JPS5813599Y2 - lamp check circuit - Google Patents

Description

[Detailed description of the invention] The present invention relates to a lamp check circuit, and its purpose is to provide an economical lamp check circuit in which the number of backflow prevention diodes is only the number of display lamps used. It is in.

The alarm display circuit shown in Figure 1 is used for sprinklers,
When the control section B receives an activation signal from an external device A such as a fire detector, a corresponding indicator lamp of the activated external device A is displayed on the alarm display section C.

By the way, the reliability of the system cannot be improved unless the display lamp of the alarm display section C is constantly checked to see if it is operating properly or not and the button is pressed.

For this reason, the alarm display circuit is always provided with a lamp check circuit.

The present invention relates to this lamp check circuit.

By the way, the conventional lamp check circuit, as shown in Fig. 2, in the case of one alarm system, each indicator lamp L1...
・The buzzer 4 is connected in parallel to Ln through the diodes D1...Dn, and each indicator lamp L1...
...Ln were connected to the DC power supply 1 via the diodes DI...Dnl and the lamp check switch 3, respectively.

In such a conventional example, when a switch S1...Sn provided in an external device A such as a sprinkler is operated during normal times, the indicator lamp L1 connected in series to the switch Sl...Sn is activated. . . . Ln and the buzzer 4 are connected to the DC power supply 1, and perform alarm display and sound notification.

In addition, when checking the lamp, press the lamp check switch 3.
When the lamp is turned on, each lamp L1...Ln and the buzzer 4 are connected to the DC power supply 1 via the lamp check switch 3.
is connected to the indicator lamp L1...L.

Also, it is possible to check whether the buzzer 4 is operating properly.

However, in the case of such a conventional example, two diodes are required for one display lamp, which has the disadvantage of not only being uneconomical but also reducing reliability.

The present invention has been devised in view of the above-mentioned drawbacks, and will be explained below with reference to Examples.

FIG. 3 shows a circuit diagram of an embodiment implemented in one alarm system.

In the figure, reference numeral 2 denotes a control relay, and this control relay 2 is controlled by turning on and off a lamp switch 3, and is used to switch between a normal operation circuit and a check circuit.

Each indicator lamp L1...Ln constitutes a series circuit with a switch Sl...Sn provided on the corresponding external device A, and each series circuit is connected in parallel to each other. , one end of this parallel circuit is connected to the common terminal of the first relay contact r1 of the control relay 2, and the other end is connected to the N of the control relay 2.
It is connected to the negative electrode side of the DC power supply 1 via a C-type second relay contact r2.

Further, a buzzer 4 is connected in parallel to each indicator lamp L1...Ln through a backflow prevention diode DI...Dn, respectively.

The above relay contact r1 connects the NC terminal to the positive pole of the DC power supply 1,
The No terminal is connected to the negative electrode side.

r3 is the No type third relay contact of the control relay 2.

Next, the operation of the lamp check circuit of the present invention will be explained.

In normal times, when one of the switches S1...Sn is turned on, as shown in Fig. 3a, a lamp connected in series with the switch, for example Ll, is connected to the DC power supply 1, the control NC terminal of first relay contact r1 of relay 2,
A current flows through the circuit of the lamp L1, the switch S1, the second relay contact r2 of the control relay 2, and the DC power supply 1, and the lamp lights up to indicate the operation of the corresponding external device A.

At the same time, a current flows through the backflow prevention diode DI to the buzzer 4 to issue a sound alert.

In this case, no current flows through the other display lamps L2...t, n due to the backflow prevention diodes D2...Dn.

In the figure, the two-dot chain line indicates the flow of current.

Next, when performing a lamp check, when the lamp check switch 3 is turned on, the control relay 2 is energized and operated, closing the third relay contact r3 and preventing the second relay contact r2 from opening. Switch the first relay contact r1 to the NC side terminal side.

Therefore, as shown by the two-dot chain line in Figure 3, the DC power supply 1,
Each backflow prevention diode DI...D n s Each indicator lamp L1...L nN Through the first relay contact r1 and the DC power supply 1 circuit, each indicator lamp LL...
...A current flows through Ln, and each indicator lamp L1...
・You can check whether Ln is lit.

At the same time, current also flows to the buzzer 4, allowing the operation of the buzzer 4 to be tested.

The circuit shown in FIG. 4 shows an example circuit for use in a multi-system alarm display circuit, and is composed of a combination of a lamp check switch 3 and a rotary switch 5 in a lamp check circuit, and the lamp check circuit for each system is sequentially control relay 2
1...2o are switched by a rotary switch 5.

Moreover, rll-r1n and r21-r2n are the fourth relay contacts and second relay contacts of the control relays 21-2o, respectively.

Since the present invention is constructed as described above, lamp checks can be performed without affecting normal operation in any way.
Compared to the conventional method, the number of backflow prevention diodes can be reduced by half, improving the reliability of the circuit, and when using a large number of indicator lamps, the cost can be reduced by the amount of diodes, and the number of assembly steps can also be reduced. .

[Brief explanation of the drawing]

Figure 1 is a circuit block diagram of the alarm display circuit, Figure 2 is a circuit diagram of a conventional example, Figures 3a and b are circuit diagrams explaining the operation of an embodiment of the present invention, and Figure 4 is a circuit diagram of the present invention. 1 is a circuit diagram of another embodiment, 1 is a DC power supply, 2 is a control relay, 3 is a lamp check switch, 4 is a buzzer, Ll...Lo
is an indicator lamp, A is an external device, St...Sn is a switch, rl is a first relay contact, r2 is a second relay contact, and r3 is a third relay contact.

Claims (1)

[Claim for Utility Model Registration] A series circuit consisting of a control relay and a lamp check switch is connected to a DC power source, and the NC terminal of the first relay contact of the control relay is connected to the positive terminal of the DC power source. Each terminal is connected to the negative pole, and the indicator lamp and the external device are provided between the common terminal of the first relay contact and the other end of the NC type second relay contact whose one end is connected to the negative pole of the DC power supply. Connect a circuit in which multiple sets of series circuits with switches that turn on are connected in parallel to the external device, connect the buzzer in parallel to the indicator lamp via a backflow prevention diode, and connect the NO type third relay contact of the control relay. A lamp check circuit having one end connected to the positive pole of a DC power supply and the other end connected to a connection point between the buzzer and each backflow prevention diode.