JPH07176253A - Latch relay device - Google Patents

Abstract

PURPOSE:To enable a contact to be restored to a normal condition while detecting a contact condition reversed by external force, by switching a condition of the contact when the contact condition of a latch relay part is not in agreement with a signal held by a signal holding means. CONSTITUTION:A set/reset selective signal from a control part 8 is supplied through an FF13 to a strobed pulse generating part 6 and to an XOR gate 14, and the gate 14 outputs 0 when both agree and outputs 1 when not agree. Here, a self supervisory circuit control signal from the control part 8 is generated 0 only when a switching timing pulse signal from the control part 8 is input to a control part 6, and generated 1 except when input. Thus when the set/reset selection signal agrees with a condition of a contact 2, an output of a gate 15 generates 0, to provide no change in a contact condition. On the other hand, in the case of reversing the contact condition by a shock or the like from the outside, the gate 14 outputs 1, and since an output of the gate 15 generates 1, a normal contact condition is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relay device, and more particularly to a self-monitoring type latch relay device which detects a malfunction caused by vibration or shock of a latch relay and restores it to a normal state.

[0002]

2. Description of the Related Art Relays are roughly classified into two types according to their contact control methods. One of them is one in which a contact is turned on / off depending on whether a contact control coil is excited or de-excited, and does not continue to be energized. The other one is a type that can not maintain that state, and the other one is to switch the contact by the pulse drive voltage that turns ON / OFF (set / reset). Even after the drive voltage is cut off, there is no energization. It is a latch type relay (latch relay) in which circuit contacts are previously provided with a biasing means such as a permanent magnet or a spring so that the ON or OFF state can be maintained.

FIG. 2 is a diagram showing a latch relay device having two contacts and a structure for controlling the same. In this example, the latch relay 1 has two latch-type contacts 2 and 3 which are interlocked with each other, and the contacts 2 and 3 are turned on and off.
A contact control circuit 4 and 5 for F control is provided, wherein the contacts 2 and 3 are turned on by a set signal input to the contact control circuit 4 and the reset signal input to the contact control circuit 5 The contacts 2 and 3 are switched to the OFF state, and constitute a relay device 7 together with the strobe pulse generator 6.

The relay device 7 operates as follows based on the control signal from the control unit 8. A selection signal for setting or resetting is supplied from the control unit 8 to the strobe pulse generating unit 6 via the line 9 and a switching timing pulse signal for the relay contact via the line 10. Based on these control signals, the strobe pulse generator 6 generates a pulse signal having a time length sufficient to operate the contact control circuits 4 and 5 and supplies it to the contact control circuit 4 or 5 as a set signal or a reset signal. . The latch relay 1 receives the contact 2 based on the set signal or the reset signal.
3 is switched to the OFF state.

However, in this latch relay, after the switching timing pulse signal from the control unit is cut off, the contact is kept ON or OFF by the biasing means until the next pulse signal arrives. There is a drawback that the contact state is reversed when an external force that exceeds the urging force of the urging means is applied to the contact, and when used in a device installed in an environment where vibration or shock is likely to occur, its reliability may be a problem. There were many.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to eliminate the drawbacks of the conventional latch relay as described above, and detects and reverses the contact state due to an external force such as vibration or shock. It is an object of the present invention to provide a latch relay device capable of restoring the contact to a normal state based on the above.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is a relay device for switching the state of contacts based on a control signal from a control unit, which relay device includes a latch relay unit having a latch type relay contact. A signal holding means for holding the control signal until the next control signal arrives, and a comparing means for comparing the contact state of the latch relay section with the signal held by the signal holding means, When the comparing means detects a disagreement, the state of the contact is switched so that the comparing means detects the coincidence based on the output of the comparing means regardless of the control section.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. 1 is a block diagram showing an embodiment of a latch relay device according to the present invention and a configuration of a control unit for controlling the same. The latch relay device 11 has a strobe pulse generator 6, and contacts 2 and 3 are turned on or O based on a set or reset signal from the strobe pulse generator 6.
It is composed of two latch relays 1 that switch to FF, and a self-monitoring circuit 12 that keeps the contact state of the latch relays 1 in a predetermined state.

The self-monitoring circuit 12 receives the set or reset selection signal from the control unit 8, stores the set or reset signal until the next selection signal arrives, and generates the strobe pulse. A flip-flop 13 for continuing to hold the output to the unit 6, one output terminal of the flip-flop 13 and one input terminal of the latch relay 1 at the other input terminal of the latch relay 1 via a resistor 17. XOR (exclusive OR) connected after pulling up
The AND gate 15 and the AND gate 15 in which the output of the XOR gate 14 is input to one input terminal and the self-monitoring circuit control signal from the control section 8 is input to the other input terminal.
The output of the gate 15 is provided at one input end, and the other input end is provided with an OR gate 16 to which the switching timing pulse signal from the control section 8 is input. The other terminal of the contact 2 of the latch relay 1 is connected to the ground.
Thereby, the contact 2 serves to monitor the contact state, and the contact 3 is provided as a normal contact.

The latch relay device configured as described above operates as follows. The set / reset selection signal from the control section 8 is supplied to the strobe pulse generation section 6 and the XOR gate 14 via the flip-flop 13, and the XOR
The gate 14 constantly compares the set / reset selection signal with the state of the contact 2, and outputs "0" if they match and "1" if they do not match. Here, the control unit 8
The self-monitoring circuit control signal from the XOR gate 14 to the AND gate 1 is applied only when the switching timing pulse signal from the control unit 8 is input to the strobe pulse generation unit 6.
It becomes "0" to prohibit the signal to 5, and otherwise becomes "1" to enable the self-monitoring function. Therefore, if the set / reset selection signal and the state of the contact 2 match, the output of the AND gate 15 becomes "0", the control to the relay is not performed, and the state of the contact does not change.

On the other hand, when the contact state is reversed by a mechanical shock or vibration from the outside, the XOR gate 14 outputs "1" because the set / reset selection signal and the state of the contact 2 are different. Since the output of the AND gate 15 is "1", the strobe pulse generating unit 6 is in the same state as when the switching timing pulse signal is supplied to the strobe pulse generating unit 6 via the OR gate 16, and the strobe pulse generating unit 6 is The set or reset signal is supplied to the latch relay 1 in accordance with the signal held by the latch relay 1 to restore the normal contact state. As described above, when the contact state is switched by the control unit 8, the self-monitoring circuit control signal is set to "0", and the switching timing pulse signal and the set / reset selection signal are set to O respectively.
It is supplied to the R gate 16 and the flip-flop 13, and after a lapse of a sufficient time to complete the switching, the self-monitoring circuit control signal is set to "1" to operate the self-monitoring function.

Although the present invention has been described above by taking the case of using two latch relays as an example, the present invention is not limited to this, and it is also applicable to three or more latch relays. Absent. Further, although the self-monitoring function is realized by using the flip-flop and the plurality of gate elements in the embodiments, it is obvious that the present invention may be realized by using other signal holding means or signal comparing means. Further, the control unit may be a microprocessor or a keyboard switch of the control board.

[0013]

Since the present invention is constructed and operates as described above, the addition of a simple circuit is very effective in improving the reliability of a system using a latch relay against disturbance. Therefore, even if one contact of the latch relay is provided for self-monitoring, this is a very effective effect.

[0014]

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a latch relay device according to the present invention and a configuration of a control unit for controlling the same.

FIG. 2 is a diagram showing a conventional latch relay device and a configuration for controlling the same.

[Explanation of symbols]

 1 ... Latch relay 2, 3 ... Contact 4, 5 ... Contact control circuit 6 ... Straw part pulse circuit 8 ... Control part 11 ... Latch relay device 12 ... Self-monitoring circuit 13 ... Flip-flop 14 ... XOR gate 15 ... AND gate 16 ... OR gate

Claims (2)

[Claims] 1. A relay device for switching a state of a contact based on a control signal from a control part, wherein the relay device has a latch relay part having a latch type contact, and the next control signal reaches the control signal. A signal holding means for holding the contact state of the latch relay section and a comparing means for comparing the contact state of the latch relay section with the signal held by the signal holding means, and the state of the contact when the comparing means detects a mismatch. A self-monitoring type latch relay device characterized by being configured to switch between. 2. The latch relay section has a plurality of contacts interlocking with each other, and detects the contact state of one of the contacts, and the comparator holds the signal held by the signal holding means. 2. The self-monitoring latch relay device according to claim 1, wherein the self-monitoring latch relay device is configured to be compared with each other.