JPH06169524A - Input device for make and break contact - Google Patents

Abstract

PURPOSE:To provide an input device for a make and break contact capable of reducing the failures of internal parts to a minimum even though a make and break contact having voltage output is connected and also capable of reducing detection errors due to contact resistance of a make and break contact having no-voltage output. CONSTITUTION:Overcurrent protection means F1 and F2 are connected in series to a pair of input terminals C, 1 and 2; capacitors C1 and C2 are connected in parallel to a series circuit of these overcurrent protection means and a pair of input terminal; and load L1 and L2 such as lamps or solenoid relays are connected in series to the capacitors and then a DC power supply E is connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input terminal of an open / close contact, which is housed in an alarm panel or a control panel and connected to a non-voltage output open / close contact for outputting the open / close by opening / closing or short circuit.

[0002]

2. Description of the Related Art Generally, an alarm panel, a control panel, or the like has an input terminal to which an externally provided opening / closing contact which is operated in the event of an abnormality or remote control is connected, and an opening / closing input to this input terminal is made. In response to a signal from a contact, a load such as an internal lamp or an electromagnetic relay is activated to issue an alarm or control the operation of equipment.

On the other hand, the above-mentioned open / close contacts include both a voltage output that outputs open / close depending on the presence / absence of a voltage and a non-voltage output that outputs open / close due to opening / closing or a short circuit. There are also input devices for opening and closing contacts housed in an alarm panel or a control panel to which contacts are connected, each of which corresponds to a dedicated one.

[0004]

Therefore, in the input device of the switching contacts to which the above-mentioned non-voltage output switching contacts are connected,
If the open / close contact for voltage output is mistakenly connected, an abnormal voltage may be applied to a pair of input terminals from the outside of the input device of the open / close contact, resulting in overcurrent, which may damage internal parts. there were.

Therefore, the input device of the switching contact, to which the switching contact of the non-voltage output is connected, protects the internal impedance between the pair of input terminals in order to protect the input of the high current from the outside. Although it has been adopted to raise it, if the internal impedance is raised, the contact resistance of the open / close contact of the non-voltage output connected to the input terminal becomes a problem, and if the contact resistance is large, a detection error will occur. I was afraid.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to minimize the destruction of internal parts even when a switching contact for a voltage output is connected and to switch a non-voltage output. An object of the present invention is to provide an input device for switching contacts, which reduces detection errors due to contact resistance of the contacts.

[0007]

In order to solve such a problem, an input / output device for a switching contact according to the present invention includes a pair of input terminals to which a non-voltage output switching contact for opening / closing by opening or shorting is connected. , An input device of a switching contact having a load such as a lamp or an electromagnetic relay to which a voltage is applied via this input terminal and actuating the load in response to the operation of the switching contact, in the pair of input terminals The overcurrent protection means is connected in series, a capacitor is connected in parallel to the series circuit of the overcurrent protection means and a pair of input terminals, and a load is connected in series to the capacitor to apply a voltage.

[0008]

The input device of the switching contact according to the present invention shuts off the overcurrent protection means by the charging current to the capacitor when the switching contact for voltage output is mistakenly connected and an overvoltage is applied between the input terminals. The internal components are prevented from being destroyed, and when the non-voltage output switching contacts are closed, the charged electric charge of the capacitor is also passed through the switching contacts to reduce the contact resistance and to detect the closing contacts.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An input device for a switchgear according to the present invention will be described below with reference to FIG.
2 will be described with reference to FIG.

Between the common pole C and the individual poles 1 and 2 of the input terminal, to which the open / close short-circuiting open / close contacts A and B of the non-voltage output are connected, the side of the common pole C is provided. In this order, capacitors C1 and C2 and fuses or circuit protectors such as overcurrent protection means F1 and F2 connected in series are connected in parallel, and the common pole C of the input terminal is connected to the positive pole (+) of the DC power source E. ) From the reverse voltage impressing diode D1 and the resistor R1 in series circuit,
Therefore, the potential of the positive electrode (+) is applied.

Diodes D2 and D3 are respectively connected in parallel to the capacitors C1 and C2 via a resistor R1, and a diode D4 is provided at a connection point between the capacitors C1 and C2 and the overcurrent protection means F1 and F2. , D5, current limiting resistors R2 and R3, and loads L1 and L2 such as lamps or electromagnetic relays are sequentially connected and connected to the negative electrode (−) of the DC power source E.

However, when the switching contacts A and B are open, no overcurrent flows through the loads L1 and L2, and the capacitors C1 and C2 have a voltage substantially equal to the voltage of the DC power source E. Is in a charged state.

When the open / close contacts A and B are closed from the open state, a diode is applied from the positive electrode (+) of the direct current E.
D1, resistance R1, switching contacts A and B, overcurrent protection means F
1, F2, diodes D4 and D5, current limiting resistors R2 and R3,
A current flows to the negative electrode (−) of the DC power source E through the loads L1 and L2, the loads L1 and L2 start to operate, and the charges charged in the capacitors C1 and C2 are opened and closed.
An inrush current is instantaneously superimposed on B and flows.
Due to the discharging action of the charge stored in the capacitors C1 and C2, even if the contact resistance is increased due to dirt on the contacts when the contacts A and B are closed, the contact current is increased by increasing the instantaneous current. The resistance can be displaced to a small value, and the loads L1 and L2 can be reliably operated when the pole is closed.

FIG. 2 shows a state in which the open / close contacts A and B are closed, and the current flowing through the overcurrent protection means F1 and F2 is represented by a solid curve and is indicated by a load. L1, L2
The current flowing through is shown by the dotted curve. The solid curve is set so as not to exceed the operating current I of the overcurrent protection means F1 and F2.

On the other hand, a case will be described in which an open / close contact having a high voltage output having a high voltage is connected to the input terminal.

First, when the open / close contact for voltage output is connected with the common pole C side as a positive pole, the currents corresponding to the difference between the applied voltage of the capacitors C1 and C2 and the applied voltage are the capacitors C1 and C2. As a charging current for the current, it instantaneously flows to the overcurrent protection means F1 and F2, and in response to this current, the overcurrent protection means F1 and F2 perform a cutoff operation to protect the internal circuits after the overcurrent protection means F1 and F2. To do. At this time, the action of the diodes D4 and D5 also prevents the overcurrent from flowing into the internal circuit.

The open / close contacts for voltage output are the individual poles 1,
When the 2 side is connected as the positive electrode, the capacitor C1,
A voltage equivalent to the voltage applied to the switching contact and the voltage applied to the switching contact is added to the switching contact for voltage output, and the current is the value obtained by dividing this voltage by the impedance of the switching contact for voltage output. Power is supplied to F1 and F2. Since this current becomes larger than the short-circuit current of the applied voltage of the capacitors C1 and C2, the overcurrent protection means F1 and F2 perform the cutoff operation,
The internal circuit after the overcurrent protection means F1 and F2 is protected. When a voltage is applied to this switching contact, the action of diodes D2 and D3 also causes overcurrent protection means F1 and
Protect the internal circuit after F2.

When the open / close contact for voltage output is connected between the individual poles 1 and 2 of the input terminal, the diode D2,
The action of D3, D4 and D5 provides protection against the flow of current.

[0019]

The input device for switching contacts according to the present invention is provided with overcurrent protection means by charging current to the capacitor when the switching contacts for voltage output are mistakenly connected and an overvoltage is applied between the input terminals. In order to suppress the destruction of internal parts by shutting off, and also to close the contact of the non-voltage output, the charging charge of the capacitor is also flown to the contact to make the contact resistance low and to detect the closing contact. It becomes possible to perform a reliable operation.

[Brief description of drawings]

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

FIG. 2 is an operation waveform diagram of FIG.

[Explanation of symbols]

 A, B Switching contacts C Input terminal common pole 1, 2 Input terminal individual poles C1, C2 Capacitors F1, F2 Overcurrent protection means E DC power supply D1 ~ D5 Diodes R1 ~ R3 Resistance L1, L2 Lamps or electromagnetic relays etc. load

[Procedure amendment]

[Submission date] January 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003] Further, on the other hand, the switching contacts of the above, those of organic voltage output for outputting opening and closing in the presence or absence of voltage and, some <br/> physician release opening things no voltage output for outputting opening and closing at short There is also an input device for opening and closing contacts housed in an alarm panel, a control panel, or the like to which the opening and closing contacts are connected and which corresponds to each of them.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

Therefore, in the input device of the switching contacts to which the above-mentioned non-voltage output switching contacts are connected,
If the open / close contact for voltage output is mistakenly connected, an abnormal voltage is applied to the input device of the open / close contact to cause an overcurrent, which may damage internal components.

Claims (1)

[Claims] 1. A pair of input terminals, to which a non-voltage output switching contact that outputs switching when opened or short-circuited is connected, and a load such as a lamp or an electromagnetic relay to which a voltage is applied via the input terminals. Then, in the input device of the switching contact that operates the load in response to the operation of the switching contact, the overcurrent protection means is connected in series to the pair of input terminals, and the overcurrent protection means and the series circuit of the pair of input terminals are connected. An input device for a switchgear, wherein a capacitor is connected in parallel with the capacitor, a load is connected in series with the capacitor, and a voltage is applied.