JPH10302584A - Hybrid type dc switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid type dc switch in which the deterioration and the dispersion of shutoff performance are very little, and complete insulation can be conducted at the off time. SOLUTION: A switch with contact 1 turns main make and break contacts X1 , X2 on when a control signal INPUT inputted to a control signal input terminals I1 , I2 becomes 'H'. MOSFETs Q2 , Q3 conduct on-operation when the auxiliary make and break contact X3 of the switch with contact 1 is turned on delaying from the on-operation of the main make and break contacts X1 , X2 . Thereby, a dc power source DC is connected to a load 5 causing a load current to flow. When the control signal INPUT becomes 'L', the switch with contact 1 turns off the auxiliary make and break contact X3 first of all so as to turn off the MOSFETs Q2 , Q3 . The load current is broken by this off, and thereafter the main make and break contact X1 , X2 are brought into an off state. No arc is generated at this off time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct current (DC) for controlling opening and closing between a charger and a battery in a case of urgently charging or refreshing a battery in a high voltage battery such as an electric vehicle or a large DC device. The present invention relates to a switch, and more particularly to a hybrid DC switch suitable for switching control of a high-voltage, low-current DC load.

[0002]

2. Description of the Related Art In a general contact switch, when a voltage applied to a load is a DC high voltage, a general contact mechanism is:
The arc voltage is very small and stable as compared with the power supply voltage (voltage between contacts) as shown in FIG. 10 (b). As shown, there is a problem that the current cannot be reduced and the arc continues and cannot be interrupted. Therefore, if it cannot be cut off, the contact block and its housing may be ignited.

A conventional mechanical DC switch is provided with a grid like a circuit breaker at a point where an arc is generated at a contact, or drives an arc generated between the contacts by a permanent magnet or the like.
By taking measures such as increasing the arc length,
As shown in FIG. 1 (b), a method is adopted in which the arc voltage is made higher than the power supply voltage (voltage between contacts), the flowing current is reduced to zero as shown in FIG.
In recent years, a method of shortening the breaking time by sealing the contact block and sealing the gas therein to increase the arc voltage when the breaking is performed has been studied.

As another DC switch, there is a semiconductor switch. In the case of a semiconductor switch, an arc is not generated, a high-voltage current can be cut off, and there is a characteristic that a cutoff characteristic (cutoff time) does not deteriorate due to the number of cutoffs.

[0005]

However, in the above-mentioned conventional mechanical DC switch, there is a problem that the contact block becomes large, such as a grid structure, a permanent magnet structure and a long gap structure in order to increase the arc voltage. In addition, there is a problem that the cost is high due to the complexity of the contact block. In addition, when the arc generated at the contact is caused to travel by a permanent magnet, a grid, or the like, a phenomenon called "sticking" occurs as shown in FIG. There is also. Further, there is a problem that the variation in the time is very large, and the variation is further increased due to the deterioration due to the opening and closing of the contact portion, and the interruption time is deteriorated by the opening and closing.

Further, the specifications of the contact block of the high-voltage DC switch are designed around the contacts according to the specification corresponding to the high-voltage voltage value. Therefore, when the high-voltage voltage is different, it is necessary to design separately. There is also a problem. On the other hand, in the case of a semiconductor switch, variation and deterioration of the cutoff characteristics do not occur. However, since it is a semiconductor, a leakage current flows when the switch is off, and it is not possible to completely insulate a high voltage. There is a title. Furthermore, the semiconductor switch is very susceptible to noise and has a problem that it is turned on by external noise without sending a control signal. A relay in which a semiconductor switch called a hybrid type and a mechanical contact are connected in parallel (Japanese Unexamined Patent Publication No. Hei.
However, there is a problem that leakage current of the semiconductor switch flows because the semiconductor switches are connected in parallel, and a problem that the current cannot be cut off when the semiconductor switches are broken and short-circuited.

An object of the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a small-sized and low-cost device capable of controlling the opening and closing of a high-voltage direct current, and to provide a shut-off performance by opening and closing. It is an object of the present invention to provide a hybrid DC switch that can be completely insulated when the switch is off and has very small deterioration and variation, and is free from a malfunction caused by noise.

It is another object of the present invention to provide a hybrid DC switch capable of easily changing the specifications even when the high voltage is changed.

[0009]

According to the first aspect of the present invention, both ends of a load are connected to both ends of a high-voltage DC power supply by a first contact switch.
Each is connected via the second main switching contact, and a semiconductor switch is inserted in series into an electric circuit opened and closed by at least one of the main switching contacts, and the semiconductor switch and the contact switch are operated in response to a control signal input. And controlling the semiconductor switch to be turned off prior to turning on the main switching contact when the main switching contact of the contacted switch is turned on. Since the two main switching contacts are completely insulated by turning off the two main switching contacts, no leakage current flows through the semiconductor switch, and at the time of the OFF operation, the semiconductor switch is turned off before the two main switching contacts of the contact switch are turned off. An arc does not occur when the switching contact is turned off, and stable breaking characteristics can be obtained. In addition, since the load current is cut off by the semiconductor switch, the breaking characteristics due to breaking are reduced. Reduction does not occur, the variation of the resulting cut-off time does not occur. Also, when the voltage of the high-voltage DC power supply is changed, the voltage specification can be changed easily by changing the maximum voltage rating of the semiconductor switch. No malfunction occurs because the main switching contact of the container does not turn on. In addition, since a general contact switch can be used, it can be manufactured small and at low cost.

According to a second aspect of the present invention, in the first aspect of the present invention, a contact switch, a semiconductor switch, a control circuit for controlling the contact switch and the semiconductor switch, and an external control signal to the control circuit. A pair of control signal input terminals for inputting more, a pair of load connection terminals for connecting a load, and a pair of power terminals for connecting a high voltage DC power supply, between one power terminal and one load terminal. A first main switching contact is connected, and a series circuit of a semiconductor switch and a second main switching contact is inserted between the other power supply terminal and the other load terminal. Further, by simply connecting the load to the load terminal and the control signal to the control signal input terminal, the high-voltage DC power supply can be opened and closed with respect to the load.

A third aspect of the present invention is the semiconductor switch according to the first or second aspect, wherein the semiconductor switch is constituted by a MOSFET. According to a fourth aspect of the present invention, in the third aspect, the contact switch is turned on after the main switching contact is turned on when the main switching contact is turned on, and is turned off when the main switching contact is turned off. A normally open type auxiliary switching contact that is turned off earlier is provided, and the application of a control signal to the semiconductor switch is controlled by controlling the voltage between a pair of power terminals or a pair of load terminals with the auxiliary switching contact. The semiconductor switch can be reliably turned on and off by an auxiliary switching contact that is linked to the switching control of the contact switch.

According to a fifth aspect of the present invention, in the third aspect of the present invention, a light emitting element which is turned on / off by a control signal output from a control circuit for controlling opening and closing of a contact switch, and optically coupled to the light emitting element Switch means for turning on and off the light-emitting element by turning on and off the light-emitting element. The switch means insulates the control input side and the output side. The switch element of the switch means is provided between a pair of power terminals or a pair of loads. Controlling the application of a control signal to the semiconductor switch by controlling the voltage between the terminals to control the switching of the contact switch and switch means by the same control signal, and the main switching of the switch means and contact switch When turning off both contacts, the operating speed of the switch means is turned off faster than the main switching contact of the mechanical contact switch, and the control signal of the semiconductor switch is interrupted. As a result, the semiconductor switch composed of the MOSFET can be turned off more reliably and the load current can be cut off earlier than the main switching contact, and the variation in the operation time of the switch means is smaller than that of the mechanical contact. , The cutoff characteristics, especially the timing variations, are very small.

According to the sixth aspect of the present invention, in the fifth aspect of the present invention, since the switch means is a normally-open type photo MOS relay, the operation of the switch means becomes very fast, and the breaking characteristics can be further improved. In the invention of claim 7, claim 3
In the invention, a first resistor, a Zener diode, and a capacitor are respectively connected in parallel between the gate and the source of the MOSFET, and a control signal of the MOSFET is generated at both ends of the parallel circuit. Due to the time constant, the timing of turning on the semiconductor switch can be delayed, so that at the time of the ON operation, the switch means is turned on earlier than the main switching contact of the contact switch is turned on, and the control signal is output earlier than the main switching contact is turned on. When an attempt is made to apply the voltage to the semiconductor switch, the ON operation of the MOSFET can be delayed from the ON of the main switching contact by the time constant, and as a result, no arc is generated at the main switching contact when the MOSFET is turned on.

According to an eighth aspect of the present invention, in the seventh aspect of the present invention, one end of the first resistor is connected to the MOSF via the second resistor.
ET, and a series circuit of a third resistor and a discharging diode is connected in parallel to the second resistor. The charge of the capacitance of the MOSFET gate is turned off by the diode and the third resistor during the OFF operation. Discharge can be performed promptly, so that a delay in the off time during the off operation can be eliminated, and as a result, high-speed interruption can be achieved.

According to a ninth aspect of the present invention, in the invention of the fourth aspect, the contact switch includes a normally-closed auxiliary switching contact interlocking with the opening and closing of the main switching contact. Since the connection is made between the gate and the source, the charge of the capacitance of the gate of the MOSFET can be discharged at a higher speed during the OFF operation, and a higher-speed cutoff can be performed.

According to a tenth aspect of the present invention, in the third aspect of the present invention, the control circuit is turned on / off by a low-voltage direct-current control signal output from the control circuit, and controls opening and closing of a voltage between a pair of power terminals or a pair of load terminals. A normally open photomos relay that controls the application of a control signal to the semiconductor switch, and the output signal is connected between the gate and source of the semiconductor switch and the control signal is input in parallel or series with the normally open photomos relay. And a normally closed photomos relay that discharges the charge of the gate capacitance of the MOSFET during the off operation,
Higher speed cutoff can be performed. .

An eleventh aspect of the present invention is the semiconductor switch according to the first or second aspect, wherein the semiconductor switch is constituted by a bipolar transistor.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) A circuit diagram of this embodiment is shown in FIG. In this embodiment, a contact switch 1 such as an electromagnetic relay, MOSFETs Q ₂ and Q ₃ which are semiconductor switches, and a MOSFET
A T drive circuit 3, a control circuit 2 for the MOSFETs Q ₂ and Q ₃ and the contact switch 1 and a snubber circuit 4 for absorbing a breaking surge voltage generated when the currents of the MOSFETs Q ₂ and Q ₃ are cut off are provided. A control signal input terminal I ₁ , for inputting a control signal INPUT from the outside to the control circuit 2 as a connection terminal to the outside, is provided in the same body (not shown). and I _2, a power supply terminal I _3, I ₄ which connects the high-voltage DC power source DC, a hybrid type and a load connection terminal O _1, O ₂ for connecting the load 5 comprises the same apparatus body DC switch Make up.

The contact switch 1 includes first and second main switchgears.
Point X₁, X_TwoAnd the main switching contact X₁, X_TwoDelayed due to
Auxiliary switching contact X_ThreeAnd the main switching contact X₁Directly
Power supply terminal I for connecting the positive terminal of_ThreeAnd load connection end
Child O₁And the main opening / closing connection
Point X_TwoIs connected to a power supply terminal I for connecting the negative electrode of the DC power supply DC. _Four
And load connection terminal O_TwoMOSFET connected in parallel between
Q_Two, Q_ThreeConnected via

The control circuit 2 comprises a stabilized DC power supply inserted between the exciting coil CL of the contact switch 1 and the control signal input terminals I ₁ , I _2, and the control signal input terminals I ₁ , I ₂
Emitter by an applied control signal Zener diode ZD ₁ even when the voltage varies in the INPUT transistor Q ₁ controls the base current so that the base voltage and the voltage of the emitter of the transistor Q ₁ is always constant during · voltage always a constant between ground and the transistor Q emitter ground stable voltage by applying a reed switch in Reed exciting coil CL of the switch 1 which is connected between the first ₁ to stabilize operation Has become. Control signal input terminal I
_The surge absorbing element ZNR and the capacitor C ₁ connected between ₁ and I ₂ are for removing surge voltage and noise, and the capacitor C ₂ connected between the emitter and the ground of the transistor Q ₁ is used for stabilizing the power supply. For the capacitor. The resistor R ₁ is bias resistor.

The control circuit 2 may be omitted when the control signal INPUT is a stable voltage signal. The MOSFET drive circuit 3 is connected between the power supply terminals I ₃ and I ₄ via the auxiliary switching contact X ₃ of the contact switch 1, and is connected to the power supply terminals I ₃ and I 4.
_A resistor R for dividing the voltage of the DC power supply DC applied between the _four
2, a series circuit of R _3, a Zener diode ZD ₂ to applied between the gate and source of MOSFET Q _2, Q ₃ voltages divided by this series circuit with a predetermined voltage, MO
It is inserted between the gates of the SFETs Q ₂ and Q ₃ and the connection point of the resistors R ₂ and R ₃ , and includes a current limiting resistor R ₄ at the time of starting the MOSFETs Q ₂ and Q ₃ .

The snubber circuit 4 is constituted by a series circuit of a resistor R ₅ and capacitor C ₃ connected between the drain and source of MOSFETQ _2, Q _3. Next, the operation characteristics of the present embodiment will be described. Now, when the control signal INPUT input to the control signal input terminals I ₁ and I ₂ becomes “H” as shown in FIG. 2A, the exciting current is applied to the exciting coil CL of the contact switch 1 through the control circuit 2. Flows, and the contact switch SM operates. By this operation, first, the main switching contacts X ₁ and X ₂ are set to the operation time T as shown in FIG.
_The state is turned on via _{on (SMR)} .

However, at this time, since the MOSFETs Q ₂ and Q ₃ are off as shown in FIG. 2C, no load current flows through the load 5. Thereafter, becomes ON auxiliary switching contact X ₃ through the operation time T _{on (X3)} as shown in FIG. 2 (b), a current flows through the auxiliary switching contact X _3, resistors R _2, R _3, defined gate-source voltage by the Zener diode ZD ₂ is applied between the gate and source of MOSFETQ _2, Q _3, both MOSFET Q _2, Q ₃ is turned on the load current as shown in FIG. 2 (e) Flows. Note This on auxiliary switching contact X ₃ ON from the operation time T
Delay by _{on (MOS)} .

The reason why the two MOSFETs Q ₂ and Q ₃ are connected in parallel is to shunt the load current, and one MOSFET may be used when a large-capacity MOSFET is used. Next, the operation during the disconnection operation will be described. Now control signal
When INPUT becomes "L", the output of the control circuit 2 is eliminated, to the exciting coil CL of reed switch 1 off auxiliary switching contact X ₃ through a not exciting current flows return time T _{off (X3)} Due to this turning off, charges between the gate and source of MOSFETs Q ₂ and Q ₃ are discharged through resistors R ₄ and R ₃ , and M
The OSFETs Q ₂ and Q ₃ are turned off after the recovery time T _{off (MOS)} . This off cuts off the load current.

Thereafter, with no load current flowing,
Main switching contact X₁, X_TwoIs the recovery time T _{off (off)}Off via
No arc is generated because of the state. (Embodiment 2) In Embodiment 1, a MOSFET drive circuit
3 is an auxiliary switching contact X of the contact switch 1 _ThreeThrough the power end
Child I_Three, I_FourIn the present embodiment, FIG.
Two light emitting diodes LED on the input side as shown in₁, L
ED_TwoAn input section consisting of a series circuit of
Photo MOSFET Q_FourOr
A so-called photo MOS relay 6 composed of
Used, the photo MOSFET Q_FourMOSFET through
Drive circuit 3 is connected to power supply terminal I_Three, I_FourThe feature is that it is connected to
The light emitting part of the photo MOS relay 6 is a current limiting resistor.
R₆Through the capacitor C of the control circuit 2_TwoConnected in parallel to
I have. The Zener die of the MOSFET drive circuit 3
Aether ZD_TwoHas a Zener diode ZD_TwoM in parallel to
OSFETQ_Two, Q_ThreeGate-source charge faster
Capacitor C for pulling out_FourIs connected. That
Other configurations are the same as those of the first embodiment.
The description of is omitted.

Next, the operation durability will be described. Now control signal
Signal input terminal I₁, I_TwoInput to the control circuit 2 via the
The control signal INPUT becomes "H" as shown in FIG.
And the exciting coil CL of the contact switch 1 is excited,
The point switch 1 starts to turn on, and as shown in FIG.
The photomos relay 6 is operated for the operating time T._{on (p1)}Works through
And Photo MOSFET Q_FourTurns on. Photo mothli
Since the operating speed of the race 6 is very fast, the resistance R_Two,
R _ThreeCurrent starts to flow through the capacitor C_ThreeAnd
Anti-R_Two, R_ThreeMOSFET with characteristics determined by the time constant of
Q_Two, Q_ThreeFIG. 4 (c) shows the gate-source voltage of
Ascend. Next, the operating time T_{on (SMR)}Through M
OSFETQ_Three, Q _ThreeContact switching before the switch is turned on
Main switching contact X of switch 1₁, X_TwoIs as shown in FIG.
Turns on but MOSFET Q_Three, Q_ThreeIs off
Therefore, no load current flows through the load 5.

After that, the gate-source voltage becomes the minimum gate voltage.
Voltage reaches MOSFET Q_Two, Q_ThreeIs a photo MOS
FETQ_FourOperating time T from turning on_{on (MOS)}FIG. 4 through
(D) turns on and the load current is applied to the load 5 as shown in FIG.
It flows as shown in FIG. Next, the breaking operation is explained.
I will tell. When the control signal INPUT becomes "L", the contact opens.
The closing device 2 starts off operation. That is, the excitation of the contact switch 1
The magnetic coil CL includes a Zener diode ZD of the control circuit 2.
₁The regenerative current flows through the
You. The control signal of the photo MOS relay 6 has become “L”.
The recovery time T_{off (p1)}High-speed cutoff through the resistor R
_Two, R_ThreeNo current flows through Therefore MOSFET
Q_Two, Q_ThreeBetween gate and source and capacitor C_Four
Charge of the resistor R_Four, R_ThreeThrough the MOSFET
Q_Two, Q_ThreeIs the recovery time T_{off (MOS)}Through the off state
As a result, the load current is interrupted. As mentioned above, contact switches
Since the cutoff time of 1 is long, no current is flowing after that.
Main contact X₁, X_TwoIs the recovery time T_{off (SMR)}
To turn off the load current without arcing.
And

[0028] (Embodiment 3) In the configuration of Embodiment 1, in order to provide a delay of operation during the closing operation, of the resistance of the MOSFET drive circuit 3 R _2, R _3, R _4, resistors R _2, R ₃
Since the voltage is divided with respect to the high voltage to control the gate-source voltage, it cannot be set to an excessively large value. Therefore constant need to increase the resistance of the resistor R ₄ in order to increase the time, it is impossible to reduce the value of the resistor R _4. And during the breaking operation, when the resistance value of the resistor R ₄ is large, the time becomes long to discharge the gate-source of MOSFET Q _2, Q _3, reed switch 1
May not be able to be shut off before the main switching contacts X ₁ and X ₂ are turned off. Therefore, the resistance R ₄ of the MOSFET drive circuit 3 in the present embodiment, as shown in FIG. 5, the diode D ₁ of the orientation with a series circuit connected in parallel with the small resistor R ₇ and diode D ₁ resistance value is the anode MOSFETs Q ₂ and Q ₃ should be on the gate side, and MOSFETs should be connected in parallel with Zener diode ZD _2.
The Q _2, Q capacitor C ₄ for pulling out quickly charge between the gate and source of the ₃ are connected. The other configuration is the same as that of the first embodiment, and the description is omitted.

In this embodiment, however, the resistance is set at the time of the OFF operation.
Resistance R with small resistance₆And resistance R_ThreeThrough the capacitor
C_FourAnd MOSFET Q_Two, Q_ThreeBetween gate and source
Discharge the charge, MOSFET Q_Two, Q_ThreeThe breaking speed
Main switching contact of contact switch 1
X₁, X_TwoMake sure that the MOSFET
Q _Two, Q_ThreeIt can be turned off.

(Embodiment 4) This embodiment corresponds to Embodiment 2
Connect the photo MOSFET Q ₅ of depletion type photo MOS relay 7 normally closed in parallel as shown in FIG. 6 to the resistor R ₃ of the MOSFET drive circuit 3 in, the input portion of the light emitting diode LED _3, LED ₄ The series circuit is connected to the output of the control circuit 2 via the series circuit of the light emitting diodes LED ₁ and LED ₂ of the photo MOS relay 6 and the current limiting resistor R ₆ . This light emitting diode LED ₁ , L
Instead of connecting the series circuit of the ED _{2 and} the series circuit of the LEDs ₃ and ₄ in series, they may be connected in parallel to the output of the control circuit 2 via separate current limiting resistors.

Next, the operating characteristics of this embodiment are shown in FIG.
It will be described based on the following. Now the control signal INPUT is shown in Fig. 7 (a).
As shown in FIG.
As a result, the contact switch 1 starts to turn off.
As shown in FIG._{on (p1)}Through photo moss
Photo MOSFET Q of relay 6_FourTurns on and also works
Time T_{off (p2)}The photo MO of the photo mos relay 7
SFETQ_FiveOperate off as shown in FIG. 7 (c).
The operation of both photo MOS relays 6 and 7 operates in substantially the same time.
You. The operation of both photo MOS relays 6 and 7 is very fast
So, immediately resistance R_Two, R_ThreeCurrent begins to flow through
Is the capacitor C_FourAnd resistance R_Two, R_Three, R_FourWith a time constant of
MOSFET Q with determined characteristics_Two, Q_ThreeGate So
The source-to-source voltage rises as shown in FIG. Next
MOSFET Q _Two, Q_ThreeIs connected before the
Main switching contact X of point switch 1₁, X_TwoIs shown in FIG.
Operating time T_{on (SMR)}Is turned on through M
OSFETQ_Two, Q_ThreeBefore turning on, load 5
No fuka current flows.

Thereafter, the gate-source voltage is
MOSFET Q_Two, Q_ThreeIs shown in FIG.
T as shown_{on (MOS)}To operate on. This ON motion
As a result, a load current flows through the load 5 as shown in FIG.
It is. Next, a description will be given of the time of the cutoff operation. First the control signal
When INPUT becomes “L”, contact switch 1 starts to operate.
You. The excitation coil CL of the contact switch 1 includes a control circuit 2
Zener diode ZD₁Regenerative current flows through
So it works slowly off. Photomos relay 6 is controlled
When the signal INPUT becomes “L”, the recovery time T
_{off (p1)}Off at high speed, and Futmos relay 7
Release time T_{on (p2)}To turn on at high speed. Therefore resistance
R _Two, R_ThreeCurrent stops flowing and MOSFET Q_Two,
Q_ThreeThe charge between the gate and the source of the resistor R_Four, Photo moss
Photo MOSFET Q of relay 7_FiveDischarge through M
OSFETQ_Two, Q_ThreeIs the recovery time T_{off (MOS)}Off via
State and the load current is cut off. In this case,
MOSFET Q_FiveThe on-resistance of the
High speed MOSFET Q_Two, Q_ThreeIs turned off. Up
As described above, the switching time of the contact switch 1 is long.
When the rear load current is not flowing, the main switching contact X₁, X
_TwoIs the recovery time T_{off (SMR)}Is turned off through the
The load current is cut off without the occurrence of.

The circuit shown in FIG.
But, instead of the photo-MOS relay 6, provided with an auxiliary switching contact X ₃ of normally open reed switch 1 as shown in FIG. 8, and an auxiliary switching contact X ₄ normally closed May be. In this case, the same operation as the circuit of FIG. 6 can be obtained. (Embodiment 5) This embodiment is connected in series with the main switching contact X ₂ of the transistor Q ₆ a reed switch 1, such as a bipolar transistor instead of the MOSFET according to the second embodiment as shown in FIG. 9, differs from the second embodiment in that it is not provided a resistance R ₃ for time constant. The other configuration is the same as that of the second embodiment, and the description is omitted.

Next, the operation characteristics of this embodiment will be described. First, when the control signal INPUT becomes “H”, the contact switch 1 starts to be turned on, and the photo M of the photomos
OSFETQ ₄ is turned on. Since this operation is very fast, current starts to flow immediately through the resistors R ₂ and R ₄ , but the base emitter voltage is determined by the characteristics determined by the time constant of the capacitor C ₄ and the resistors R ₂ and R _4. Rises. Next primarily switching contact X _1, X ₂ of the reed switch 1 before the transistor Q ₆ is turned on is turned on, the transistor Q ₆
Is off, no load current flows through the load 5. Then, the transistor Q ₆ is turned on by the base current flows,
Load current will flow.

Next, at the time of the cutoff operation, the control signal INPU
When T becomes "L", the contact switch 1 starts to turn off. The excitation coil CL of the contact switch 1 includes a control circuit 2
Regenerative current through the Zener diode ZD ₁ of works slowly about release flows through. Photo Moss photo MOSFETQ ₄ of the relay 6 is that the control signal INPUT is turned to "L", the off at high speed. Therefore, the current of the resistors R ₂ and R ₄ does not flow, the base current does not flow, the transistor Q ₆ is turned off, and the load current is cut off. As shown in the above, since the switching time of the contact switch 1 is long,
Then, with no load current flowing, the main switching contact X
_1, X ₂ is turned off, so that will cut off the load current at the arc without.

In each embodiment, the semiconductor switch connected in series to the main switching contact X ₂ of the contact switch 1 is a MOSFE.
Although T and a transistor were used, other semiconductor switches such as SCR may be used, and the present invention is not particularly limited to the embodiment.

[0037]

According to the first aspect of the present invention, both ends of a load are connected to both ends of a high-voltage DC power supply via first and second main switching contacts of a contact switch, respectively. A semiconductor switch is inserted in series into an electric circuit that is opened and closed by the switching contact, and the semiconductor switch and the contact switch are controlled in accordance with a control signal input. It is characterized by turning off the semiconductor switch before turning it on, and by completely turning off the two main switching contacts of the contact switch between the load and the high-voltage DC power supply, leakage current can flow through the semiconductor switch. It does not flow, and at the time of off operation, the semiconductor switch turns off before the two main switching contacts of the contact switch turn off, so no arc is generated when the main switching contact turns off, and a stable breaking characteristic is obtained. Can also it means to cut off the load current at the semiconductor switches, no deterioration occurs in the cutoff characteristics by blocking, unevenness resulting interruption time does not occur. Also, when the voltage of the high-voltage DC power supply is changed, the voltage specification can be changed easily by changing the maximum voltage rating of the semiconductor switch. Since the main switching contact of the switch does not turn on, no malfunction occurs, and since a general contact switch can be used, there is an effect that it can be manufactured at a small size and at low cost.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a contact switch, a semiconductor switch, a control circuit for controlling the contact switch and the semiconductor switch, and an external control signal to the control circuit. A pair of control signal input terminals for inputting more, a pair of load connection terminals for connecting a load, and a pair of power terminals for connecting a high voltage DC power supply, between one power terminal and one load terminal. The first main switching contact is connected, and a series circuit of the semiconductor switch and the second main switching contact is inserted between the other power supply terminal and the other load terminal. To the load terminal,
By simply connecting a control signal to the control signal input terminal, the high-voltage DC power supply can be switched on and off for the load.A contact switch, a semiconductor switch, and a control circuit are incorporated in one body, and the power supply terminal and load Since the terminal and the control signal input terminal are provided, there is an effect that the same handling as a normal switch can be performed.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the contact switch is turned on after the main switching contact is turned on when the main switching contact is turned on, and the main switch is turned on when the main switching contact is turned off. A normally-open auxiliary switching contact that is turned off before the contact is turned off is provided, and the auxiliary switching contact controls the voltage between a pair of power terminals or a pair of load terminals to open and close the control signal for the semiconductor switch. Since the application is controlled, there is an effect that the semiconductor switch can be reliably turned on and off by the auxiliary switching contact interlocking with the switching control of the contact switch.

According to a fifth aspect of the present invention, in the third aspect of the present invention, a light emitting element which is turned on / off by a control signal output from a control circuit for controlling the opening and closing of the contact switch, and optically coupled to the light emitting element Switch means for turning on and off the light-emitting element by turning on and off the light-emitting element. The switch means insulates the control input side and the output side. The switch element of the switch means is provided between a pair of power terminals or a pair of loads. Since the application of a control signal to the semiconductor switch is controlled by controlling the opening and closing of the voltage between the terminals, the contact switch and the switch means are controlled by the same control signal to connect the switch means and the contact switch to the main switching contact. When both are turned off, the operating speed of the switch means may be turned off earlier than the main switching contact of the mechanical contact switch, and the control signal of the semiconductor switch may be cut off. As a result, the semiconductor switch composed of the MOSFET can be turned off reliably and the load current can be cut off earlier than the main switching contact, and the variation in the operating time of the switch means is much greater than that of the mechanical contact. Because of the small number, there is the effect that the cutoff characteristics, especially the timing variation, are very small, and furthermore, even if the semiconductor switch is turned on due to noise, the main switching contact of the contact switch does not turn on, and the malfunction does not occur. There is.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, since the switch means is a normally-open type photo MOS relay, the operation of the switch means becomes very fast, and the cutoff characteristics can be further improved. effective. According to a seventh aspect of the present invention, in the third aspect, the gate of the MOSFET
A first resistor, a zener diode, and a capacitor are connected in parallel between the sources, respectively, and a control signal of the MOSFET is generated at both ends of the parallel circuit. Therefore, the timing of turning on the semiconductor switch is delayed by the time constant of the first resistor and the capacitor. Therefore, at the time of the ON operation, the switch means is turned on earlier than the ON of the main switching contact of the contact switch,
When an attempt is made to apply a control signal to the semiconductor switch earlier than the turning on of the main switching contact, the ON operation of the MOSFET can be delayed from the turning on of the main switching contact by the time constant,
As a result, there is an effect that it is possible to prevent an arc from being generated in the main switching contact at the time of turning on.

According to an eighth aspect of the present invention, in the seventh aspect of the invention, one end of the first resistor is connected to the MOSFE via the second resistor.
T, and a series circuit of a third resistor and a discharging diode is connected in parallel to the second resistor.
The charge of the capacitance of the gate of the OSFET can be quickly discharged by the diode and the third resistor, so that the delay of the off time during the off operation can be eliminated, and as a result, high-speed cutoff can be achieved. .

According to a ninth aspect of the present invention, in the invention of the fourth aspect, the contact switch includes a normally-closed auxiliary opening / closing contact interlocked with opening / closing of the main opening / closing contact, and the auxiliary opening / closing contact is connected to a semiconductor switch. Since the connection is made between the gate and the source, the electric charge of the capacitance of the gate of the MOSFET can be discharged at a higher speed during the OFF operation, and there is an effect that a higher speed cutoff can be performed. According to a tenth aspect of the present invention, in the third aspect of the present invention, the on / off state is controlled by a low-voltage direct-current control signal output from the control circuit, and a voltage between a pair of power supply terminals or a pair of load terminals is opened and closed. A normally open photo MOS relay that controls the application of control signals to the semiconductor switch, and the output side is the gate of the semiconductor switch.
A normally-closed-type photo MOS relay connected between the sources and inputting a control signal in parallel or in series with the normally-open type photo-mos relay is provided, so that the charge of the gate capacitance of the MOSFET is discharged at a higher speed during the OFF operation. Thus, there is an effect that higher-speed cutoff can be performed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram according to a first embodiment of the present invention.

FIG. 2 is a timing chart for explaining the above operation.

FIG. 3 is a circuit diagram according to a second embodiment of the present invention.

FIG. 4 is a timing chart for explaining the above operation.

FIG. 5 is a circuit diagram of a third embodiment.

FIG. 6 is a circuit diagram according to a fourth embodiment of the present invention.

FIG. 7 is a timing chart for explaining the above operation.

FIG. 8 is a circuit diagram of another example of the above.

FIG. 9 is a circuit diagram according to a fifth embodiment of the present invention.

FIG. 10 is a timing chart for explaining the operation of a general contact switch.

FIG. 11 is a timing chart for explaining the operation of a conventional DC switch.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 contact switch 2 control circuit 3 MOSFET drive circuit 5 load X ₁ , X ₂ main switching contact Q ₁ transistor Q ₂ , Q ₄ MOSFET ZD ₁ , ZD ₂ Zener diode R _{1 to} R ₅ resistance C _{1 to} C ₃ capacitor DC High voltage DC power supply INPUT Control signal I ₁ , I ₂ Control signal input terminal I ₃ , I ₄ Power connection terminal O ₁ , O ₂ Load connection terminal

Claims (11)

[Claims] An electric circuit which connects both ends of a load to both ends of a high-voltage DC power supply via first and second main switching contacts of a contact switch, and is opened and closed by at least one of the main switching contacts. A semiconductor switch is inserted in series, and the semiconductor switch and the contact switch are controlled in accordance with the control signal input. When the main switch of the contact switch is turned off, the semiconductor switch is turned off before the main switch is turned off. A hybrid type DC switch characterized by being turned off. 2. A contact switch, a semiconductor switch, a control circuit for controlling the contact switch and the semiconductor switch, a pair of control signal input terminals for externally inputting control signals to the control circuit, and a load. And a pair of power supply terminals for connecting a high-voltage DC power supply, a first main switching contact is connected between one power supply terminal and one load terminal, and the other 2. The hybrid DC switch according to claim 1, wherein a series circuit of a semiconductor switch and a second main switching contact is inserted between the power supply terminal and the other load terminal. 3. The hybrid DC switch according to claim 1, wherein the semiconductor switch is constituted by a MOSFET. 4. A contact switch having the same opening and closing operation as the first and second main switching contacts, and the first and second main switching contacts when the first and second main switching contacts are turned on. And an auxiliary switching contact which is turned on after turning on the power supply and is turned off before the first and second main switching contacts are turned off when the first and second main switching contacts are turned off. 4. The hybrid DC switch according to claim 3, wherein the application of a control signal to the semiconductor switch is controlled by controlling the voltage between the power terminals or the pair of load terminals. 5. A light emitting element which is turned on / off by a control signal for controlling the opening / closing of a contact switch output from a control circuit, and a switch which is optically coupled to the light emitting element and turned on / off by turning on / off the light emitting element. A switching means for insulating the control input side and the output side from each other, and controlling the opening and closing of a voltage between a pair of power terminals or a pair of load terminals with the switching element of the switching means. 4. The hybrid DC switch according to claim 3, wherein application of a control signal to the switch is controlled. 6. The hybrid DC switch according to claim 5, wherein the switch means is a normally-open type photo MOS relay. 7. The hybrid according to claim 3, wherein a first resistor, a Zener diode, and a capacitor are connected in parallel between the gate and the source of the MOSFET, respectively, and a control signal of the MOSFET is generated at both ends of the parallel circuit. Type DC switch. 8. One end of the first resistor is connected to M through a second resistor.
The hybrid DC switch according to claim 7, wherein the hybrid resistor is connected to an OSFET, and a series circuit of a third resistor and a discharging diode is connected in parallel to the second resistor. 9. The contact switch includes a normally-closed auxiliary switching contact interlocked with the opening and closing of the main switching contact, and the auxiliary switching contact is connected between the gate and the source of the semiconductor switch. The hybrid DC switch according to claim 4. 10. A control signal applied to a semiconductor switch by being turned on / off by a low-voltage direct-current control signal output from a control circuit and controlling opening and closing of a voltage between a pair of power terminals or a pair of load terminals. Normally open photomoss relay, and a normally closed photomoss relay whose output side is connected between the gate and source of the semiconductor switch to input control signals in parallel or in series with the normally open photomoss relay. The hybrid DC switch according to claim 3, wherein 11. The hybrid type DC switch according to claim 1, wherein the semiconductor switch comprises a bipolar transistor.