JP3306701B2 - Output relay multiplex operation detection circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output relay multiplex operation detecting circuit for detecting multiplex operation of output relays for control output in a remote control system. In the remote control system, a single output relay among a plurality of output relays of the remote control device is operated to control a controlled device. Therefore, since a multiplex operation in which a plurality of output relays operate simultaneously is a malfunction, it is necessary to detect this and invalidate the control.

[0002]

2. Description of the Related Art A remote control system is, for example, a system for performing remote control of switches such as substations and switchyards in an electric power transmission and distribution system, or a system for installing a monitoring camera or the like to perform remote monitoring and control. This is applied to the case where the remote control of each device is performed. FIG. 2 shows an outline of such a remote control system. The remote control device includes a selection relay drive circuit 21 for driving output relays each having output contacts 25-1 to 25-n, and detection of output relays. Operation detecting circuit 22 for detecting a multiplex operation by a contact for use
And a common control relay control circuit 23 that turns off the contact 24 of the common control relay by detecting multiple operations.
The controlled devices include relays RL1 to RLn corresponding to the output contacts 25-1 to 25-n, and contacts 2 of the common control relay.
4 corresponding to the relay RL0.

Accordingly, when the contact 25-1 of the output relay is turned on by the selection relay drive circuit 21 of the remote control device and the contact 24 of the common control relay is turned on by the common control relay drive circuit 23, the power supply of the controlled device is The voltage V (for example, 100 V) is applied to the relay RL1 through the contacts 25-1,
The relay RL1 is operated by being applied via the switch 24, and for example, a switch can be turned on via the contact (not shown).

At this time, if another output relay operates simultaneously for some reason and a multiplex operation in which its contact is turned on occurs, a plurality of relays operate in the controlled device and malfunction. Therefore, the multiplex operation detection circuit 22 detects whether the multiplex operation is performed by the detection contact of the output relay, and when the multiplex operation is detected, the multiplex operation detection circuit 22 controls the common control relay driving circuit 23 to turn off the common control relay contact 24. And As a result, since the voltage V of the power supply is not applied to the relay of the controlled device, all the devices are turned off, and malfunction can be prevented.

FIG. 3 is an explanatory view of a main part of a conventional multiplex operation detecting circuit, which includes 25-1a, 25-1b, 25-2a, and 2-2.
5-2b, 25-3a, and 25-3b are output contacts 25.
A detection contact of an output relay having -1, 25-2, and 25-3, 31 is a DC power supply, 32 is a photocoupler, and 33 is a detection output terminal.

When the output relay is not operating, the detection contacts 25-1a, 25-1b, 25-2a, 25-2
Since b, 25-3a, and 25-3b are in the illustrated state, the photocoupler 32 is in the off state, and the detection output terminal 33 is at the high level. When any one of the output relays operates, for example, if the detection contacts 25-2a and 25-2b are switched from the illustrated state, the detection contacts 25-3b and 25
Since a voltage is applied from the DC power supply 31 to the photocoupler 32 through the paths -2b and 25-1a, and the photocoupler 32 is turned on, the detection output terminal 33 is at a low level.

[0007] When two of the contacts are simultaneously operated, for example, the detection contacts 25-1a, 25-1b, 25-2a,
Assuming that 25-2b is simultaneously switched from the illustrated state, the voltage applied from the DC power supply 31 to the photocoupler 32 is cut off by the detection contact 25-1a. Therefore,
The photocoupler 32 is turned off, and the detection output terminal 33 becomes high level. Therefore, since the detection output terminal 33 becomes a low level only in the case of the single operation, it can be determined whether the operation is the single operation.

[0008]

The output relay described above is
Each output relay may have at least one output contact and two detection contacts, and each output relay has a problem that the size is increased and the cost is increased. By connecting the detection contacts in series, there is a problem that the failure of one detection contact adversely affects the entire detection operation, and the detection contacts are not connected when the output relay is added or reduced. There was a problem that the work of changing the connection became complicated. SUMMARY OF THE INVENTION It is an object of the present invention to reduce the number of contacts of an output relay and detect a multiplex operation with a relatively simple circuit configuration.

[0009]

An output relay multiplex operation detecting circuit according to the present invention comprises: (1) a detecting circuit for detecting a multiplex operation of a plurality of remote-controlled output relays, the output contact and the detecting contact; A resistor connected in series to the detection contact of the output relay having: a circuit in which the detection contact and the resistor of the output relay are connected in series to the secondary winding in parallel; A sine wave oscillator that applies a sine wave signal to the primary winding via an input resistor, a sine wave signal level output from the sine wave oscillator, and a sine wave applied to the primary winding of the isolation transformer via an input resistor A test logic circuit for comparing the signal level with the signal level to determine whether the output relay has a single operation or a multiple operation.

(2) The test logic circuit sets the output sine wave signal level of the sine wave oscillator to (1/2) + α and (1/2)
−α, the levels of the divided voltage output signals of the first and second voltage dividers and the sine wave signal applied to the primary winding of the insulating transformer are compared. The first and second comparators and the sine wave signal level applied to the primary winding of the insulating transformer are within the voltage division ranges of (1/2) + α and (1/2) -α, respectively. A single operation, and a non-operation or multiplex operation when the voltage is not within the voltage division range.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an embodiment of the present invention, wherein 1 is a sine wave oscillator, 2 is an isolation transformer, 3 is a test logic circuit, 4, 5 are level converters, 6, 7 Is the first
A second voltage divider, 8, 9 are first and second comparators, 10 is a judgment circuit, R0 is an input resistor, and R1 to Rn are detection contacts 11
A resistor connected in series to -1 to 11-n, and 12 is a detection output terminal. In this case, for example, a relationship of R1 to Rn = R0 is set.

Each output relay has an output contact (not shown) and one detection contact 11-1 to 11-n. An output relay having two detection contacts according to a conventional example. It is possible to reduce the size and cost as compared with the case of (1). Also, detection contacts 11-1 to 11-n and resistors R1 to R
n is connected in parallel to the secondary winding of the insulating transformer 2. Therefore, when the output relay is added or reduced, the connection of the detection contacts 11-1 to 11-n can be easily changed.

The sine wave oscillator 1 can have a relatively simple configuration for outputting a sine wave signal having an arbitrary frequency of about several kHz. The output sine wave signal of the sine wave oscillator 1 is applied to the primary winding of the insulating transformer 2 via the input resistor R0. The insulating transformer 2 has detection contacts 11-1 to 11-1.
11-n and an output contact (not shown). The sine wave signal level applied to the primary winding of the insulation transformer 2 is converted into a DC voltage by a level converter 5. Convert to Further, the output sine wave signal level of the sine wave oscillator 1 is converted into a DC voltage by the level converter 4. That is, the level converters 4 and 5 can be configured to detect a sine wave signal and convert it to a DC voltage.

The test logic circuit 3 includes first and second voltage dividers 6 and 7, first and second comparators 8 and 9, and a decision circuit 10.
When the resistances are set in a relationship of R1 to Rn = R0, the first voltage divider 6 is (１ ／) + α, and the second voltage divider 7 is (１ ／) − α. The partial pressure is applied, for example, α = 1/12. In that case, the first voltage divider 6 has a voltage divider of 7/12 and the second voltage divider 7
Are configured to respectively perform a partial pressure of 5/12.

When the output relay is not operating, the secondary winding of the insulating transformer 2 is in an open state, so that the level does not decrease due to the input resistance R0, and the DC voltage converted by the level converters 4, 5 does not occur. Is substantially equal to V. And
The voltage is divided by the first voltage divider 6 to 7V / 12, and is divided by the second voltage divider 7 to 5V / 12. Therefore, in the first comparator 8, the relationship of V> (7V / 12) is satisfied.
The comparison output signal is “0”, and in the second comparator 9, V> (5
V / 12), the comparison output signal becomes “1”. The determination circuit 10 can be configured as, for example, an AND circuit. In this case, the determination circuit 10 outputs “0” from the detection output terminal 12.

When a single output relay operates, for example, when the detection contact 11-2 is turned on, the resistor R2 is equivalently connected in series with the input resistor R0. Therefore, as described above, since there is a relationship of R0 = R2, the output sine wave signal level of the sine wave oscillator 1 is divided into １ ／ and input to the level converter 5, where it is converted. The DC voltage becomes V / 2.

Therefore, in the first comparator 8, V / 2 and
7V / 12 and (V / 2) <(7
V / 12), the comparison output signal becomes “1”.
In the second comparator 9, V / 2 is compared with 5V / 12, and since (V / 2)> (5V / 12), the comparison output signal becomes "1". Therefore, the judgment circuit 1
0 outputs a detection signal of "1".

In a multiplex operation in which two output relays operate simultaneously, for example, in a multiplex operation in which the detection contacts 11-1 and 11-2 are simultaneously turned on, the resistors R1 and R2 are connected to the secondary of the insulating transformer 2. The sine wave signal applied to the primary winding of the insulating transformer 2 via the input resistor R0 is connected to the winding in parallel, and is divided into １ ／. 3
When the output relays operate simultaneously, the three resistors are connected in parallel to the secondary winding of the insulating transformer 2, so that the sine wave signal is divided into 1/4. .

Therefore, in the multiplex operation in which two output relays operate simultaneously, the first comparator 8 sets (V / 3) <(7
V / 12), the comparison output signal becomes “1”. However, in the second comparator 9, (V / 3) <(5V / 12)
Therefore, the comparison output signal becomes “0”. Therefore, the judgment circuit 10 outputs a detection signal of “0”,
This indicates that it is not a single operation. The same applies to the multiplex operation of three or more output relays.

As described above, when the output voltage of the level converter 5 is in the range of (5V / 12) to (7V / 12), "1" indicating the single operation is the detection output terminal. 1
2 output. If the detection output terminal 12 is "0" when the output relay operates, a multiplex operation is performed, so that a process for invalidating the remote control via the output contact of the output relay is performed. For example, the common control relay in FIG. 2 is turned off.

The present invention is not limited to the above-described embodiment, but can be variously modified. For example, the first and second comparators 8 and 9 constitute a window comparator. Therefore, the width of the window can be set by the voltage dividing ratio of the first and second voltage dividers 6 and 7, and the width of the window can be set in accordance with the accuracy of the resistors R0 and R1 to Rn. You can set the width.
For example, the width of the window can be increased by increasing the value of α in the case of performing a partial pressure of (α) ± α.
In this case, it is necessary to satisfy the condition of (1/2) -α >> (1/3) in order to enable the test at the time of single operation and at the time of multiple operation. By setting the input resistor R0 and the resistors R1 to Rn connected in series to the detection contact to have the same value, the change in the multiplex operation can be larger than that in the single operation. Can be set to different values if is slightly smaller.

[0022]

As described above, according to the present invention, the resistor R1 is connected in series to the detection contacts 11-1 to 11-n of the output relay.
To Rn, and connected in parallel to the secondary winding of the insulating transformer 2, and the input resistance R
0 to apply the output sine wave signal of the sine wave oscillator 1;
By comparing the sine wave signal level applied to the primary winding of the isolation transformer 2 with the output sine wave signal level,
It detects multiple operations of the output relay, and the output relay can be configured to have an output contact and one detection contact, so that downsizing and cost reduction can be achieved.

The test logic circuit 3 has a relatively simple configuration, and can be reduced in size by being integrated. In addition, since the detection contacts 11-1 to 11-n and the resistors R1 to Rn are connected in series and connected in parallel to the secondary winding of the insulating transformer 2, the output contacts may be used when expanding output relays. There is an advantage that connection at the terminal becomes easy. Also, the input resistance R0 and the resistances R1 to R
Since n does not need to be highly accurate, a small and inexpensive configuration can be achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a schematic explanatory diagram of a remote control system.

FIG. 3 is an explanatory diagram of a main part of a conventional multiplex operation detection circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sine wave oscillator 2 Isolation transformer 3 Test logic circuit 4, 5 Level converter 6, 7 First and second voltage divider 8, 9 First and second comparator 10 Judgment circuit 11-1 to 11-n Detection Contact R0 Input resistance R1-Rn Resistance

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02J 13/00-13/00 311 H04Q 9/00-9/16

Claims (2)

(57) [Claims] 1. A detection circuit for detecting a multiplex operation of a plurality of remote-controlled output relays, comprising: a resistor connected in series to the detection contact of the output relay having an output contact and a detection contact. An insulation transformer in which a circuit in which the detection contact and the resistor are connected in series is connected in parallel to a secondary winding; and a sine for applying a sine wave signal to the primary winding of the insulation transformer via an input resistor. And comparing the output sine wave signal level of the sine wave oscillator with the sine wave signal level applied to the primary winding of the isolation transformer via an input resistor to determine whether the output relay has a single operation. An output relay multiplex operation detection circuit, comprising: a test logic circuit that tests whether the operation is multiplex operation. 2. The test logic circuit according to claim 1, wherein the output sine wave signal level of the sine wave oscillator is set to (1/2) + α and (1 /
2) first and second voltage dividers respectively dividing the voltage into -α;
First and second comparators for comparing the levels of a divided voltage output signal of the first and second voltage dividers and a sine wave signal applied to a primary winding of the insulating transformer, respectively; The level of the sine wave signal applied to the primary winding is (1)
/ 2) + α and (1/2) −α, each of which has a determination circuit that determines a single operation when the voltage is within the voltage division range and a non-operation or multiplex operation when the voltage is not within the voltage division range. 2. The output relay multiplex operation detection circuit according to claim 1, wherein: