JPS5922631Y2 - fire alarm equipment - Google Patents

Description

[Detailed explanation of the idea] This invention relates to fire alarm equipment.

Fire alarm equipment generally consists of a fire detector that detects heat, smoke, and other fire phenomena that occur during a fire and converts it into an electrical signal, and a human that detects a fire and generates an electrical signal by operating a push button switch. It consists of a transmitter and a receiver that receives these electrical signals and displays the location of the fire or issues a fire alarm.

The above transmitter is locked in the closed state by pressing the push button switch and generates a fire signal, and when the receiver receives this signal, it sends a response signal back to the transmitter via the response line. , is configured to be displayed on a response display provided on the transmitter.

Since fire detectors detect extremely delicate conditions such as heat and smoke in the early stages of a fire, false alarms are likely to occur due to non-fire heat, smoke, or electrical noise such as heating, cigarette smoke, and lightning strikes. .

Therefore, immediately ringing an alarm such as a bell as a fire alarm based on the fire detection signal from these fire detectors may unnecessarily confuse people.

On the other hand, although the signal from the transmitter is a button that a person directly presses when determining that there is a fire, it is highly reliable, and therefore it is desirable to promptly activate an alarm device such as a bell.

In view of the above points, this invention cleverly uses a response line provided between the transmitter and the receiver and a timer circuit to solve these problems.

Next, the fire alarm system of this invention will be explained in detail based on drawings showing one embodiment thereof.

As shown in Figure 1, district lines C and 1 extend from receiver R to each warning area, and between these district lines C and 1, low impedance is provided during fire response. The short-circuited fire detector S is connected to the terminal end of the district line, and by operating the push button switch P, the contact point P1. P
2 is locked in the closed state, short-circuiting between the district lines C and 1, and the response line m and the transmitter configured to close the circuit between the district lines C and 1 are respectively connected. has been done.

In addition, the receiver R is equipped with a DC power supply E and district lines C, l.
district relays L1 to RLo and resistors R1, R2) that are connected to and respond to the operation of the fire detector S or transmitter.
Disconnected from transistor Q, and the above district relays RL1 to RLn
a fire detection circuit in which the transistor Q2 is made conductive by being positively biased through the resistor R4 by one of the operations; a fire detection relay RA driven by the output signal of the fire detection circuit; a power supply positive terminal and a transmitter; A series circuit is connected between the response line m extending from the fire detection relay RA, the normally open contact ra1 of the transmitter response relay RC1, the interference prevention diode D2, and the normally open contact rC1 of the transmitter response relay RC. a parallel circuit, a timer circuit M whose input is the normally open contact ra2 of the fire detection relay RA, and one end of which is connected to the normally open contact ra2 of the fire detection relay RA.
2, an alarm relay RF whose other end is connected to the output terminal 2 of the timer circuit M, and a diode n connected to the output terminal 2 of the timer circuit M and one end of the transmitter response relay RC.
They each have the following.

In the above configuration, first, a case where the fire detector S operates will be described.

When the fire detector S becomes low impedance during a fire response, the positive terminal of the DC power supply E connects the district line RL1 and the district line 1.
, fire detector S, district line C1, and the negative terminal circuit of DC power supply E, district relay RL1 operates, and normally open contacts r11□ and rl□2 close.

When normally open contact r1□2 closes, current flows through the emitter-base of transistor Q2 between DC power supply E, resistors R2 and R4, normally open contact r1.2, district line l, fire detector S, and district line C circuit. The current flows and brings conduction between the emitter and collector of transistor Q2.

Therefore, a current flows through the emitter-collector circuit of the transistor Q2, the resistor R3, and the base-emitter circuit of the transistor Q1 between the DC power source E, making the transistor Q1 conductive and causing the fire detection relay RA connected in series to the DC power source E to flow. make it work.

Normally open contact ra1. of this fire detection relay RA. ra2 is closed, the positive side of the DC power source E is connected to the alarm relay RE, and a delay operation start signal is applied to the input terminal 1 of the timer circuit M.

In this embodiment, the timer circuit M is composed of a known monostable multivibrator circuit, and its operation is based on the second
As shown in the figure, when a signal is applied to output terminal 1,
A rectangular wave voltage approximately equal to the voltage of the power source E is output to the output terminal 2 for a preset time (for example, 15 to 30 seconds).

Therefore, immediately after the fire detector S operates, there is no voltage between both terminals of the alarm relay RF, and the alarm relay RF does not operate.

However, if the fire detector S continues to operate for more than the set time, the voltage at the output terminal 2 of the timer circuit M drops to the negative side of the DC power supply E, and the alarm relay RF is activated.

Therefore, when the normally open contact rf of the alarm relay RF closes, the district relay RL1 is self-maintained via the normally open contact r1□1 and the diode D1, and an alarm device such as a bell (not shown) is driven to issue a fire alarm. .

Next, the operation when operating the transmitter will be explained.

When push button switch P is operated, contact P1. P2 is closed, first shorting the lines C and 1 by closing contact P1.

Since this operation is the same as that of the fire detector S, a description of this operation will be omitted.

Next, when contact P2 linked to contact P1 is closed, normally open contact ra1 of fire relay RA is closed, so the positive side of DC power supply E, normally open contact ra1, and transmitter response relay RC
, the diode D2, the response line m, the response display lamp L, the contact P2 of the pushbutton switch, and the line C. Current flows through the circuit, and the transmitter response relay RC operates.

Therefore, the normally open contact rC1 of the transmitter response relay RC closes, the response display lamp L lights up, the normally open contact rC2 performs self-holding, and the diode D
Alarm relay RF operates via 3.

Therefore, the operation of the transmitter bypasses the timer circuit M and is applied to the alarm relay RF, which immediately drives an alarm (not shown) to issue a fire alarm.

As described above, according to this invention, the signal from the fire detector S is activated by the timer circuit M after a predetermined period of time has elapsed, so that the signal from the fire detector S is temporarily activated by noise or the like.
It is also possible to issue a preliminary alarm during this delayed operation and confirm by performing recovery operations, etc. On the other hand, the signal from the transmitter will immediately trigger an alarm as a fire alarm. etc. alarms will sound.

Therefore, confusion caused by false alarms can be extremely reduced.
Furthermore, since the response line m of the transmitter is used, a useful fire alarm system is provided that does not require the installation of a new line.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the fire alarm system of this invention, and FIG. 2 is a diagram showing output waveforms for explaining the operation of the timer circuit. R... Receiver, C, l... District line, S... Fire detector, D... Transmitter, E... DC power supply, RL1~
RLn...District relay, RA...Fire detection relay,
RC...transmitter response relay, RF...alarm relay,
M...Timer circuit, R1, R2, R3, R4...
Resistance, Dl, D2. D3...diode, C...condenser, Ql, Q2...transistor, m...
response line.

Claims (1)

[Scope of utility model registration request] It has a fire detector that short-circuits terminals with low impedance when responding, and first and second switches and a response indicator that are linked together, and when responding, the first switch short-circuits the district line with low impedance and , a response line extending from the receiver and a transmitter whose response indicator is lit by the second switch are connected to a district line extending from the receiver, and the operation of the fire detector and transmitter is detected. In a fire alarm system equipped with a fire detection circuit and an alarm driven by the circuit, a timer circuit is provided between the fire detection circuit and the alarm, and when the transmitter responds, the 2. A fire alarm system characterized in that said switch is configured to drive said alarm without going through said timer circuit.