JPS5819839Y2 - lamp test circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lamp test circuit for a lamp indicator provided in a supervisory control panel.

=Generally, industrial and electric power monitoring and control panels are equipped with a large number of indicators, and these indicators use incandescent lamps, which are superior in terms of brightness and color. There are many things.

However, since incandescent lamps have a shorter lifespan than light-emitting diodes, in the case of lamp indicators using incandescent lamps, lamp test circuits are provided and tests are performed periodically.

Normally, this lamp test is performed by checking and lighting a large number of lamp indicators at the same time, so the power source for lighting the lamps must be of a correspondingly large capacity.

However, in steady state, it is unlikely that many lamp indicators on the supervisory control panel will light up at the same time, so it is not recommended to determine the power capacity for lamp lighting based on the power capacity required during lamp testing. .

In other words, even though the lamp test is only performed for a very short time, it is necessary to have a large-capacity power supply for lighting the lamp, which is a waste of time.

Therefore, the purpose of this invention is to minimize the power supply to the lamp indicators when testing a large number of lamp indicators in a supervisory control panel, reduce the power supply capacity for lighting, and test the lamp indicators. The goal is to obtain a lamp test circuit that can properly perform the following steps.

Hereinafter, the present invention will be described with reference to an embodiment based on the drawings.

In FIG. 1, a plurality of lamp indicators 11 are installed in advance at A and B.
The lamp test circuit 12 of the present invention corresponds to the two groups of
It is a circuit diagram to which this is applied.

The lamp test circuit 12 includes a pulse oscillator 13 that periodically generates pulses, and a test signal generator that obtains a test signal ayb for the lamp indicator 11 based on the pulse signal from the pulse oscillator 13.

This test signal generating section is composed of a plurality of NAND circuits 14.

That is, the test signal a is output from the NAND circuit 14A to the A group lamp display 11AK, while the NAND circuit 1
From 4B, the test signal is the B group lamp indicator 11B.
It is now output to .

This lamp test circuit 12 is activated by operating a switch 15.

FIG. 2 shows the signal waveforms of each part of the lamp test circuit 12 and the operation of the lamp indicator.

The pulse oscillator 13 outputs a pulse signal X1.

This pulse signal X1 is used to obtain test signals a and b.
It is input to the NAND circuits 14A and 148,
In order to make both signals different in phase, the pulse signal X2 input to the NAND circuit 14A is the pulse signal X0.
is inverted by the NAND circuit 14C, and the pulse signal X1 is inverted.

Therefore, the test signals a and b have phases inverted from each other.

One end of the old switch 15 is connected to the logic common, and when the switch 15 is in an off state, that is, in a state other than the lamp test, the Lebel signal is input to the NAND circuit 14D.

Therefore, in this state, the output of the NAND circuit 14D is at O level.

From this, in a steady state in which the lamp indicator 11 monitors failures of field equipment, both test signals a and t) have a logical value of 1.

Therefore, whether the lamp indicator 11 lights up is determined by the state of the output signal S of the lamp lighting logic circuit 17 that is input to the NAND circuit 16.

The lamp lighting logic circuit 17 outputs a signal of logical value O when an abnormality occurs in the field equipment, and outputs a signal of logical value 1 when the field equipment is normal.

First, the lamp indicator 11 does not light up unless an abnormality occurs in the field equipment.

(・1. Assume that the switch 15 is turned on at time t1.

As mentioned above, one end of the switch 15 is connected to the logic common, so when the switch 15 is turned on, O
A level signal is input to the NAND circuit 14DK.

As a result, the output signal X3 of the NAND circuit 14D becomes the second
As shown in the figure, the signal is at l level.

This output signal X3 is input to both NAND circuits 14A and 14B.

Therefore, the test signal a output from the NAND circuit 14A becomes an inverted pulse signal of the pulse signal X2, that is, in phase with the oscillator 13, while the test signal a output from the NAND circuit &14B becomes an inverted pulse signal of the pulse signal X1.

These test signals a and b are each sent to a NAND circuit 16.
When input to each lamp display 11 via The transistor 18 in the lamp indicator 11 is turned on and off in an inverted manner.

In this case, the test signals a and l) are mutually inverted pulse signals, so when the lamp indicator 11A1, that is, the lamp indicator 11 of group A is in the on state, the lamp indicator 11B of group B is in the off state, Repeat on and off mutually.

1. During a lamp test, the lamp indicator 11
The power supplied to the lamp 19 in the transistor 18
Since the lamp 19 is supplied only when it is in the on state VC,3, the lamp 19 repeats blinking at the cycle of the pulse signal.

In reality, since there is a delay in response, the brightness of the lamp 19 is
This is approximately half of what it would be if the power was input continuously.

Generally, even if the brightness of the lamp 19 is reduced to half, the lamp 19
It is possible to determine whether the lamp is lit or not, so there is no problem with the lamp test.

Next, if an abnormality occurs in the field equipment during this lamp test, the output signal S of the lamp lighting logic circuit 17 becomes O, regardless of the presence or absence of the test signals a, l) input to the NAND circuit 16. The lamp indicator 11 corresponding to the field equipment in which the abnormality has occurred becomes in the QN state.

Therefore, the lamp 19 is supplied with continuous power.

First, the brightness of the lamp 19 of the lamp indicator 11 corresponding to the field device in which the abnormality has occurred is approximately twice that of the other lamps 19.

As a result, even if the field equipment exhibits an abnormality during the lamp test, it can be detected by the difference in brightness of the lamp 19 as long as the lamp 19 is normal.

As described above, according to the present invention, during a lamp test, power is intermittently supplied to the lamp from the power source for lighting the lamp, so the power source for lighting the lamp is small. Any capacity is fine.

In addition, if a field device exhibits an abnormality during a lamp test, power is continuously supplied to the corresponding lamp, so the lamp under test and the lamp that detected the field device's abnormality are connected. Differences can also be easily distinguished.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram in which the lamp test circuit of the present invention is applied to a lamp indicator, and FIG. 2 is a characteristic diagram thereof. 11...Lamp indicator, 12...Lamp test circuit, 13...Pulse oscillator, 14,
16...NAND circuit, 15...Switch, 17...Lamp lighting logic circuit, 18...
・-Transistor, 19... Lamp.

Claims (1)

[Scope of utility model registration request] In a lamp test circuit that tests a plurality of lamp indicators that indicate abnormalities in field equipment, a pulse oscillator that periodically generates pulses; 1. A lamp test circuit comprising a test signal generating section that provides a test signal of the same phase and a test signal generating section that provides a test signal of a phase different from the test signal to the other number of units.