JPS6355120B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fire alarm equipment that allows a receiver to individually know the operation and output changes of a large number of fire detectors connected in parallel on the same line in the same warning area.

In conventional fire alarm systems, multiple fire detectors are connected in parallel to a pair of wires in each fire warning area, and when physical phenomena such as heat or smoke from a fire reach a predetermined value, the wires are short-circuited and the receiver is alerted to the fire. I was trying to send a signal. Therefore, the receiver only displays the general area where the fire occurred, but cannot display activated fire detectors and changes in the output of those detectors, that is, the status of the fire, and cannot display smoke prevention equipment or fire extinguishing equipment. etc. could not be properly controlled.

In view of the above points, when a fire detector operates, this invention sends a fire signal to the receiver in the same way as conventional fire detectors, and also sends an address signal indicating the activated fire detector and changes in the output of that detector to the receiver. The present invention provides a fire alarm system that displays on a receiver the area where a fire has occurred, the activated fire detector, and changes in its output.

Hereinafter, a fire alarm system according to an embodiment of the present invention will be described.
This will be explained with reference to FIGS.

In Figure 1, D ₁₁ - D ₁ n - Dn ₁ - Dnn are fire detectors connected in parallel between a pair of lines l ₁ , l - ln, l for each warning area, and Re is the receiver thereof. .
The fire detectors connected in parallel in each warning zone have the same structure except for the decoder provided to generate an address signal unique to the detector, so detector _D11 is used as a representative and the This will be explained with reference to Figure 3. In the figure, 1 is a fire detection circuit, which includes a fire detection section 2 equipped with series-connected inner and outer ion chambers CH ₁ and CH ₂ and an FET that detects potential changes at their midpoints, and a predetermined output of the detection section 2. It is composed of a comparator 3 such as an operational amplifier A that detects. 4 is an inhibit circuit whose input is connected to the output of comparator 3, and whose inhibit input is connected to a pair of lines l ₁ ,
It is connected to a line voltage detection circuit 5 that detects and outputs a voltage drop of a predetermined value between 1 and 1. This detection circuit 5 includes a transistor T ₁ , a Zener diode Z ₁ , a resistor R ₁ ,
The Zener diode _Z1 is conductive in the monitoring state, and _the transistor _T1 is turned on and the line is turned on.
When another sensor connected in parallel between l ₁ and l operates and the line voltage drops, the sensor is selected to become non-conductive and turn off the transistor T ₁ . Reference numeral 6 denotes a latch circuit, which is composed of an RS flip-flop circuit, and its set terminal is connected to the inhibit circuit 4, and its output is connected to the switching circuit 7 and the delay circuit 8. The switching circuit 7 has a pair of lines l ₁ , l
This is a switching circuit for transmitting a fire signal connected between the zener diode Z ₂ and the transistor T ₂ , which has a smaller zener voltage than _the zener diode Z ₁ . Connected to output. The delay circuit 8 is a delay circuit that delays the output of the latch circuit 6 by a certain period of time and outputs it. It is composed of a resistor _R3 and a capacitor _C1 , and its output is made unstable through a Schmitt trigger inhibit circuit 9 and an OR circuit 10. It is connected to the multivibrator 11. 12 is a counter that counts the pulse output of the multivibrator 11, and 13 is a decoder that outputs a predetermined count value of the counter 12. In the case of this sensor D ₁₁ , it is "1".
is configured so that it is counted and output. In this case, the decoders of the other sensors (see Figure 1) connected in parallel between the same lines l ₁ and l are those that output a count value of "2" for sensor D ₁₂ , and the decoder for sensor D ₁ n that outputs a count value of "2". Each is provided with a device that outputs the count value “n”. Reference numeral 14 denotes a latch circuit, which is composed of an RS flip-flop circuit, and its set terminal is connected to the output of the decoder 13, and its output is connected to the clear terminal of the counter 12 through the inhibit input of the inhibit circuit 9 and the OR circuit 15. Ru. 16 is a switching circuit which is connected between the lines l ₁ and l in the same way as the switching circuit 7, and is used to send out the address and fire detection amount signals of this sensor D ₁₁ , and is a zener diode with a smaller zener voltage than the zener diode Z ₂ .
Z ₃ and a transistor T ₃ , and the base of the transistor T ₃ as its input is connected to the output of the astable multivibrator 11 . Reference numeral 17 denotes a delay circuit connected to the output of the latch circuit 14, which includes a resistor _R4 , a capacitor _C2 , and a Schmitt trigger circuit B, and is constructed so that its delay time is sufficiently longer than the address signal sending time.
Reference numeral 18 designates an astable multivibrator operated by the output of the delay circuit 17, which has a pulse width and period longer than the transmission time of the fire detection amount signal sent to the receiver Re via the multivibrator 11. , its output is connected to an astable multivibrator 11 through a flip-flop circuit 19 and an OR circuit 10. Further, 20 is an analog-to-digital converter whose analog input is connected to the source of the FET of the fire detection section 2, its digital output is connected to one input of the digital matching circuit 21, and its strobe input is connected to the output of the astable multivibrator 18. Connected. The digital matching circuit 21 includes an absolute value comparator (Magnitude
The other comparison input is connected to the output of the counter 12, and the coincidence output is connected to the clear terminal of the counter 12 through the OR circuit 15 and reset the flip-flop circuit 19 through the OR circuit 22. Connected to the terminal. A reset circuit 23 is provided on the output side of the constant voltage circuit 24 and is composed of resistors _R5 to _R7 , _a capacitor _C3 , and a transistor _T4 . reset terminal and OR circuit 15, 22
through the clear terminal of counter 12 and the flip terminal.
They are respectively connected to reset terminals of the flop circuit 19.

25 is a fire signal receiving circuit provided in the receiver Re, which includes resistors _R8 to _R11 and a Zener diode _Z4 , a transistor _T5 that detects the fire signal from the fire detector and conducts, a transistor _T6 , and a relay. It is composed of a self-holding circuit having N and its contact _n1 .
Reference numeral 26 designates an address and fire detection amount signal receiving circuit, which includes resistors R ₈ , R ₁₂ to R ₁₄ and a Zener diode Z ₄ and is composed of a transistor T ₇ that conducts in response to a pulse such as an address signal from a fire detector. be done. Reference numeral 27 denotes a warning display circuit for indicating the fire area, which is composed of a lamp L, etc., which is lit at contact _n2 of the relay N. 28 is an AND circuit, which is composed of a series circuit of a transistor T8 whose base is connected to the collector of a transistor _T7 and a contact _n3 of a relay N, and _a resistor _R15 . A counter 29 counts the number of pulses as an address signal and a fire detection amount signal sent through the AND circuit 28, and is constituted of, for example, a 4-bit binary counter like the counter 12 of the sensor. 30 is resistance R ₁₆ , R ₁₇
This is a pulse generation circuit consisting of a capacitor _C4 and a contact _n4 of a relay N, and a flip-flop circuit 3.
1 is connected to the output of the counter 29 and each input of the AND circuit 32, and only the number of pulses as an address signal is transmitted to the register 3 at the subsequent stage.
3. A decoder 34 converts the binary numbers stored in the register 33 into different signals, for example, a decoder that converts binary numbers into decimal numbers. 35
1 is an address display circuit that displays the sensor activated by the output of the decoder 34, and is composed of, for example, a numeric display tube. Further, 36 is a timer circuit that generates a single pulse after a predetermined time after receiving a fire signal, address signal, or fire detection amount signal from a fire detector, and the input is a monostable multivibrator M ₁ connected to the collector of a transistor T ₅ . It consists of an OR circuit OR ₁ whose respective inputs are connected to the emitter of a transistor T ₈ and the output of a vibrator M ₁ , a timer T, and a monostable multivibrator M ₂ , whose output is connected to a counter 2 through an OR circuit 37 .
9, a reset terminal of the flip-flop circuit 31, and a set terminal of the flip-flop circuit 38. The output of the flip-flop circuit 38 is connected to the output of the counter 29 and each input of the AND circuit 39, and the number of pulses as the fire detection amount signal is input to the register 4 at the subsequent stage.
It is configured to be temporarily stored in 0. Also 41
is a decoder that converts the binary numbers stored in the register 40 into different values, for example, a decoder that converts a binary number into a decimal number. 42 is a fire detection amount display circuit that displays the amount of fire detected based on the output of the decoder 41, and is constituted by, for example, a numerical display tube. Also, 43 is a push button switch for recovery, 44 is a reset circuit, and resistor R ₁₈ ~
_R20 , a capacitor _C5 , and a transistor _T9 , and the collector of the transistor _T9 as its output is a flip-flop circuit 38 and a resistor 33.
It is also connected to the reset terminal of the counter 29 and the reset terminal of the register 40 through OR circuits 37 and 45, respectively.
The other input of 5 is connected to the output of timer circuit 36.

Next, its operation will be explained. In FIG. 1, fire detectors D ₁₁ to D ₁ n are connected in parallel between lines l ₁ and l.
For example, the ion chamber of the fire detection section 2 of D ₁₁
When smoke from a fire enters CH ₂ , the source potential of the FET rises, and the comparator 3 operates at a predetermined value, which is output to the inhibit circuit 4 . in this case,
Another sensor D ₁₂ connected in parallel between the lines l ₁ and l
Since D ₁ n is not operating and the line voltage detection circuit 5 is in an inoperable state, and the inhibit input of the inhibit circuit 4 is at a low level, the output from the fire detection circuit 1 is passed through the inhibit circuit 4 to the latch circuit 6. Set up the flip-flop circuit of
The output is transmitted to a switching circuit 7 and a delay circuit 8.

This output causes the switching circuit 7 to turn on the transistor _T2 and connect the line as shown in Figure 4a.
The voltage V _Q between l ₁ and l is determined by the Zener diode Z ₂
V _F and sends a fire signal to the receiver Re.
This causes a voltage drop across the resistor _R8 of the fire signal receiving circuit 25 of the receiver Re, turning the transistor _T5 ON.
Next, the monostable multivibrator _M1 of the timer circuit 36 is operated and the timer T is activated through the OR circuit _OR1 .
At the same time, the relay N is operated and its operation is self-maintained by its contact _n1 , the contact _n2 of the alarm display circuit 27 is closed, the lamp L is lit, and the sensors _D11 , _D12 to _D1n are activated. It is displayed that a fire has occurred in the caution area where lines l ₁ and l are connected in parallel.

Further, while the fire signal is being received by the receiver Re, the output of the latch circuit 6 delayed by the delay circuit 8 is transmitted to the inhibit circuit 9 and the OR circuit 10.
The astable multivibrator 11 is operated to generate a pulse output. These pulses are counted by the counter 12, and when the number of pulses "1" is counted, the decoder 13 is activated, the flip-flop circuit as the latch circuit 14 is set, the inhibit input of the inhibit circuit 9 is set to high level, and the OR circuit 10 is set. Astable multivibrator through 11
The counter 12 is stopped through the OR circuit 15.
is cleared and output to the delay circuit 17.
In addition, the single pulse output from the multivibrator 11 causes the transistor _T3 of the switching circuit 16 to operate for a short time, increasing the voltage between the lines _l1 and l to the fourth
This sensor D ₁₁ is lowered to V _A as shown in figure a.
One pulse as the address signal of the receiver Re
Send to. In the receiver Re, the transistor of the address and fire detection amount signal receiving circuit 26
T ₇ responds to this pulse, and the transistor T ₈ of the AND circuit 28 is turned on through the already closed contact n ₃ , and the counter 29 counts the number of pulses “1”. Also, in the pulse generation circuit 30, the contact _n4 of the relay N switches and flips.
Since the flop circuit 31 is set, the count value of the counter 29 is temporarily stored in the register 33 through the AND circuit 32, and furthermore, "1" is displayed on the numeric display tube of the address display circuit 35 through the decoder 34. , that is, it is displayed that fire detector D ₁₁ has been activated. Then, the monostable multivibrator _M2 is operated by the output of the timer T which operates after a predetermined time, and the flip-flop circuit 31 is reset by the pulse, the counter 29 is cleared through the OR circuit 37, and the flip-flop circuit 38 is set. Also like this the address signal is sent to the receiver
While being received at Re, the output of the latch circuit 14 delayed by the delay circuit 17 of the fire detector D ₁₁ operates the astable multivibrator 18 to periodically generate pulses with a long pulse width. Each pulse causes an astable multivibrator 11 to be activated through a flip-flop circuit 19 and an OR circuit 10, and an analog-to-digital converter 20.
is operated intermittently, and a digital coincidence circuit 21 compares the number of pulses generated by the multivibrator 11, that is, the count value of the counter 12, and the amount of fire detected by the fire detector 2, that is, the output of the analog-to-digital converter 20. , is output when the analog value of the fire detection section 2 and the count value of the counter 12 match. This output resets the flip-flop circuit 19 through the OR circuit 22, stops the astable multivibrator 11 through the OR circuit 10, and clears it through the counter 2 through the OR circuit 15, so that the monostable multivibrator 11 detects a fire. A pulse is generated according to the amount of fire detected in the area. The flip-flop circuit 19 is set for each successive pulse generated by the astable multivibrator 18, and operates the astable multivibrator 11 and the analog-to-digital converter 20 to detect the fire at that point under the control of the digital matching circuit 21. The monostable multivibrator 11 continues to generate pulses according to the detected amount. This pulse output causes the transistor T ₃ of the switching circuit 16 to operate for a short time, and the lines l ₁ ,
By dropping the voltage between V _A twice and then three times as shown in FIG. sent to the receiver. In the receiver Re, the transistor _T7 of the address and fire detection amount signal receiving circuit 26 responds to this pulse,
Transistor _T8 of AND circuit 28 intermittently
The timer circuit 36 is activated and the counter 29 counts the number of pulses "2", and the counted value is temporarily stored in the register 40 through the AND circuit 39, and then displayed as a number in the detected amount display circuit 42 through the decoder 41. "2" is displayed on the tube, indicating that the output of the fire detection section 2 of the fire detector D ₁₁ is 2V. Then, monostable multivibrator _M2 is activated by the output of timer T, which operates after a predetermined time, and OR circuit 3
7, the counter 29 is cleared, and the OR circuit 45 resets the register 40.
Then, the subsequent fire detection amount signal is received by the receiving circuit 26, and "3" is displayed on the detection amount display circuit 42, indicating that the output of the fire detector _D11 has increased to 3V. This action is repeated and the sensor
D ₁₁ 's momentary fire detection amount is displayed on the receiver Re. Note that the other sensors D ₁₂ to _{D 1} n connected in parallel between the lines l ₁ and l are connected to their line voltage detection circuits 5
The transistor _T1 is turned off, the inhibit input of the inhibit circuit 4 becomes high level, the transmission of the output from the fire detection circuit 1 is prohibited, and the fire detection circuit 1 is maintained in an inoperable state.

Furthermore, if fire detector D ₁₂ operates instead of fire detector D ₁₁ , the operation of the astable multivibrator 11 of that detector is stopped with two pulses being sent out by the output of decoder 12, so the fourth Diagram b
If two pulses are activated through the switching circuit 16 as shown in _FIG .
n pulses are sent out as shown in
At Re, the pulses are counted by the counter 29 and the address display circuit 35 displays that the second or nth sensor has operated. In addition, if fire detector Dn ₁ in another warning area is activated,
The fire signal receiving circuit 25 (not shown) operates and displays the fire area, and the number of pulses "1" as an address signal from the sensor is detected by the address and fire detection amount signal receiving circuit, etc., and the first sensor is detected. It will be displayed that it has been activated, and the subsequent fire detection amount signal will indicate the output of that detector. Further, when the recovery push button switch 43 of the receiver Re is pressed for a short time, the sensor reset circuit 23 and the receiver reset circuit 44 are activated, and the sensor and receiver are restored to their normal state. Further, in the above embodiment, an ion chamber is used as the fire detection section 2, but a photoelectric type or a thermal type fire detection section such as a thermistor that detects light scattered by smoke may be used.

Since the present invention is configured and operates as described above, with a simple circuit configuration, the operation of a large number of fire detectors connected in parallel on the same line in the same warning area and the output changes of the detectors due to a fire can be individually monitored at the receiver. This has the effect of providing a fire alarm system that can distinguish between fire alarms.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the connection relationship between the fire detector and the receiver of the fire alarm system of the present invention, Fig. 2 is a circuit diagram of the fire detector shown in Fig. 1, and Fig. 3 is the receiver shown in Fig. 1. The circuit diagram of the machine, FIG. 4, is a voltage waveform diagram for explanation. 1... Fire detection circuit, 2... Fire detection section, 3...
...Comparator, 4,9...Inhibit circuit,
5... Line voltage detection circuit, 6, 14... Latch circuit, 7, 16... Switching circuit, 8, 17...
...Delay circuit, 11,18...Astable multivibrator, 12,29...Counter, 13,34,
41...Decoder, 19...Flip-flop circuit, 20...Analog-digital converter, 2
DESCRIPTION OF SYMBOLS 1... Digital coincidence circuit, 25... Fire signal receiving circuit, 26... Address and fire detection amount signal receiving circuit, 27... Alarm display circuit, 28... AND circuit, 35... Address display circuit, 41... Fire detection amount display circuit.

Claims (1)

[Claims] 1. A fire detection circuit that detects and outputs a predetermined output of a fire detection amount of a fire detection unit such as an ion chamber or a thermistor that detects fire phenomena such as smoke or heat, and a pair of receivers. a first inhibit circuit that detects a drop in the line voltage of the line and prohibits transmission of the output from the fire detection circuit; a first latch circuit that stores the output from the first inhibit circuit; a first switching circuit that reduces the voltage of the line and sends a fire signal to the receiver by the operation of the first latch circuit; a first delay circuit that generates an output after a certain period of time by the operation of the first latch circuit;
a second inhibit circuit in which transmission of the output of the first delay circuit is inhibited by the output of a second latch circuit to be described later; a first astable multivibrator operated by the second inhibit circuit; a second switching circuit that operates intermittently by the output of the multivibrator and is connected between the lines together with the first switching circuit to further lower the line voltage and send an address and fire detection amount signal to the receiver, and a first astable multivibrator. a decoder for generating an address signal that detects a predetermined value of a counter that counts the output of the vibrator; a second latch circuit that stores the output of the decoder; and a second latch circuit that generates an output after a certain period of time by the operation of the second latch circuit. a delay circuit, a second astable multivibrator operated by the output of the second delay circuit, and a flip-flop set by the second astable multivibrator to operate the first astable multivibrator.
an analog-to-digital converter that converts the analog outputs of the flop circuit and the fire detection section into digital values, and a digital matching circuit that compares the output of this converter with the output of the counter and stops the first astable multivibrator when they match. a fire signal receiving circuit that operates by detecting a predetermined value of line voltage dropped by the operation of the first switching circuit of the fire detector, and a second switching circuit of the fire detector. an address and fire detection amount signal receiving circuit that receives the address and fire detection amount signal sent by the operation of the above, an AND circuit that passes the address and the output of the fire detection amount signal receiving circuit by the operation of the fire signal receiving circuit; A fire alarm comprising a counter that counts the pulse output of the circuit, and a receiver that includes a separate decoder and display circuit that detects the counted value and displays an address and the amount of fire detected. Facility.