JP2012119106A - Direct current plug - Google Patents

Abstract

Disclosed is a small-sized direct current plug with low power loss.
An input terminal A and an input terminal B for connection to an outlet 19, an output terminal C and an output terminal D for connection to a load 30a, an input terminal A through which a direct current flows, an input terminal B and an output terminal An electronic opening / closing switch 15 inserted in the DC current path to open or close the DC current path between C and the output terminal D, and a parallel mechanical switch connected in parallel to the electronic switching switch 15 An open / close switch 16 and a switch control circuit 14 for controlling a mutual open / close time difference between the parallel mechanical open / close switch 16 and the electronic open / close switch 15. After the input terminal A and the input terminal B are connected to the outlet 19, the electronic open / close switch 15 is closed, and then the parallel mechanical open / close switch 16 is closed.
[Selection] Figure 2

Description

  The present invention relates to a DC plug for flowing a DC current.

  Conventionally, AC power is supplied to ordinary households, factories, and facilities from an AC power system (commercial power supply) using a synchronous generator. In such an AC power system, when AC power is supplied to various electric devices, power is supplied through an outlet and a plug, which are connecting devices. On the other hand, in recent years, distributed power sources that supply direct-current power from solar power generation, wind power generation, and the like have attracted attention. In various electric devices, inverter control is widely adopted in which alternating current is once converted into direct current inside the device and the device is controlled using a semiconductor device. In addition, as a power supply device for various electric devices, a switching power supply that once converts alternating current into direct current is frequently used. With such changes in technology, the adoption of a DC power system that supplies DC power has begun to be studied.

  The DC power system and the AC power system have completely different performances required for plugs interposed between the power system and various electric devices. A combination of a plug and an outlet used in an AC power system that has been widely used in the past cannot be used in a DC power system. In other words, in the case of direct current, there is no time when the current becomes zero as in the case of alternating current, so an electrical device that is a live load (conducting state) is connected to an outlet via a conventional plug and separated from the outlet. Then, once generated arc (arc discharge) continues without disappearing. As a result, current continues to flow continuously. In addition, the outlet and plug may be damaged, the electrical device may fail, and a fire may occur. Therefore, it is difficult to separate and connect the current path between the DC power system and various electric devices using a conventional AC plug.

  In order to solve such a problem, a technique of a DC plug that is a plug suitable for use in a DC power system is provided (see Patent Document 1). As a related technique, a switch technique suitable for cutting a direct current path is provided (Patent Document 2).

JP 2005-294077 A JP 2007-213842 A

  When supplying electric power by connecting various electric devices to the DC plug described in Patent Document 1, a current always flows through the semiconductor element disposed inside the DC plug, and thus power loss occurs in the semiconductor element. There was a problem. For this reason, it is difficult to reduce the size of the DC plug.

  The problem to be solved by the present invention is to provide a direct-current plug that has less power loss, is smaller in size, and does not generate an arc.

  In order to solve this problem, the DC plug according to the first aspect of the present invention includes an input terminal for connection to an outlet, an output terminal for connection to a load, and between the input terminal and the output terminal. An electronic on / off switch inserted into the direct current path to open or close a direct current path through which a direct current flows, a parallel mechanical on / off switch connected in parallel to the electronic on / off switch, A switch control circuit for controlling a difference in opening / closing time between a parallel mechanical on / off switch and the electronic on / off switch, the switch control circuit having the input terminal connected to the outlet when the DC current path is closed After the electronic open / close switch is closed, the parallel mechanical open / close switch is closed.

  A DC plug according to a second aspect of the present invention includes an input terminal for connecting to an outlet, an output terminal for connecting to a load, and a DC current path through which a DC current flows between the input terminal and the output terminal. Electronic open / close switch inserted into the DC current path to open or close the circuit, a parallel mechanical open / close switch connected in parallel to the electronic open / close switch, the parallel mechanical open / close switch, and the A switch control circuit for controlling a difference in opening / closing time between the electronic open / close switch and the switch control circuit, when the DC current path through which the DC current flows is opened, the parallel mechanical open / close switch And the electronic opening / closing time is longer than the time when chattering caused by opening the parallel mechanical opening / closing switch is closed. In less time shorter than the time that the temperature of the switch is increased to a predetermined temperature which predetermined, and open the electronic off switch.

  The DC plug according to the present invention includes a mechanical open / close switch, an electronic open / close switch, a mechanical open / close switch, and a switch control circuit that controls the electronic open / close switch. In addition, it is possible to provide a small-sized DC plug at a low price by reducing the power loss of the electronic open / close switch when the DC current path is made conductive (closed) without generating an arc.

It is a figure which shows the DC power supply system using the DC plug of embodiment. It is a figure which shows the DC plug of 1st Embodiment. It is a figure which shows the procedure of opening and closing of a parallel mechanical opening / closing switch and an electronic opening / closing switch in the DC plug of 1st Embodiment with a timing chart. It is a figure which shows the Example of the DC plug of 1st Embodiment shown in FIG. It is a figure which shows the DC plug of 2nd Embodiment. It is a figure which shows the procedure of opening / closing of a parallel mechanical opening / closing switch, an electronic opening / closing switch, and a serial mechanical opening / closing switch in the DC plug of 2nd Embodiment with a timing chart. It is a figure which shows the DC plug of 3rd Embodiment. It is a figure which shows the 1st modification of a DC plug. It is a figure which shows the 2nd modification of a DC plug. It is a figure which shows the 3rd modification of a DC plug. It is a figure which shows the 4th modification of a DC plug. It is a figure which shows the 5th modification of a DC plug. It is a figure which shows the 6th modification of a DC plug. It is a figure which shows the 7th modification of a DC plug. It is a figure which shows the DC plug of 4th Embodiment. It is a figure which shows the DC plug of 5th Embodiment. It is a figure which shows the outlet socket used in combination with the DC plug of 5th Embodiment. It is a figure which shows another modification of the DC plug of 5th Embodiment. It is a figure which shows the electrical outlet used in combination with another modification of the DC plug of 5th Embodiment. It is a figure which shows the DC plug of 6th Embodiment. It is a figure which shows the outlet socket used in combination with the DC plug of 6th Embodiment.

  In order to open or close a DC current path between a DC power system and an output terminal, a DC plug according to an embodiment for carrying out the invention is arranged in parallel with an electronic open / close switch and an electronic open / close switch. A parallel mechanical on / off switch connected thereto, and a switch control circuit for controlling a difference in open / close time between the parallel mechanical on / off switch and the electronic on / off switch. The switch control circuit prevents heat generation of the electronic on / off switch by closing the parallel mechanical on / off switch after the electronic on / off switch is closed when the DC current path through which the direct current flows is closed. .

  In addition, when the DC current path is opened, the switch control circuit has a time longer than the time when chattering caused by opening the parallel mechanical switch is opened and the parallel mechanical switch is opened. The occurrence of an arc is prevented by opening the electronic on / off switch within a time shorter than the time during which the temperature of the electronic on / off switch rises to a predetermined temperature.

[Outline of DC plug]
The technology of the embodiment will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a DC power supply system using the DC plug of the embodiment. A DC generator is connected to the DC power system 10 to supply DC power. The DC power system 10 includes a DC plug 20a, a DC plug 20b, a DC plug 20c, a DC plug 20d, a DC plug 20e, a DC plug 20f, a DC plug 20g, a DC plug 20h, a DC plug 20i, a DC plug 20j, a DC plug 20k, A DC plug 201, a DC plug 20m, and a DC plug 20n are connected (DC plug 20d to DC plug 20j, DC plug 20m are not shown in FIG. 1). Each of the DC plugs 20a to 20n includes an input terminal A that is an input terminal, an input terminal B, and an output terminal C and an output terminal D that are output terminals. The input terminal A is a positive terminal with positive polarity, the input terminal B is a negative terminal with negative polarity, the output terminal C is a positive terminal with positive polarity, and the output terminal D is a negative terminal with negative polarity.

  An outlet 19 is connected to the DC plug 20a to the DC plug 201, an outlet 19a is connected to the DC plug 20k, and an outlet 19b is connected to the DC plug 20n to achieve electrical continuity. For example, the outlet 19, the outlet 19a, and the outlet 19b have, as contact points, cylindrical conductors that have a spring function and generate a pressing force in the central direction so as to contact each of the input terminals A and B of each DC plug. is doing. The input terminal A and the input terminal B of the DC plug 20a to DC plug 20n are rod-shaped conductors, and the rod-shaped conductor of the DC plug is inserted into the cylindrical conductor of the outlet so as to be conductive. The contact of the outlet may be two plates having a spring function as used in a conventional AC outlet, and a plate as a contact of the DC plug between the two leaf springs of each contact of the outlet. A conductive plate may be inserted so that the DC plug and the outlet become conductive.

  The DC plug 20a to DC plug 20k are provided with a control switch pressing portion 191 that is a protruding member so as to protrude toward the outlet. The position of the control switch pressing portion 191 is moved to the inner side of the DC plug 20a to the DC plug 20k when it hits the wall surface of the outlet. Then, a control switch 17, which will be described in detail later, is pushed by the projecting control switch pushing portion 191. The control switch 17 is a push switch and conducts only when it is pressed. Here, the control switch 17 is pushed after the outlet 19 and the DC plugs 20a to 20j are connected. The input terminals of the DC plugs 20a to 20k are determined by predetermining the arrangement of the control switch 17 and the position of the tip of the control switch pressing portion 191 in each DC plug of the DC plug 20a to DC plug 20j. The control switch 17 can be pressed by the control switch pressing portion 191 after being connected to the outlet 19.

  As will be described in detail later, while the outlet 19 is connected to the DC plug 20a to DC plug 20k, the DC current is prevented while preventing the arc from being generated inside the DC plug 20a to DC plug 20k. Open and close the road.

  In the combination of the outlet 19 at the third stage from the bottom of FIG. 1 and the DC plug 20k, the DC switch 20k is not provided with the control switch pressing portion 191. A slide switch 177 is used as the control switch. The slide switch 177 functions as a control switch. The slide switch 177 is provided with a lever that can be operated from the outside of the DC plug 20k. If the lever is slid to the arrow ON side, the slide switch 177 becomes conductive, and if the lever is slid to the arrow OFF side, the slide switch 177 is disconnected. In this way, by controlling the lever of the slide switch 177, conduction and disconnection of the DC current path inside the DC plug 20k can be controlled. Further, by turning off the slide switch 177 and then removing the DC plug 20k from the outlet 19 after a while, it is possible to prevent the occurrence of an arc due to a regenerative current described later.

  In the combination of the second-stage outlet 19a and the DC plug 20l from the bottom of FIG. 1, and the combination of the lowest-stage outlet 19b and the DC plug 20n in FIG. 1, the DC switch is provided with a control switch pressing portion 191. It is not done. Although details will be described later, the DC current path can be opened and closed while preventing the generation of an arc between the outlet and the DC plug without providing the control switch pressing portion 191.

"DC plug of embodiment"
The DC plug according to the first embodiment is connected in parallel to an electronic open / close switch inserted into the DC current path to open or close a DC current path through which a DC current flows, and the electronic open / close switch. A parallel mechanical opening / closing switch, and a switch control circuit for controlling a difference in opening / closing time between the parallel mechanical opening / closing switch and the electronic opening / closing switch. The switch control circuit closes the parallel mechanical open / close switch after a predetermined time after the electronic open / close switch is closed.

  The DC plug of the second embodiment is connected in parallel to an electronic open / close switch inserted into the DC current path to open or close a DC current path through which a DC current flows, and the electronic open / close switch. Parallel mechanical on / off switch, serial mechanical on / off switch connected in series with the electronic on / off switch and parallel mechanical on / off switch, parallel mechanical on / off switch, serial mechanical on / off switch and electronic on / off And a switch control circuit for controlling a difference in opening / closing time between the three switches of the switch. Then, when closing the DC current path through which the DC current flows, the switch control circuit closes the electronic opening / closing switch after a predetermined time after the series mechanical opening / closing switch is closed, and finally turns on the parallel mechanical opening / closing switch. Closed. Also, when opening a DC current path through which a DC current flows, the electronic switch is opened after a predetermined time after the parallel mechanical switch is opened, and finally the series mechanical switch is opened. is there.

  The DC plug according to the third embodiment includes an electronic on / off switch inserted into a DC current path to open or close a DC current path through which a DC current flows, and a series machine connected in series to the electronic on / off switch. Parallel mechanical on / off switch connected in parallel to a series connection circuit formed by a mechanical on / off switch, an electronic on / off switch, and a mechanical on / off switch connected in series, and a parallel mechanical on / off switch in series A switch control circuit for controlling a difference in opening / closing time between the three switches of the mechanical opening / closing switch and the electronic opening / closing switch. Then, when closing the DC current path through which the DC current flows, the switch control circuit closes the electronic opening / closing switch after a predetermined time after the series mechanical opening / closing switch is closed, and finally turns on the parallel mechanical opening / closing switch. Closed. Also, when opening a DC current path through which a DC current flows, the electronic switch is opened after a predetermined time after the parallel mechanical switch is opened, and finally the series mechanical switch is opened. is there.

  The direct-current plug according to a modification of the embodiment (hereinafter referred to as a modification of the embodiment) further includes an electronic opening / closing switch and a series mechanical opening / closing with respect to the direct-current plug according to the first to third embodiments. A commutation diode or a regenerative diode is added to the DC plug of the embodiment having only a switch. The addition of the commutation diode is to solve the problem of preventing the generation of the back electromotive voltage immediately after the DC switch formed inside the DC plug is cut. The addition of the regenerative diode is to solve the problem that power generated in the motor as a load is regenerated to the DC power system via the DC plug.

  The DC plug of the fourth embodiment can be implemented in combination with any of the first to third embodiments described above and all of the modifications. In the DC plug of the fourth embodiment, a trigger signal for controlling the switch control circuit is given by a slide switch. This slide switch includes a lever that can be operated from the outside of the DC plug. Operate this lever to open the DC current path in the DC plug, and after returning the regenerative power to the power supply system, remove the DC plug from the outlet to effectively return the regenerative power to the power supply system and An arc can be prevented from occurring between the DC plugs.

  The DC plug of the fifth embodiment can be implemented in combination with any of the first to third embodiments described above and all of the modifications. In the DC plug of the fifth embodiment, in addition to the above-described embodiment, the information including the predetermined password, which is emitted from the electromagnetic wave emission unit (transmission unit) of the outlet to the DC plug, is received and the predetermined password is reproduced. A receiving unit is provided. Then, the switch control circuit is started after the connection of the input terminal of the DC plug and the outlet is started at a distance farther than the outlet approaches the predetermined distance at which the predetermined password can be reproduced, and the predetermined password is reproduced at the receiving unit. Is to close the DC current path in the DC plug. In addition, the electrical connection between the DC plug and the outlet is maintained even when the outlet is further away than the predetermined distance at which the predetermined password can be reproduced. The direct current path in the plug is opened.

  The DC plug of the sixth embodiment can be implemented in combination with any of the first to third embodiments described above and all of the modifications. In the DC plug according to the sixth embodiment, a capacitance detector is further provided in the above-described embodiment. Then, the connection between the input terminal of the DC plug and the outlet is started at a distance apart from the predetermined separation distance that is the separation distance between the outlet and the DC plug detected based on the change in capacitance by the capacitance detection unit, When the distance is within the separation distance, the switch control circuit closes the DC current path in the DC plug. In addition, the electrical connection between the DC plug and the outlet is maintained at a distance apart from a predetermined separation distance, which is a separation distance between the outlet and the DC plug, detected based on the change in capacitance by the capacitance detection unit. When the separation distance is not within the predetermined separation distance, the switch control circuit opens the direct current path in the direct current plug.

  Hereinafter, the direct current plugs of the first embodiment to the direct current plugs of the sixth embodiment, and modifications of these embodiments will be described in detail. In the DC plug of the first embodiment, a parallel mechanical opening / closing switch, and in the DC plug of the second embodiment and the DC plug of the third embodiment, the parallel mechanical opening / closing switch and the series mechanical opening / closing switch are components of the DC plug. To do. In the modification of the DC plug of the fourth embodiment and the fifth embodiment and the modification of the DC plug of the embodiment as well, these components are used as one component, so these mechanical on / off switches will be described first.

  The mechanical on / off switch has two contacts formed of a conductor, and the mechanical on / off switch is inserted into a direct current path that is a path through which current flows, and each contact of the mechanical on / off switch is divided into two. Are connected to the respective DC current paths. A DC current path is formed when the two contacts are brought into contact with each other and closed, and a DC current path is disconnected when the two contacts are separated and opened.

  In the direct current plug of the first embodiment and the direct current plug of the second embodiment, a mechanical opening / closing switch 16 described later is connected in parallel to an electronic opening / closing switch 15 described later. The parallel mechanical opening / closing switch 16 is also described to clarify its function. Further, in the DC plug of the third embodiment, the mechanical on / off switch 16 is connected in parallel to the electronic on / off switch 15 through the mechanical on / off switch 161, so in the DC plug of the third embodiment. Is also referred to as a parallel mechanical switch 16.

  In the DC plug of the second embodiment, the mechanical on / off switch 161 is connected in series to a parallel connection circuit of the parallel mechanical on / off switch 16 and the electronic on / off switch 15, and at least in series with the electronic on / off switch 15. Since they are connected, the mechanical on / off switch 161 is also described as a series mechanical on / off switch 161 to clarify its function. Further, in the DC plug of the third embodiment, the mechanical on / off switch 161 is connected in series to the electronic on / off switch 15, so that the mechanical on / off switch 161 is also the same as the series mechanical on / off switch 161. Describe and clarify its function.

  Here, the parallel in the parallel mechanical on / off switch means that current is shunted between the electronic on / off switch and the mechanical on / off switch arranged in the DC current path (including the case where the current shunted to one side is 0). This means a connection mode. That is, when an electronic on / off switch and a mechanical on / off switch are connected in parallel, the resistance value of the electronic on / off switch is higher than the resistance value of the mechanical on / off switch, so that most of the current flowing in the DC current path is mechanical. Flows to open / close switch. In addition, when the electronic on / off switch does not function as a resistor but functions as an element having a constant on-voltage (voltage across the switch when conducting), only the mechanical on-off switch has an on-voltage close to 0. Current flows.

  The series in the series mechanical on / off switch means a connection mode in which the current flowing through the electronic on / off switch arranged in the DC current path flows through the mechanical on / off switch. That is, when the electronic on / off switch and the mechanical on / off switch are connected in series, if one of them is disconnected (opened), the electronic on / off switch and the mechanical on / off switch are connected in series. No current flows in the direct current path of the part. In electrical equipment that requires the installation of a mechanical switch according to safety standards, etc., this duty can be met by using such a series connection.

(DC plug of the first embodiment)
FIG. 2 is a diagram showing the DC plug of the first embodiment. A DC plug 20a having a DC switch inside according to the first embodiment will be described with reference to FIG. The DC plug 20a is used by connecting each of an output terminal C and an output terminal D to a load 30a (see FIG. 1).

  The DC plug 20 a includes a parallel mechanical on / off switch 16, an electronic on / off switch 15, a switch control circuit 14, and a control switch 17. The parallel mechanical open / close switch 16 and the electronic open / close switch 15 are connected in parallel, and the parallel connection circuit of the parallel mechanical open / close switch 16 and the electronic open / close switch 15 is connected between the input terminal B and the output terminal D. Is inserted in the DC current path.

  The load is an electrical device. The electric device may be not only a stationary device (for example, a television receiver) but also a rotating device (for example, a compressor of a refrigerator). As the rotating device, for example, through a power converter such as a DC motor or an inverter. An AC motor driven by The parallel mechanical open / close switch 16 and the electronic open / close switch 15 of the DC plug 20a open a DC current path through which a DC current flows (a state where no DC current path is formed) or a closed circuit (a state where a DC current path is formed). Has been inserted for.

  That is, the parallel mechanical open / close switch 16 and the electronic open / close switch 15 connected in parallel are inserted into the negative bus 13 on the input terminal B side. The DC power system 10 and the load 30a are connected in series via the DC plug 20a. For this reason, when either one of the parallel mechanical on / off switch 16 or the electronic on / off switch 15 is closed (conducted), the DC current path is made on (closed), and the parallel mechanical on / off switch 16 and the electronic on / off switch 15 are connected. When both are opened (cut), the DC current path is cut (open). By this opening / closing operation, the power supply to the load 30a can be cut off, or the power from the DC power system 10 can be supplied to the load 30a.

  However, as will be described later, the generation of an arc between the contacts of the parallel mechanical opening / closing switch 16 and the opening / closing order of the parallel mechanical opening / closing switch 16 and the electronic opening / closing switch 15 are closely related. In FIG. 2, the parallel mechanical open / close switch 16 and the electronic open / close switch 15 are inserted into the negative bus 13, but the same effect can be obtained by inserting them into the positive bus 12 on the input terminal A side. There is an effect.

  The switch control circuit 14 controls the difference between the open / close times of the parallel mechanical open / close switch 16 and the electronic open / close switch 15. At this time, the control switch 17 opens and closes, and gives a trigger signal that triggers opening and closing of the parallel mechanical opening and closing switch 16 and the electronic opening and closing switch 15 to the switch control circuit 14. The control switch 17 is a switch that is operated by pressing the tip of the control switch pressing portion 191 by the outlet 19 (see FIG. 1).

  FIG. 3 is a timing chart showing the operation of the control switch 17 and the opening / closing procedure of the parallel mechanical opening / closing switch 16 and the electronic opening / closing switch 15 in the first embodiment. FIG. 3A shows disconnection (disconnection state) in which the control switch 17 is open and conduction (conduction state) in which the control switch 17 is closed, and FIG. 3B shows disconnection (disconnection state) in which the electronic open / close switch 15 is open. FIG. 3C shows disconnection (cutting state) in which the parallel mechanical open / close switch 16 is open and conduction (conduction state) in the closed state. The horizontal axis indicates time t. With reference to FIG. 3, the operation of the control switch 17 and the opening / closing operation of the electronic opening / closing switch 15 and the parallel mechanical opening / closing switch 16 will be described.

  First, the procedure when the DC current path is closed by the DC plug 20a will be described. The control switch 17 is pressed by the control switch pressing portion 191 to change the control switch 17 from disconnection to conduction (see time t1 in FIG. 3A). The switch control circuit 14 changes the parallel mechanical opening / closing switch 16 and the electronic opening / closing switch 15 from disconnection to conduction based on a trigger signal generated by the operation of the control switch 17 (at time t1, FIG. 3 (B)). (See time t2 in C)). That is, as shown in FIG. 3B, when the control switch 17 becomes conductive (closed), the electronic open / close switch 15 has no operation delay in principle and has a slight operation delay in an actual semiconductor element. Then, it becomes conductive (closed). On the other hand, as shown in FIG. 3C, when the control switch 17 becomes conductive (closed), the parallel mechanical open / close switch 16 becomes conductive (closed) at a time t2 after a predetermined time τ1 from the time t1. Become. Here, during a predetermined time τ1 between time t1 and time t2, only the electronic open / close switch 15 is conducted. During the predetermined time τ1, power loss occurs in the electronic switch 15 so that the temperature of the electronic switch 15 does not rise above a predetermined temperature (for example, 60 ° C. or higher) for a predetermined time. τ1 is set.

  The predetermined time τ1 may be longer than the operation delay of the electronic open / close switch 15. By increasing the length of the predetermined time τ1, the parallel mechanical opening / closing switch 16 is turned on after the electronic opening / closing switch 15 is sufficiently turned on (after the on-voltage of the electronic opening / closing switch 15 is sufficiently lowered). Can be ensured. By setting the predetermined time τ1 in this way, the circuit is closed while a high voltage is applied to the contacts of the parallel mechanical on / off switch 16, and as a result, no heat loss occurs at the contacts.

  That is, the maximum allowable time of the predetermined time τ1 is determined by the allowable temperature of the electronic open / close switch 15, and the minimum allowable time of the predetermined time τ1 is determined by the conduction speed of the electronic open / close switch 15. Furthermore, the longer the predetermined time τ1, the greater the power loss that occurs in the electronic switch 15 in the DC current path. Considering the above, the predetermined time τ1 is determined.

  In this way, the parallel mechanical open / close switch 16 is prevented from conducting before the electronic open / close switch 15. If the parallel mechanical open / close switch 16 is conducted before the electronic open / close switch 15, an arc may be generated at the contact of the parallel mechanical open / close switch 16 to damage the contact. In particular, the possibility of arcing due to contact chattering is doubled. Here, chattering means that when the contact of the parallel mechanical switch 16 is switched, the contact repeats contact and non-contact by the minute and very fast mechanical vibration, and the current flowing through the DC current path is cut and conducted. For example, it is a phenomenon that lasts for about 1 to 100 ms (milliseconds).

  When the DC current path of the DC plug 20a is made conductive, not only the arc does not occur inside the DC plug 20a as described above, but also the control switch 17 is controlled by the protruding control switch pressing portion 191. Since the input terminal A and the input terminal B are both connected to the outlet 19 when they are pushed and closed (conducting), an arc is generated between the DC plug 20a and the outlet 19 as well. It does not occur (see the positional relationship between the DC plug 20a and the outlet 19 in FIG. 1).

  Next, the procedure when the DC current path is opened by the DC plug 20a will be described. Here, when the supply of current to the load 30a is cut off, that is, when an operation for cutting the current path is performed inside the load 30a, a big problem occurs even if the DC plug 20a is removed from the outlet 19. Absent. A problem arises when the DC plug 20a is removed from the outlet 19 in a state where a current flows through the load 30a.

  In the process of removing the DC plug 20a from the outlet 19, the control switch pressing portion 191 stops pressing the control switch 17, and the control switch 17 is changed from conduction to disconnection (see time t3 in FIG. 3A). The switch control circuit 14 changes the parallel mechanical opening / closing switch 16 from conduction to disconnection based on a trigger signal generated by operating the control switch 17 (see time t3 in FIG. 3C). Further, the switch control circuit 14 changes the parallel mechanical on / off switch 16 from conduction to disconnection based on a trigger signal generated by the operation of the control switch 17, and the electronic on / off switch 15 at time t4 after a predetermined time τ2 from time t3. Is changed from conduction to disconnection. Here, the predetermined time τ2 between the time t3 and the time t4 is set to be longer than the time when the chattering of the parallel mechanical on / off switch 16 is settled, and the predetermined time τ2 is The temperature is set within a time shorter than the time during which the temperature rises to a predetermined temperature. Further, it is desirable that the electronic opening / closing switch 15 be disconnected before the contact between the DC plug 20a and the outlet 19 is cut from the viewpoint of preventing arcing between the DC plug 20a and the outlet 19.

  When switching from conduction to disconnection in such a procedure, the predetermined time τ2 is set to a time longer than the time during which chattering of the parallel mechanical on / off switch 16 is settled. Therefore, after the chattering of the parallel mechanical open / close switch 16 is settled, the electronic open / close switch 15 is still closed when the parallel mechanical open / close switch 16 is fully opened. Therefore, when the electronic open / close switch 15 is a MOS-FET, for example, within a predetermined time τ2, the resistance value of the electronic open / close switch 15 is small, and the voltage generated across the electronic open / close switch 15 is small. Therefore, even if chattering occurs at the contacts of the parallel mechanical on / off switch 16 within the predetermined time τ2, the chattering is settled after a time longer than the predetermined time τ2, so the contact between the contacts of the parallel mechanical on / off switch 16 is reduced. There is no arcing. Further, it is desirable that the electronic open / close switch 15 is disconnected before the contact between the DC plug 20a and the outlet 19 is cut off so that no arc is generated between the DC plug 20a and the outlet 19. From this point of view, it is most desirable to set the predetermined time τ2 at a time equal to the time when chattering of the parallel mechanical opening / closing switch 16 is settled.

  Further, when the electronic open / close switch 15 is not a MOS-FET, for example, a bipolar transistor, a voltage higher than the ON voltage of the electronic open / close switch 15 does not occur at both ends of the contact. Therefore, no arc is generated between the contacts of the parallel mechanical switch 16.

  From the viewpoint of heat generation, the predetermined time τ2 is set to a time shorter than the time during which the temperature of the electronic open / close switch 15 rises to a predetermined temperature (for example, a temperature defined by safety standards, a temperature defined by semiconductor ratings). Therefore, the electronic open / close switch 15 maintains a safe low temperature and does not break down by heat. When the electronic open / close switch 15 is opened, the direct current path is cut (open). That is, the minimum allowable time of the predetermined time τ2 is the chattering duration of the parallel mechanical on / off switch 16, and the predetermined time τ2 is a time longer than the chattering duration. Furthermore, the longer the predetermined time τ2, the greater the power loss that occurs in the electronic switch 15 in the DC current path. Considering the above, the predetermined time τ2 is determined.

  In addition, the maximum allowable time of the predetermined time τ2 is a viewpoint that prevents an arc from being generated between the DC plug 20a and the outlet 19 when the DC plug 20a is pulled out from the outlet 19 in a live state where a DC current flows through the load 30a. It is also determined from. Here, it can be said that unplugging the DC plug 20a from the outlet 19 in a live state where a DC current is flowing to the load 30a is an abnormal handling, but it is also possible for a general user to sufficiently handle this. It is desirable to deal with such a case in advance. That is, the maximum allowable time of the predetermined time τ2 is related to the time from when the control switch pressing unit 191 stops pressing the control switch 17 until the contact between the DC plug 20a and the outlet 19 is cut off.

  When the DC current path of the DC plug 20a is cut off, if the predetermined time τ2 is appropriately determined as described above, an arc is not generated at the contact of the parallel mechanical switch 16 inside the DC plug 20a. Heat generation in the electronic open / close switch 15 can be within an allowable range. Not only the control switch 17 is not pressed by the protruding control switch pressing portion 191 but from the open (cut) (see the positional relationship between the DC plug 20c and the outlet 19 in FIG. 1) to the DC current path of the DC plug 20a. The DC plug 20a is disconnected from the outlet 19 until it is opened by the electronic open / close switch 15, so that the DC plug 20a An arc is not generated between the outlet 19 and the outlet 19.

  In short, in the DC plug of the first embodiment, the electronic time is covered so as to cover the conduction time of the parallel mechanical open / close switch 16 in the front-rear direction (from the earlier time to the later time (backward)). The time during which the open / close switch 15 is conducted is determined. The predetermined time τ1 that is the time to cover in the forward direction and the predetermined time τ2 that is the time to cover in the backward direction are set within a time shorter than the time during which the temperature of the electronic open / close switch 15 rises to the predetermined temperature. At the same time, the power loss occurring in the electronic open / close switch 15 is assumed to be negligible. The predetermined time τ2 is set to a time longer than the time during which chattering of the parallel mechanical opening / closing switch 16 is settled. In this way, the connection between the input terminal and the output terminal of the DC plug is conducted while the electronic open / close switch 15 is conducting. This prevents arcing between the contacts of the parallel mechanical switch 16.

  Most preferably, the electronic opening / closing switch 15 having a high conduction speed is used to shorten the predetermined time τ1 as much as possible and set the predetermined time τ2 to a time equal to the time when chattering of the parallel mechanical opening / closing switch 16 is settled. . As a result, a relationship of (predetermined time τ1 + predetermined time τ2) <(time from when the control switch pressing portion 191 stops pressing the control switch 17 until contact between the DC plug 20a and the outlet 19 is cut off) is established. It is possible to make it. In this way, even when the DC plug 20a is quickly pulled out from the outlet 19, the generation of an arc between the DC plug 20a and the outlet 19 can be prevented.

  FIG. 4 is a diagram showing a circuit example of the DC plug 20a shown in FIG. An example of a more specific configuration of the DC plug 20a will be described with reference to FIG. A parallel mechanical on / off switch 16a, which is an embodiment of the parallel mechanical on / off switch 16, includes a relay (relay) 50 that mechanically opens and closes electrical contacts, and a bipolar transistor 51 that drives the relay 50, and is a bipolar transistor. The current flowing through the coil winding of the relay 50 can be controlled via the relay 51. For example, the contact is closed when a current is passed through the coil winding, and the contact is opened when no current is passed through the coil winding.

  An electronic open / close switch 15a, which is an embodiment of the electronic open / close switch 15, is formed of a MOS-FET (Metal Oxide Semiconductor Field Transducer) 53 and a bipolar transistor 54 as main components. The connection point of the resistors R1 and R2 and the collector of the bipolar transistor 54 are connected to the gate of the MOS-FET 53, so that the MOS-FET 53 opens and closes the DC current path. Here, when the electronic open / close switch 15a is opened, the gate voltage is lowered to increase the resistance between the drain and the source, and when the electronic open / close switch 15a is closed, the gate voltage is increased. Thus, the resistance between the drain and the source is made low.

  A switch control circuit 14a, which is an embodiment of the switch control circuit 14, is composed of a digital logic circuit 18 and peripheral circuits. The resistor R4 is for supplying an operating voltage to the digital logic circuit 18, and the operating voltage is made constant by a Zener diode ZD and a capacitor C. A resistor R3 is connected to one end of the control switch 17, and the bus 13 is connected to the other end. A change between disconnection and conduction of the control switch 17 is generated as a trigger signal, and the trigger signal is input to the signal input terminal I of the digital logic circuit 18. The digital logic circuit 18 includes a signal output terminal O1 and a signal output terminal O2. A signal from the signal output terminal O1 is applied to the base of the bipolar transistor 51, and a signal from the signal output terminal O2 is applied to the bipolar transistor 54. Applied to the base. The operation shown in the timing chart of FIG. 3 can be realized by the switch control circuit 14a which is an embodiment of such a switch control circuit 14. When the level of the signal from the signal output terminal O1 is high, the contact of the relay 50 is closed, and when the level of the signal from the signal output terminal O2 is low, the drain and source of the MOS-FET 53 are connected. In order to make the resistance low, that is, the electronic open / close switch 15a is closed.

  In the circuit example described above, a MOS-FET is used as an electronic open / close switch, and a bipolar transistor is used as a circuit unit for driving the MOS-FET. In the combination of the two, a MOS-FET, a bipolar transistor, an IGBT, etc. Similar effects can be obtained by any combination of these semiconductor devices. For example, a bipolar transistor can be used as the electronic open / close switch, and a MOS-FET can be used as a circuit unit for driving the bipolar transistor.

(DC plug of the second embodiment)
FIG. 5 is a diagram showing a DC plug according to the second embodiment. FIG. 5 shows a DC plug 20b having a DC switch inside according to the second embodiment. The DC plug 20b of the second embodiment includes a parallel mechanical on / off switch 16 and a series mechanical on / off switch 161 inserted in the DC current path to open or close a DC current path through which a DC current flows, and an electronic switch A switch 15 and a switch control circuit 141 are provided. Here, since the series mechanical opening / closing switch 161 is connected in series with the electronic opening / closing switch 15, it is referred to as a series mechanical opening / closing switch as described above.

  The DC plug of the second embodiment is characterized in that the power loss in the closed state of the DC current path in the first embodiment is maintained, and further, in series with the electronic open / close switch 15 of the DC current path. By inserting a series mechanical opening / closing switch 161, the DC current path can be more reliably disconnected, and the safety can be further improved.

  The parallel mechanical on / off switch 16 and the series mechanical on / off switch 161 in the DC plug 20b of the second embodiment have the same configuration as the parallel mechanical on / off switch 16 of the DC plug 20a of the first embodiment. The electronic open / close switch 15 in the DC plug 20b of the second embodiment has the same configuration as the electronic open / close switch 15 in the DC plug 20a of the first embodiment.

  The parallel mechanical open / close switch 16 and the electronic open / close switch 15 are connected in parallel, and the parallel connection circuit and the series mechanical open / close switch 161 are connected in series. Therefore, a series connection circuit formed by the parallel connection circuit of the parallel mechanical opening / closing switch 16 and the electronic opening / closing switch 15 and the series mechanical opening / closing switch 161 connected in series to the parallel connection circuit is a DC plug 20b. Is arranged.

  FIG. 6 is a timing chart showing the operation of the control switch 17, the opening / closing procedure of the parallel mechanical opening / closing switch 16, the electronic opening / closing switch 15, and the series mechanical opening / closing switch 161. 6A shows disconnection (disconnection state) and conduction (conduction state) of the control switch 17, and FIG. 6B shows disconnection (disconnection state) and conduction (conduction state) of the series mechanical open / close switch 161. FIG. 6C shows disconnection (disconnection state) and conduction (conduction state) of the electronic on / off switch 15, and FIG. 6D shows disconnection (disconnection state) of the parallel mechanical opening / closing switch 16. It shows conduction (conduction state). The horizontal axis indicates time t. Such control is performed by the switch control circuit 141.

  Here, the disconnection (disconnection state) and conduction (conduction state) of the electronic on / off switch 15 and the disconnection (disconnection state) of the parallel mechanical on / off switch 16 shown in FIG. 6 (C) and FIG. 6 (D). The mutual relationship with conduction (conduction state) is the same as that shown in FIG. 3 (B) and FIG. 3 (C). That is, the parallel mechanical opening / closing switch 16 shown in FIGS. 6 and 3 operates with the same time relationship as the electronic opening / closing switch 15 shown in FIGS. 6 and 3.

  That is, the parallel mechanical on / off switch 16 is turned on at a time t7 after the predetermined time τ4 from the time t6 when the electronic open / close switch 15 is turned on, but the predetermined time τ4 (see FIG. 6) and the predetermined time τ1 (see FIG. 6). 3) is determined based on the same standard. Further, the electronic opening / closing switch 15 is disconnected at a time t9 after a predetermined time τ5 from the time t8 when the parallel mechanical opening / closing switch 16 is disconnected, but the predetermined time τ5 (see FIG. 6) and the predetermined time τ2 (FIG. 6). 3) is determined based on the same standard.

  With reference to FIG. 6, the procedure in the case where the DC current path inside the DC plug 20b is closed will be described first.

  The control switch pressing portion 191 presses the control switch 17 to change the control switch 17 from disconnection to conduction (see time t5 in FIG. 6A). The switch control circuit 141 changes the serial mechanical opening / closing switch 161 from disconnection to conduction based on a trigger signal generated by operating the control switch 17 (see time t5 in FIG. 6B). That is, as shown in FIG. 6B, when the control switch 17 becomes conductive (closed), the series mechanical opening / closing switch 161 becomes conductive (closed). Here, even if the series mechanical on / off switch 161 is turned on, since both the electronic on / off switch 15 and the parallel mechanical on / off switch 16 are open, no current flows through the series mechanical on / off switch 161. Then, the switch control circuit 141 turns on the electronic open / close switch 15 after a predetermined time τ3 from the time t5.

  At time t6 when the series mechanical on / off switch 161 and the electronic on / off switch 15 are turned on, the DC current path is closed and power is supplied to the load 30b. Here, the length of the predetermined time τ3 between the time t5 and the time t6 is longer than the time until the chattering of the contact of the series mechanical on / off switch 161 is settled (disappears). In this way, an arc is prevented from occurring at the contact point of the series mechanical opening / closing switch 161.

  In such a procedure, in the case of switching from disconnection to conduction, when the series mechanical on / off switch 161 is closed, the electronic on / off switch 15 is still open, and the contact of the series mechanical on / off switch 161 is not connected. Since no voltage is applied, even if chattering occurs, no arc is generated at the contact point of the series mechanical switch 161.

  As described above, the time relationship between the operations of the electronic open / close switch 15 and the parallel mechanical open / close switch 16 is the same as that in the first embodiment, and will be described below. The parallel mechanical on / off switch 16 is turned on (closed) at time t7 after a predetermined time τ4 from time t6 when the electronic on / off switch 15 is turned on. Here, the predetermined time τ4 is desirably a short time such that the temperature of the electronic open / close switch 15 does not rise above a predetermined temperature.

  In the case where there is no operation delay of the electronic open / close switch 15 and the conductive state is directly established by the control signal from the switch control circuit 141, the predetermined time τ4 may be 0, but the length of the predetermined time τ4. It is possible to ensure that the parallel mechanical opening / closing switch 16 is turned on after the electronic opening / closing switch 15 is sufficiently turned on (after the on-voltage of the electronic opening / closing switch 15 is sufficiently lowered). If the parallel mechanical on / off switch 16 conducts before the electronic on / off switch 15, an arc may be generated by chattering of the contacts of the parallel mechanical on / off switch 16, and such control is adopted. Can not.

  Next, the procedure when the DC current path inside the DC plug 20b is opened will be described. The control switch pressing unit 191 does not press the control switch 17 and changes the control switch 17 from conduction to disconnection (see time t8 in FIG. 6A). The switch control circuit 141 changes the parallel mechanical open / close switch 16 from conduction to disconnection based on a trigger signal generated by the operation of the control switch 17 (see time t8 in FIG. 6C). Further, the switch control circuit 141 conducts the electronic on / off switch 15 at time t9 after a predetermined time τ5 after changing the parallel mechanical on / off switch 16 from conduction to disconnection based on a trigger signal generated by the operation of the control switch 17. Change from to cutting. Here, the predetermined time τ5 is set to be longer than the time when chattering of the parallel mechanical on / off switch 16 is settled, and is shorter than the time at which the temperature of the electronic on / off switch 15 rises to a predetermined temperature. Set within. Furthermore, the longer the predetermined time τ5, the greater the power loss that occurs in the electronic switch 15 in the DC current path. In consideration of the above, the predetermined time τ5 is determined.

  Then, after a predetermined time τ6 after the electronic open / close switch 15 is opened, the series mechanical open / close switch 161 is opened. Here, the predetermined time τ6 may be 0, but by increasing the length of the predetermined time τ6, it is ensured that the series mechanical opening / closing switch 161 is disconnected after the electronic opening / closing switch 15 is sufficiently disconnected. it can.

  In this procedure, when switching from conduction to disconnection, when the parallel mechanical switch 16 is opened, the electronic switch 15 is still closed, and the contact of the parallel mechanical switch 16 is not connected. Even if chattering occurs, a voltage equal to or higher than the ON voltage of the electronic on / off switch 15 does not occur at both ends of the contacts of the parallel mechanical on / off switch 16, and no arc is generated between the contacts. When the electronic open / close switch 15 is opened, the direct current path is cut (open).

  Finally, the series mechanical opening / closing switch 161 is disconnected (opened), thereby making the disconnection of the direct current path more reliable. The switch control circuit 141 performs control so that the series mechanical opening / closing switch 161 is disconnected at time t10, which is delayed by a predetermined time τ6 from time t9. It is desirable to select the length of the predetermined time τ6 so that it is performed after the electronic opening / closing switch 15 is sufficiently cut (opened) (after the electronic opening / closing switch 15 is completely turned off). . That is, when the operation delay of the electronic open / close switch 15 is large, the predetermined time τ6 is lengthened so that the contacts of the series mechanical open / close switch 161 are not damaged.

  When the DC current path of the DC plug 20b is turned on and off, no arc is generated inside the DC plug 20b as described above. More preferably, as described in the first embodiment, the predetermined time τ4 is set as short as possible, and the predetermined time τ5 is set to a time equal to the time when chattering of the parallel mechanical opening / closing switch 16 is settled. As a result, even when the DC plug 20b is quickly pulled out from the outlet 19, the (predetermined time τ4 + predetermined time τ5) <(control switch pressing portion 191 does not press the control switch 17 until the DC plug 20b and the outlet 19 are connected. It is possible to maintain the relationship of the time until contact between the DC plug 20b and the outlet 19 is prevented.

  In short, in the DC plug of the second embodiment, the time for which the electronic on / off switch is conducted is determined so as to cover the time for which the parallel mechanical on / off switch is conducted in the front-rear direction. Further, the time for which the series mechanical on / off switch is conducted is determined so as to cover the time for which the electronic on / off switch is conducted in the front-rear direction. Here, the time when the chattering of the contacts of the series mechanical switch is settled and the time when the electronic switch is turned on are covered forward. In this way, the DC plug is conductive while the electronic open / close switch 15 is conductive.

(DC plug of the third embodiment)
FIG. 7 is a diagram illustrating a DC plug according to the third embodiment. FIG. 7 shows a DC plug 20c as a DC plug of the third embodiment. The DC plug 20c of the second embodiment includes a parallel mechanical open / close switch 16 and a series mechanical open / close switch 161 inserted in the DC current path so as to open or close a DC current path through which a DC current flows, and an electronic switch A switch 15 and a switch control circuit 141 are provided. The DC plug of the third embodiment is characterized by the fact that the power loss in the conduction state of the DC current path in the first embodiment is small, and a series mechanical switch 161 is inserted in series with the DC current path. Thus, the DC current path is more reliably cut and the safety is further improved.

  The parallel mechanical switch 16 and the series mechanical switch 161 in the DC plug 20c of the third embodiment have the same configuration as the parallel mechanical switch 16 in the DC plug 20a of the first embodiment. The electronic open / close switch 15 in the DC plug 20c of the third embodiment has the same configuration as the electronic open / close switch 15 in the DC plug 20a of the first embodiment.

  The series mechanical open / close switch 161 and the electronic open / close switch 15 are connected in series, and the series connection circuit and the parallel mechanical open / close switch 16 are connected in parallel. Therefore, the parallel connection circuit formed by the series connection circuit of the series mechanical opening / closing switch 161 and the electronic opening / closing switch 15 and the parallel mechanical opening / closing switch 16 connected in parallel to the series connection circuit is a DC plug 20c. Is arranged.

  Focusing on the connection mode between the mechanical on-off switch and the electronic on-off switch inserted in the busbar 13, the DC plug of the second embodiment shown in FIG. 5 is compared with the DC plug of the third embodiment shown in FIG. To do. In both of the DC plug of the second embodiment shown in FIG. 5 and the DC plug of the third embodiment shown in FIG. 7, the series mechanical on / off switch 161 and the electronic on / off switch 15 are connected in series. In the DC plug of the second embodiment shown in FIG. 5, the parallel mechanical on / off switch 16 is connected in parallel with the electronic on / off switch 15. In the DC plug of the third embodiment shown in FIG. The mechanical on / off switch 16 is connected in parallel with the electronic on / off switch 15 via a series mechanical on / off switch 161.

  From the commonality of such connection modes of the DC plug 20b of the second embodiment and the DC plug 20c of the third embodiment, the operation of the control switch 17, the parallel mechanical switch 16 and the electronic switch in the third embodiment. The timing chart showing the procedure for opening / closing the switch 15 and the series mechanical opening / closing switch 161 is the same as that shown in FIG. 6, and will be described with reference to FIG. 6 again.

  6A shows disconnection (disconnection state) and conduction (conduction state) of the control switch 17, and FIG. 6B shows disconnection (disconnection state) and conduction (conduction state) of the series mechanical open / close switch 161. FIG. 6C shows disconnection (disconnection state) and conduction (conduction state) of the electronic on / off switch 15, and FIG. 6D shows disconnection (disconnection state) of the parallel mechanical opening / closing switch 16. It shows conduction (conduction state). The horizontal axis indicates time t. Such control is performed by the switch control circuit 141.

  That is, the parallel mechanical on / off switch 16 is turned on at a time t7 after the predetermined time τ4 from the time t6 when the electronic open / close switch 15 is turned on, but the predetermined time τ4 (see FIG. 6) and the predetermined time τ1 (see FIG. 6). 3) is determined based on the same standard. Further, the electronic opening / closing switch 15 is disconnected at a time t9 after a predetermined time τ5 from the time t8 when the first mechanical opening / closing switch is disconnected, but the predetermined time τ5 (see FIG. 6) and the predetermined time τ2 (FIG. 3) is determined based on the same standard. Also, the predetermined time τ3 (see FIG. 6) and the predetermined time τ6 (see FIG. 6) are times having the same meaning as in the second embodiment.

  Since the procedure for opening and closing the DC plug 20c of the third embodiment is the same as that shown in the second embodiment, description thereof will be omitted.

  When the DC current path of the DC plug 20c is turned on and off, no arc is generated in the DC plug 20c as described above. As described in the second embodiment, more preferably, the predetermined time τ4 is set as short as possible and the predetermined time τ5 is set to a time equal to the time when chattering of the parallel mechanical opening / closing switch 16 is settled. By doing so, the risk of arcing between the DC plug 20c and the outlet 19 can be minimized.

  In short, in the DC plug of the third embodiment, the conduction time of the electronic opening / closing switch 15 is determined so as to cover the conduction time of the parallel mechanical opening / closing switch 16 in the front-rear direction. Further, the time for which the serial mechanical on / off switch 161 is conductive is determined so as to cover the time for which the electronic on / off switch 15 is conductive in the front-rear direction. Here, the time when the chattering of the contacts of the mechanical opening / closing switch (series mechanical opening / closing switch) is settled and the time when the electronic opening / closing switch is conducted are covered forward.

  In any of the DC plug of the first embodiment or the DC plug of the third embodiment described above, an electronic on / off switch inserted into the DC current path to open or close the DC current path through which the DC current flows And a parallel mechanical on / off switch connected in parallel to the electronic on / off switch, and a switch control circuit for controlling a mutual open / close time difference between the parallel mechanical on / off switch and the electronic on / off switch, The switch control circuit closes the parallel mechanical open / close switch after a predetermined time after the electronic open / close switch is closed.

  By doing so, when the parallel mechanical on / off switch is closed, an arc is not generated at the contacts of the parallel mechanical on / off switch due to chattering. In addition, since the parallel mechanical on / off switch is closed after a predetermined time after the electronic on / off switch is closed, current flows through the electronic on / off switch only during this predetermined time, and the temperature of the electronic on / off switch increases. Can be prevented. Further, the parallel mechanical open / close switch and the electronic open / close switch can be miniaturized, and further, the heat sink provided in the electronic open / close switch can be miniaturized.

  In addition, when the DC current path through which the DC current flows is opened, the switch control circuit opens the parallel mechanical on / off switch, and is longer than the time during which chattering generated by opening the parallel mechanical on / off switch is settled. The electronic on / off switch is opened within a period of time that is shorter than the time during which the temperature of the electronic on / off switch rises to a predetermined temperature.

  Further, in both of the DC plug of the second embodiment and the DC plug of the third embodiment described above, in addition to the electronic on-off switch and the parallel mechanical on-off switch, the electronic on-off switch is connected in series. When a direct current path through which a direct current flows is closed, a series mechanical open / close switch is provided, and after a predetermined time longer than the time when chattering generated by closing the series mechanical open / close switch is closed, The open / close switch is closed.

  Further, when the direct current path through which the direct current flows is opened, the series mechanical on / off switch is opened after the electronic on / off switch is opened.

  By doing so, in both of the DC plug of the second embodiment and the DC plug of the third embodiment, as with the DC plug of the first embodiment, a predetermined time after the electronic open / close switch is closed. Since the parallel mechanical opening / closing switch is closed, when the parallel mechanical opening / closing switch is closed, no arc is generated at the contact of the parallel mechanical opening / closing switch due to chattering. Further, only during this predetermined time, a current flows through the electronic open / close switch, and the temperature increase of the electronic open / close switch can be prevented. Further, the parallel mechanical open / close switch and the electronic open / close switch can be miniaturized, and further, the heat sink provided in the electronic open / close switch can be miniaturized. In addition, since the series mechanical on / off switch and the electronic on / off switch are arranged in series in the DC current path, the two contacts of the series mechanical on / off switch are separated by opening the series mechanical on / off switch. The DC current path is physically cut, and safety is further increased. Further, since the series mechanical switch is opened last, no arc is generated at the contact of the series mechanical switch.

"Variation of DC plug of embodiment"
(DC plug with power regeneration circuit)
In the DC plug of the first embodiment to the DC plug of the third embodiment, when the wiring from the output terminal C of the DC plug 20a and the output terminal D to the load 30a is long and the wiring has inductance, the output terminal C of the DC plug 20b When the wiring from the output terminal D to the load 30b is long and the wiring has inductance, or when the wiring from the output terminal C of the DC plug 20c and the output terminal D to the load 30c is long and the wiring has inductance, For the DC plug, special consideration for the generation of the back electromotive force is applied to either the load side, the bus bar side, or each DC plug (DC plug 20a, DC plug 20b, DC plug 20c) side. This is a problem to be solved from the viewpoint of preventing the application of a high voltage. Further, when the load is a load having an inductance component such as a motor, it is desirable to give the same consideration even if the wiring is short. Furthermore, when the load is a motor, how to effectively use the generated electromotive force is a problem to be solved.

  That is, when an inductance load (a load having an inductance component) is connected to the output side of each DC plug, a large reverse occurs immediately after the disconnection of the switch functioning as a DC switch provided inside each DC plug described above. An electromotive voltage is applied between the output terminal C and the output terminal D. This back electromotive voltage may affect each DC switch of each DC plug and other devices on the line, and each DC switch of each DC plug and other devices may be destroyed.

  In order to prevent the occurrence of such a back electromotive voltage, it is desirable to provide a commutation diode inside the load. Generation of a large counter electromotive voltage can be prevented by the action of the commutation diode. Whether or not the commutation diode is provided in the load depends on the intention of the manufacturer of the electric device that is the load, and therefore, there may be a case where the commutation diode is not provided in the electric device. In this case, a countermeasure against the counter electromotive voltage is taken in the line from the DC plug to the load or in the DC plug.

  Furthermore, when the load is a motor (electric motor), it is more desirable to provide a regenerative diode that returns the electromotive force to the power system. The commutation diode itself and the regenerative diode (power regenerative diode) are known techniques. However, how to use the technology of commutation diodes and regenerative diodes in a DC plug in which the DC current path between the power system and the load is cut by an electronic switch or a mechanical switch. I don't know about it yet.

  The following embodiments further provide a DC plug to which a commutation diode and a regenerative diode are added. And the subject of preventing generation | occurrence | production of a counter electromotive voltage and returning an electromotive force to the electric power system side is solved.

  As a countermeasure against the counter electromotive voltage in each DC plug, a commutation diode can be provided in advance between the output terminal C and the output terminal D inside each DC plug.

  FIG. 8 is a diagram illustrating a first modification of the DC plug. In the DC plug 20d shown in FIG. 8, a diode Df functioning as a commutation diode is provided inside the DC plug. Since each part of the DC plug 20d shown in FIG. 8 is the same as the DC plug 20a shown in FIG. 2 except for the diode Df, the description thereof is omitted. The diode Df may be provided so as to be reverse-biased between the output terminal C and the output terminal D, and the position thereof is not strictly specified. Thus, by providing the diode Df in the DC plug 20d so as to be reverse-biased, a forward current is applied to the diode Df immediately after the DC current path of the load 30d (not shown) having inductance is opened. Therefore, the back electromotive voltage can be prevented from being generated, and the DC plug 20a can be prevented from being broken.

  Regarding the regenerative diode, in the DC plug 20d, when the MOS-FET 35 is used as an electronic open / close switch, the body diode (see FIG. 4) which is reversely biased with the MOS-FET 35 performs the function of the regenerative diode. Become. Therefore, it is not always necessary to add a regenerative diode. When a bipolar transistor is used as the electronic open / close switch, a regenerative diode is provided at the same position as the body diode. In this manner, immediately after the DC plug 20d is opened, the power generated in the load 30d can be regenerated in the power system by supplying a regenerative current to the body diode that is reverse-biased during normal operation.

  FIG. 9 is a diagram illustrating a second modification of the DC plug. A DC plug 20e shown in FIG. 9 is connected to a diode Df functioning as a commutation diode and a diode Dr functioning as a regenerative diode with respect to the DC plug 20b shown in FIG. The diode Dr is connected between the input terminal B and the output terminal D so as to be reverse-biased. The diode Df is connected between the output terminal C and the output terminal D so as to be reverse-biased.

  By adopting such a configuration, immediately after the DC current path of the load 30e (not shown) having inductance is opened, a forward current is passed through the diode Df to prevent the generation of a counter electromotive voltage, It is possible to prevent the plug 20e from being broken. Moreover, the electric power which generate | occur | produces the load 30e when a forward direction current is sent through the diode Dr can be regenerated to an electric power grid | system.

  FIG. 10 is a diagram illustrating a third modification of the DC plug. The DC plug 20f shown in FIG. 10 connects a diode Df that functions as a commutation diode and a diode Dr that functions as a regenerative diode to the DC plug 20c shown in FIG. The diode Dr is connected between the input terminal B and the output terminal D so as to be reverse-biased. The diode Df is connected between the output terminal C and the output terminal D so as to be reverse-biased.

  By adopting such a configuration, immediately after the DC current path of the load 30f (not shown) having inductance is opened, a forward current is passed through the diode Df to prevent the generation of a counter electromotive voltage, It is possible to prevent the plug 20f from being broken. In addition, it is possible to regenerate power generated in the load 30f by causing a forward current to flow through the diode Dr in the power system.

  FIG. 11 is a diagram illustrating a fourth modification of the DC plug. A DC plug 20g shown in FIG. 11 connects a diode Df functioning as a commutation diode and a diode Dr functioning as a regenerative diode to the electronic switch 15 and the series mechanical switch 161. The diode Dr is connected between the input terminal B and the output terminal D so as to be reverse-biased. The diode Df is connected between the output terminal C and the output terminal D so as to be reverse-biased.

  In the DC plug 20g, when the DC current path through which the DC current flows is closed, the switch control circuit 114 closes the electronic ON / OFF switch 15 after the series mechanical ON / OFF switch 161 is closed, and the DC current is When opening the flowing DC current path, the series mechanical opening / closing switch 161 is opened after the electronic opening / closing switch 15 is opened. In this way, it is possible to prevent arc discharge from occurring in the series mechanical opening / closing switch 161. In this way, the DC plug is conductive while the electronic open / close switch 15 is conductive.

  By adopting such a configuration, immediately after the DC current path of the load 30g (not shown) having inductance is opened, a forward current is passed through the diode Df to prevent the generation of a counter electromotive voltage, The plug 20g is prevented from being broken. Moreover, the electric power which generate | occur | produces the forward direction current through the diode Dr and can generate | occur | produce in the load 30g can be regenerated to a power grid | system.

  FIG. 12 is a diagram illustrating a fifth modification of the DC plug. The DC plug 20h shown in FIG. 12 connects a diode Df that functions as a commutation diode and a diode Dr that functions as a regenerative diode to the DC plug 20b shown in FIG. The diode Dr is connected to the series mechanical opening / closing switch 161 so as to be reverse-biased in parallel. The diode Df is connected between the output terminal C and the output terminal D so as to be reverse-biased.

  By adopting such a configuration, immediately after the DC current path of the load 30h (not shown) having inductance is opened, a forward current is passed through the diode Df to prevent the generation of a counter electromotive voltage, It is possible to prevent the plug 20h from being broken. In addition, it is possible to regenerate power generated in the load 30h by causing a forward current to flow through the diode Dr and the body diode of the electronic open / close switch 15.

  FIG. 13 is a diagram illustrating a sixth modification of the DC plug. A DC plug 20i shown in FIG. 13 connects a diode Df functioning as a commutation diode and a diode Dr functioning as a regenerative diode to the DC plug 20c shown in FIG. The diode Dr is connected to the series mechanical opening / closing switch 161 so as to be reverse-biased in parallel. The diode Df is connected between the output terminal C and the output terminal D so as to be reverse-biased.

  By adopting such a configuration, immediately after the DC current path of the load 30i (not shown) having inductance is opened, a forward current is passed through the diode Df to prevent the generation of a counter electromotive voltage, The plug 20i can be prevented from being destroyed. In addition, it is possible to regenerate power generated in the load 30i by causing a forward current to flow through the diode Dr and the body diode of the electronic switch 15.

  FIG. 14 is a diagram illustrating a seventh modification of the DC plug. A DC plug 20j shown in FIG. 14 connects a diode Df functioning as a commutation diode and a diode Dr functioning as a regenerative diode to the electronic switch 15 and the series mechanical switch 161. The diode Dr is connected to a mechanical open / close switch (series mechanical open / close switch) 116 so as to be reverse-biased. The diode Df is connected between the output terminal C and the output terminal D so as to be reverse-biased.

  In the DC plug 20j, when closing the DC current path through which the DC current flows, the switch control circuit 114 closes the electronic opening / closing switch 15 after the series mechanical ON / OFF switch 161 is closed, and the DC current is When opening the flowing DC current path, the series mechanical opening / closing switch 161 is opened after the electronic opening / closing switch 15 is opened. In this way, it is possible to prevent arc discharge from occurring in the series mechanical opening / closing switch 161. In this way, the DC plug is conductive while the electronic open / close switch 15 is conductive.

  Further, by adopting the above-described configuration, immediately after the DC current path of the load 30j having inductance (see FIG. 1) is opened, a forward current is passed through the diode Df to prevent the occurrence of a back electromotive voltage. The DC plug 20j can be prevented from being destroyed. In addition, a forward current can be passed through the diode Dr and the body diode of the electronic open / close switch 15 to regenerate power generated in the load 30j to the power system.

  In the above-described modification of the embodiment, the diode Df (commutation diode) connected to be reverse biased is provided at both ends of the output end of the DC plug. Further, the reverse polarity is applied to the diode Dr (regenerative diode) connected in parallel so as to be reverse-biased with respect to the electronic open / close switch, or to the series connection circuit of the electronic open / close switch and the series mechanical open / close switch. Thus, a diode Dr (regenerative diode) connected in parallel or a diode Dr (regenerative diode) connected in parallel so as to be reverse-biased with respect to the mechanical opening / closing switch is provided.

  In the above-described modification of the embodiment, it has been described that both the diode Df that functions as a commutation diode and the diode Dr that functions as a regenerative diode are provided. However, when the load has an inductance component (for example, a wiring inductance component from both ends of the commutation diode to the load, or an inductance component of the load itself), even when only the commutation diode is provided, it is between the output terminals of the DC plug. Generation of the counter electromotive voltage that occurs can be prevented. In addition, when the load generates an electromotive force with a motor (electric motor), the regenerative power can be returned to the power system even when only the regenerative diode is provided.

  In the case where both the commutation diode and the regenerative diode are provided, as described above, the load includes an inductance component, the case where the load is a motor, and a DC plug for a wide variety of loads. Generation of a counter electromotive voltage generated between the output terminals can be prevented and / or regenerative power can be returned to the power system.

  For example, when the load is a motor, each of the commutation diode and the regenerative diode operates with a time difference as follows. Immediately after cutting off the DC plug, a counter electromotive voltage due to the wiring inductance component and the inductance component of the motor winding is generated, but the commutation diode can prevent the occurrence of this counter electromotive voltage, The motor is rotated by the forward current flowing through the commutation diode. Thereafter, when the forward current of the commutation diode disappears, the motor becomes a generator, and the forward current flows through the regenerative diode so that the regenerative power can be returned to the power system.

(Modification example of the insertion point of each DC switch in the DC plug)
In the modification of the direct current plug of the first embodiment to the direct current plug of the third embodiment and the direct current plug of the embodiment having a commutation diode and a regenerative diode, both the mechanical open / close switch and the electronic open / close switch are In the above description, the terminal is inserted between the input terminal B and the output terminal D. However, even if the mechanical open / close switch, the electronic open / close switch, and the regenerative diode are inserted between the input terminal A and the output terminal C, a desired effect can be produced. In other words, the same effect can be obtained even if a serial mechanical switch or / and a parallel mechanical switch, an electronic switch, and a regenerative diode are inserted on either side of the bus 12 and the bus 13. Can do.

(DC plug of the fourth embodiment)
FIG. 15 is a diagram illustrating a DC plug according to the fourth embodiment. The DC plug 20k of the fourth embodiment can be implemented in combination with any of the first to third embodiments and all the modifications described above.

  The DC plug 20k according to the fourth embodiment uses a control switch pressing portion 191, a control switch 17, and a slide switch 177 that functions as another control switch. The switch control circuit 214 functions similarly to the switch control circuit 14 of the first embodiment described in FIG. A difference from the switch control circuit 14 is that when either the control switch 17 or the slide switch 177 is opened, a series of operations for opening the DC current path is started. The switch control circuit 14 also differs from the switch control circuit 14 in that a series of operations for closing the DC current path is not started unless both the control switch 17 and the slide switch 177 are closed.

  Therefore, in the description of each embodiment described above and the timing charts of FIGS. 3 and 6, the state in which the control switch 17 is closed is read as both the control switch 17 and the slide switch 177 are closed. In the timing charts of FIGS. 3 and 6, the state in which the control switch 17 is open is read as either the control switch 17 or the slide switch 177 being open. The slide switch 177 is provided with a lever that can be operated from the outside of the DC plug 20k. If the lever is slid to the arrow ON side, the slide switch 177 is conductive (closed), and if the lever is slid to the arrow OFF side, the slide switch 177 is disconnected (open).

  By controlling the lever of the slide switch 177 in addition to the control switch 17, it is possible to control conduction and disconnection of the DC current path inside the DC plug 20k. Therefore, after the slide switch 177 is turned OFF, the regenerative current is returned to the DC power system 10 through the outlet, and then the DC plug 20k is removed from the outlet 19 so that the regenerative power is effectively returned to the power supply system and the outlet 19 It is possible to prevent an arc from occurring between the DC plugs 20k. Furthermore, even when the DC plug 20k is disconnected from the outlet without operating the slide switch 177, the risk of arcing due to the regenerative current between the DC plug 20k and the outlet due to the action of the control switch 17 is described above. In this way it can be made smaller.

(DC plug of a modification of the fourth embodiment)
A modification (not shown) of the DC plug 20k of the fourth embodiment will be described. The modification of the DC plug 20k according to the fourth embodiment is equivalent to the DC plug 20k according to the fourth embodiment, in which the control switch 17 is always opened without providing the control switch pressing portion 191. . Further, in the DC plug 20a of the first embodiment, instead of the control switch 17, a slide switch 177 that functions as a control switch is used. Therefore, the control switch 17 in the description of each embodiment described above and the timing charts of FIGS. 3 and 6 is replaced with the slide switch 177.

  By controlling the lever of the slide switch 177, conduction and disconnection of the DC current path inside the DC plug can be controlled. In addition, after the slide switch 177 is turned OFF, the regenerative current is returned to the DC power system 10 through the outlet, and then the DC plug is removed from the outlet so that the regenerative power is effectively returned to the power system and the outlet and the DC plug are connected. It is possible to prevent an arc from occurring between them. The direct-current plug of the modification of the fourth embodiment can be implemented in combination with the first to third embodiments and all of the modifications described above.

(DC plug of the fifth embodiment)
FIG. 16 is a diagram showing a DC plug according to the fifth embodiment. The DC plug 20l of the fifth embodiment shown in FIG. 16 uses a receiving unit 42 instead of the protruding control switch pressing unit 191 and the control switch 17 with respect to the DC plug 20a of the first embodiment. ing. When the receiving unit 42 detects the predetermined password, when the control switch 17 is pushed and closed (conducted) by the protruding control switch pressing unit 191 in the DC plug 20a, a similar trigger signal is sent to the switch control circuit 14. Is sent out. Here, power to the receiving unit 42 is supplied from the input terminal A and the input terminal B.

  FIG. 17 is a diagram showing an outlet for use in combination with the DC plug of the fifth embodiment. The outlet 19a shown in FIG. 17 includes an electromagnetic wave emitting unit 41 (transmitting unit) and a memory 46 that stores a predetermined password.

  The operation of the DC plug 20l and the outlet 19a of the fifth embodiment will be described. The electromagnetic wave emitting unit 41 of the outlet 19a modulates the electromagnetic wave and transmits it to the receiving unit 42 of the DC plug 20l. A memory 46 storing a predetermined password is connected to the electromagnetic wave emitting unit 41, and an electromagnetic wave modulated by information including the predetermined password is transmitted from the electromagnetic wave emitting unit 41. The predetermined password is repeatedly transmitted every 1 ms (milliseconds), for example.

  When the distance between the receiving unit 42 of the DC plug 20l and the electromagnetic wave emitting unit 41 (transmitting unit) is close enough to detect the predetermined password, the receiving unit 42 detects the predetermined password every 1 ms. As long as the receiving unit 42 of the DC plug 20l continues to receive the predetermined password, the DC plug 20a operates in the same manner as when the control switch 17 is kept pressed (closed) by the protruding control switch pressing unit 191. To do. The receiving unit 42 has a mono-multi circuit function that maintains the previous state for 1 ms. After a predetermined password is received every 1 ms, the control switch 17 is pressed and closed for 1 ms. It works in the same way if you continue.

  This password includes a DC voltage value desired by the DC plug 201, a desired current amount, and the like. When this password is a predetermined password determined in advance, that is, the DC voltage that the outlet 19a is to output and the allowable current of the outlet 19a are desired by the load 30l (see FIG. 1) connected to the DC plug 20l. When the voltage is equal to the voltage and larger than the desired current, the DC current path inside the DC plug 20l is made conductive, and power is supplied to the load 30l.

  Further, the distance between the facing surfaces of the DC plug 20l and the outlet 19a will be described. . The receiving part 42 of the DC plug 20l and the electromagnetic wave emitting part 41 of the outlet 19a are opposed to each other through an insulating wall surface. If the distance between the insulating material wall surface shown in FIG. 16 and the insulating material wall surface shown in FIG. 17 is equal to or less than a predetermined distance, the DC plug 20l can read the password. This predetermined distance depends on the intensity of the electromagnetic wave output from the outlet 19a. For example, the predetermined distance is very small as 2 mm (millimeter), and communication is not possible between the DC plug 20l and the outlet 19a unless the distance is within this predetermined distance. This distance is set to be smaller than the distance at which the connection between the input terminal A and the input terminal B of the DC plug 20l and the outlet 19a is started. Therefore, in a state where password communication is possible, the connection between the input terminal A and the input terminal B of the DC plug 20l and the outlet 19a is already secured.

  That is, the connection between the input terminal A and the input terminal B of the DC plug 20l and the outlet 19a is started at a distance farther than the DC plug 20l and the outlet 19a approach each other at a predetermined distance at which the predetermined password can be reproduced. After that, the reception unit 42 reproduces the predetermined password, and the switch control circuit 14 controls the operation of the predetermined procedure in the DC plug 201 to close the DC current path. Therefore, when the DC current path of the DC plug 201 is closed, no arc is generated in the DC plug 201 and no arc is generated between the DC plug 201 and the outlet 19a.

  Further, when the receiving unit 42 cannot reproduce the predetermined password, the switch control circuit 14 controls the operation of the predetermined procedure described above so as to open the DC current path of the DC plug 20l. At this time, the predetermined distance, which is the distance between the receiving unit 42 of the DC plug 20l and the electromagnetic wave emitting unit 41 of the outlet 19a, at which the predetermined password cannot be reproduced is 2 mm. The connection between the input terminal A and the input terminal B of the DC plug 20l and the outlet 19a is maintained. Therefore, when the direct current path of the direct current plug 20l is opened, no arc is generated inside the direct current plug 20l.

  In addition, when the DC plug 20l is suddenly pulled out from the outlet 19a while the load 30L is energized, the DC plug 201 cannot reproduce the predetermined password, and the DC current path of the DC plug 20l is opened. The operation of a predetermined procedure is controlled. Therefore, even in such a case, the risk of occurrence of an arc between the DC plug 20l and the outlet 19a can be minimized.

  Also, in the case of providing a plurality of DC power supply systems to which a plurality of voltages are fed using the same shape outlets and plugs, outlets belonging to a specific DC power supply system have a predetermined specific power supply. Power can be supplied only to a DC plug that can receive a predetermined password unique to the DC power supply system. Therefore, a DC plug that can supply power is specified for each DC power supply system. In this way, the power used is leveled for each power system, and the DC current system can be used efficiently. In addition, the management of electricity charges becomes easy.

  Even if the DC plug is inserted into the wrong DC power supply system with different power supply voltage, if the password obtained from the DC plug receiver is not the specified password specified for the DC power supply system, Since energization is not started, the destruction of the load can be prevented and the safety can be improved.

  As described above, in the fifth embodiment, the outlet having the memory storing the password and the electromagnetic wave emitting unit is used. The DC plug is provided with a receiving unit. As described above, if the receiving unit is provided in each of the above-described embodiments instead of the control switch, the same operations and effects can be obtained in all the embodiments.

(Modified DC plug of the fifth embodiment)
Various modifications are possible as modifications of the DC plug of the fifth embodiment. In the following modifications, in place of the protruding control switch pressing portion 191 and the control switch 17, various communication devices that communicate between the DC plug and the outlet are used. The communication device is provided separately in a DC plug and an outlet, and a receiving unit is used on the DC plug side. Similar to the DC plug of the fifth embodiment, the receiving unit starts operating after the input terminal A of the DC unit plug and the input terminal B of the DC plug are inserted into the outlet.

  In other words, the modification of the DC plug of the fifth embodiment is similar to the fifth embodiment in that the input terminal and the outlet are separated at a distance farther than the outlet approaches a predetermined distance at which a predetermined password can be reproduced. After the connection is started and the predetermined password is reproduced by the receiving unit, the switch control circuit closes the DC current path. In addition, the connection between the input terminal and the outlet is maintained at a distance away from the predetermined distance where the predetermined password can be reproduced, and when the predetermined password cannot be reproduced at the receiver, the switch control circuit switches the DC current path. Open circuit.

  As a first modification, a receiving unit that receives ultrasonic waves is used instead of the receiving unit 42 of the DC plug 20l, and an ultrasonic emitting unit is used as a transmitting unit that transmits a password instead of the electromagnetic wave emitting unit 41 of the outlet. Can do. In this way, the same effect as that of the fifth embodiment can be obtained. In addition to using ultrasonic waves (a combination of an ultrasonic wave emitting unit having an ultrasonic oscillation element and an ultrasonic wave receiving unit having an ultrasonic detector), using infrared rays (a combination of an infrared light emitting element and a photodiode), The password sent from the plug can also be demodulated. Furthermore, the predetermined password is not limited to a specially coded signal, and may be any password that can be distinguished from others. For example, the frequency and wavelength may simply be set to predetermined values.

  FIG. 18 is a view showing a DC plug 20m of a second modification which is another modification of the DC plug of the fifth embodiment. FIG. 19 is a diagram showing an outlet used corresponding to the DC plug 20m.

  In the outlet 19b, an electric field is generated in the electric field generating unit 45 (transmitting unit) according to a predetermined password stored in the memory 46 and transmitted to the conductive plate Pc2. In the DC plug 20m, the receiving unit 43 is connected to the conductive plate Pc1, detects a change in the electric field, and further reproduces the predetermined password to notify the switch control circuit 14 that the predetermined password has been reproduced. Subsequent processing is performed in the same manner as in the fifth embodiment.

  In short, the DC plug of the fifth embodiment includes a receiving unit that receives and reproduces a password sent from an outlet. Then, the connection between the input terminal and the outlet is started at a distance farther than the outlet approaches the predetermined distance at which the predetermined password can be reproduced, and after the predetermined password is reproduced by the receiving unit, the switch control circuit The road may be closed. In addition, the connection between the input terminal and the outlet is maintained at a distance away from the predetermined distance where the predetermined password can be reproduced, and when the predetermined password cannot be reproduced at the receiver, the switch control circuit switches the DC current path. It can be opened. Therefore, as described above, not only electromagnetic waves and electric fields but also ultrasonic waves can be used.

(Modified DC plug of the sixth embodiment)
FIG. 20 is a diagram showing a DC plug of the sixth embodiment, and FIG. 21 is a diagram showing an outlet used in combination with the DC plug of the sixth embodiment. In the DC plug 20n of the sixth embodiment, the distance between the DC plug 20n and the outlet 19c is detected in a non-contact manner instead of the protruding control switch pressing portion 191 and the control switch 17 of the first embodiment. .

  The outlet 19c is provided with a conductive plate Pc5. The DC plug 20n is provided with a capacitance detection unit 47, and a conductive plate Pc3 (first conductive plate) and a conductive plate Pc4 (second conductive plate) are connected to the capacitance detection unit 47. The capacitance detection unit 47 detects the capacitance between the conductive plate Pc3 and the conductive plate Pc4. The capacitance between the conductive plate Pc3 and the conductive plate Pc4 increases as the separation distance between the DC plug 20n and the outlet 19c decreases. When the electrostatic capacitance between the conductive plates Pc3 and Pc4 exceeds a predetermined capacitance, the electrostatic capacitance detection unit 47 sends an approach signal to the switch control circuit 14. The approach signal is a signal notifying that the distance between the DC plug and the outlet is within a predetermined distance.

  The connection between the input terminal and the outlet is started at a distance farther than the outlet approaches the predetermined distance at which the detection of the approach signal is started. After the proximity signal is detected by the capacitance detection unit 47, the switch control circuit The DC current path is closed. In addition, when the connection between the input terminal and the outlet is maintained at a distance that is more than the predetermined distance at which the approach signal can be detected, and the capacitance detection unit 47 cannot detect the approach signal, the switch control circuit Open the DC current path.

(Modified DC plug of the seventh embodiment)
In the DC plug (DC plug 20a, DC plug 20b, DC plug 20c, DC plug 20k) of the embodiment shown in FIG. 1, the control switch pressing portion 191 is provided on the DC plug side. However, the control switch pressing portion 191 may be provided not on the DC plug side but on the outlet 19 side. A control switch pressing portion 191 is provided in a protruding shape so as to extend from the outlet 19, and a guide hole into which the control switch pressing portion 191 is inserted is provided on the DC plug side. The control switch pressing portion 191 on the outlet 19 side inserted along the guide hole may press the control switch 17. DC plug 20d shown in FIG. 8, DC plug 20e shown in FIG. 9, DC plug 20f shown in FIG. 10, DC plug 20g shown in FIG. 11, DC plug 20h shown in FIG. 12, DC plug 20i shown in FIG. Similarly, in each DC plug of the DC plug 20j shown in FIG. 5, a guide hole into which the control switch pressing portion 191 is inserted is provided on the DC plug side, and the outlet 19 side to be inserted along the guide hole is provided. The control switch pressing unit 191 may press the control switch 17.

  New embodiments combining the individual techniques disclosed in the various embodiments described above can also be implemented. Further, the present invention is not limited to the scope of the above-described embodiment and the combination of these embodiments.

  10 power system, 12, 13 bus, 14, 14a, 114, 141 switch control circuit, 15, 15a electronic on / off switch, 16, 161, 16a mechanical on / off switch (parallel mechanical on / off switch), 17 control switch, 18 Digital logic circuit 19, 19a Outlet, 20a, 20b, 20c, 20d, 20e, 20f, 20g, 20h, 20i, 20j, 20l DC plug, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30i , 30j, 30k, 30l load, 41 electromagnetic wave emitting part (transmitting part), 42, 43 receiving part, 45 electric field generating part (transmitting part), 46 memory, 47 capacitance detecting part, 50 relay, 51, 54 bipolar transistor 53 MOS-FET ), 177 slide switch, 191 control switch pressing part, A, B input terminal, C, D output terminal, Df diode (commutation diode), Dr diode (regenerative diode), I signal input terminal, O1, O2 signal Output terminal, Pc1, Pc2, Pc3, Pc4, Pc5 conductive plate, R1, R2, R3, R4 resistance, t, t1, t2, t3, t4, t5, t6, t7, t8, t9, t10, time τ1, τ2 , Τ3, τ4, τ5, τ6 Predetermined time, ZD Zener diode

Claims (10)

An input terminal for connection to an outlet,
An output terminal for connection to the load;
An electronic open / close switch inserted into the DC current path to open or close a DC current path through which a DC current flows between the input terminal and the output terminal;
A parallel mechanical on / off switch connected in parallel to the electronic on / off switch;
A switch control circuit for controlling a mutual opening / closing time difference between the parallel mechanical opening / closing switch and the electronic opening / closing switch,
The switch control circuit includes:
When closing the DC current path,
After the input terminal is connected to the outlet,
After closing the electronic opening / closing switch, closing the parallel mechanical opening / closing switch,
DC plug. In addition, a series mechanical on-off switch connected in series to the electronic on-off switch,
The switch control circuit includes:
The electronic on / off switch is closed after a predetermined time longer than the time when chattering caused by the series mechanical on / off switch being closed is settled,
The direct-current plug according to claim 1. An input terminal for connection to an outlet,
An output terminal for connection to the load;
An electronic open / close switch inserted into the DC current path to open or close a DC current path through which a DC current flows between the input terminal and the output terminal;
A parallel mechanical on / off switch connected in parallel to the electronic on / off switch;
A switch control circuit for controlling a mutual opening / closing time difference between the parallel mechanical opening / closing switch and the electronic opening / closing switch,
The switch control circuit includes:
When opening the DC current path through which the DC current flows to the outlet,
The parallel mechanical open / close switch is opened,
Within a time longer than the time when chattering caused by the parallel mechanical on / off switch being opened is settled and shorter than the time when the temperature of the electronic on / off switch rises to a predetermined temperature, The electronic open / close switch is opened;
DC plug. In addition, a series mechanical on-off switch connected in series to the electronic on-off switch,
The switch control circuit includes:
After opening the electronic on / off switch, the serial mechanical on / off switch is opened.
The direct-current plug according to claim 3. Furthermore, it comprises a commutation diode connected at both ends of the output terminal so as to be reverse biased.
The direct-current plug according to claim 1. A regenerative diode connected in parallel so as to be reverse-biased with respect to a series connection circuit of the electronic on-off switch and the series mechanical on-off switch,
The direct-current plug according to claim 4. Furthermore, a receiving unit for receiving and playing back a password sent from the outlet,
The switch is started after the connection between the input terminal and the outlet is started at a distance farther than the outlet approaches a predetermined distance at which the predetermined password can be reproduced, and the predetermined password is reproduced by the receiving unit. The DC plug according to claim 1, wherein the control circuit closes the DC current path. Furthermore, a receiving unit for receiving and playing back a password sent from the outlet,
The switch control circuit is configured such that the connection between the input terminal and the outlet is maintained at a distance apart from the predetermined distance at which the predetermined password can be reproduced and the reception unit cannot reproduce the predetermined password. The DC plug according to claim 3, wherein the DC current path is an open circuit. Furthermore, a first conductive plate and a second conductive plate for detecting a separation distance from the outlet, and a capacitance detection unit for detecting an approach signal indicating that the separation distance is within a predetermined distance,
Connection of the input terminal and the outlet is started at a distance farther than the outlet approaches the distance for detecting the approach signal detected by the capacitance detection unit, and the approach signal is detected. The DC plug according to claim 1, wherein the switch control circuit closes the DC current path after starting. Furthermore, a first conductive plate and a second conductive plate for detecting a separation distance from the outlet, and a capacitance detection unit for detecting an approach signal indicating that the separation distance is within a predetermined distance,
The connection between the input terminal and the outlet is maintained at a distance apart from the predetermined distance from which the approach signal can be detected, and the switch control circuit detects the direct current when the approach signal cannot be detected. The DC plug according to claim 3, wherein the path is an open circuit.