JPS5916012A - Actuator testing device - Google Patents

Abstract

PURPOSE:To prevent malfunction by flowing an operating current only in a short time when an actuator does not operate actually by transformer coupling, or intercepting the operating current only in a short time when the actuator does not stop actually, and testing a circuit. CONSTITUTION:The output of a logical circuit 22 is off in a normal state, so the actuator 28 is not in operation. A test circuit 31 applies an AC voltage to the 2nd winding 23-2 of a transformer 23 only in a short time shorter than the operation time of the actuator 28 to generate induced electric power at the 3rd winding 23-3, flowing a pulse current from an AC power source 30 to a triac 26a and the actuator 28. This current is detected by a current pickup 32 and a discriminating circuit 33 judges the soundness of the actuator circuit. When the output of the logical circuit 22 is on and an AC current flows through the 1st transformer winding, such a negative-phase AC current as magnetic flux by the 1st winding is canceled is flowed through the 2nd winding and AC electromotive force generated at the 3rd winding is eliminated to confirm the soundness of the circuit similarly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an actuator testing device that tests the health of a drive circuit including an actuator without actually operating or stopping the actuator during plant operation.

The structure, function, and operation of the conventional device will be explained with reference to FIGS. 1 to 3. In FIG. 1, / is a digital input signal that is turned on and off by a control circuit not shown in the figure.

The number of input signals is plural depending on the logic, but one is representative in the figure.

- is a relay, 3 is a logic circuit, DA is an actuator driven by the contact of the relay, and 5 is an AC power source for the actuator.

In FIG. 1, the symbols /, ko, J, 4' and S' indicate the same things as in FIG. d is the block contact used during the test, g is the indicator light used during the test, and t is the resistance.

In FIG. 3, the symbols /, 2 and 3 indicate the same things as in FIG. 1 and FIG. IO is the actuator, ll is the contact used during testing, /2./
3 is the indicator light used during the test, /'+, /j is the resistance,
1A is a DC power supply for the actuator 10, and /7, 1g is a diode for preventing recirculation current.

Next, the operation will be explained. In FIG. 1, when the input signal 1 becomes OFF/on by a control circuit not shown in the figure, the output of the logic circuit J excites relay 2, the contact of relay 2 turns on, and the actuator DA operates. Here, the actuator q is assumed to be a pulp, a motor, a breaker, etc.

In FIG. 1, the actuator is normally stopped and is activated when necessary. It is clear that if the contact point of relay 2 is changed from a normally open contact to a normally closed contact, the actuator will normally operate and can be stopped when necessary.

When an actuator is very important to plant operation or essential for personal protection, it is necessary to periodically test whether the actuator and its drive circuit are in good working order. If operating or stopping the actuator does not affect plant operation, the test method is simple and only requires actually operating or stopping the actuator.

However, if operating or stopping the actuator has a significant impact on the operation of the plant, tests are conducted using the methods shown in FIGS. 2 and 3.

Figure 1 shows a case where the actuator is normally stopped. Block contact 7 is normally on, and indicator light g is normally on terminal -
The structure is such that current flows between terminals @ and lights up, and only when the indicator light is pressed, current flows between terminals - and lights up.

In Figure 1, the indicator light is lit because the resistance current flows through the terminal ■→@→resistance of the indicator light. Before turning on the input signal l to the control circuit, the block contact 7 is first turned off. At this time, no current flows through the indicator lamp, so it turns off. After confirming that indicator light g has gone out, turn on contact l to energize relay 2. Press the indicator light g to confirm that the relay-〇 contact is on and that the actuator is normal (no wire breakage, etc.) and the indicator light lights up. At this time, terminal of indicator light g→
■→Relay 2 contact→Actuator tag and current flows.

FIG. 3 shows the actuator in normal operation. The bypass contact // is normally off, and the indicator light,
The structure of the /3 is the same as that of the indicator lamp shown in Figure 1, but the color of the lamp is changed to prevent malfunction.

The indicator light /- is lit because current flows through the second relay contact → terminal ■ → ■ → resistor /da. When the bypass contact is turned on, indicator light /3 lights up. After confirming that the bypass contact is definitely turned on by this lighting, input signal / is turned on and the second relay contact is turned off. Confirm that the second contact of relay is turned off by turning off the indicator light /-.

Since the conventional actuator test circuit is configured as described above, it is necessary to add movable contacts such as block contacts and bypass contacts and indicator lights to the circuit. This increased the number of parts and lowered the overall reliability. Furthermore, incorrect operation may cause the actuator to start or stop.
There were drawbacks such as the risk of having a serious impact on the plant.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above.
The health of the actuator and drive circuit is checked by cutting off the operating current for a short period of time that does not lead to an actual stop, so there is no need to worry about erroneous operation, and by eliminating movable contacts, etc., reliability is improved. The aim is to provide a high actuator test bag.

An embodiment of the present invention will be described below with reference to the drawings. In the figure, / indicates an input signal that is turned on and off by a control circuit not shown in the figure. Although the number of input signals is plural depending on the logic, one signal is representative in the figure. 22 is a logic circuit 1; 23 is a transformer; 1st and U
WX3 (consisting of 0 volume m23-/, ko3-2.λ3-3., 2 O is the power amplifier circuit, 26a is the triac 1 that constitutes the output circuit of the /ζ power increase 1@circuit roller)
．． 2g is the actuator, 30 is the AC power source for the actuator, and 31 is the second winding 23- for a short time during the test.
2 is a test circuit that applies a pulse frost current, 3 is a current pickup that non-contact detects the current flowing through the actuator circuit, and 33 is a judgment circuit that fully amplifies the ib force of the current pickup and determines whether the actuator circuit is normal or not. It is.

First, normal operation will be explained. Depending on the condition of the input signal l, the logic circuit 2λ may or may not output an alternating current voltage. For example, if the logic circuit is 2/2, if one or less of the inputs is on, the logic output will be off (
(no AC voltage output), and no AC current flows through the first winding λ3-/ of transformer 2J6D. When one or more of the q inputs turns on, the logic output turns on (alternating current output is present) and an alternating current flows through the first winding 23-7 of the transformer 23. Transformer, Volume 1 of 23 M-23-/
When an alternating current is applied to the winding 23-3, an alternating electromotive force is generated in the winding 3, 23-3, which becomes the input to the power amplifier 2a, and when the triac 2a becomes conductive, the actuator 2g is activated. drive. If the logic output is off and no alternating current flows through the first winding, 2.7-/ of the transformer 23, then the third winding, 23. - No alternating current electromotive force is generated at j, and the triac, 2Aa, is cut off.
Actuator, Xt does not operate.

Next, the test will be explained. In the normal state, the output of the logic 22 is off, so the actuator uA' is not operating. From the test circuit 31, an AC voltage is applied to the first winding JJ-J of the transformer 23 only for a time interval shorter than the operating time of the actuator 2g, and the third winding: 1
3-,? An electromotive force is generated, and a pulse is applied to the triac 26a1 actuator 2g from the AC power supply 30. This current is detected by a current pickup 32, and a determination circuit 33 determines the soundness of the actuator circuit.

The above is a description of the normal state, in which the output of the logic controller λ is off and no alternating current is flowing through the first winding 23-/ of the transformer 3. When the output of logic 22 is on and an alternating current is flowing through the first transformer winding, an alternating current with an opposite phase is caused to flow through the first winding to cancel the alternating magnetic flux caused by the first winding. Accordingly, the AC electromotive force generated in the third winding can be set to θ. This results in three current probes, three pickups, and three current detection circuits.
The soundness of the actuator circuit can be confirmed in the same manner as in step 3.

In the above embodiment, a triac is used as the power amplification circuit output element in order to drive the actuator 2g, but when the DC power supply 30' is used to drive the actuator 2g', As shown in diagram S, a power transistor λ6b can also be used as an output element of the power amplifier circuit 2A'.

In addition, in the embodiments of FIGS. 9 and S, the test circuit 31
The current detection and judgment circuit 33 is set to [IJ, but the current detection and judgment circuit may be included in the test circuit.Furthermore, as the output semiconductor of the power amplifier, fi+, which was explained as a triac in an AC circuit and a transistor in a DC circuit, is This is just one example, and the same effect can be achieved even if other semiconductors are used.

In addition, although we have shown a device that uses a current pickup to detect the current in the actuator circuit, it is also possible to determine the health of the circuit by inserting a low resistance into the actuator circuit and measuring the voltage across it. You can also do it.

As described above, according to the present invention, the actuator can be operated by using transformer coupling to allow the operating current to flow only for a short time when the actuator does not actually operate, or to cut off the operating current only for a short time when the actuator does not actually stop. Now that we have configured it to test the circuit,
Since there is no possibility of erroneous operation and there is no need to use movable contacts in the actuator circuit, there is an effect that a highly reliable product can be obtained.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the actuator drive circuit when no test equipment is required, Figures 2 and 3 are block diagrams showing conventional actuator testing equipment, and Figure 1 shows the actuator normally stopped. , FIG. 3 shows the case of normal operation. FIG. 4 is a block diagram showing an actuator testing device according to an embodiment of the present invention, and shows a case where the actuator is normally stopped. ITS figure is a block diagram showing an actuator installation according to another embodiment of the present invention. In the figure, l is an input signal, 2 is a logic circuit,
23 is a transformer, 26 and 2A'i, l: power amplifier circuit, colo a is a triac 1.16b is a power transistor, -g and 2g'lJ, actuator, 3
0 is an AC power supply for the actuator, 30' is a DC current for the actuator, 31 is a test circuit, 3.2 is a current probe, and 33 is a determination circuit. Agent Makoto Kuzuno - 2, Name of the invention Actuator test device 3, Person making the amendment Representative piece 111 Part 4, Agent (1) Detailed description of the invention in the specification (2) Description Column for a brief explanation of the drawings Contents of the amendment (1) Changed "Normally closed contact" on page 3 of the specification, line lt to "
"Normally open contact" and "Normally closed contact" on the same line 76 is corrected to "Normally closed contact." (2) Correct "on" in line S of page D to "normally on". (3) In the same page 1/page ff-9 line, [It is a block diagram, .

Claims (1)

[Claims] In an actuator drive circuit that energizes or deenergizes an actuator according to a signal from a logic circuit, a transformer provided between the logic circuit and the actuator drive circuit, and the presence of a current in the actuator drive circuit are provided. The transformer includes a current detection judgment circuit for detecting the presence or absence of a current, and a test circuit for testing the actuator drive circuit, and the transformer has, on the negative side,
It has a first winding connected to the logic circuit, a first winding connected to the test circuit, and on the secondary side, a third winding connected to the actuator drive circuit. Accordingly, the test circuit may cause the operating current to flow only for a short time when the actuator is not actually operating;
Alternatively, the actuator drive circuit is tested by applying a signal to the first winding that cuts off the operating current only for a short time before the actuator actually stops. Device.