the control circuit 20, drive the electromagnetic switch assembly 10 to close; it is also configured to receive the second voltage and, upon receiving a second drive control signal input from the control circuit 20, drive the electromagnetic switch assembly 10 to open. Wherein, the second voltage is an odd multiple of the first voltage, and the odd multiple is not 1.

[0025] In this embodiment, the electromagnetic switch assembly 10 is implemented as a switch assembly that can be driven and controlled by the drive circuit 40, such as a circuit breaker or contactor. The control circuit 20 can be implemented using a main controller, such as a System On Chip (SOC), Microcontroller Unit (MCU), Digital Signal Processor (DSP), or Field Programmable Gate Array (FPGA).

[0026] In this embodiment, the power input terminal is used to connect to external AC power. The external AC power can be 220V AC mains power. It is understood that the voltage multiplier circuit 30 requires a varying input voltage to achieve voltage superposition.

[0027] In this embodiment, the voltage multiplier circuit 30 can be selected according to actual needs to multiply the input voltage by a corresponding factor before outputting. It can be understood that the first voltage output from the first output terminal of the voltage multiplier circuit 30 is the DC voltage after rectification of the external AC power, and the second voltage output from the second output terminal of the voltage multiplier circuit 30 is the DC voltage after rectification and voltage multiplication of the external AC power. For example, if the voltage multiplier circuit 30 is a 5x voltage multiplier circuit, and the external AC power is 220V AC mains, the first voltage output from the first output terminal of the voltage multiplier circuit 30 will be 310V DC, and the second voltage output from the second output terminal of the voltage multiplier circuit 30 will be 1550V DC. To ensure that the voltage multiplier circuit 30 and the drive circuit 40 share a common ground, the first voltage output from the first output terminal of the voltage multiplier circuit 30 needs to be 2M+1 times the DC voltage after rectification of the external AC power, where M is a natural number; the second voltage output from the second output terminal of the voltage multiplier circuit 30 needs to be 2N+1 times the first voltage, where N is a positive integer. For example, when M is 0 and N is 1, the first voltage output by the first output terminal of the voltage multiplier circuit 30 is the DC voltage after rectification of the external AC power, and the second voltage output by the first output terminal of the voltage multiplier circuit 30 is 3 times the first voltage.

[0028] In this embodiment, the drive circuit 40 can be implemented using an H-bridge DC drive circuit 40. The drive circuit 40 drives the electromagnetic switch assembly 10 to close and open by receiving the first voltage and the second voltage output from the voltage multiplier circuit 30. To avoid reduced lifespan and abnormal bouncing of the magnetic switch assembly due to excessively fast closing speed, and to increase the overall closing and opening rate of the magnetic switch assembly, the current change rate of the electromagnetic switch assembly 10 is increased, i.e., the input voltage for opening the electromagnetic switch assembly 10 is increased, thereby keeping the input voltage for closing the electromagnetic switch assembly 10 constant. Furthermore, the controlled terminal of the drive circuit 40 is electrically connected to the control circuit 20, thereby controlling the opening and closing of the electromagnetic switch assembly 10 upon receiving the first and second drive control signals output from the control circuit 20.

[0029] By employing a voltage multiplier switch drive circuit in an electromagnetic switch device, the overall opening and closing speed of the electromagnetic switch assembly 10 can be effectively increased without affecting its service life or abnormal bouncing. The voltage multiplier switch drive circuit includes a power input terminal for connecting to external AC power, a voltage multiplier circuit 30 for outputting a first voltage and a second voltage, and a drive circuit 40 for driving the electromagnetic switch assembly 10 to open and close. It is important to note that the second voltage used to drive the electromagnetic switch assembly 10 to open is 2N+1 times the first voltage used to drive it to close, where N is a positive integer. This method effectively increases the opening speed of the electromagnetic switch assembly 10, thereby improving its overall opening and closing speed. Since the closing speed remains constant, the reduced service life and abnormal bouncing of the electromagnetic switch assembly 10 due to excessively fast closing speed are avoided.

[0030] refer to Figure 2 In one embodiment of this utility model, the voltage multiplier circuit 30 is a triple voltage multiplier circuit.

[0031] In this embodiment, the voltage tripler circuit rectifies the AC voltage input to the power input terminal into a DC voltage and outputs a first voltage through the first output terminal of the voltage tripler circuit, and outputs a second voltage through the second output terminal of the voltage tripler circuit. The second voltage is three times the first voltage.

[0032] Optionally, the tripler circuit includes a first diode D1, a second diode D2, a third diode D3, a first capacitor C1, a second capacitor C2, and a third capacitor C3; Wherein, the anode of the first diode D1 is electrically connected to the first terminal of the second capacitor C2 and the first terminal of the power input terminal; the cathode of the first diode D1 is electrically connected to the second terminal of the first capacitor C1, the first input terminal of the driving circuit 40, the anode of the second diode D2, and the first terminal of the third capacitor C3; the second terminal of the second capacitor C2 is electrically connected to the cathode of the second diode D2 and the anode of the third diode D3; the first terminal of the first capacitor C1 is electrically connected to the second input terminal of the power input terminal; and the second terminal of the third capacitor C3 is electrically connected to the cathode of the third diode D3 and the second input terminal of the driving circuit 40.

[0033] In this embodiment, when the power input terminal is in the positive half-cycle of the AC input, the first diode D1 is turned on, and the first capacitor C1 is charged through the first diode D1, reaching the first voltage. At this time, the second diode D2 and the third diode D3 are in the off state due to reverse bias, and no current flows through the second capacitor C2 and the third capacitor C3. When the power input terminal is in the negative half-cycle of the AC input, the first diode D1 is turned off, and the second diode D2 is turned on. The voltage of the first capacitor C1 is superimposed with the input negative half-cycle voltage, causing the second capacitor C2 to charge to twice the first voltage; the third diode D3 remains off, and the third capacitor C3 does not participate in charging and discharging for the time being. When the power input terminal is in the next positive half-cycle of the AC input, the second diode D2 is turned off, and the third diode D3 is turned on. The first voltage of the second capacitor C2 is superimposed with the input positive half-cycle voltage, causing the third capacitor C3 to charge to three times the first voltage. At this time, the second output terminal of the tripler circuit can output a DC voltage three times the first voltage.

[0034] Optionally, the first capacitor C1 is an electrolytic capacitor.

[0035] Optionally, the second capacitor C2 and the third capacitor C3 are thin-film capacitors.

[0036] In this embodiment, the electrolytic capacitor has a large capacitance and low withstand voltage, which can effectively meet the energy required for closing the electromagnetic switch assembly 10; the film capacitor has a small capacitance and high withstand voltage, which can effectively meet the large current change rate required for opening the electromagnetic switch assembly 10. The withstand voltage of the film capacitor can typically reach around 4000V, therefore the second voltage is an odd multiple of the first voltage, which can be at least 3 times and at most 11 times.

[0037] refer to Figure 2 In one embodiment of the present invention, the driving circuit 40 includes a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, and an inductor L; Wherein, the first terminal of the first switching transistor Q1 is electrically connected to the first output terminal of the voltage multiplier circuit 30, the second terminal of the first switching transistor Q1 is electrically connected to the first terminal of the inductor L and the first terminal of the second switching transistor Q2, and the controlled terminal of the first switching transistor Q1 is electrically connected to the control circuit 20; the second terminal of the second switching transistor Q2 is electrically connected to the second terminal of the third switching transistor Q3 and the ground terminal, and the controlled terminal of the second switching transistor Q2 is electrically connected to the control circuit 20; the first terminal of the third switching transistor Q3 is electrically connected to the second terminal of the inductor L and the second terminal of the fourth switching transistor Q4, and the controlled terminal of the third switching transistor Q3 is electrically connected to the control circuit 20; the first terminal of the fourth switching transistor Q4 is electrically connected to the second output terminal of the voltage multiplier circuit 30, and the controlled terminal of the fourth switching transistor Q4 is electrically connected to the control circuit 20.

[0038] In this embodiment, the first, second, third, and fourth switching transistors can be implemented using IGBTs, MOSFETs, or other fully controlled power electronic devices. When the control circuit 20 controls the first switching transistor Q1, the third switching transistor Q3, or the fourth switching transistor Q4 and the second switching transistor Q2 to be turned on, the power supply delivers current to the coil through the inductor L. Because the inductor L has the characteristic that current cannot change abruptly, it stores a large amount of magnetic field energy during this period. When the circuit is suddenly turned off, the inductor L generates an extremely high reverse induced electromotive force to resist this sudden change. By utilizing this instantaneously released enormous energy, the moving iron core of the switch overcomes the spring tension to complete the closing or releasing action. Specifically, when the control circuit 20 controls the drive circuit 40 to drive the electromagnetic switch assembly 10 to close, it controls the first and third switches to conduct, thereby causing the current to flow from the first output terminal of the voltage multiplier circuit 30, the first switch Q1, the inductor L, and the third switch Q3 of the drive circuit 40 to the common reference ground, thus driving the electromagnetic switch assembly 10 to close. When the control circuit 20 controls the drive circuit 40 to drive the electromagnetic switch assembly 10 to open, it controls the fourth and second switches to conduct, thereby causing the current to flow from the second output terminal of the voltage multiplier circuit 30, the fourth switch Q4, the inductor L, and the second switch Q2 of the drive circuit 40 to the common reference ground, thus driving the electromagnetic switch assembly 10 to open.

[0039] Optionally, the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are all NMOS transistors.

[0040] In this embodiment, during DC drive, if the reverse high voltage generated by the coil has nowhere to be released when the NMOS transistor is turned off, it can easily damage the NMOS transistor. Therefore, by connecting diodes in parallel with the source and drain of the NMOS transistor in corresponding directions, a freewheeling circuit is formed, thereby protecting the NMOS transistor.

[0041] This utility model also proposes an electromagnetic switch device, which includes an electromagnetic switch assembly 10 and a voltage multiplier switch drive circuit as described in any of the above claims. It is worth noting that since the electromagnetic switch device of this utility model is based on the aforementioned voltage multiplier switch drive circuit, the embodiments of the electromagnetic switch device of this utility model include all the technical solutions of all embodiments of the aforementioned voltage multiplier switch drive circuit, and the achieved technical effects are completely identical, and will not be repeated here.

[0042] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A voltage multiplier switch drive circuit for use in an electromagnetic switching device, characterized in that, The electromagnetic switch device includes an electromagnetic switch assembly and a control circuit, and the voltage multiplier switch drive circuit includes: Power input terminal, used to connect to external AC power; A voltage multiplier circuit, wherein the input terminal of the voltage multiplier circuit is electrically connected to the power input terminal; the voltage multiplier circuit is used to output a first voltage and a second voltage; The driving circuit has a first input terminal electrically connected to the first output terminal of the voltage multiplier circuit, a second input terminal electrically connected to the second output terminal of the voltage multiplier circuit, and a controlled terminal electrically connected to the control circuit. The driving circuit is configured to receive the first voltage and, upon receiving a first driving control signal input from the control circuit, drive the electromagnetic switch assembly to close; it is also configured to receive the second voltage and, upon receiving a second driving control signal input from the control circuit, drive the electromagnetic switch assembly to open. Wherein, the second voltage is an odd multiple of the first voltage, and the odd multiple is not 1.

2. The voltage doubler switch drive circuit as described in claim 1, characterized in that, The voltage multiplier circuit is a triple voltage multiplier circuit.

3. The voltage multiplier switch drive circuit as described in claim 2, characterized in that, The tripler circuit includes a first diode, a second diode, a third diode, a first capacitor, a second capacitor, and a third capacitor; Wherein, the anode of the first diode is electrically connected to the first terminal of the second capacitor and the first terminal of the power input terminal; the cathode of the first diode is electrically connected to the second terminal of the first capacitor, the first input terminal of the driving circuit, the anode of the second diode, and the first terminal of the third capacitor; the second terminal of the second capacitor is electrically connected to the cathode of the second diode and the anode of the third diode; the first terminal of the first capacitor is electrically connected to the second input terminal of the power input terminal; and the second terminal of the third capacitor is electrically connected to the cathode of the third diode and the second input terminal of the driving circuit.

4. The voltage multiplier switch drive circuit as described in claim 3, characterized in that, The first capacitor is an electrolytic capacitor.

5. The voltage multiplier switch drive circuit as described in claim 3, characterized in that, The second capacitor and the third capacitor are thin-film capacitors.

6. The voltage multiplier switch drive circuit as described in claim 3, characterized in that, The first output terminal of the voltage multiplier circuit is electrically connected to the second terminal of the first capacitor, the cathode of the first diode, the anode of the second diode, and the first terminal of the third capacitor; the second output terminal of the voltage multiplier circuit is electrically connected to the first terminal of the third capacitor and the cathode of the third diode.

7. The voltage doubler switch drive circuit as described in claim 1, characterized in that, The driving circuit includes a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, and an inductor; Wherein, the first terminal of the first switching transistor is electrically connected to the first output terminal of the voltage multiplier circuit; the second terminal of the first switching transistor is electrically connected to the first terminal of the inductor and the first terminal of the second switching transistor; and the controlled terminal of the first switching transistor is electrically connected to the control circuit. The second terminal of the second switching transistor is electrically connected to the second terminal of the third switching transistor and the ground terminal; and the controlled terminal of the second switching transistor is electrically connected to the control circuit. The first terminal of the third switching transistor is electrically connected to the second terminal of the inductor and the second terminal of the fourth switching transistor; and the controlled terminal of the third switching transistor is electrically connected to the control circuit. The first terminal of the fourth switching transistor is electrically connected to the second output terminal of the voltage multiplier circuit; and the controlled terminal of the fourth switching transistor is electrically connected to the control circuit.

8. The voltage doubler switch drive circuit as described in claim 7, characterized in that, The first switch, the second switch, the third switch, and the fourth switch are all NMOS transistors.

9. An electromagnetic switching device, characterized in that, The electromagnetic switch includes an electromagnetic switch assembly and a voltage multiplier switch drive circuit as described in any one of claims 1 to 8.

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