JPH048380Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] It is necessary to check whether the heaters, thermocouples, etc. built into the equipment are disconnected before operation or during maintenance and inspection of the equipment.

The present invention relates to a disconnection detector that performs such checking operations.

[Prior art and its problems] (1) When no connector is used at the cable end: (Figure 4) Reference numeral 10 is the test object, which consists of a heater, thermocouple, etc. Reference numeral 12 denotes these cables, including compensation conductors for thermocouples and the like.

Reference numeral 14 denotes a preparation means, which includes a power regulator for a heater, a thermometer for a thermocouple, etc., and 16 is an entire control device including these.

When the terminal 18 of the control device 16 and the cable 12 are directly connected, a method is often used in which one side of each circuit is opened at the terminal 18 and continuity is checked using a tester 20 or the like.

This method has no problem with accuracy, but it takes a very long time.

(2) When using a connector as a cable terminal (Figure 5): 22 is the entire connector, 24 is a plug, and 26 is a receptacle. Plug 24 for each circuit
Check continuity by applying a tester 20 or the like to the pins.

This method also takes a long time, and at the same time short-circuits the positive and negative terminals of the tester rod at the pin part,
There is a possibility that the actual disconnection may be overlooked.

(3) Detection method based on the ratio of heater voltage and current: Since the actual operating voltage must be applied to the heater, the heater must be heated unnecessarily in order to check before starting equipment operation.

(4) How to detect thermocouple disconnection using a temperature controller/recorder with a burnout function: This method is effective while the equipment is in operation, but it is also recommended to turn on the power to each temperature controller etc. before starting work. There are inconveniences that must be done.

[Means for solving the problem] This invention aims to solve the above problem by detecting disconnection or continuity in many test objects in a short time and displaying it for each circuit. ,
It also prevents the heater from generating heat or damaging the thermocouple by applying unnecessary voltage to the test object.

[Embodiment] In FIG. 1, 30 is a power transformer, and three secondary windings 31, 32, and 33 are provided in this.

The first secondary winding 31 forms a relay circuit.

In other words, RF1 is a rectifier (single-phase full wave), C1 is a ripple absorption capacitor, X is an output relay (see below for contact Xa), TR1 and TR
2 is a transistor for turning relay X on and off. R1, R2, R4, R5, R6 are TR1,
This is a resistor for TR2 to operate normally.
Among them, R1 and R2 on the input side of TR1 are as follows.
Use a variable resistor.

The second secondary winding 32 forms a test circuit.

That is, 34 is a test circuit, and the test object 1
Corresponding to the 0's from #1 to #n, these are also provided from #1 to #n.

Further, in this case, these test circuits 34 and the cable 12 of the test object 10 are connected together by the connector 22 as shown in FIG. 5 above. Note that 13 indicates a cable that is a combination of the cables 12.

A common rectifier RF2 is provided for each test circuit 34, and each test circuit 3 is connected to the input side of RF2.
4 are connected in parallel.

On the other hand, a variable resistor R3 is connected to the output side of the rectifier RF2 together with a smoothing capacitor C2, and the other side of this resistor R3 is connected to the midpoint of the base resistors R1 and R2 of the transistor TR1.

The third secondary winding 33 forms a display circuit.

That is, #1 corresponds to the test circuit 34 above.
A parallel circuit of indicator lamps L from to #n is provided. Then, connect the contact Xa of the above-mentioned relay X to that circuit.

It is also a push button switch with two A contacts.
One contact of the PB is inserted into each of the test circuits 34, and the other contact is connected in series with the corresponding indicator lamp L. Note that the push button switch PB is an illuminated type that is integrated with the indicator lamp L.

Reference numeral 40 in FIG. 2 indicates the entire disconnection detector having the above configuration. A plug 24 is attached to the end of the cable 13, and the plug 24 is connected to the receptacle 26 of the control device 16. When testing, the plug 24 of the cable 13 is connected to the receptacle 26 of the disconnection detector 40. Connect to.

In addition, as shown in FIG. 3, in case the plug 24a of the cable 13 and the receptacle 26b of the disconnection detector 40 do not match, the necessary relay cable 4
2 is prepared so that various cables and the disconnection detector 40 can be connected.

[Function] (1) In steady state, transistor TR1 is on,
Base resistor R1, so that TR2 is turned off.
Set R2.

(2) Operation method When all push button switches PB are not pressed, TR1 is on and TR2 is off.
Therefore, relay X is off. Each indicator lamp L
are all off.

Press #1 push button switch PB,
If the test object 10 of the circuit is conductive,
The input side of the rectifier RF2 becomes a closed circuit, and the current rectified by the rectifier RF2 flows through R1,
3 and flows into the rectifier RF1 side.

Therefore, in steady state, the base voltage of TR1, which was given by dividing the output voltage of RF1 by R1 and R2, decreases, turning TR1 off, and TR2 turns on as the base voltage increases. , relay X turns on.

Since the two-contact type push button switch PB is pressed and the contact Xa closes, the #1 indicator lamp L lights up.

If the test object 10 is disconnected, the lamp L will not light up even if the push button switch PB is pressed because the condition remains the same.

Thereafter, check up to #n in the same manner.

As mentioned above, each push button switch PB and indicator lamp L are integrated and illuminated, so you can judge whether the switch PB you press lights up or not, and there is no need to worry about misreading the corresponding indicator lamp L. do not have.

[Effects of the invention] (1) Since each test circuit and the disconnection indicator circuit are separate circuits, the power supplied to each test circuit can be made low voltage.

Therefore, the heater is not heated unnecessarily and the thermocouple etc. are not damaged.

(2) Since each test circuit 34 and each test object 10 can be connected together using a multi-pole connector, the workability of checking can be greatly improved. Furthermore, the greater the number of circuits, the greater the improvement in workability can be expected.

(3) By adjusting the resistance provided in each test circuit and the base resistance of the transistor,
It is also possible to check continuity of high resistance circuits such as potentiometers.

(4) Connect contact Xa of relay X to the indicator lamp circuit,
By inserting the other contact of a push button switch with two A contacts, the relay circuit and each test circuit are electrically isolated from the display circuit, so the current of each circuit can be set arbitrarily. .

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of an embodiment of the present invention;
FIG. 2 is an explanatory diagram of the usage situation, FIG. 3 is an explanatory diagram of the case where a relay cable 42 is used, and FIGS. 4 and 5 are explanatory diagrams of different examples of the prior art. 10...Test object, 12...Cable, 13...
...Cable, 16...Control device, 22...
... Connector, 24 ... Plug, 26 ... Receptacle, 30 ... Power transformer, 31, 32, 33
... Secondary winding, 34 ... Test circuit, 40 ... Disconnection detector, RF1, 2 ... Rectifier, TR1, 2 ...
Transistor, X...Relay, PB...Push button switch, L...Display lamp.

Claims (1)

[Scope of Claim for Utility Model Registration] A first circuit consisting of a transistor on/off circuit with a relay connected to the load side and a test circuit corresponding to each test object are provided in parallel,
Each of these test circuits and each test object can be connected together using a multi-pole connector, and a common power source and a variable resistor are connected to each test circuit, so that the current flowing through the variable resistor causes the transistor A second circuit configured to control on/off of the circuit; and a third circuit configured to provide indicator lamps corresponding to each of the test circuits in parallel, and connect the contacts of the relay in series to all of the indicator lamps. Disconnection detection characterized in that one contact of a push button switch consisting of a circuit and having two A contacts is inserted into each of the test circuits, and the other contact is inserted in series with the corresponding indicator lamp. vessel.