WO2018131250A1 - Arc-quenching device for direct current switch - Google Patents

Abstract

In order to improve compactness and reduce price, an arc-quenching device (1) is equipped with a semiconductor switch (TR4) connected in parallel to a mechanical first switch (SW1), a constant voltage circuit (22) for outputting a voltage which switches the semiconductor switch (TR4) on by using the voltage produced between the two contacts of the first switch (SW1), and a protection resistor (R11) which is connected in series to the semiconductor switch (TR4), and disconnects as a result of the current flowing when the semiconductor switch suffers a short-circuit failure.

Description

Arc extinguishing device for DC switch

The present invention relates to an arc erasing device for a DC switch that erases an arc generated between contacts of the DC switch.

Conventionally, an arc erasing device for erasing an arc generated in a DC switch is known. As disclosed in Patent Document 1, for example, the arc erasing device is connected in parallel with the DC switch, and erases an arc generated between the contacts of the DC switch.

Specifically, the arc extinguishing apparatus described in Patent Document 1 includes a DC power supply, a mechanical switch, a semiconductor switch, a power supply circuit, and a control circuit. The mechanical switch is connected in series with the DC power supply, the semiconductor switch is connected in parallel with the mechanical switch, the control circuit turns on and off the semiconductor switch, and the power supply circuit drives the control circuit. With such a configuration, the arc erasing device diverts the arc current flowing through the mechanical switch to the semiconductor switch to erase the arc.

In addition, in this type of arc extinguishing device, as disclosed in, for example, Patent Document 2, when the semiconductor switch is short-circuited, a fuse is incorporated to isolate the semiconductor switch from the circuit and protect the circuit. It is.

Japanese Patent Gazette “Patent No. 3441813” Japanese Patent Notice “Japanese Patent Publication No. 7-62970”

However, fuses generally have a larger component shape as the rated current increases. For example, a fuse capable of energizing a large current even instantaneously has a considerably large part shape. For example, when it is necessary to energize 150 A only for 1 msec, it is necessary to use a fuse having a rated current of 17 A or more. In this case, the fuse has a considerably large external dimension (length × width × thickness), for example, 6.1 × 2.5 × 2.5, and is expensive. For this reason, the use of a fuse increases the substrate size of the arc erasing apparatus including the fuse, and is an obstacle to miniaturization and cost reduction of the arc erasing apparatus.

Therefore, an object of one embodiment of the present invention is to provide an arc erasing device for a DC switch that can be reduced in size and price.

An arc extinguishing device for a DC switch according to an aspect of the present invention includes a semiconductor switch connected in parallel to a mechanical first switch connected in series with a DC power source of a load device, and both contacts of the first switch A power supply circuit that outputs a voltage for turning on the semiconductor switch by a voltage generated between the two contacts when the first switch is opened, and the semiconductor switch is connected in series with the semiconductor switch. And a protective resistor composed of a chip resistor that is disconnected by a current flowing when the switch is short-circuited.

According to one aspect of the present invention, it is possible to reduce the substrate size of the arc erasing apparatus, that is, to reduce the size and price of the arc erasing apparatus.

It is a block diagram which shows the state which connected the arc extinguishing apparatus of embodiment of this invention to the load apparatus. FIG. 2 is a circuit diagram of the load device and the arc extinguishing device shown in FIG. 1. It is a circuit diagram which shows the state which connected the arc extinguishing apparatus of other embodiment of this invention to the load apparatus. FIG. 4 is a circuit diagram of the load device and the arc extinguishing device shown in FIG. 3. FIG. 24 is a block diagram illustrating still another embodiment of the present invention and illustrating an application example of the arc erasing apparatus.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a state in which the arc extinguishing device of this embodiment is connected to a load device.

(Configuration of load device 1)
As shown in FIG. 1, the load device 1 includes a DC power supply E1, a load 11, and a first switch (DC switch) SW1, and these are connected in series so as to form a closed loop. The DC power supply E1 is, for example, a battery, the load 11 is, for example, a motor, and the first switch SW1 is a mechanical switch having a contact.

(Configuration of arc erasing device 2)
As shown in FIG. 1, the arc erasing device 2 includes a semiconductor switch TR4, a first timer circuit 21, a power supply circuit 22, a protection circuit 23, and a protection resistor R11.

The semiconductor switch TR4 is an FET (field effect transistor) in the present embodiment, and has a drain connected to the first current path 25a on the positive side and a source connected to the second current path 25b on the negative side. The first energization path 25a is connected to the positive side connection terminal T1, and the positive side connection terminal T1 is connected to one terminal of the first switch SW1. The second energization path 25b is connected to the negative connection terminal T2, and the negative connection terminal T2 is connected to the other terminal of the first switch SW1. A circuit from the positive side connection terminal T1 to the negative side connection terminal T2 via the semiconductor switch TR4 is a bypass circuit 28 for the first switch SW1, and the semiconductor switch TR4 is connected in parallel with the first switch SW1. .

The power supply circuit 22 is connected to the first energizing path 25a and the second energizing path 25b. The connection between the power circuit 22 and the first current path 25a is made via a diode D2 whose forward direction is from the first current path 25a toward the power circuit 22. The power supply circuit 22 is a constant voltage circuit that is supplied with power from the first energizing path 25a and the second energizing path 25b and outputs a constant voltage to the semiconductor switch TR4.

The first timer circuit 21 is provided in the first energization path 25a between the connection between the first energization path 25a and the semiconductor switch TR4 and the connection between the first energization path 25a and the diode D2. The first timer circuit 21 cuts off the first energization path 25a when a certain time has elapsed from the start of the operation of the arc extinguishing device 2, that is, when the charging of the capacitor C1 is completed (when the charge of the capacitor C1 is full).

The protection circuit 23 is provided between the power supply circuit 22 and the semiconductor switch TR4, and supplies the voltage supplied from the power supply circuit 22 to the gate of the semiconductor switch TR4. Further, the protection circuit 23 protects the semiconductor switch TR4 by preventing a voltage exceeding the maximum rating from being applied to the gate of the semiconductor switch TR4. Note that the protection circuit 23 is not essential for the basic operation of the arc erasing apparatus 2 and can be omitted.

Further, a diode D1 and a capacitor C2 are provided between the first energizing path 25a and the second energizing path 25b at a position opposite to the semiconductor switch TR4 side with respect to the power supply circuit 22. The diode D1 is connected to the first energizing path 25a and the second energizing path 25b with the direction from the second energizing path 25b toward the first energizing path 25a as the forward direction. The diode D1 discharges the charge accumulated in the first timer circuit 21 and resets the first timer circuit 21 by a closed loop formed by the first timer circuit 21, the semiconductor switch TR4, and the diode D1. The capacitor C2 removes noise from the first current path 25a and the second current path 25b, and stabilizes the voltage between the first current path 25a and the second current path 25b. The capacitor C2 is not essential for the basic operation of the arc erasing device 2, and can be omitted.

(Configuration of protection resistor R11)
The protective resistor R11 is connected in series with the semiconductor switch TR4 in the bypass circuit 28. The position where the protective resistor R11 is provided is not limited to the position between the semiconductor switch TR4 and the positive connection terminal T1 shown in FIG. 1, and may be between the semiconductor switch TR4 and the negative connection terminal T2. For example, the protective resistor R11 may be provided between the connection part of the semiconductor switch TR4 between the load 11 and the first timer circuit 21 (first conduction path 25a) and the semiconductor switch TR4.

The protective resistor R11 is a chip resistor having a small resistance value of, for example, about 1 mΩ to 10 mΩ, and is preferably a chip resistor whose conductive portion (that is, the resistance portion) is a metal thin film. In this case, in the chip resistor, the metal thin film is formed on a ceramic substrate, for example. When the semiconductor switch TR4 is short-circuited due to a failure, the protective resistor R11 prevents the current from continuing to flow through the bypass circuit 28, for example, by fusing and being disconnected. A commercially available metal foil low resistance chip resistor can be used as the protective resistor R11.

(Specific circuit of the arc erasing device 2)
FIG. 2 is a circuit diagram of the load device 1 and the arc extinguishing device 2 shown in FIG. As shown in FIG. 2, the first timer circuit 21 of the arc extinguishing device 2 includes a capacitor C1 and a resistor R1 connected in series. Note that the capacitance of the capacitor C1 is much larger than the capacitance of the capacitor C3 of the power supply circuit 22. The resistor R1 is a resistor having a low resistance value and is preferably provided for preventing an excessive current from flowing through the circuit. However, the resistor R1 is not essential for the basic operation of the arc extinguishing device 2. It can be omitted.

The power supply circuit 22 includes a transistor TR1, a capacitor C3, resistors R2 and R3, and a Zener diode ZD1. The emitter of the transistor TR1 is connected to the third conduction path 27 from this emitter toward the gate of the semiconductor switch TR4. The capacitor C3 is between the collector of the transistor TR1 and the second conduction path 25b, the resistor R2 is between the base and collector of the transistor TR1, and the Zener diode ZD1 is between the base of the transistor TR1 and the second conduction path 25b. The resistor R3 is provided between the emitter of the transistor TR1 and the second energization path 25b. The cathode of the diode D2 described above is connected to the collector of the transistor TR1.

The protection circuit 23 includes a resistor R10 and a Zener diode ZD2. The resistor R10 is provided between the emitter of the transistor TR1 and the gate of the semiconductor switch TR4 in the third conduction path 27, and the Zener diode ZD2 is provided between the gate of the semiconductor switch TR4 and the second conduction path 25b. . The resistor 10 is called a gate resistor, and limits the current flowing into the parasitic capacitance between the gate and the source of the FET that is the semiconductor switch TR4.

(Operation of Arc Eraser 2)
In the above configuration, the operation of the arc erasing apparatus 2 will be described below.

(When closing the first switch SW1)
When the load device 1 and the arc extinguishing device 2 are stopped, the first switch SW1 is open. Therefore, a voltage by the DC power supply E1 is generated between the contacts of the first switch SW1.

When the first switch SW1 is closed from the above state, a current flows through the load 11 through the path of the DC power supply E1, the load 11, the first switch SW1 and the DC power supply E1, and the load 11 (load device 1) operates.

(When opening the first switch SW1)
When the first switch SW1 is opened, the current flowing through the load 11 is interrupted, and the load 11 (load device 1) stops operating.

In this case, when the first switch SW1 is opened, a voltage is generated between the contacts of the first switch SW1. The power supply circuit 22 operates by the voltage generated between the contacts, the output voltage of the power supply circuit 22 is applied to the gate of the semiconductor switch TR4, and the semiconductor switch TR4 is turned on. Therefore, the detour circuit 28 is closed, and the occurrence of an arc between the contacts of the first switch SW1 is suppressed.

Specifically, when the first switch SW1 is opened, a voltage is generated for a moment between the contacts of the first switch SW1. When a voltage is generated between the contacts of the first switch SW1, a current flows from the positive connection terminal T1 toward the first timer circuit 21 through the first energization path 25a. This current flows through the first timer circuit 21 and then flows into the capacitor C3 of the power supply circuit 22 via the diode D2. As a result, a base current flows through the transistor TR1 of the power supply circuit 22, and the transistor TR1 is turned on. A constant voltage is applied to the base of the transistor TR1 by the operation of the Zener diode ZD1.

When the transistor TR1 is turned on, the voltage output from the power supply circuit 22 is applied to the gate of the semiconductor switch TR4, and the semiconductor switch TR4 is turned on. When the semiconductor switch TR4 is turned on, the bypass circuit 28 changes from the open state to the closed state. Therefore, no current flows between the contacts of the first switch SW1, and all the current flows through the bypass circuit 28, so that arcing between the contacts of the first switch SW1 is suppressed.

In the arc erasing device 2, the voltage between the contacts of the first switch SW1 (for example, 10V) when the first switch SW1 is opened is the voltage between the contacts of the SW1 when the arc is generated in the first switch SW1 (for example, 12V). ) Is set to be lower. Therefore, the arc erasing apparatus 2 can prevent the occurrence of arc itself when the first switch SW1 is opened. This is the same in other embodiments.

接点 Between the contact points of the first switch SW1, the bypass circuit 28 is closed, so that the impedance becomes low. Similarly, a current continuously flows through the load 11 of the load device 1.

Thereafter, when no current flows through the first current path 25a, the power supply circuit 22 stops operating, the semiconductor switch TR4 is turned off, and the bypass circuit 28 is opened. When the semiconductor switch TR4 is turned off, the first switch SW1 is in an open state, so that no current flows through the load 11, and the voltage between the contacts of the first switch SW1 returns to the voltage of the DC power supply E1.

Further, when the charging of the capacitor C1 of the first timer circuit 21 is completed, the first current path 25a is blocked by the first timer circuit 21. Therefore, the arc extinguishing device 2 is in a stable state that is electrically disconnected from the load device 1, that is, the DC power supply E1.

Even when the first switch SW1 is closed, in the process until the first switch SW1 is completely closed, as in the case where the first switch SW1 is opened, the arc extinguishing device is generated by the voltage generated between the contacts of the first switch SW1. 2 works.

(Advantages of providing the protective resistor R11)
The arc extinguishing device 3 has the following advantages due to the provision of the protective resistor R11.

The chip resistor used for the protective resistor R11 is small and inexpensive. For example, in the case of the above chip resistor that energizes 150 A only for 1 msec, there are external dimensions (length × width × thickness) of 1.25 × 2.0 × 0.5, which have the same fusing characteristics. Compared with the fuse, the volume ratio is about 1/30. Therefore, if the protective resistor R11 made of a chip resistor is used in place of the fuse, the substrate size can be reduced, that is, the arc erasing device 3 can be reduced and the price can be reduced.

Further, the protective resistor R11, which is a chip resistor, can be configured such that if the conductive portion (that is, the resistance portion) through which electricity flows is a metal thin film, the current to be blown or the time to blow when the semiconductor switch TR4 is broken. It is easy to set conditions and is suitable as a substitute for fuses.

[Embodiment 2]
Another embodiment of the present invention will be described below with reference to the drawings. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

FIG. 3 is a block diagram showing a state where the arc extinguishing device of the present embodiment is connected to a load device. FIG. 4 is a circuit diagram of the load device and the arc extinguishing device shown in FIG.

(Configuration of arc erasing device 3)
As shown in FIG. 3, the arc erasing device 3 has a configuration in which a second timer circuit 24 is added to the arc erasing device 2, and the other configuration is the same as that of the arc erasing device 2.

The second timer circuit 24 is provided between the power supply circuit 22 and the protection circuit 23. When a certain time has elapsed from the start of operation, the second timer circuit 24 cuts off the voltage supply from the power supply circuit 22 to the semiconductor switch TR4 and turns off the semiconductor switch TR4. To.

(Specific circuit of the arc erasing device 3)
FIG. 4 is a circuit diagram of the load device 1 and the arc extinguishing device 3 shown in FIG. As shown in FIG. 4, the second timer circuit 24 includes transistors TR2 and TR3, resistors R4 to R9, and a capacitor C4. The emitters of the transistors TR2 and TR3 are connected to the second energizing path 25b. The capacitor C4 and the resistor R4 are connected in series and are provided between the third conduction path 27 and the base of the transistor TR2. The resistor R5 is between the base of the transistor TR2 and the second current path 25b, the resistor R6 is between the third current path 27 and the collector of the transistor TR2, and the resistor R7 is between the collector of the transistor TR2 and the base of the transistor TR3. The resistor R8 is between the connection between the resistor R6 and the collector of the transistor TR3 in the third conduction path 27, and the resistor R9 is between the base of the transistor TR3 and the second conduction path 25b. Are provided respectively.

Further, a surge circuit 26 including a diode D3 and a Zener diode ZD3 connected in series is provided between the gate and drain of the semiconductor switch TR4. The surge circuit 26 protects the semiconductor switch TR4 by turning on the semiconductor switch TR4 when an excessive voltage exceeding the withstand voltage is applied to the semiconductor switch TR4.

(Operation of Arc Eraser 3)
In the above configuration, the operation of the arc erasing apparatus 3 will be described below. When the first switch SW1 is opened, a voltage is generated between the contacts of the first switch SW1, as in the case of the arc erasing device 2. When a voltage is generated between the contacts of the first switch SW1, a current flows from the positive connection terminal T1 toward the first timer circuit 21 through the first energization path 25a. This current flows through the first timer circuit 21 and then flows into the capacitor C3 of the power supply circuit 22 via the diode D2. As a result, a base current flows through the transistor TR1 of the power supply circuit 22, and the transistor TR1 is turned on. Further, a base current flows through the capacitor C4 and the resistor R4 to the transistor TR2 of the second timer circuit 24, and the transistor TR2 is turned on.

The transistor TR3 of the second timer circuit 24 maintains the off state when the transistor TR2 is on. Therefore, the voltage output from the power supply circuit 22 is applied to the gate of the semiconductor switch TR4, and the semiconductor switch TR4 is turned on. When the semiconductor switch TR4 is turned on, the bypass circuit 28 changes from the open state to the closed state. Therefore, no current flows between the contacts of the first switch SW1, and all the current flows through the bypass circuit 28, so that arcing between the contacts of the first switch SW1 is suppressed.

After a predetermined time has elapsed after the semiconductor switch TR4 is turned on, the second timer circuit 24 cuts off the voltage supply from the power supply circuit 22 to the semiconductor switch TR4, turns off the semiconductor switch TR4, and the bypass circuit 28 opens. It becomes a state.

Specifically, after the semiconductor switch TR4 is turned on, the current does not flow into the first conduction path 25a, but the power supply circuit 22 and the second timer circuit 24 use the charges accumulated in the capacitors C1 and C3. And continue operation.

When a predetermined time determined by the values of the capacitor C4 and the resistor R4 elapses after the semiconductor switch TR4 is turned on, charging of the capacitor C4 of the second timer circuit 24 is completed. As a result, the base current does not flow to the transistor TR2, and the transistor TR2 is turned off.

When the transistor TR2 is turned off, a base current flows to the transistor TR3 via the resistors R6 and R7, the transistor TR3 is turned on, and the third current path 27 is connected to the first current path 25a by the transistor TR3. As a result, the gate voltage of the semiconductor switch TR4 becomes 0V, the semiconductor switch TR4 is turned off, and the bypass circuit 28 is opened.

When the semiconductor switch TR4 is turned off, the first switch SW1 is in an open state, so the voltage between the contacts of the first switch SW1 returns to the voltage of the DC power supply E1. Thereafter, when charging of the capacitor C1 of the first timer circuit 21 is completed, the first current path 25a is cut off by the first timer circuit 21. Therefore, the arc extinguishing device 3 is in a stable state that is electrically disconnected from the load device 1, that is, the DC power supply E1.

Thus, in the arc extinguishing device 3, the second timer circuit 24 forcibly turns off the semiconductor switch TR4 within a period during which the power supply circuit 22 is operating normally.

Further, as described above, the function of the first timer circuit 21 is to electrically disconnect the arc erasing device 3 from the load device 1 after the semiconductor switch TR4 is turned off and stop the operation of the power supply circuit 22. Thereby, the first timer circuit 21 prevents a situation in which the electric power of the DC power source E1 of the load device 1 is continuously consumed by the arc erasing device 3. Therefore, the arc extinguishing device 3 is a circuit for electrically disconnecting the arc extinguishing device 3 (particularly the power supply circuit 22) from the load device 1 after the semiconductor switch TR4 is turned off, instead of the first timer circuit 21 including the resistor R1 and the capacitor C1. May be provided. This is the same in other embodiments.

(Advantages of Arc Eraser 3)
The advantage of the arc extinguishing device 3 including the protective resistor R11 is the same as that of the arc extinguishing device 2.

Further, in the arc erasing apparatus 3, when the first switch SW1 is opened, the semiconductor switch TR4 is turned on, and after a predetermined time has elapsed, the second timer circuit 24 supplies voltage from the power supply circuit 22 to the semiconductor switch TR4. And the semiconductor switch TR4 is turned off, and the bypass circuit 28 by the semiconductor switch TR4 is opened.

In this case, the second timer circuit 24 arbitrarily sets the conduction time of the semiconductor switch TR4 regardless of the voltage applied to the first switch SW1 and the opening / closing speed of the first switch SW1, and between the contacts of the first switch SW1. The semiconductor switch TR4 can be turned on only for the minimum time required for erasing the arc current.

That is, the semiconductor switch TR4 can transition from the on state to the off state without having a transition period when the second timer circuit 24 operates to change from the on state to the off state.

As a result, the semiconductor switch TR4 has a reduced power loss, a reduced amount of heat generation, and no risk of failure due to an increased power loss. Therefore, it is not necessary to use an expensive and large element or provide a heat dissipation device for the semiconductor switch TR4. As a result, the arc erasing device 3 can be configured with high reliability, small size, and low cost.

The arc erasing device 3 includes a constant voltage circuit as the power supply circuit 22 and outputs a stable and constant DC voltage from the constant voltage circuit. Accordingly, the second timer circuit 24 can accurately turn off the semiconductor switch TR4 after a lapse of a predetermined time from the ON point even when the voltage of the DC power supply E1, the load current, or the like changes. Thereby, the heat loss of the semiconductor switch TR4 can be suppressed to a certain amount, and the semiconductor switch TR4 can be reliably protected.

The power supply circuit 22 may include a power supply circuit that simply drives the semiconductor switch TR4 instead of the constant voltage circuit. The power supply circuit in this case is obtained by omitting, for example, the transistor TR1, the resistor R2, and the Zener diode ZD1 from the power supply circuit 22.

In this embodiment, the case where the semiconductor switch TR4 as the switching element is an FET has been described as an example. However, the semiconductor switch TR4 may be an IGBT (Insulated Gate Bipolar Transistor) or other power transistor in addition to the FET. This also applies to the other embodiments described below.

[Embodiment 3]
Still another embodiment of the present invention will be described below with reference to the drawings. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

FIG. 5 is a block diagram showing an application example of the arc erasing apparatus of the present embodiment. The arc extinguishing devices 2 and 3 shown in the above-described embodiment can be applied to a device (for example, an electric tool) that includes the trigger switch 41 and incorporates the first switch SW1 into the trigger switch 41. As another application example, the arc extinguishing devices 2 and 3 can be incorporated in a socket 31 connected to a load 11 as shown in FIG. In this case, the arc extinguishing devices 2 and 3 are configured as a unit having a casing.

5, the load 11 is, for example, a vehicle-mounted motor, and the first switch SW1 is, for example, a relay connected to the socket 31. In this case, the socket 31 may include connection terminals 31a and 31b for the load 11 and the DC power supply E1, and connection terminals 31c and 31d for the relay (first switch SW1).

In the configuration as described above, the arc extinguishing devices 2 and 3 prevent the occurrence of an arc between the contact points of the relay, or erase the arc generated between the contact points of the relay, thereby extending the life of the relay.

Arc extinguishing devices 2 and 3 can be applied to other industrial equipment having a switch.

[Summary]
An arc extinguishing device for a DC switch according to an aspect of the present invention includes a semiconductor switch connected in parallel to a mechanical first switch connected in series with a DC power source of a load device, and both contacts of the first switch A power supply circuit that outputs a voltage for turning on the semiconductor switch by a voltage generated between the two contacts when the first switch is opened, and the semiconductor switch is connected in series with the semiconductor switch. And a protective resistor composed of a chip resistor that is disconnected by a current flowing when the switch is short-circuited.

According to the above configuration, when the first switch is opened, a voltage is generated between both contacts of the first switch, and the power supply circuit outputs a voltage for turning on the semiconductor switch by the voltage, and the semiconductor switch is turned on. It becomes. When the semiconductor switch is turned on, current flows through the semiconductor switch bypassing the first switch. Therefore, the arc is eliminated or no arc is generated between the contacts of the first switch.

On the other hand, when the semiconductor switch is short-circuited, the chip resistor connected in series with the semiconductor switch is disconnected, and current is prevented from continuing to flow through the bypass circuit including the semiconductor switch and the chip resistor.

Chip resistors are a substitute for commonly used fuses and are small and inexpensive. That is, if a chip resistor is used in place of the fuse, it is possible to reduce the substrate size of the arc erasing device, that is, to reduce the size and cost of the arc erasing device.

In the above-described direct-current switch arc extinguishing device, the chip resistor may be configured such that the conductive portion is a metal thin film.

According to the above configuration, in the chip resistor, a conductive portion (that is, a resistance portion) through which electricity flows is a metal thin film, and when an overcurrent flows, the metal thin film is melted and disconnected. Therefore, when the semiconductor switch breaks, it is easy to set conditions such as the current to be blown and the time to blow, and it is suitable as a substitute for a fuse.

The above-mentioned arc extinguishing device for a DC switch has a housing (for example, a socket), a connection portion connected to the first switch of the load device, and a DC power source and a load of the load device. It is good also as a structure provided with the connection part to connect.

According to the above configuration, the arc extinguishing device can be configured in such a way that the circuit components are housed in the casing and can be configured as a unit, which makes it easy to apply to various load devices.

In the above-described DC switch arc extinguishing device, the load may be a vehicle-mounted motor, and the first switch may be a relay that turns on and off the vehicle-mounted motor.

According to the above configuration, the arc extinguishing device can prevent the wear of the contact point due to the arc for the frequently operating relay and prolong the service life, and can be configured to be suitable for in-vehicle use.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Load apparatus 2-3 Arc eliminator 11 Load 21 1st timer circuit 22 Power supply circuit 23 Protection circuit 24 2nd timer circuit 25a 1st electricity path 25b 2nd electricity path 27 3rd electricity path 28 Detour circuit 31 Socket E1 DC power supply T1 Positive side connection terminal T2 Negative side connection terminal SW1 1st switch TR4 Semiconductor switch R11 Protection resistance

Claims (4)

A semiconductor switch connected in parallel to a mechanical first switch connected in series with the DC power supply of the load device;
A power supply circuit connected to both contacts of the first switch and outputting a voltage for turning on the semiconductor switch by a voltage generated between the two contacts when the first switch is opened;
An arc erasing device for a DC switch, comprising: a chip resistor connected in series with the semiconductor switch, and disconnected by a current flowing when the semiconductor switch is short-circuited. 2. The arc erasing device for a DC switch according to claim 1, wherein the chip resistor is a metal thin film at a conductive portion. It has a housing | casing, The connection part which connects the said 1st switch of the said load apparatus, and the connection part which connects the DC power supply and load of the said load apparatus are provided in the said housing | casing. Item 3. An arc extinguishing device for a DC switch according to Item 1 or 2. 4. An arc erasing device for a DC switch according to claim 3, wherein the load is a vehicle-mounted motor, and the first switch is a relay for turning on and off the vehicle-mounted motor.

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