JPS64757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a system for detecting gas leaks and fires that can transmit trouble signals, monitoring signals, and alarm signals from a plurality of gas leak detectors installed in the same warning area to a central receiver using fewer electrical circuits. Concerning repeaters for alarm equipment.

Currently popular gas leak detectors each have at least a power supply circuit and a gas detection circuit, and output a 0V trouble signal when the power is cut off, and a 6V trouble signal when monitoring.
It was configured to transmit a 12V alarm signal to the receiver through a pair of signal lines in the event of a gas leak. However, when multiple detectors are installed in one room, in order to save wires, these detectors are connected to a pair of common signal lines via a loop prevention diode to transmit the above signals to the receiver. By doing this, even if a trouble signal is sent out from some of the detectors, the 6V monitoring signal sent out from other normal detectors will be given priority and transmitted to the receiver, so it will not be possible to detect a malfunction in the detector. It will not be displayed. Therefore, even if the room where the gas leak occurred was displayed as one warning area, each detector was connected to the receiver via a dedicated signal line, so the number of electrical lines was reduced. The drawback is that it takes more time and the equipment is expensive.

In view of the above points, the present invention provides a gas leak fire alarm that is provided between a plurality of gas leak detectors and a receiver in the same warning area, and that can save electrical lines between these warning areas and the receiver. It provides repeaters for equipment.

An embodiment of the present invention will be described below with reference to the drawings. FIG. ₁ is a block diagram showing the relationship between the repeater, gas leak detector _, and receiver of this invention.
are each equipped with a power supply circuit and a gas detection circuit, and output a 0V trouble signal when the power is cut off, a 6V monitoring signal during normal monitoring conditions, and a 12V alarm signal when a gas leak is detected. It is a detector. Two gas leak detectors are installed at store A and three gas leak detectors each at stores B and C, which form different warning zones, and these are connected to relays installed in each warning zone via a pair of signal lines l. It is connected to the receivers Xa, Xb, and Xc, and is further connected to the central receiver Re via a pair of common signal lines L.

Each of the repeaters Xa, Xb, and Xc connects a pair of signal lines l to multiple gas leak detectors G ₁ to _{G 3} in the same warning area, as shown in FIG. Connect the positive and negative input terminals p ₁ .n ₁ , p ₂ .n ₂ , p ₃ .
n ₃ , and the positive input terminals P ₁ to _{P 3} are connected to anti-circuit diodes D ₁₁ to _{D 31} and field effect transistors.
to the positive output terminal P through the constant current circuit r as a resistance element composed of FET, and to the negative input terminal
_n1 to _n3 are directly connected to the negative output terminal N. Also
R ₁₁ , R ₁₂ , R ₂₁ .R ₂₂ , R ₃₁ , R ₃₂ are series resistors connected between the input terminals p ₁ , p ₂ , p ₃ and the output terminal N, respectively, and their connection point is a diode _D11 ～ _D31
A resistor is connected between the cathode side of the terminal and the output terminal N.
Transistors connected through R ₁₃ , R ₂₃ , R ₃₃
Connected to the bases of Q ₁ , Q ₂ , Q ₃ , and further connected to their collectors with diodes D ₁₂ , D ₂₂ , D ₃₂ to detect and output trouble signals from gas leak detectors G ₁ to _{G 3} A trouble signal detection circuit is configured. Furthermore, R ₄ and R ₅ are resistors connected in series between the cathodes of the diodes D ₁₁ to _{D 31} and the output terminal N, and their connection point is connected to the diodes D ₁₂ to D 31 .
It is connected to the base of the transistor _Q4 connected between the cathode side of _D32 and the output terminal N, thereby forming an alarm signal detection circuit that detects and outputs the alarm signals of the gas leak detectors _G1 to _G3 . _Q5 is a transistor connected between a pair of signal lines L and L, that is, between terminals P and N, and its base is connected to the transistor.
It is connected between the collector of Q ₄ and the cathode side of diodes D ₁₂ to _{D 32} , and when the trouble signal detection circuit operates, it prohibits the transmission of the monitoring signal, and if the alarm signal detection circuit operates during that time, it gives priority to the alarm signal. A switch element is configured to transmit the signal. c and
_R6 is a capacitor and a resistor placed between the base and emitter of transistor _Q5 .

Next, the operation of the repeater of the above embodiment will be explained. Gas leak detector G ₁ installed in each warning area A to C
~G If all ₃ continue to monitor normally,
A 6V monitoring signal is input from the detectors G ₁ to _{G 3} to the associated repeaters Xa to Xc through the signal line l, respectively.
Transistors Q ₁ to Q ₃ (see FIG. 2 below) of each repeater Xa to Xc are turned ON, Q ₄ is turned OFF, and transistor Q ₅ as a switch element is turned OFF. Therefore, the 6V monitoring signal input to the repeater is transmitted to the receiver Re through the diodes _D11 to _D31 , the constant current circuit r, and the associated dedicated signal line L (see Figure 1 below). This monitoring signal is detected by the detection circuit, and it is displayed that the gas leak detectors G ₁ to _{G 3} in the respective caution areas A to C are continuing to monitor normally. For example, when gas leak detector G ₁ in warning area A detects a gas leak and sends a 12V alarm signal to repeater Xa, the transistor of repeater Xa
Q ₄ (see _Figure 2 below) is turned ON, but transistor Q ₅ continues to be OFF as in the monitoring state. The alarm signal from ₁ is
Diode _D11 , constant current circuit r, and dedicated signal line L
(See Figure 1 below) is transmitted to the receiver Re, and the detection circuit detects the occurrence of a gas leak in warning area A.

In addition, if the gas leak detector continues to monitor normally, for example, the gas leak detector in warning area B
G ₁ 's power is cut off and a 0V trouble signal is sent to the repeater.
When input to Xb, transistor Q ₁ (hereinafter the second
(see figure) is turned off, transistor _Q5 is turned on, and the pair of signal lines L are short-circuited, so the monitoring signals from the other normal detectors _G2 and _G3 are prohibited from being transmitted to the receiver, and the relay From device Xb (see Figure 1 below)
A trouble signal of 0V is transmitted to the receiver Re, and detected by the detection circuit, indicating that one of the detectors G ₁ to _{G 3} in the warning area B has failed. Also, in this situation, when another gas leak detector _G2 in this warning area B detects a gas leak and sends out a 12V alarm signal, the repeater Xb, which has been transmitting the trouble signal to the receiver Re, Transistor Q ₄ (see Figure 2 below) turns on and transistor Q _{5 turns} on again.
is turned OFF, so the alarm signal from the above detector G ₂ having the maximum voltage value is transmitted to the other detectors G ₁ and G ₃ .
It is transmitted to the receiver Re through the diode D ₂₁ , the constant current circuit r, and the signal line L (see Figure 1 below) with priority over the trouble signal and supervisory signal sent from the receiver, and is detected by the detection circuit and replaced with a failure indication. Then, it is displayed that a gas leak has occurred in warning area B.

FIG. 3 is a circuit diagram showing another embodiment of the repeater of the present invention, in which a bipolar transistor Q ₅ ' with a resistor R ₇ between the collector and base is provided instead of the FET shown in FIG. 2, and the base is connected to the transistor. Since it is the same as the repeater of the embodiment shown in FIG. 2 except that it is connected to the collector of _Q5 , the same reference numerals are given and the explanation will be omitted.

In _{this repeater} and an alarm signal is transmitted to the receiver. Furthermore _, when _{a trouble} signal is input _to repeater Transmission is prohibited and a 0V trouble signal is sent from repeater X to the receiver. In addition, when an alarm signal is input from another detector in such a state, the transistor Q ₅ is turned OFF again and the transistor Q ₅ ' is turned ON, as in the case of Fig. 2, and the signal from the other detector is turned off. The alarm signal is transmitted to the receiver with priority over the trouble signal and the supervisory signal.

In addition, in the embodiment shown in Fig. 2 above, while the trouble signal is being transmitted from the repeater X to the receiver Re, the alarm signals from the associated gas leak detectors G ₁ to _{G 3} are reliably detected by the repeater X. can diode
A constant current circuit r as a resistance element was provided between the cathode side of D ₁₁ to _{D 31} and the output terminal P, but the receiver Re
It is also possible to replace the resistor with a resistor having a value sufficiently smaller than the impedance of the detection circuit of the gas leak detectors G ₁ to _{G 3} and larger than the impedance of the power supply circuit of the gas leak detectors G 1 to G 3 .

As explained above, in the present invention, a plurality of gas leak detectors are provided between a plurality of gas leak detectors and a receiver, and trouble signals, monitoring signals, and alarm signals from the gas leak detectors are transmitted to the receiver via a pair of signal lines. This has the effect of providing a repeater that can perform

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the connection relationship between the repeater, gas leak detector, and receiver of the present invention;
3 and 3 are circuit diagrams of different embodiments of the repeater of the present invention. A~C...Restricted area, Re...Receiver, _G1 ~ _G3 ...Gas leak detector, X, Xa~Xc...Relayer, _D11 ,
_D12 , _D21 , _D22 , _D31 , _D32 ...Diode, Q1 _~
Q ₅ , Q ₅ ′...Transistor, R ₁₁ , R ₁₂ , R ₂₁ , R ₂₂ ,
R ₃₁ , R ₃₂ , R ₄ , R ₅ ...resistor, r...constant current circuit as a resistance element, l...a pair of signal lines from a gas leak detector, L...a pair of signal lines from a repeater.

Claims (1)

[Scope of Claims] 1. The device is equipped with a power supply circuit and a gas detection circuit, and is capable of generating a trouble signal, a monitoring signal, and an alarm signal having different voltage values, respectively, to indicate the interruption of its own power supply, a normal monitoring state, and a state in which a gas leak is detected. When multiple output gas leak detectors are installed in the same warning area, a repeater is installed between the gas leak detectors in the same warning area and the central receiver, and each relay has one end. A bypass prevention diode connected to the output of the detector in the same warning area, the other end of which is connected to one of the pair of signal lines of the repeater, and for transmitting the signal of the detector to the receiver, and these diodes and A trouble signal detection circuit and an alarm signal detection circuit are provided to detect the trouble signal and alarm signal of the connected detector, and the monitoring signal is transmitted to the signal line side of the repeater by the operation of the trouble signal detection circuit. 1. A repeater for gas leakage fire alarm equipment, characterized in that a switch element is provided, which transmits a trouble signal when the warning signal is prohibited, and when an alarm signal detection circuit operates during that time, transmits the alarm signal with priority. 2. The repeater for gas leakage and fire alarm equipment according to claim 1, wherein the switch element is a switch circuit that is inserted in series into one of a pair of signal lines of the repeater and is always ON. 3. The gas leak fire alarm equipment according to claim 1, wherein the switch element is a switch circuit connected between a pair of signal lines of a repeater and one end of which is connected to a diode via a resistive element. Repeater. 4. A repeater for gas leak fire alarm equipment according to claim 3, wherein the resistive element is a resistor with a low resistance value. 5. A repeater for gas leak fire alarm equipment according to claim 3, wherein the resistive element is a constant current circuit.