JPH0353347Y2 - - Google Patents

Description

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

[Conventional technology]

In fire alarm equipment, a timer circuit is installed in the fire receiver to prevent false alarms from being triggered by electrical noise such as heating, cigarette smoke, or lightning strikes. The alarm will not be triggered by a temporary operation signal from the fire detector, but will be triggered after confirming the continuous operation of the fire detector for a predetermined period of time or more. In this case, what should be immediately notified is the Utility Model Publication Act filed in 1983, which was filed earlier by the applicant and published.
-There is a publication No. 22631.

[Problem that the invention attempts to solve]

These conventional fire alarms use a response line between the transmitter and receiver to identify the operation of the fire detector and transmitter in the receiver, so fire alarms of the type without a response line are Regarding equipment, it was necessary to install new dedicated lines. This invention enables the operation of fire detectors and transmitters to be distinguished without installing a new dedicated line even in fire alarm equipment that does not have a response line, and makes it possible to differentiate the alarm time when each is activated. It is.

[Means for solving problems]

As a means to solve the above problems, this invention connects a diode in series with the transmitter, and also provides a polarity reversal circuit that temporarily reverses the polarity of the district line when the fire detector or transmitter is activated. By identifying the presence or absence of continuity of the district line at the time of polarity reversal, it is possible to identify which type of alarm is being issued.

[Effect]

While fire detectors are generally non-polar,
Transmitters with diodes connected in series are polarized, so if the polarity of the district line to which they are connected is reversed, if the transmitter is activated, the district line will become non-conducting, but When the transmitter is activated, this non-conductive signal bypasses the receiver's timer circuit and immediately issues an alarm.

〔Example〕

FIG. 1 shows a circuit diagram of this invention, and FIGS. 2A and 2B show time charts for explaining FIG. 1, respectively.

In the figure, one end of the district relay RL constituting the fire detection circuit 1 is connected to the positive side of the power supply to the receiver R, and the other end is connected to the normally closed relay RX connected to the output side of the timer circuit MM, which will be described later. It is connected to one of the district lines _{L1 and L2} extending from the receiver R via the contact RX and the first switching contact _RA1 constituting the polarity reversal circuit 2, which will be described later, through the normally closed contact _A. . still,
The other contact RO of the switching contact ra ₁ of the polarity inversion circuit 2 is
Connected to the negative side of the power supply.

The other of the district lines l ₁ and l ₂ l ₂ is connected to a second switching contact ra ₂ constituting the polarity inversion circuit 2, and is connected to the negative side of the power supply via this normally open contact ra.

The polarity inversion circuit 2 includes an emitter collector circuit of a transistor _Q1 connected between the power supply, positive and negative, and
Series circuit with relay RA and above transistor _Q1
The circuit consists of a circuit whose base electrode is connected to the district line _l1 through a resistor r and a capacitor C, respectively, and the aforementioned switching contacts _ra1 and _ra2 of the relay RA.

The timer circuit 3 includes a relay RB, which has one end connected to the positive side of the power supply and the other end connected to the normally open contact d of the second switching contact RA ₂ , and the normally open contact RB of the relay RB. It consists of a monostable multivibrator MM to which an input signal is applied, and a relay RX connected to the output side of the multivibrator MM.

A fire detector 4 and a transmitter T consisting of a diode D connected in series to a push button switch 5 are connected in parallel between the district lines l ₁ and l ₂ extending from the receiver R having such a circuit configuration. It is connected.

Next, the operation of the circuit of such a fire alarm system will be explained based on the time chart shown in FIG.

First, when the fire detector 4 is activated, the district railway
l ₁ and l ₂ are short-circuited with low impedance, turning on transistor Q ₁ and turning on the relay as shown in Figure 2
RA operates and its contacts ra ₁ and ra ₂ are closed to their normally open side ro,
Switch to D. At this time, voltage is applied to the district relay RL for a moment, but it does not operate because the normally closed side A of contact RA ₁ is opened. By switching the switching contacts ra ₁ and ra ₂ of the relay RA, voltage is applied and activated via the fire detector 4 where the relay RB has activated, and when the contact rb is turned on, the monostable multivibrator MM is also turned on, Relay RX connected to its output side also operates.

Relay RA of polarity reversing circuit 2 is restored after a time _t1 determined by the time constant of its resistor R and capacitor C, and therefore relay RB is also restored almost at the same time.

Thereafter, after a predetermined time _t2 has elapsed, the monostable multivibrator MM is restored, the relay RX is restored, and its contact rx is turned ON. At this time,
If the fire detector 4 is still operating, the district relay RL is activated to sound an alarm (not shown). In addition, if the time _t2 of the timer circuit 3 is set in advance to several tens of seconds to several minutes, the fire detector 4
False alarms due to noise, etc. can be prevented.

Next, the operation when the transmitter T is manually operated will be described.

When the push button 5 of the transmitter T is turned on, the connection between the district lines l ₁ and l ₂ is normally established via the diode D connected in the forward direction with respect to the voltage polarity when monitoring the district lines l ₁ and l ₂ . It is short-circuited with low impedance, and each operation of the polarity inversion circuit 2 is driven in the same way as when the fire detector 4 is activated. Based on the operation of the polarity reversing circuit 2, switching contacts ra ₁ and ra ₂ become contacts ro and ra 2, respectively.
When the polarity of the district lines l ₁ and l ₂ is reversed, the diode D of the transmitter T becomes reverse polarity, and at this time, the relay RB connected to the district line l ₂ from the positive side of the power supply becomes It doesn't work. As a result, the timer circuit 3 is not driven, and the district relay RL is activated when the relay RA of the polarity reversal circuit 2 is restored as shown in FIG. Alarms that do not sound are set off. Incidentally, the fire detection circuit 1, the polarity reversal circuit 2, the timer circuit 3, etc. may be electronic circuits using semiconductors instead of relays.

[Effect of idea]

As mentioned above, the fire alarm system of this invention uses only a pair of district lines without adding any new lines.In response to the activation signal from the fire detector, it is activated after a predetermined time has elapsed via a timer circuit. The fire alarm will not be triggered if the fire detector is activated temporarily due to noise, etc., and the fire alarm will be triggered immediately in response to an activation signal from a transmitter that is operated by a person after confirming a fire. Therefore, there is very little confusion due to false alarms from fire detectors, and it also has the effect of being able to quickly issue alarms for highly accurate fire signals, such as the activation signal of a transmitter. .

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of this invented fire alarm system, and FIG. 2 X and Y show a time chart for explaining FIG. 1. 1...Fire detection circuit, 2...Polarity reversal circuit, 3
...Timer circuit, 4...Fire detector, T...Transmitter, D...Diode.

Claims (1)

[Scope of claim for utility model registration] Consisting of a fire receiver, a pair of district lines extending from the fire receiver to a warning area, and a fire detector and transmitter connected between the pair of district lines,
When the above fire detector is activated, an alarm is issued by reactivation after a preset predetermined time, and when the above transmitter is activated, an alarm is issued immediately. A diode is connected in series to the transmitter so that the polarity of the pair of district lines is determined when the fire detector or the transmitter is activated and short-circuits the pair of district lines with low impedance. a timer circuit that opens a normally closed contact for a predetermined period of time triggered by the operating current of the fire detector when the polarity of the pair of district lines is reversed by the polarity reversal circuit; A fire alarm system comprising a fire detection circuit for detecting the operating current of the pair of district lines through a normally closed contact of a timer circuit and issuing an alarm.