JPH0353354Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a gas leak alarm device.

[Background technology]

Conventionally, this type of gas leak alarm device has a repeater 2 to which a plurality of gas leak detectors 1 are connected, as shown in FIG.
The receiver 3 connects multiple units using wiring and sequentially sends signals to the receiver 3. The receiver 3 supplies power VG to each repeater 2 and discriminates the signal voltage from the first repeater 2 to detect gas leakage or normal operation. , or detect abnormalities such as wire breaks and issue alarms. FIG. 5 shows the circuit of the conventional repeater 2, in which 4 is a priority discrimination circuit, and the priority discrimination circuit 4 has three pairs of signal input terminals G ₁₀ , G ₁₁ , G ₂₀ , G ₂₁ , G ₃₀ ，
G ₃₁ , diode bridges DB ₁ , DB ₂ , and DB ₃ are connected between each pair of signal input terminals, and the negative output terminals of each diode bridge DB ₁ , DB ₂ , and DB ₃ are commonly connected. It is connected to the common connection terminal _Gc which also serves as the ground side output terminal. Further, the + output terminals are connected to the bases of transistors Tr ₁ to _{Tr 3} provided correspondingly through resistors R ₅ , R ₆ , and R ₇ .
Each signal input terminal G ₁₀ , G ₁₁ , G ₂₀ , G ₂₁ , G ₃₀ , G ₃₁
are commonly connected via diodes _D5 to _D10 , respectively, and between this common connection point and the common connection terminal _Gc are an output transistor _Tr0 , an output resistor _R0 , and a diode _D11 . A series circuit is connected. A series circuit including resistors R ₁ , R ₂ and a Zener diode ZD ₁ is connected to this series circuit, and the cathode of the Zener diode ZD ₁ is connected to the base of an output transistor Tr ₀ via a resistor R ₂ . . In addition, the Zener diode ZD ₁ is connected to the transistor Tr ₁ ~
A series circuit of Tr ₃ is connected.

Therefore, the priority determination circuit 4 has each signal input terminal G ₁₀ ,
In normal times when the AC output voltage of the gas leak detector 1 connected to G ₁₁ , G ₂₀ , G ₂₁ , G ₃₀ , and G ₃₁ is, for example, 6V, all transistors Tr ₁ to _{Tr 3} are turned on. Then, the base current of the output transistor Tr ₀ flows to turn it on, generating a voltage of 6V across the output resistor R ₀ and the diode D ₁₁ . Also, when any of the gas leak detectors 1 is powered off and generates an output voltage of 0V, the transistors Tr ₁ ~
The corresponding one of Tr ₃ is turned off, cutting off the base current of the output transistor Tr ₀ , turning off the transistor Tr ₀ , and switching off the output resistor R ₀ and diode D _11.
Let the voltage across both ends be 0V. Furthermore, when one of the gas leak detectors 1 detects a gas leak and generates a voltage of 12V, the Zener diode ZD ₁ , which is set to conduct when this 12V voltage is applied, becomes conductive, and the transistor Tr ₁ ~ Regardless of the state of Tr ₃ , the base current of the output transistor Tr ₀ flows, turning on the output transistor Tr ₀ . Therefore, a voltage of 12V is generated across the output resistor _R0 and the diode _D11 . 5 in the figure is a trouble detection circuit, and this trouble detection circuit 5 uses a reference voltage obtained by dividing the voltage of the first constant voltage circuit 6 by a resistor R ₈ , a Zener diode ZD ₂ , and a resistor R ₆ , and the above-mentioned output. When the voltage across the series circuit of resistor R ₀ and diode D ₁₁ reaches 0V, it is composed of comparator CP1, etc., which generates the output as an abnormal signal.When the output of comparator CP1 becomes "H", that is, 0V Disconnection lighting circuit 7 when detected
The light-emitting diode LED that makes up the system lights up to indicate the occurrence of a problem. 8 is a gas leak detection circuit, and this gas leak detection circuit 8 has an output resistor.
The voltage across the series circuit of R ₀ and diode D ₁₁ is
Comparator that generates an alarm signal when it reaches 12V
It consists of CP2 etc. Furthermore, comparator CP2
The reference voltage is the Zener diode ZD ₂ and the resistor above.
Set by series circuit with R ₉ . The constant voltage circuit 6 is for obtaining a constant voltage output of 12V, and is designed to generate a voltage having the same value as the signal voltage when gas leakage is detected. ZD ₃ is a Zener diode for setting the reference voltage, and Tr ₁₁ is a control transistor.

Now, the output voltage of this constant voltage circuit 6 is further increased by a second constant voltage circuit 9 consisting of a Zener diode _ZD4 .
The voltage is stepped down to the same voltage as the normal signal voltage of 6V, and the 12V output is sent to correction circuit 1, which will be described later.
It is connected to the output terminal G _p via the transistor Tr ₄ of zero. The correction circuit 10 includes a transistor Tr ₅ that is turned on by a current flowing when the Zener diode ZD ₅ becomes conductive when the output of the comparator CP2 or the voltage applied to the additional connection terminal _GI reaches a value close to about 12V, and the Zener diode ZD 5 becomes conductive.
It is composed of the above-mentioned transistor Tr ₄ , etc., and when the transistor Tr ₅ is turned on, the transistor Tr ₄ is turned on, and when the transistor Tr ₅ is off, the transistor Tr ₄ is turned off, and the voltage is applied to the output terminal G _p via the transistor Tr ₄ . It applies or cuts off the voltage. D ₁₃ and D ₁₄ are diodes for preventing wraparound. 11 in the figure is a discrimination circuit, and this discrimination circuit 11 turns on the transistor Tr ₆ when the voltage applied to the expansion connection terminal G _I is 6V or more, and turns on another transistor Tr ₇ via this transistor Tr ₆ . Let this transistor Tr ₇
and a transistor Tr ₈ which controls the application of the 6V voltage from the second constant voltage circuit 9 to the output terminal G _p through the diode D ₁₂ and is turned on by the output of the comparator CP1 _.
By grounding the emitter of the transistor _Tr7 and preventing the voltage of 6V from being applied to the output terminal _Gp , the output terminal _Gp can be set to 0V. In the figure, R ₀ ' is an output resistance connected between the output terminal G _p and the common connection terminal G _c . In the figure, reference numeral 12 indicates a gas leak indicator circuit. In this gas leak indicator circuit 12, when there is an output from the comparator CP2, a transistor Tr ₉ is turned on, and this turns on a transistor Tr ₁₀ , which turns on the lamps L ₁ and L _2. It lights up. In this case, the transistor
After Tr ₉ turns on, the 24V power supply voltage increased from 12V is applied to the power supply terminal _GV from the receiver B side,
The Zener diode ZD ₆ connected in series to the collector of the transistor Tr ₉ becomes conductive, and the transistor
Tr ₁₀ is now turned on. In the figure _, G _X is a shorting terminal, and this shorting terminal _G

However, when a system is configured by connecting the repeaters of the present invention as shown in FIG. If there is, send the 6V output of constant voltage circuit 6 to the previous stage repeater Discrimination circuit 1
1, or if it is a 12V input, the constant voltage circuit 6
The 12V output is sent to the previous-stage repeater from the output terminal _Gp via the correction circuit 10, and is sequentially transmitted to the receiver B. Furthermore, when the input is 0V, the transistors Tr ₆ and Tr ₇ of the discrimination circuit 11 are turned off.
The 6V output of the constant voltage circuit 9 is cut off, and the output is set to 0V. Of course, when any of the gas leak detectors 1 connected to the repeater detects a gas leak, the signal voltage of 12V is discriminated and outputted by the priority discrimination circuit 4, and the gas leak detection circuit 8 and the correction circuit 10
12V is applied to the output terminal G _p by the function of the constant voltage circuit 6.
generates a voltage of In addition, if any of the gas leak detectors 1 is powered off, it is discriminated by the priority discrimination circuit 4, and the trouble detection circuit 5 and discrimination circuit 11 operate to connect the constant voltage circuit 9 to the output terminal G _p . Cut off the applied 6V voltage and set it to 0V,
This is transmitted to the previous stage repeater.

In addition, when all the gas leak detectors 1 are in the normal state, the transistors Tr ₆ and Tr ₇ of the discrimination circuit 11 are turned on by the 6V voltage from the relay in the subsequent stage.
The output voltage of 6V from the constant voltage circuit 9 is applied to the output terminal G _p .

By the way, in this conventional example, the gas leak display circuit 12 changes the power supply voltage supplied from the receiver 3 from 12V to 24V when the receiver 3 determines that there is a gas leak.
Since the lamps L ₁ and L ₂ are turned on only when the gas is raised to Since the lamps L ₁ and L ₂ light up, the relay 2 that issued the first alarm can be identified, but the power supply voltage has already reached the repeater 2 after the second alarm.
Since the voltage has increased to 24V, the gas leak display circuit 12 operates at the same time as gas leak detection, and the lamps L ₁ and L ₂ light up. Therefore, after the second report, the relay 2 determines that the lamps L ₁ and L ₂ light up. The drawback was that you couldn't tell just by looking at it.

[Purpose of invention]

The present invention was developed in view of the above-mentioned problems, and its purpose is to provide a gas leak alarm device in which relays after the second alarm can be identified by the lighting of the display element of the gas leak display circuit. be.

[Disclosure of invention]

(Example 1) Figure 1 shows a circuit configuration diagram of Example 1.
3 is a gas leak detection priority circuit, and this gas leak detection priority circuit 13 operates in the same way as a combination of the priority discrimination circuit 4, the trouble detection circuit 5, and the gas leak detection circuit 8 shown in FIG. Signal input terminals G ₁₀ , G ₁₁ to which multiple leak detectors 1 are connected
G _o0 and G _o1 , the voltage of each signal input terminal is discriminated and the input voltage of one of the signal input terminals is the first.
If the voltage level is 12V, an alarm signal is generated, if the input voltage of any signal input terminal is 0V, an abnormality signal is generated, and if the input voltage of any signal input terminal is not at the first voltage level, the second signal is generated. If a voltage level, that is, an input voltage of 6V is present at any signal input terminal, a monitoring signal is output respectively. 14 is a repeater input priority circuit, and this repeater input priority circuit 14 corresponds to the discrimination circuit 11 in FIG.
Connect the output of another repeater to the expansion connection terminal G _I and distinguish whether the voltage level of the output is the first voltage level, the second voltage level, or 0V to handle alarm signals, monitoring signals, and abnormal signals. It is now output as follows. 15 is a priority output circuit, and this priority output circuit 15 is connected to the constant voltage circuits 6 and 9 and the correction circuit 1 in FIG.
0, gas leak detection priority circuit 1
3. Input the output of the repeater input priority circuit 14,
If there is an alarm signal input, a signal with a voltage of 12V will be output; if any input is a monitoring signal, a signal with a voltage of 6V will be output; if no alarm signal is input and an abnormal signal is input, a signal with a voltage of 0V will be output. It is generated from terminals G _p and G _c . 7 is gas leak detection priority circuit 13
The device is operated in response to an abnormality signal from the device to display a disconnection indication by lighting up a display element such as a light emitting diode. 12' is a gas leak display circuit, which corresponds to the gas leak display circuit 12 shown in FIG. When the power supply voltage VG increases to 12V, it operates and lights up the display element LED, such as a light emitting diode. 16 is the alarm signal gas leak display circuit 1
This is a delay circuit that delays the input to 2 for a certain period of time, for example, about 60 seconds.

Then, the gas leak detector 1 connected to the existing repeater 2 detects a gas leak, and a first 12V signal indicating that a gas leak has been detected is sent from the repeater 2 to the receiver 3. Then, the receiver 3 increases the supplied power supply voltage VG from 12V to 24V. Therefore, in the relay 2, the display element LED is turned on in the gas leak display circuit 12'. Next, when the gas leak detector 1 connected to another repeater 2 detects a gas leak and a 12V signal indicating that the gas leak has been detected is sent from the repeater 2 to the receiver 3, the power supply voltage is already Since the voltage has increased to 24V, the gas leak indicator gas 12 of the relevant relay 2 is delayed by the delay time caused by the delay circuit 16, and the display element LED is activated.
lights up. In other words, when the second report is received on the receiver 3 side, the display element LED is not lit by the delay circuit 16 until the watcher goes to the installation location of the repeater 2, so the watcher issues the second report. Therefore, it is possible to identify which repeater 2 has been used. After that, even if an alarm is issued from another repeater 2, the display element will be activated a little later than when the alarm was issued.
Since the LEDs light up one after another, the order in which the alarms are issued can be easily identified.

(Example 2) Figure 2 shows a circuit configuration diagram of Example 2,
This circuit includes a power supply voltage detection circuit 17 that detects the power supply voltage VG from the receiver 3, and a flicker circuit 18 that turns on and off the display element LED of the gas leakage display circuit 12.
A of the changeover switch SW that is switched by the output of
The alarm signal of the gas leak detection priority circuit 13 is directly connected to the signal input terminal of the gas leak display circuit 12 through the contact, and the alarm signal of the gas leak detection priority circuit 13 is connected directly to the signal input terminal of the gas leak display circuit 12 through the contact B and the flicker circuit 18. It is connected to the signal input terminal of the leakage indicator circuit 12.
The power supply voltage detection circuit 17 has a power supply voltage of 12V to 24V.
If the alarm signal is input before the alarm signal changes to 24V, the changeover switch SW is switched to the a contact side and latched. If the power supply voltage VG changes to 24V before the alarm signal is input, it is switched to the b contact side and latched. .
The flicker circuit 18 is for intermittent input signals.

Then, the gas leak detector 1 connected to a certain repeater 2 detects a gas leak, and a first 12V signal indicating that a gas leak has been detected is sent from the repeater 2 to the receiver 3. Then, the receiver 3 increases the supplied power supply voltage VG from 12V to 24V a little later than the first notification, as shown in FIG. 3a. By the way, in the relay 2, since an alarm signal is generated before the power supply voltage VG changes, the power supply voltage detection circuit 17 latches the changeover switch SW to the a contact. Therefore, the gas leakage display circuit 12 of the repeater 2 is shown in Fig. 3b.
The display element LED is displayed continuously as shown in .
On the other hand, the power supply voltage detection circuit 17 of the other repeater 2 detects that the power supply voltage VG has changed to 24V, switches the changeover switch SW to the b contact, and latches it. Next, when the gas leak detector 1 connected to another repeater 2 detects a gas leak and a 12V signal indicating that the gas leak has been detected is sent from the repeater 2 to the receiver 3, the power supply voltage is already Since the voltage has increased to 24V, an alarm signal is input to the gas leakage display circuit 12 of the repeater 2 via the flicker circuit 18, causing the display element LED to blink as shown in FIG. 3c. In other words, the repeater 2 that issued the second and subsequent reports can be identified by blinking the display element LED.

[Effect of idea]

The present invention is configured to set the lighting operation of the display element when an alarm signal is generated after the power supply voltage from the receiver changes to a predetermined level so that it can be distinguished from the lighting state of the display element of the repeater that was lit by the first alarm signal. Since a means is attached to each repeater, the first alarm and subsequent alarms can be easily identified by the state of the display element of the gas leak display circuit, which is useful for investigating gas leak locations and detecting gas leaks at an early stage. This has the advantage of making it easier to find the problem and take countermeasures against it.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of the first embodiment of the present invention, and Fig. 2 is a circuit diagram of the first embodiment of the present invention.
The figure is a circuit diagram of Embodiment 2 of the present invention, Figure 3 is an explanatory diagram of the same operation as above, Figure 4 is an overall diagram of the gas leak alarm system, and Figure 5 is a circuit diagram of a conventional repeater. 1 is a gas leak detector, 2 is a repeater, 3 is a receiver, 12 is a gas leak display circuit, 13 is a gas leak determination priority circuit, 14 is a relay input priority circuit, 15 is a priority output circuit, 16 is a delay circuit , 17 is a power supply voltage detection circuit, 18 is a flicker circuit, G ₁₀ , G1 ₁ ...
is a signal input terminal, and LED is a display element.

Claims (1)

[Claims for Utility Model Registration] (1) When gas such as city gas is detected, the output is at the first voltage level, and when it is not detected, the output is at the second voltage level lower than the first voltage level, and the power is turned off. Sometimes, a gas leak detector with an output voltage of OV is provided, and a signal input terminal to which a plurality of the gas leak detectors are connected is provided, and the voltage of each signal input terminal is discriminated to determine whether the input voltage of one of the signal input terminals is the first one. If the input voltage of any signal input terminal is OV, an alarm signal is generated. If the input voltage of any signal input terminal is not at the first voltage level, an alarm signal is generated. a gas leak detection priority circuit that generates a monitoring signal if the input voltage is at either signal input terminal;
Connect the output of another repeater and determine whether the voltage level of the output is the first voltage level or the second voltage level.
A repeater input priority circuit that discriminates whether it is OV or not and outputs an alarm signal, monitoring signal, and abnormal signal accordingly;
Input the outputs of the gas leak detection priority circuit and repeater input priority circuit, and if there is an alarm signal input, the first
If any input is a monitoring signal, the second voltage level signal is input, and if neither alarm signal is input and an abnormal signal is input, the second voltage level signal is input.
A repeater that has a priority output circuit that generates an OV signal from the output terminal, and a gas leak display circuit that lights up a display element when the alarm signal input and power supply voltage reach a predetermined level, as well as supplying power to the repeater. A receiver that discriminates the voltage level of the output of the repeater connected to the signal input terminal and determines whether it is a gas leak, normal, or abnormal such as a disconnection, and changes the power supply voltage supplied to the repeater to a predetermined level in the event of a gas leak. In the equipped gas leak alarm device,
Setting means for setting the lighting operation of the display element when an alarm signal is generated after the power supply voltage from the receiver changes to a predetermined level to be distinguishable from the lighting state of the display element of the repeater that was lit by the first alarm signal. A gas leak alarm device characterized by being attached to a repeater. (2) The gas leak alarm device according to claim 1, wherein the setting means comprises a delay circuit for delaying input of the alarm signal to the gas leak display circuit for a certain period of time. (3) As the above setting means, if the alarm signal is input before the power supply voltage changes to a predetermined level, the alarm signal is directly connected to the gas leak display circuit, and if the alarm signal is input after the power supply voltage changes to the predetermined level. a power supply voltage detection circuit that operates a flicker circuit and uses the output of the flicker circuit to turn on and off a display element of a gas leakage display circuit, and the above-mentioned flicker circuit. Gas leak alarm device according to scope 1.