JPH0142226Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a repeater for fire alarm equipment, and particularly to a repeater that can significantly reduce false alarms by being added to existing fire alarm equipment.

Conventionally, in fire alarm equipment, a plurality of fire detectors are connected to a district line extending from a fire receiver, and a fire alarm is issued by detecting smoke, heat, etc. associated with a fire. However, smoke detectors that detect fire by detecting smoke sometimes generate false alarms due to cigarette smoke or noise. For this reason, fire receivers have recently been developed that issue an alarm when an operating signal from a fire detector is detected a plurality of times in advance.

This invention can be easily added to existing fire alarm equipment that is already installed in buildings, and can significantly reduce false alarms. Regarding repeaters for fire alarm equipment.

FIG. 1 is a circuit diagram showing an embodiment of the repeater for fire alarm equipment of this invention, and FIG. 2 is a time chart for explaining the operation of each part of FIG. 1.

In Figure 1, R indicates a fire receiver, K indicates a repeater, and D indicates a fire detector.The receiver R is connected to the district line from the first power source _E1 via the fire signal detection relay device A. l ₁ and l ₂ extend, and this district line
A repeater K is connected between l ₁ and l ₂ and a fire detector D.

The repeater K is connected to a second power source E ₂ , and a monitoring voltage is applied from the second power source E ₂ to the fire detector D during normal fire monitoring via the sensor operation detection circuit ₂ from the power source E 2 . a switch 1 consisting of a switching contact b of a relay B, a delay circuit 3 that delays the sensor operation signal output from the sensor operation detection circuit 2, and a pulse of a predetermined width triggered by the output signal of the delay circuit 3. A timer circuit 4 such as a monostable multivibrator that outputs , and a switching circuit 5 driven by the output of the timer circuit 4 to control switching of the switching device 1 and consisting of a relay B and a driver circuit for this relay B. ing.

Under normal fire monitoring conditions, the timer circuit 4
The output of this timer circuit 4 is at low level.
The transistor connected to the switching circuit 5 is in an off state, the transistor for driving relay B is in an on state, and relay B of the switching circuit 5 is in an energized state.
At this time, switching contact b of relay B of switching device 1 connects the power supply to the fire detector to the second power source E ₂ of relay K.
Closed on the side to which more voltage is applied.

When fire detector D is activated due to a fire outbreak,
It becomes conductive and maintains this state until the power is cut off. When the district lines l ₁ and l ₂ are short-circuited, the transistor Tr of the sensor operation detection circuit 2 becomes
It turns on, and an operation signal is applied to the delay circuit 3. When this operation signal is applied to the delay circuit 3, a trigger signal is applied to the timer circuit 4 after a predetermined delay time (about several hundred milliseconds). When the trigger signal is applied from the delay circuit 3, the timer circuit 4 outputs a high-level pulse signal for a certain period of time from the time of being triggered. This certain period of time is set to be longer than the time required for the fire detector D to recover and to enter the re-monitoring state. When a pulse signal is applied from the timer circuit 4, the switching circuit 5 switches this relay B.
remains inactive while the pulse is applied. The switching contact b of the relay B, which is the switching device 1, is switched to the side that supplies power from the first power source _E1 of the receiver R to the fire detector D. The fire detector D is restored because the power supply is cut off when the switching contact b is switched, and when the switching operation is completed, power is supplied from the first power source _E1 of the receiver R.

If the fire detector D operates due to a real fire, it will operate again, the fire signal detection relay device A of the receiver R will be driven, and its contact a will self-hold, and an alarm (not shown) will sound. Report.

The time chart of each part at this time is shown in Fig. 2. In Fig. 2, A represents the voltage between the lines l ₁ and l ₂ of the repeater K, and at t ₁ the fire detector D operates,
After a predetermined time _t2 , when the output of the delay circuit 3 is applied to the timer circuit 4, the relay B of the switching circuit 5 is deenergized, and the switching contact b of the switching device 1 is connected to the first power source _E1 of the receiver R. It is closed on the side that supplies power to the fire detector D, and at this time, the power supply to the fire detector D is temporarily cut off, so that the activated fire detector D is restored. A case is shown in which the fire detector D restarts _t3 after power is supplied again. B shows the output state of the delay circuit 3. C shows the output state of the timer circuit 4, in which pulse signals from _t2 to _t4 are output. Relay (relay device for fire signal detection) A shows a case where fire detector D, which was supplied with power from power source _E1 of receiver R, restarts at _t3 .

If the operation of the fire detector D is due to cigarette smoke, noise, etc., the fire signal detection relay device A of the fire receiver R will not operate, and then the second
As shown in FIG. 3C, since the output of the timer circuit 4 is restored at _t4 , the switching circuit 5 and the switching device 1 return to the normal monitoring state.

Further, when the second power source E ₂ is cut off, the relay B of the switching circuit 5 is restored, and power is supplied to the fire detector D from the receiver R by the switching contact b of the switching device 1. Therefore, the power supply _E2 of repeater K is
A poor-quality one without spare batteries is fine. Note that the relay B of the switching circuit 5 can be replaced with an electronic circuit.

The repeater of this invention can be easily added to existing fire alarm equipment as described above, and has the effect of significantly reducing false alarms.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of this invention, and FIG. 2 is a time chart for explaining the operation of FIG. 1. R... Fire receiver, K... Repeater, D... Fire detector, E ₁ ... First power source, E ₂ ... Second power source,
A...Fire detection relay device, _l1 , _l2 ...district line,
1...Switcher, 2...Sensor operation detection circuit, 3...
...Delay circuit, 4...Timer circuit, 5...Switching circuit.

Claims (1)

[Scope of utility model registration request] In a fire alarm system in which a fire detector is connected to a district line extending from a first power source in the fire receiver via a relay device for fire signal detection, the district line between the fire receiver and the fire detector. is equipped with a repeater having a second power supply separate from the receiver, and the repeater normally includes a switch for supplying power to the fire detector from the second power supply, and a switch for supplying power to the fire detector from the second power supply. a sensor operation detection circuit that detects the operating current of the sensor operation detection circuit; a timer circuit that is triggered based on the output signal of the sensor operation detection circuit and outputs a pulse signal of a predetermined time width; and a timer circuit that is driven based on the pulse signal of the timer circuit. and the power supply for the fire detector is switched to the second
A switching circuit for controlling the switching circuit which is disconnected from the power supply of the receiver to restore the fire detector and connected to the first power supply of the receiver.