SU934524A1 - Fire alarm - Google Patents

Description

(54) FIRE ALARM CONSTITUTION

I

This invention relates to alarms and can be used in fire alarms.

Fire alarm devices are known in which the sensors are made on the basis of a reference diode, the breakdown voltage of which corresponds to the characteristic parameters of sensor 1.

The disadvantage of these devices is their relatively low operational reliability, since there is no constant monitoring of the device's performance and it is impossible to signal from several one-time activated sensors.

The closest technical solution to the present invention is a fire alarm device containing fire detectors connected to nmaat, to which a frequency signal generator is connected, fire detectors with a blocking element connected to a frequency discriminator 21.

A disadvantage of the known device is the low reliability of the device, so

as it is impossible to control the device’s performance and control on the breakdown and short circuit in the line.

The purpose of the invention is to increase the reliability of the device.

The goal is achieved by the fact that a fire alarm device containing fire detectors of the central station, a characteristic frequency generator and frequency discriminators that are connected to

10 with a buzzer, LC circuits, optical indicators, self-blocking relays, thresholds and amplifying and detecting elements, fire detectors made in the form of sensor contacts included in

15 one LC circuits, which are connected in series and included in one of the arms of a resistive bridge, in the other arm of which other LC circuits are connected in series, each of which is included

Claims (2)

20 optical indicator, in one of the diagonals of the bridge a generator of characteristic frequencies is included, and in the other diagonal a threshold element, the output of which is connected to the acoustic signaling device, each frequency discriminator is connected to the winding of the corresponding self-idling relay, the contacts of which are connected to the corresponding LC- contour of the other shoulder of the bridge. The drawing shows a schematic diagram of a fire alarm device. The device contains a group of fire detectors 1, each of which includes a circuit on elements L and C and contacts 2 triggered at a certain temperature, a group of other LC circuits 3 connected in series, to each of which an optical indicator 4 is connected, for example, a neon lamp, as well as resistors 5 and 6, which are the two other arms of the bridge. The device also contains a characteristic frequency generator, made in the form of a oscillating frequency generator 7, included in one of the diagonals, and a threshold element 8 in Another bridge diagonal connected by its output to the inputs of the buzzer 9 and the discriminator entered into the view of the group of LC filters 10. Each of the LC filters of the discriminator is conductive through an amplifying-detection element I connected to the winding of the corresponding self-blocking relay 12 which is its own the queue with its contacts is connected to the corresponding LC circuit of the second shoulder of the bridge. In this case, a signal lamp 13 is switched on in the self-blocking circuit of the relay. The device operates as follows. In the absence of signs, the AC bridge is balanced over the entire range of characteristic frequencies of the fire detectors 1 generated by the oscillating frequency generator 7. Therefore, the signal at the input of the threshold element 8 is missing. At the same time, the frequency is periodically scanning over a range. The oscillating frequency generator 7 resonates alternately in all LC circuits 3, alternately lighting optical indicators 4, since at the moment of resonance the resistance of the frequency-dependent arm is determined by the equivalent resistance of the resonating UC circuit 3, therefore, almost all the bridge arm voltage will be applied to this circuit sufficient for the ignition of the optical indicator 4. The periodically lit optical indicators 4 indicate that the central station is operational. In the event of a fire situation, the contacts 2 of the sensor shunt (or release) the LC circuit of any fire detector I, which leads to an unbalance of the bridge at the characteristic frequency of the activated detector. The unbalance signal of the bridge is fed to the input of the threshold element 8, and from its output to the input of the acoustic signaling device 9. At the same time, it enters through the frequency discriminator LCfllntr 10 and through the amplifying-detecting element I (where it is detected and amplified if necessary) ) to the winding of the corresponding self-blocking relay 12. Perfe 12 triggers, shunt (or break) circuit 3, while the warning light 13 lights up and continues to light up, the optical indicator 4 goes out, and the bridge ihodit a state of balance. During an open or short circuit in the line of firefighters; detector 1, the bridge balance is also violated at all characteristic frequencies, all signal lamps 13 light up and optical indicators 4 go out and the buzzer 9 turns on. short-term disconnection from the mains. Thus, the proposed device has a higher reliability. Claims of the Invention A fire alarm device comprising fire detectors of a central station, a generator of characteristic frequencies and frequency discriminators that are connected to an audible warning device, so that with the purpose of increasing the reliability of the device, B1 includes LC -contours, optical indicators, self-blocking-. relays, threshold and amplifier-detecting elements, fire Detectors are made in the form of sensor contacts included in some LC circuits, which are connected in series and connected to one of the arms of the resistive bridge, in the other arm of which are connected in series other LC circuits, each of which includes an optical indicator, a generator of characteristic frequencies is included in one of the diagonals of the bridge, and the other element has a threshold element, the output of which is connected to an audible alarm, each The discriminator is connected to the winding of the corresponding self-blocking relay through the amplifier-detecting element, the contacts of which are connected to the corresponding LC circuit of the other arm of the bridge. Sources of information taken into account in the examination 1. German patent N 2118304, cl. G 08 C 17/00, 1973. 2. The patent of Germany No. 2115758. to. G 08 C 17/06. 1973 (prototype).