JPS58169079A - Abnormality detector - Google Patents

Abstract

PURPOSE:To prevent the generation of erroneous trip or the like by gnerating an abnormality signal when more than one relays of those arranged three per circuit to be excited with multi-decision circuit operate. CONSTITUTION:First-third multi-decision circuits B1-B3 are provided to receive outputs of all detection terminals A1-A3 at points P1-Pn to be measured. The multi-decision circuits B1-B3 are each provide with a majority circuit M adapted to generate an output when more than one of first-third OR circuits O1-O3 which receive outputs of first-third terminals A1-A3 at all points P1-Pn to be measured. Relays C1-C3 each fails to be excited with relays C1- C3 by outputs of the multi-decision circuits B1-B3. The contacts the relays C1-C3 are connected to each other to form a merging circuit C0 of contacts to conduct when more than one thereof fail to be excited.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an abnormality detection device, and particularly to a device suitable for detecting radiation abnormalities.

[Technical background of the invention]

FIG. 1 shows an example of a conventional radiation abnormality detection device. As shown in the figure, a plurality of measured points P1~
Each of Pn is provided with three detection ends. And all the measured points P.

A majority determination circuit 3 is provided to receive the outputs of all the detection terminals ~Pn, ~A. This multiple determination circuit 1 receives the outputs of the first, second and @J detection terminals M, , M3 and M1 of all the measured points P, -Pn, respectively. 2nd and J OR circuit 01m ON and 0. and OR circuit 0. .

The circuit is provided with a majority circuit M that generates an output when five or more of the signals 0, 0, and 0 generate signals. Relay coil 4-C is excited by the output of majority determination circuit B and operates normally open contact C5.

Contact C5 connects and connects the power terminal E and the output terminal, but when it is energized, contact C6 operates and the voltage of the power terminal indigo appears at the output terminal, which is now used as an abnormal signal. . That is, this abnormal signal '''1 output terminal DKI
A connected device, not shown, is tripped or generates an alarm.

With the above configuration, even if one of the detection terminals M, ~M performs one operation and generates a signal indicating an abnormality, the number decision circuit IC does not generate an output, so the output terminal The voltage on the other side does not change.

[Problems with Background Art] However, if the majority determination circuit B or the relay C fails, the voltage at the output terminal changes from the circuit K, causing a problem such as erroneous tripping.

In particular, since the majority determination circuit B and the relay C are provided in common for a large number of measured points, the above-mentioned trend has become even more serious.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an abnormality detection device that does not cause false trips even if seven of the multiple determination circuits or relays fail.

[Summary of the invention]

The present invention includes a majority determination circuit and three relays each excited by the circuit, and when one or more of the three relays operates, an abnormal signal for tripping or the like is generated. . [Embodiment of the Invention] Figure 1 shows an embodiment of the present invention.

In this figure, members similar to those in FIG. 1 are designated by the same reference numerals. As shown, all the target I11 fixed points P1~
The first .
Second and third majority determination circuits B1-B are provided. Each of the majority determination circuits l, ~B, similarly to the majority determination circuit 8 in FIG.
A first OR circuit 0. receives the output of the detection terminal M1. and a second OR circuit 0. which receives the outputs of the second detection terminals of all the measured points P, -Pn. and all measured points P, ~
A 30th OR circuit 01 receiving the output of the third detection terminal of Pn, and the first to third OR circuits 01 to 0. and a majority circuit M that generates an output when one or more of them is generating a signal. The output of the majority decision circuit M is combined with the outputs of the majority decision circuit Ble m,,"a to form a combination circuit C0, that is, a relay CI.

Series circuit of supply contacts C, , C, of C1, relay C1s
Series circuit of stem contacts C2,,C,, of C1 and 1# of relays C,,C,! A series circuit of contacts Csb C1b connected in parallel is provided between the power supply terminal E and the output terminal. Normally, when the power is closed, the voltage of the key terminal E appears at the output terminal, and the voltage at the key terminal E appears.
This is used as an abnormal signal.

The operations of the majority determination circuits B1 to B are similar to those shown in FIG. 1, but an abnormal signal appears at the output terminal only when one of the three majority determination circuits operates. That is,
Even if one majority determination circuit erroneously generates an output due to a failure, or even if one relay fails, no abnormal signal will be generated at the 4th output terminal of the sample, and no trip will occur.

By configuring as shown in Figure 1, when a single component (multiple judgment circuit, relay) in the abnormality detection device fails, the failed component can be repaired without stopping the entire detection device. . Faults can be discovered by detecting faults in one majority judgment circuit or relay by means not shown and generating an alarm, or by periodic inspection.

Therefore, the MTTF (Mean Time to Repair) is significantly improved. FIG. 3 (&) @ (kl) is an explanation for calculating the MTTF in FIG. 1 and FIG. 1, respectively, and λ8. λ is the failure rate of the majority judgment circuit and relay (Nem4r), respectively.
Assume that λ1+λ, t=/Q −'/hy.

In the case of Figures 1 and 3 (,), it is a series system, so
When a failure occurs, it cannot be repaired, but in the cases shown in Figures 1 and 3 (b), it can be repaired.If the repair rate is μmo, i/by, then MTT
F is significantly improved.

〔Effect of the invention〕

As described above, according to the present invention, even if seven majority determination circuits or relays fail, an abnormal signal is not generated, and the malfunctioning majority determination circuits or relays are can be repaired. Therefore, MTTF improves considerably.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional radiation abnormality detection device, FIG. 1 is a block diagram showing a radiation abnormality detection device according to an embodiment of the present invention, and FIG. FIG. 2 is an explanatory diagram for calculating MTTFtt of the apparatus shown in FIG. P, -Pn...Measurement point, A, -A, -...Detection end,
B1-B,... Majority judgment circuit s01-03... OR circuit, M... Majority decision circuit, c, -c,... Relay, cl, C2,. C5b... A combination of tension points, C0... Contact points.

Claims (2)

[Claims] (1) An 11th sensor and a second detection terminal installed at each of the plurality of measurement points to detect an abnormality, and a first detection terminal that receives the outputs of all the detection terminals, respectively. 1st or 1st. and a relay circuit that has a first and a first relay, and generates a signal from a buckle K of a contact of the relay when one or more of the relays is operated, and the eleventh and third Each of the multiple determination circuits includes a first OR circuit that receives as input the output of the seventh detection terminal of all the measured points, and a first OR circuit that receives as input the output of the first detection terminal of all the fixed points to be measured. One OR circuit,
a third OR circuit which receives as input the outputs of the third detection terminals of all the measured points; An abnormality detection device comprising: a majority circuit that generates an output when one or more of the first and first OR circuits outputs a signal. (2) The relay circuit includes a series circuit of the front contacts of the first and first relays, a series circuit of the front contacts of the first and third relays, and a series circuit of the front contacts of the first and third relays, and an ll1v of the third and first relays.
! 2. The device according to claim 1, wherein the device comprises a series circuit of contacts and a series circuit of contacts connected in parallel.