JPH05149978A - Detecting apparatus for operating state of switch, and switch with built-in detecting apparatus of operating state - Google Patents

Abstract

PURPOSE:To quickly detect the ON/OFF state of a main contact of a switch without time lag. CONSTITUTION:A series-connected circuit of a power source 11 separate from a main power source, a resistance 12 and a current detecting means 14 is connected between the source side and load side of a main contact 4 of a switch inserted between the main power source 2 and a load 5. If the main contact 4 of the switch 3 is in the OFF state, no current flows in the series-connected circuit. However, when the main contact 4 is turned ON, a current is supplied to the series-connected circuit from another power source 11. Therefore, the ON/OFF state of the main contact 4 of the switch can be detected without time delay by detecting the presence/absence of the current.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch operating state detecting device capable of detecting an operating state of a switch main contact without causing a time delay, and a switch incorporating the operating state detecting device.

[0002]

2. Description of the Related Art An electromagnetic contactor, a circuit breaker for wiring (also called a no-fuse breaker) or the like is used as a switch for supplying or cutting power from a power source to a load by inserting and closing the main contact in an electric circuit. The electromagnetic contactor will be described below as an example.

An electromagnetic contactor supplies or shuts off electric power from a power source in order to operate or stop a load such as an electric motor. This electromagnetic contactor is an indispensable tool for the operation of a plant using many electric motors. is there. In such a plant, whether or not each electric motor is operating is determined by whether or not the electromagnetic contactor that supplies power to the electric motor is operating. Judgment is made based on the on / off state of the auxiliary contact that is linked to the operation of the main contact of the electromagnetic contactor. In general, this auxiliary contact has a structure such that it is simultaneously driven by an electromagnet that drives the main contact of the electromagnetic contactor.

[0004]

However, the ON / OFF state of the auxiliary contact does not match the ON / OFF state of the main contact of the electromagnetic contactor, and there is a time difference. For this reason, for example, in the case of an electric motor that operates by switching the rotation direction, while the electric motor is operating in the forward direction with a forward contact electromagnetic contactor,
Even if the main contact of the forward contact electromagnetic contactor is still on, the auxiliary contact may give a signal that allows reverse rotation to the reverse contact electromagnetic contactor. The main contacts of both the divert and reversing electromagnetic contactors are turned on, and the power supply is short-circuited. Such a problem can be prevented by adjusting the mounting state of the main contact and the auxiliary contact, but it takes time and effort to adjust and the operating time difference between both contacts cannot be completely eliminated. .

By the way, recently, an apparatus using a semiconductor switching element such as an inverter or a chopper is often controlled by an electromagnetic contactor. Since the operation delay time of such a device using a semiconductor switching element is extremely short, there is a time lag of about several tens of milliseconds to several milliseconds existing between the main contact and the auxiliary contact, which can be allowed in the past. However, in the case of a device using these semiconductor switching elements, it has become unacceptable because it adversely affects the operation.

Therefore, an object of the present invention is to make it possible to immediately detect the on / off state of a switch main contact without causing a time difference.

[0007]

In order to achieve the above object, the operating state detecting device of the present invention is installed between a main power source and a load, and supplies power to the load by opening and closing a main contact. In a switch that turns on or off, another power source independent of the main power source, a resistor, and a current detection unit that detects whether or not current is flowing are connected in series, and one end of this series connection circuit is connected. Is connected to the main power source side of the main contact, and the other end of the series connection circuit is connected to the load side of the main contact.

[0008]

According to the present invention, between the power source side and the load side of the switch main contact inserted between the main power source and the load, another power source independent from the main power source, a resistor and a current are provided. A series connection circuit with the detection means is connected. If the main contact of the switch is off, no current flows in this series connection circuit, but if the main contact is on, the separate power supply supplies the current to this series connection circuit, so the presence or absence of this current is detected. By doing so, the on / off state of the switch main contact is detected without causing a time delay.

[0009]

1 is a circuit diagram showing a first embodiment of the present invention. In FIG. 1, an electromagnetic contactor 3 as a switch
Turns on / off the main contact 4 to supply or cut off the AC power from the main power source 2 to the load 5. First of the present invention
In the embodiment, the main contact 4 of the electromagnetic contactor 3 is provided with an operating state detecting device constituted by a series connection of an AC power source 11, a resistor 12 and a current transformer 13 as another power source which is independent of the main power source 2. Connect in parallel. With such a circuit configuration, when the main contact 4 is in the off state, no current flows through the operating state detecting device, but when the main contact 4 is on, current flows through the operating state detecting device and the current transformer 13 And the current detector 14 can detect this current without a time delay. Further, since the current flowing through the current transformer 13 becomes zero at the same time when the main contact 4 is turned off, the turning off of the main contact 4 can be detected via the current detector 14 without causing a time delay.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention. In FIG. 2 as well, the electromagnetic contactor 3 as a switch supplies or cuts off the AC power from the main power supply 2 to the load 5 by turning on / off the main contact 4. In the second embodiment of the present invention, an operating state detection device constituted by a DC power supply 15 as a separate power supply independent from the main power supply 2, a resistor 12 and a photocoupler 16 as a current detection means is connected in series. The main contact 4 of the contactor 3 is connected in parallel,
The operation in this case is the same as that in the case of the circuit of the first embodiment described above, and therefore the description of the operation is omitted.

FIG. 3 is a circuit diagram showing a third embodiment of the present invention, showing a switch incorporating an operating state detecting device. In this third embodiment, the operating condition detecting device 24 is incorporated in the wiring breaker 20 as a switch, but this operating condition detecting device 24 has the same circuit configuration as that used in the second embodiment circuit described above. is there. Since the circuit breaker 20 for wiring contains the main contact 21, the operation mechanism section thereof, and the operating state detection device 24 in the insulating case, the main circuit power source side terminal 22 and load side terminal 23 and the main contact 21 are connected. An operating state signal output terminal 25 for taking out the operating state to the outside is provided in this insulating case.

[0012]

According to the present invention, in the case where the main contact is in the OFF state by connecting the series connection circuit of the separate power supply independent of the main power supply, the resistor and the current detecting means in parallel to the switch main contact. The current detecting means does not detect the current, but immediately detects the current flow when the main contact is turned on. That is, since the ON / OFF state of the switch can be immediately known from the presence or absence of the current detected by the current detecting means without causing a time delay, the control can be performed even in the case of a semiconductor switch element using device with almost no operation time delay. There is no fear of inconvenience.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of the present invention.

[Explanation of symbols]

 2 Main power supply 3 Electromagnetic contactor as switch 4 Main contact 5 Load 11 AC power supply as another power supply 12 Resistance 13 Current transformer as current detection means 14 Current detector 15 DC power supply as another power supply 16 As current detection means Photocoupler 20 Wiring circuit breaker as a switch 21 Main contact 24 Operating state detection device 25 Operating state signal output terminal

Claims (2)

[Claims] 1. A switch installed between a main power source and a load to supply or cut off power to the load by opening and closing a main contact, wherein a separate power source independent of the main power source and a resistor. And a current detection means for detecting whether or not current is flowing, are connected in series, one end of this series connection circuit is connected to the main power source side of the main contact, and the other end of this series connection circuit is connected. Is connected to the load side of the main contact, and an operating state detecting device for a switch. 2. A switch, which is installed between a main power source and a load and supplies or cuts off power to the load by opening and closing a main contact, the operating state detecting device for a switch according to claim 1. A switch with a built-in operating condition detection device characterized by being incorporated.