JPS6010533A - Operation diagnosing circuit of relay - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a relay operation diagnosis circuit that automatically diagnoses the operation of a relay.

[Prior art]

Since relay contacts are mechanical parts, they have a higher probability of failure than electric circuit parts such as ICs. on the other hand,
Relays are often used at key points in electrical circuits, so when a failure occurs, the circuit often stops working properly. By the way, conventionally there is no method for automatically diagnosing the presence or absence of a failure in a relay contact, and as a result, it has not been possible to quickly deal with the occurrence of field lightning in an electric circuit.

(Object of the Invention) The present invention has been developed in view of the above-mentioned problems, and is designed to automatically determine whether the operation of a relay contact to be measured is good or bad.

〔Example〕

Hereinafter, the present invention will be explained in detail using the drawings.

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

In the figure, X is a relay contact to be tested, and 100 is a relay operation diagnostic circuit according to the present invention. Relay contact X under test is connected to terminals 101 and 102.

Cal to Cs3 are control signals input from the first part of the circuit 100, and Dsl to DS2 are output signals.

In the diagnostic circuit 100, 11 and 12 are D-type flip-flops, 21 is a transistor, 22 is a buffer amplifier, 23 and 24 are relay contacts, and 25 is a drive circuit for driving relay contacts 23 and 24.

A signal Csl is applied to this drive circuit 25.

30 is a comparator circuit, 31 and 32 are comparators, and 33 to 36 are resistance elements, respectively. Control signal C92 is applied to transistor 21 via buffer amplifier 22. The emitter electrode of the transistor 21 is connected to the 2i!
ili is connected to the potential point COM, and the resistive element 36
is connected to one end of the relay contact X to be tested through a series circuit of the relay contact 23 and the relay contact 23, and the other end of the relay contact X is connected to the reference potential point COM through the relay contact 24.

A voltage dividing point B between the resistive elements 33 and 34 is connected to one input terminal of the comparator 31, and a voltage dividing point C between the resistive elements 34 and 35 is connected to the tenth input terminal of the comparator 32. A connection point E between the resistive element 36 and the relay contact 23 is connected to the − input terminal of the comparators 31 and 32. The preset terminals PR in the flip-flops 11 and 12 are connected to the output terminals of the comparators 31 and 32, and the D terminal is connected to the base e.
The potential point COM and the clear terminal CL'R are connected to a +5v power supply terminal, respectively. A control signal Cs3 is applied to the clock terminal CK as a clock signal.

The relay contact X under test is incorporated into another electrical circuit (not shown). When diagnosing this relay contact X,
The relay contacts 23 and 24 are connected to the diagnostic circuit 100 as a lever. When relay contact X is operating normally in another electrical circuit (when not performing diagnosis), open relay contacts 23 and 24 to isolate relay X under test from diagnostic circuit 100. . Relay contacts 23 and 24
Closing and opening driving is performed by applying a control signal Csl to the drive circuit 25. Below, regarding the case where relay contacts 23 and 24 are closed and relay contact X under test is connected to diagnostic circuit 100, (1) presence or absence of a failure in relay contact X under test, (2) relay contact under test X
The operation of the circuit of the present invention will be explained with respect to (3) determination of whether the contact resistance and insulation resistance are good or not, and (3) the presence or absence of chattering of the relay to be tested.

(1) Regarding the presence or absence of a failure in relay contact X.

The control signal C32 is applied to the transistor 21 via the buffer amplifier 22, and the voltage divider circuit in the comparator circuit 30 is connected to the resistor element 3 by the voltage source 3.
3. Supply current to 34.35. As a result, comparator levels are set at the voltage dividing points B and C.

If the potential to the voltage dividing point is ■, the potential at the voltage dividing point E is ■ when the relay contact under test
The potential is the same as that of Here, the comparator 31 determines whether the relay contact X is indeed open when it should be open. That is, the potential at the connection point E is applied to the 10 input terminal of the comparator 31, and the potential at the voltage dividing point B is applied to the - input terminal. As a result, if the relay contact X is normal and open, the output level of the comparator 31 will be ``H'''', and if it is abnormal, it will be the ``L'' level.

Next, the comparator 32 determines whether the relay contact X is closed. The potential of the connection point C is 1 applied to the terminal 11 of the comparator 32, and the potential of the connection point E is applied to the negative terminal. As a result, if the contact of relay X is normal and is closed when it should be closed, comparator 32
The output level is °°H''', and if abnormal, it becomes the "L" level, and this output is applied to the preset terminal PR of the flip-flop 11.

(2) Judging whether the contact resistance is good or bad.

As a characteristic of relays, the contact resistance of the contacts is a major problem. The contact resistance of the relay contact X is r, and the resistance elements 33 to 3
If we set the ratio of 6 to R1 to R4 and ignore the wiring resistance, r < R4X (R3/ (R1+R2)) −(1
), the comparator 32 determines this to be normal. That is, if the contact resistance of the relay contact X is normal, the output J level of the comparator 32 will be IIHII, and if T exceeds equation (1), it will be the "L" level.

The output signal of comparator 32 is
2 is applied to the preset terminal PR.

Insulation resistance in relays when the contacts are open is also a problem. In the present invention, if the insulation resistance (10) is smaller than the specified value, it can be detected. That is, if the value of the insulation resistance of the relay contact X is r',
If wiring resistance is ignored, r'>R4X ((R2+R
3)/R1)...If (2), the comparator 31 outputs an "H" level signal. This "H°" level signal is applied to the PR terminal of flip-flop 11.

Flip-flop 11 has its preset terminal PP.

Even if a II HIT level signal is applied to I, the Q output does not change, but when No. 4a at the "L" level is added, the Q output becomes "H"H.As described in 11j, the relay contact The output level of the comparator 31 is ++H++ if it is opened when it should be opened, and L″° otherwise. Also, the insulation resistance of relay contact X, F
If A is low and the resistance is good, the output level of the comparators 31 and 32 is H''', otherwise it is L''.

and these levels are flip-flop11.1
2 is applied to the preset terminal PR. Therefore, from the levels of the signals Dsl and DS2 applied from the Q output terminals of the flip-flops 11 and 12, it is possible to judge whether the operation of the relay contact X is good or not, and whether the insulation resistance and contact resistance are good or bad. This judgment of pass/fail can be automatically processed by using a computer (not shown).

(3) Regarding the problem of chattering.

It takes several milliseconds from when a command is given to relay contact X to open or close the contact to actually open or close the contact. In this case, chattering will occur for a while after the opening and closing operation. Figure 2 shows the chattering status of relay X, (a) and (c) are normal, and (b)
and (d) indicate abnormal cases. According to the present invention, it is possible to determine whether or not there is an abnormality in the operating time and return time of such a relay.

That is, in FIG. 2, tl indicates the time when the signal to close the relay X is applied, and t2 indicates the time when the signal to open the relay
From 1 to 11 until the chatter disappears and it closes normally.
5, Δt2 is relay X after a certain period of time has passed from time t2.
The time it takes to ensure the open state [Δtl and Δt2 are 3 m5ec in the example. Now, after Δt1 has elapsed since the application of the signal that makes the relay contact X idle at time t1, the control signal Cs3 is applied to the clock terminal CK of the flip-flop 11.12. This control signal Cs3 is used to clear the contents of flip-flop 11.12. At the time when the control signal Cs3 is applied, as shown in FIG.
As shown in a), if the relay contact X is reliably closed, the output level of the comparator 32 is H°, so the output of the flip-flop 12 is the level L°. On the other hand, if the relay contact X is not yet closed as shown in FIG. 2(b) at the time when the control signal Cs3 is applied, the output of the flip-flop 12 becomes the ``H'' level. That is, if the signal to close the relay contact X is applied and the relay contact X is normally closed without chattering, the level of the output signal Ds2 is H''; if there is an abnormality, the level of the output signal Ds2 is "L"''.

Here, after Δt2 has elapsed since the application of the signal to open the relay contact X at time t2 to open the relay contact X, the control signal Cs3 is applied to the flip-flop 1.
1.12 clock terminal GK. If the relay contact X is definitely open as shown in FIG. 2(A) at the time when the control signal Cs3 is applied, the output level of the comparator 31 is "H", so that The output becomes "L" level. on the other hand,
The second mark in the embossing to which the control signal Cs3 is applied
If chattering continues at contact X of the relay as shown in Figure (D), the Q output of flip-flop 11 becomes the ``H'' level. That is, if the signal to close the relay contact X is applied and it closes normally without chattering, the level of output IB Dsl is °L°.

, if it is abnormal, it becomes H゛°. These 'H' and 'L' level signals are processed by the computer.

〔Effect of the invention〕

As described above, in the present invention, if there is a problem with any one of the failure, contact resistance, insulation resistance, and chattering of the relay contact X under test, the diagnosis is automatically performed using a pair of flip-flops. You can get the equipment.

As a result, if an abnormality occurs in the electrical circuit using the relay, the abnormality can be quickly dealt with.

[Brief explanation of the drawing]

FIG. 1 is a connection diagram showing an embodiment of the relay operation diagnostic circuit according to the present invention, and FIG. 2 is a waveform diagram for explaining the operation of the circuit shown in FIG. X... Relay contact to be measured, 11.12...
...Flip-flop, 23.24...Relay, 31.32...Comparator.

Claims (1)

[Claims] A relay contact to be measured, a voltage dividing circuit driven by a control signal, a resistive element connected in series between the drive source of this voltage dividing circuit and the relay contact to be measured, and a first relay contact, nTJ to be measured. a second relay contact connected between the relay contact and the potential point of the base wall, 1) the voltage at the connection point of the 11th resistance element and the first relay contact, and the divided voltage of a different number in the voltage divider circuit; A pair of comparators are applied to their respective input terminals in reverse order, and the outputs of the pair of comparators are applied to their preset voltages 1 and 1 respectively.
A relay consisting of a D-type flip-flop, in which a control signal is applied to the clock i and 7+i terminals, and a signal is extracted from the Q terminal to determine whether the operation of the relay contact to be measured is good or not. operation diagnostic circuit.