JPS592631Y2 - emergency alarm device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an emergency alarm system.

Emergency alarm devices used as emergency alarm equipment sound the alarm when a manual start switch is closed, but depending on the location of the alarm, the alarm will sound only when the start switch is closed and the alarm will not start. It is desirable that the alarm stop sounding when the switch opens and closes again.

Furthermore, depending on the location of other equipment, it is desirable that once the starter switch is closed, the alarm continues to sound even if the starter switch is subsequently opened.

The present invention satisfies these different demands with a simple circuit configuration, and also prevents damage caused when the alarms of other emergency alarm circuits sound simultaneously when the start switch of one of the plurality of emergency alarm circuits is closed. That is.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 and 2 are positive and negative power supply lines to which the rectified and smoothed output of the commercial power supply is applied during normal times, and to which battery power is applied during power outages, and a bell 3 as an alarm and a first transistor 4 whose collector load is the bell 3. A series circuit of a relay coil 5 and a second transistor 6 whose collector load is the relay coil 5, and an indicator lamp 7 are connected in parallel.

The first and second transistors 4 and 6 are composed of transistors of different types, and in the embodiment, the first transistor 4 is a PNP transistor.
The second transistor 6 is an NPN type transistor.

A starting switch 10 is connected between the bases of both transistors via a resistor 8 and a forward diode 9 for the base current.
is inserted, and a series circuit of a resistor 12 and a silicon controlled rectifier (hereinafter referred to as SCR) 13 is inserted between the positive power supply line 1 side terminal 11 and the negative power supply line 2 of the switch. .

A series circuit of a backflow blocking diode 14 and a check switch 15 is connected in parallel to the series circuit, and a pseudo resistance 17 of the relay coil 5 is interposed between the intermediate point 16 between the diode and the check switch and the positive power supply line 1. It is inserted.

Negative power supply line 2 side terminal 18 of starting switch 10 and 5CR
An operating switch 19 and a series circuit of a diode 20 in the forward direction with respect to the gate current are inserted between the gate of 5CR13 and a protective resistor 21 between the gate and cathode of 5CR13.

Furthermore, the relay coil 5 closes the non-voltage switch 22 by excitation in order to simultaneously activate an automatic fire alarm system, for example, when the starting switch 10 is closed.
The switch is connected to the transfer terminal 23.23'.

Further, both terminals 11.18 of the start switch 10 are connected to a signal terminal 24.24', and the signal terminals of a plurality of emergency alarm circuits are commonly connected to each other as a composite device.
Closing of each start switch causes each bell of the plurality of emergency alarm circuits to ring simultaneously.

In the above configuration, when the start switch 10 is closed while the actuation switch 19 is kept open, the base current of the first and second transistors 4.6 flows through the start switch, so that both transistors become conductive. do.

Therefore, the bell 3 rings and the relay coil 5 is energized to close the non-voltage switch 22, and the transfer terminal 23.2 is closed.
For example, if an automatic fire alarm system is connected to 3', the automatic fire alarm system is activated.

If the ringing of the bell 3 is to be stopped, the starting switch 10 may be opened.

Even if the signal terminals 24, 24' of a plurality of emergency alarm circuits are connected in common, the ringing of the bells of all the emergency alarm circuits can be stopped by opening one closed start switch 10. can do.

When the signal terminals 24, 24' of the plurality of emergency alarm circuits are commonly connected, when the inspection switch 15 of one emergency alarm circuit is closed, both ends of the start switch of the other emergency alarm circuit are closed. The slave voltage is closed by the inspection switch 15.
In the present invention, a reverse bias is applied between the base and emitter of the NPN type transistor 21 through the base current. Since the diode 9 is inserted, it is possible to use a transistor having a low reverse breakdown voltage between its base and emitter as the second transistor 6 due to the diode.

Next, when the activation switch 19 is closed in advance, when the start switch 10 is closed, the bell 3 rings as described above, and the relay coil 5 is energized to turn the non-voltage switch 2.
2 is closed.

At this time, the activation switch 19 is closed, so
5CR via the starting switch 10 and the activation switch 19
13 is applied, and 5CR13 becomes conductive.

Therefore, even if the starting switch 10 is temporarily closed and then immediately opened, the first transistor 4 remains conductive due to the conduction of the 5CR13, and the bell 3 continues to ring.

To cancel the ringing of the bell 3, open the start switch 10, then temporarily close the inspection switch 15, and
It is sufficient to extinguish the arc 3 and open the inspection switch 15.

When each activation switch of the other emergency alarm circuits to which the signal terminals 24 and 24' are commonly connected is closed, each bell is closed by similarly operating the activation switch and inspection switch for each emergency alarm circuit. The sound can be stopped.

In addition, when the activation switches of other emergency alarm circuits to which the signal terminals 24 and 24' are commonly connected are closed, 5CR13 of each emergency alarm circuit becomes conductive by temporarily closing one start switch. The base current of the first transistor 4 of one emergency alarm circuit is equal to the SCR of the other emergency alarm circuit.
The current flows from the anode to the gate and flows as the base current of the second transistor 6 of the one emergency alarm circuit, increasing the power loss of the one emergency alarm circuit.

In order to eliminate this drawback, a diode 2 for backflow prevention is installed between the gate of each 5CR13 and the terminal 18 of the starting switch 10.
0 is inserted.

Next, Fig. 2 shows another embodiment, and there are two differences from Fig. 1.
One diode 25 instead of two diodes 9 and 20
, the base current path of the second transistor 6 and 5CR13
It is located at the point inserted in the common path of the gate current path of.

This diode 25 has the function of the diode 9 for lowering the reverse withstand voltage of the base and emitter of the 21st to Ranjistalo described above, and also allows the base current of the first transistor of one emergency alarm circuit to flow from the anode of the 5CR13 of the other emergency alarm circuit. It has the function of a diode 20 to prevent side flow through the gates 1 to 1.

Also, in this one emergency alarm circuit, when 5CR13 is conductive, a part of the base current of the first transistor 4 is
13 through the gate from the second transistor 6
Therefore, the voltageless switch 22 can be kept closed by excitation of the relay coil 5.

As described above, according to the configuration of the present invention, the first transistor with the alarm device as the collector load, the first transistor with the relay coil as the collector load, and the second transistor of a different type are connected in parallel between the positive and negative power supply lines, and the Since the starting switch is inserted between the bases of both transistors, the configuration of the circuit for activating the alarm and relay coil is simplified, and the SCR and operating switch keep the first transistor conductive by temporarily closing the starting switch. As a result, the alarm can be set to sound only when the starting switch is closed, or to keep the alarm sounding even when the starting switch is temporarily closed, depending on the opening and closing of the activation switch. The emergency alarm circuit can be used differently depending on the location where it is used.

Furthermore, since a forward direction diode with respect to the base current is inserted between the base of one of the NPN type transistors of the two transistors and the start switch, when a plurality of emergency alarm circuits are used as a composite device, that is, each emergency alarm When connecting both terminals of a circuit starting switch to each other,
As the NPN transistor, one having a low reverse breakdown voltage between base and emitter can be used.

Further, when the diode is inserted in a common path of the base current path of the NPN transistor and the gate current path of the SCR, the base current of the second transistor can flow from the anode through the gate when the SCR is conductive. I can,
The relay coil can be kept energized while the alarm is sounding.

[Brief explanation of drawings]

1 and 2 are electrical circuit diagrams showing different embodiments of the emergency alarm circuit according to the present invention. 3... Alarm device, 4... First transistor, 5...
relayil, 6... second transistor, 1, 2...
・Positive and negative power supply lines, 10...Start switch, 13...
・5CR119...Activation switch, 9,25...Diode.

Claims (1)

[Scope of utility model registration request] A first transistor whose collector load is an alarm device, and a second transistor of a different type whose collector load is a relay coil are connected in parallel between positive and negative power supply lines, and a start switch is interposed between the bases of both transistors. a silicon-controlled rectifier for holding the first transistor conductive by the temporary closing of the starting switch; and an activation switch for the rectifier; An emergency alarm device with a diode inserted in the forward direction of the base current.