CN112753085A

CN112753085A - Arc extinguishing device

Info

Publication number: CN112753085A
Application number: CN201980062895.2A
Authority: CN
Inventors: 郭桥石
Original assignee: Individual
Current assignee: Guangzhou Kingser Electronics Co ltd
Priority date: 2018-10-25
Filing date: 2019-10-24
Publication date: 2021-05-04
Anticipated expiration: 2039-10-24
Also published as: WO2020083323A1; CN112753085B

Abstract

An arc extinguishing device, in particular to an arc extinguishing device suitable for arc extinguishing of mechanical switches (K) such as contactors (relays) and the like, comprises a first capacitor (C1) and a detection switch (A), wherein the detection switch (A) is connected with the first capacitor (C1), the detection switch (A) is used for detecting the change rate of the voltage of a common end of a load (M) and the mechanical switches (K), the change rate reaches the turn-on value of the detection switch (A), the detection switch (A) is conducted, and the first capacitor (C1) supplies power to the load (M) through the detection switch (A). The arc extinguishing device has the advantages of strong voltage fluctuation resistance and good arc extinguishing effect.

Description

Arc extinguishing device

Technical Field

The invention relates to an arc-extinguishing device, in particular to an arc-extinguishing device which is suitable for arc-extinguishing of mechanical switches such as contactors (relays) and the like and can also be used for arc-extinguishing of other breakpoints (such as fusing of a fuse link, breakpoints between a plug and a socket and wire breakpoints).

Background

At present, in electric control systems of new energy automobiles, rail transit, ships, automation control and the like, mechanical switches such as contactors (relays) and the like are generally used for carrying out frequent connection and disconnection control on loads, and due to the fact that mechanical switches have disconnection electric arcs, particularly direct currents, and due to the fact that zero points are not arranged, the disconnection electric arcs are larger, the defect that the electrical service life of the mechanical switches is short is overcome, and the electrical service life of the mechanical switches is greatly shortened along with the increase of the disconnection voltage and the disconnection current of the mechanical switches.

Disclosure of Invention

The invention aims to solve the problem of short electric service life of a mechanical switch in the existing electric control system, and provides an arc-extinguishing device which utilizes a capacitor to extinguish arc by detecting the change rate of the common-end voltage of the mechanical switch and a load.

The purpose of the invention is achieved by the following technical scheme:

an arc extinguishing device is shown in fig. 1 and comprises a first capacitor C1 and a detection switch A, wherein the detection switch A is connected with the first capacitor C1 and used for detecting the change rate of the voltage of the common end of a load M and a mechanical switch K, the change rate reaches the opening value of the detection switch A, the detection switch A is conducted, and the first capacitor C1 supplies power to the load M through the detection switch A.

The working principle is as follows: in the breaking process of the mechanical switch K, when the contact of the mechanical switch K is broken, the change rate (namely, the falling rate; when the second capacitor C2 of the detection switch A is changed to be connected with the power supply of the power supply end of the mechanical switch K, the rising rate) of the voltage of the common end of the load M and the mechanical switch K suddenly changes, the first capacitor C1 supplies power to the load M through the detection switch A (the power supply energy can be provided by the electric charge stored in advance in the first capacitor C1, the grounding end of the first capacitor C1 can be changed to be connected with the power supply of the power supply end of the mechanical switch K, the power supply is provided through the first capacitor C1 and the detection switch A), the voltage at the two ends of the load M rapidly rises, and the potential difference at the two ends of the mechanical switch K rapidly falls, so that the aim of arc.

The arc extinguishing device is reasonable in design, utilizes the change rate of the detection voltage of the detection switch to extinguish the arc, and has the advantages of strong voltage fluctuation resistance, high arc extinguishing accuracy and good arc extinguishing effect.

Drawings

Fig. 1 is a schematic circuit diagram of an arc extinguishing device of the present invention.

Fig. 2 is a schematic circuit diagram of an embodiment of an arc extinguishing device according to the present invention.

Fig. 3 is one of two schematic circuit diagrams of the arc extinguishing device according to the embodiment of the invention.

Fig. 4 is a second schematic circuit diagram of a second embodiment of the arc extinguishing device of the present invention.

Fig. 5 is one of three schematic circuit diagrams of the arc extinguishing device according to the embodiment of the invention.

FIG. 6 is a schematic diagram of a delay unit circuit of the detection switch of the arc extinguishing device according to the present invention.

FIG. 7 is a second schematic diagram of the circuit of the delay unit of the detection switch of the arc extinguishing device of the present invention.

Fig. 8 is a schematic diagram of an equivalent circuit of a thyristor of a detection switch of the arc extinguishing device of the present invention.

Fig. 9 is a second schematic circuit diagram of a third embodiment of the arc extinguishing device of the present invention.

Fig. 10 is a fourth schematic view of an arc extinguishing device according to an embodiment of the present invention.

Fig. 11 is a schematic diagram of five circuits of an embodiment of the arc extinguishing device of the present invention.

Fig. 12 is a sixth schematic view of an arc extinguishing device according to an embodiment of the present invention.

Fig. 13 is a graph of voltage waveforms across a load without the arc extinguishing device of the present invention.

Fig. 14 is a second graph of the voltage waveform across the load using the arc extinguishing device of the present invention.

Fig. 15 is a third graph of the voltage waveform across the load using the arc extinguishing device of the present invention.

Fig. 16 is a graph of the voltage waveforms across the load using the arc extinguishing device of the present invention.

Detailed Description

Fig. 2 shows a first embodiment of the arc extinguishing device of the present invention:

an arc extinguishing device comprises a first capacitor C1 and a detection switch A, wherein the detection switch A is connected with the first capacitor C1, the detection switch A is used for detecting the change rate of the voltage at two ends of a load M (namely the change rate of the voltage at the common end of the load M and a mechanical switch K relative to the ground end of the load M), the change rate (the reduction rate) of the voltage at two ends of the load M reaches the opening value of the detection switch A, the detection switch A is conducted, and the first capacitor C1 supplies power to the load M through the detection switch A;

the charging unit B is formed by connecting a first diode D1 and a first current limiting element R1 (resistor) in series;

a detection switch A: the load M is a semi-controlled switch and comprises a second capacitor C2, a controllable device SCR1 and a second diode D2 (option), and the voltage at two ends of the load M drives the controllable device SCR1 to be conducted through the first capacitor C1, the second diode D2 and the second capacitor C2; the working energy and voltage signal of the detection switch A are provided by a first capacitor C1; the common terminal of the second diode D2 and the second capacitor C2 is connected to the common terminal of the first diode D1 and the first current limiting element R1, and the third diode D3 (optional) is connected to the trigger and the cathode of the controllable device SCR 1.

The working principle is as follows: the mechanical switch K is connected with the load M in series, the mechanical switch K is closed, the voltage at two ends of the load M charges the first capacitor C1 through the charging unit B, when the mechanical switch K is closed and bounced or the switch K is disconnected, the first capacitor C1 drives the controllable device SCR1 to be conducted through the second diode D2 and the second capacitor C2, the first capacitor C1 supplies power to the load M through the controllable device SCR1, the voltage at two ends of the load M rises rapidly, the potential difference at two ends of the mechanical switch K drops rapidly, and the purpose of arc extinction of the mechanical switch is achieved.

This embodiment has and uses components and parts quantity few, the simple advantage of circuit.

The second embodiment of the arc extinguishing device of the invention is shown in fig. 3:

an arc extinguishing device comprises a first capacitor C1 and a detection switch A, wherein the detection switch A is connected with the first capacitor C1 and is used for detecting the voltage at two ends of a load M, the change rate (the reduction rate) of the voltage at the two ends of the load M reaches the opening value of the detection switch A, the detection switch A is conducted, and the first capacitor C1 supplies power to the load M through the detection switch A;

the charging unit B is composed of a first diode D1 (option) and a first current limiting element R1 (resistor) which are connected in series.

A detection switch A: the detection switch is a semi-controlled switch and comprises a second capacitor C2, a controllable device SCR1, a second current limiting element R2 (resistor, option) and a second diode D2 (option), wherein the detection switch is a three-terminal circuit (the selection switch can be used as a multi-way mechanical switch to multiplex the first capacitor C1 for arc extinction of the multi-way mechanical switch), the second capacitor C2, a parallel circuit consisting of the second current limiting element R2 and the second diode D2, and a trigger electrode of the controllable device SCR1 are connected in series, a third terminal 3 of the detection switch A can be connected with a second terminal 2 instead, the detection switch A is used as a two-terminal circuit (the working energy and the voltage signal of the detection switch A are provided by the first capacitor C1), and the third diode D3 (option) is connected with the trigger electrode and a cathode of the controllable device SCR 1.

The working principle is as follows: when the mechanical switch K is closed and bounced or the switch K is disconnected, the second capacitor C2 drives the controllable device SCR1 to be conducted, the first capacitor C1 supplies power to the load M through the controllable device SCR1, the voltage at the two ends of the load M rises rapidly, the potential difference at the two ends of the mechanical switch K falls rapidly, and the purpose of arc extinction of the mechanical switch is achieved.

In this embodiment, the power ground of the first capacitor C1 may also be connected to the power source of the mechanical switch K (as shown in fig. 4), the third current limiting element R3 (resistor) is used to discharge the first capacitor C1, the charging unit B becomes the discharging unit B, when the switch K is closed and bounced (during the bounced closing, the first capacitor C1 is rapidly discharged through the mechanical switch K and the discharging unit B) or the switch K is disconnected, the second capacitor C2 drives the controllable device SCR1 to turn on, and the power source supplies power to the load M through the first capacitor C1 and the controllable device SCR 1.

Fig. 5 shows a third embodiment of the arc extinguishing device of the present invention:

a detection switch A: the circuit is a semi-controlled switch, consists of a second capacitor C2, a controllable device SCR1 and a time delay unit C, is a two-terminal circuit, and is used for detecting the working energy and voltage signals of the switch A and providing the working energy and voltage signals by a first capacitor C1; the third terminal 3 of the detection switch a may be connected to ground instead, and as a three-terminal circuit (in the case of a three-terminal circuit, the ground terminal of the first capacitor C1 may be connected to the power supply of the power supply terminal of the mechanical switch K instead), the voltage signal is transmitted to the delay unit C through the second capacitor C2, and the delay unit C drives the controllable device SCR1 to be turned on.

A delay unit C: as shown in fig. 6, the power supply circuit (fifth current-limiting element R5, fifth voltage-stabilizing device Z5), the delay circuit (transistor Q1, semiconductor device Z7, fourth capacitor C4, and half-controlled switch (thyristor SCR2, which can be replaced by the circuit shown in fig. 8) form a circuit, the power supply provided by the first capacitor C1 is limited by the fifth element R5, the fifth voltage-stabilizing device Z5 stabilizes voltage to provide working energy for the delay circuit, the parallel circuit formed by the second capacitor C2, the second current-limiting element R2 (resistor) and the second diode D2, and the input circuit of the delay unit C are connected in series, and in order to increase driving force, the circuit shown in fig. 7 may also be used: the circuits shown in fig. 6, 7, and 8 are preferred examples, and other digital circuits may be used.

The working principle is as follows: the mechanical switch K is connected in series with the load M, the mechanical switch K is closed, the voltage at two ends of the load M charges the first capacitor C1 through the detection switch A (through an internal circuit thereof, a charging unit B can also be added, refer to fig. 3), the voltage at two ends of the load M charges the second capacitor C2, when the mechanical switch K is in a breaking process, the second capacitor C2 drives the semi-controlled switch SCR2 to be conducted, the controllable device SCR1 is driven to be conducted through a delay circuit (the delay time is more than 100 microseconds, so that a certain opening distance exists between contacts of the mechanical switch K), the first capacitor C1 supplies power to the load M through the controllable device SCR1, the voltage at two ends of the load M rises rapidly, and the potential difference at two ends of the mechanical switch K drops rapidly, so that the purpose of arc extinction of the mechanical switch is achieved.

In order to further improve the arc extinguishing stability in high voltage and large current situations, a circuit as shown in fig. 9 can be adopted:

on the basis of fig. 5, the charging circuit further includes a third capacitor C3, a fourth current limiting element R4 (a resistor), a first charging unit B1 (composed of a first diode D1 connected in series with the first current limiting element R1, or one of the two, an option of a first voltage regulator Z1, a second charging unit B2 (composed of a tenth current limiting element and a twelfth diode connected in series, or one of the two), a first series circuit composed of the third capacitor C3 and the fourth current limiting element R4; the first charging unit B1 and the first capacitor C1 form a second series circuit; the first capacitor C1, the detection switch A and the third capacitor C3 form a third series circuit, the voltage at two ends of the load M charges the third capacitor C3 by using the first series circuit, and the voltage at two ends of the load M charges the first capacitor C1 by using the second series circuit; the third capacitor C3, the second charging unit B2, and the first capacitor C1 form a fourth series circuit, and the voltage across the load M charges the first capacitor C1 and the third capacitor C3 through the fourth series circuit. The first voltage-stabilizing device Z1 is connected in parallel with the third capacitor C3, and the third series circuit supplies power to the load M during the breaking process of the mechanical switch K.

The ninth diode D9 is connected in parallel with the third capacitor C3, and the eighth diode D8 is connected in parallel with the first capacitor C1 and is used for forming a discharge loop of the capacitor.

In this embodiment, the capacity of the third capacitor C3 (an electrolytic capacitor may be used to save the volume and reduce the cost) is greater than the capacity of the first capacitor C1, and the detection switch a of this embodiment may also be applied to the second embodiment of the present invention.

In the embodiment, the first capacitor C1 with a smaller capacity can achieve a stable arc extinguishing effect, and is particularly suitable for occasions with high voltage and large current, and has the advantages of low cost, small volume and stable arc extinguishing.

The fourth embodiment of the arc extinguishing device of the present invention is shown in fig. 10:

for the convenience of use, product authentication and standardized mass production, the embodiment described above is packaged into a device by using an insulating material (the specific shape of which can be flexibly designed according to the needs); when the grounding terminal of the first capacitor C1 is changed to be connected to the power supply of the power terminal of the mechanical switch K by using the above embodiment, a pin is added.

In the above embodiments, the arc extinguishing device is a two-terminal circuit or a three-terminal circuit, which has the advantage of convenient use.

Fig. 11 shows an arc extinguishing device according to a fifth embodiment of the present invention:

an arc extinguishing device comprises a first capacitor C1, a detection switch A, a control unit D and a first switch S1 (a semiconductor switch, a semi-controlled device and a unidirectional thyristor), wherein the detection switch A is connected with the first capacitor C1 and used for detecting the voltage at two ends of a load M, the change rate (the reduction rate) of the voltage at two ends of the load M reaches the turn-on value of the detection switch A, the detection switch A is conducted, then the control unit D controls the first switch S1 to be conducted, and the first capacitor C1 supplies power to the load M through the detection switch A; during the breaking process of the mechanical switch K, after the contact breaking of the mechanical switch is carried out for 100 microseconds (option), the first switch S1 is conducted, and the first capacitor C1, the first switch S1 and the detection switch A form a series circuit for supplying power to the load M.

A detection switch A: the switch is a semi-controlled switch, and consists of a controllable device SCR1 and a second capacitor C2, and is a three-terminal circuit (one end of the second capacitor C2 can be connected with a power supply end of a mechanical switch K instead), and a detection switch A shown in figures 3 and 4 is suggested to be used for a multi-path mechanical switch arc extinguishing selector switch. In order to prevent the controllable device SCR1 from being damaged and affecting other load operations and improve the operation reliability of the controllable device SCR1, the controllable device SCR1 is connected in series with the fourth diode D4 (the circuit is designed such that the operation reliability of the fourth diode D4 is higher than that of the controllable device SCR1, which is an option).

An optical coupler detection unit (composed of an eleventh resistor R11 and an optical coupler OPT1 which are connected in series) for detecting the conduction of the detection switch A is connected between a series circuit composed of the first capacitor C1 and the first switch S1 and the detection switch A, the power supply of the optical coupler detection unit is provided by the power supply of the power end of the mechanical switch K and can be provided by the first capacitor C1 instead, the output signal of the optical coupler OPT1 is transmitted to the control unit D, the detection switch A is also connected with a fifth capacitor C5, the second capacitor C2 drives a controllable device SCR1 (semi-controlled device) to be conducted, the power supply (provided by the power supply of the power end of the mechanical switch K and can be provided by the first capacitor C1) supplies power to the load M through the fifth capacitor C5 and the controllable device SCR1, the peak current passing through the fifth capacitor C5 is required to be larger than the holding current of the controllable device SCR1, then the fifth capacitor C5 enters a high-resistance state, and the controllable device SCR1 applies a voltage to the optical coupler detection unit 1, the controllable device SCR1 can be kept on for about two milliseconds, so that the control unit D can control the first switch S1 to be turned on during this period.

The working principle is as follows: the mechanical switch K is closed, the voltage at two ends of the load M charges the second capacitor C2, when the mechanical switch K is disconnected, the second capacitor C2 drives the controllable device SCR1 to be conducted, then the control unit D controls the first switch S1 to be conducted (the first switch S1 is conducted for more than 100 microseconds after the controllable device SCR1 is conducted, so that a certain open distance exists between contacts of the mechanical switch K), a series circuit formed by the first capacitor C1, the first switch S1, the fourth diode D4 (option) and the detection switch a supplies power to the load M, the voltage at two ends of the load M rises rapidly, the potential difference at two ends of the mechanical switch K drops rapidly, and the purpose of arc extinction of the mechanical switch is achieved.

In this embodiment, the control unit D is used to charge or discharge the first capacitor C1, or charge (reverse pre-charge, when the first capacitor C1 is connected to the PA terminal) and discharge; the PA terminal can be connected to a power supply of a power supply terminal of the mechanical switch K, the number of the mechanical switch, the detection switch and the load is one, or two or more, the PA terminal, the detection switch and the load share the first capacitor C1, the first switch S1 and the control unit D, and the multi-way switch can be used for arc extinguishing and management.

In the embodiment, the first capacitor C1 with a smaller capacity can achieve a stable arc extinguishing effect, and is particularly suitable for occasions with high voltage and large current, and has the advantages of low cost and stable arc extinguishing.

An arc extinguishing device according to a sixth embodiment of the present invention is shown in fig. 12:

put a shell in above arc control device embodiment five, as a product that the commonality is strong, through being connected such as terminal and each way external mechanical switch, host computer, convenient safety certification, popularization and use, its specific appearance can design as required in a flexible way.

In the above embodiment, the change rate of the voltage at the common end of the load M and the mechanical switch K is detected by using the detection switch a, and since the voltage fluctuation or ripple of the power supply is much slower than the voltage change rate caused at the moment of disconnection of the mechanical switch K, the second capacitor C2 presents high impedance and cannot meet the driving current requirement of the controllable device SCR1, the invention is particularly suitable for being used in occasions with large voltage fluctuation or large ripple, such as a battery power supply system, an alternating current rectification power supply system, and the like of an electric vehicle.

In the above embodiment, the voltage signal of the detection switch a can also be provided by the power source at the power end of the mechanical switch K (i.e. the voltage across the mechanical switch K, the rising rate of the detection voltage), but not the preferred technical solution, because the input loop of the detection switch A can affect the insulation and voltage resistance of the mechanical switch K, and simultaneously under the normally open state of the mechanical switch K, the input loop of the detection switch a is in series connection with the load M, and there is a certain safety risk, and a preferable example is to use the detection switch a to detect the voltage across the load M (or detect the voltage across the load M through the first capacitor C1, that is, detect the voltage between the common terminal of the mechanical switch K and the load M and the first capacitor C1), the method has the advantages that the current impact on the detection switch A when the mechanical switch K is closed can be conveniently inhibited, and the resolution of the change rate of the detection voltage can not be influenced.

In the above embodiment, the first capacitor C1 and the detection switch a form a series circuit, the load M is connected in parallel with the series circuit, and the input loop of the detection switch a is not electrically isolated from the output loop of the detection switch a; the detection switch a is a semi-controlled switch, which includes a controllable device SCR1 (which is a semi-controlled device, a unidirectional thyristor, or a semi-controlled switch composed of fully-controlled semiconductor devices, such as a thyristor equivalent circuit).

In the above embodiment, the detection switch a of the arc extinguishing apparatus of the present invention is composed of the second capacitor, the semiconductor device (diode, semi-controlled device), and the resistor (option), and is a two-terminal circuit or a three-terminal circuit, and the power supply of the detection switch is provided by the first capacitor, the second capacitor, and is provided by the voltage at two ends of the load without isolation; the circuit has the advantages of simple circuit, low cost and strong overload capacity; the definition of the load of the present invention may also include lines connected for the workload.

In the above embodiment, the detection switch a couples the input signal through the second capacitor C2, and the trigger electrode of the controllable device SCR1 is connected in series with the second capacitor C2 to connect with the load M (ground), or to connect with the power supply at the power end of the mechanical switch K, which has the advantages of no leakage current and low loss.

Fig. 13 is a graph of voltage waveforms across a load M without the arc extinguishing device of the present invention;

fig. 14 is a diagram of a voltage waveform across the load M when the second embodiment of the arc extinguishing device of the present invention is used and the first capacitor C1 is a small-capacity capacitor;

fig. 15 is a diagram of voltage waveforms across the load M when the second embodiment of the arc extinguishing device of the present invention is adopted and the first capacitor C1 adopts a large-capacity capacitor;

fig. 16 is a graph of voltage waveforms across the load M when the arc extinguishing device of the third embodiment or the fourth embodiment of the present invention is used and the first capacitor C1 is a small-capacity capacitor;

according to the comparison of the waveform diagrams, the technical effects of different embodiments of the invention are obviously observed, the arc extinguishing device can greatly shorten the arcing time, and even can realize the aim of non-arc breaking of a mechanical switch.

In conclusion, the arc extinguishing device has the advantages of strong voltage fluctuation resistance and good arc extinguishing effect.

Claims

An arc control device, characterized by: the detection switch is connected with the first capacitor and used for detecting the change rate of the voltage of the common end of the load and the mechanical switch, the change rate reaches the opening value of the detection switch, the detection switch is conducted, and the first capacitor is connected with the load through the detection switch.
The arc extinguishing device of claim 1, wherein: the detection switch is a semi-control switch; is a two-terminal circuit or a three-terminal circuit.
The arc extinguishing device of claim 1, wherein: the input loop of the detection switch is not electrically isolated from the output loop of the detection switch.
The arc extinguishing device of claim 1, wherein: the first capacitor is connected with a power supply of a power end of the mechanical switch.
The arc extinguishing device of claim 1, wherein: the change rate is a decrease rate, and the voltage is the voltage at two ends of the load or the voltage between the common end and the first capacitor; or the rate of change is a rate of rise, and the voltage is a voltage across the mechanical switch.
An arc extinguishing device according to claim 5, characterized in that: the detection switch comprises a second capacitor and a controllable device, and the voltage drives the controllable device to be conducted through the second capacitor; or the voltage drives the controllable device to be conducted through the first capacitor and the second capacitor, and the working energy and the voltage signal of the detection switch are provided by the first capacitor.
An arc extinguishing device according to claim 5, characterized in that: the detection switch is composed of a second capacitor, a resistor and a semiconductor device.
The arc extinguishing device of claim 1, wherein: the detection switch comprises a controllable device and a second capacitor, the voltage charges the second capacitor, and when the change rate reaches the opening value of the detection switch, the second capacitor drives the controllable device to be conducted.
An arc extinguishing device according to claim 8, characterized in that: the controllable device is a semi-controllable device.
An arc extinguishing device according to claim 8, characterized in that: the controllable device is characterized by further comprising a parallel circuit consisting of a second current limiting element and a second diode, wherein the second capacitor, the parallel circuit and the trigger electrode of the controllable device are connected in series.
The arc extinguishing device of claim 1, wherein: the voltage is the voltage at two ends of the load, the detection switch comprises a controllable device and a second capacitor, and the first capacitor drives the controllable device to be conducted through the second capacitor; the charging unit is formed by connecting a first diode and a first current limiting element in series, and the voltage charges the first capacitor through the charging unit; the detection switch further comprises a second diode, and the first capacitor drives the controllable device to be conducted through the second diode and the second capacitor; and the common end of the second diode and the second capacitor is connected with the common end of the first diode and the first current limiting element.
An arc extinguishing device according to claims 1 to 10, characterized in that: the charging unit is used for charging the first capacitor.
An arc extinguishing device according to claim 12, characterized in that: the charging unit is a first current limiting element or is formed by connecting a first diode and a first current limiting element in series, and the voltage charges the first capacitor through the charging unit.
An arc extinguishing device according to claim 12, characterized in that: the device is packaged by adopting an insulating material.
An arc extinguishing device according to claims 1 to 5, characterized in that: the detection switch is composed of a second capacitor, a controllable device and a time delay unit, the voltage signal is transmitted to the time delay unit through the second capacitor, and the time delay unit drives the controllable device to be conducted.
An arc extinguishing device according to claim 15, characterized in that: the delay unit is composed of a power supply circuit, a delay circuit and a semi-control type switch circuit, the power supply circuit is composed of a fifth current limiting element and a fifth voltage stabilizing device, a working power supply provided by the first capacitor is limited by the fifth current limiting element, and the fifth voltage stabilizing device stabilizes voltage to provide working energy for the delay circuit.
An arc extinguishing device according to claim 15, characterized in that: the load further comprises a third capacitor, a fourth current limiting element and a first charging unit, wherein the voltage is the voltage at two ends of the load, and the third capacitor and the fourth current limiting element form a first series circuit; the first charging unit and the first capacitor form a second series circuit; the first capacitor, the detection switch and the third capacitor form a third series circuit, the voltage charges the third capacitor through the first series circuit, the voltage charges the first capacitor through the second series circuit, and the third series circuit supplies power to the load in the breaking process of the mechanical switch.
The arc extinguishing device of claim 17, wherein: the first voltage stabilizing device is connected with the third capacitor in parallel, and the third capacitor is connected with a diode in parallel.
An arc extinguishing device according to claim 18, characterized in that: the capacitor charging circuit further comprises a second charging unit, the capacity of the third capacitor is larger than that of the first capacitor, the third capacitor, the second charging unit and the first capacitor form a fourth series circuit, and the voltage charges the first capacitor and the third capacitor through the fourth series circuit.
An arc extinguishing device according to claim 15, characterized in that: the device is packaged by adopting an insulating material.
An arc extinguishing device according to claims 1 to 10, characterized in that: the circuit also comprises a control unit and a first switch, wherein the first capacitor, the first switch and the detection switch form a series circuit, and the series circuit is used for supplying power to the load when the control unit is used for breaking the mechanical switch.
An arc extinguishing device according to claim 21, characterized in that: it is placed in a housing and connected to the mechanical switch through terminals.
An arc extinguishing device according to claim 21, characterized in that: the first capacitor and a series circuit formed by the first switch and the detection switch are connected with each other through an optical coupling detection unit used for detecting the conduction of the detection switch, the output signal of the optical coupling detection unit is transmitted to the control unit, the detection switch is further connected with a fifth capacitor, and a power supply is connected with the load through the fifth capacitor and the detection switch.
An arc extinguishing device according to claims 1 to 5, characterized in that: the first capacitor is connected with a power supply of a power end of the mechanical switch, and the first capacitor discharges through the mechanical switch and the discharging unit.
An arc extinguishing device according to claim 24, characterized in that: the discharge unit is formed by connecting a first diode and a first current limiting element in series.