JPS6250998A - Gas leak alarm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a gas leak alarm.

[Prior art and problems to be solved by the invention] Conventionally,
There are several methods for warning of gas leaks.

One of these is the alarm that sounds when it detects a gas leak, but in this case, it is of no use when a family member is away or when the person commits an act of self-inflicted harm such as suicide.

Another method is to install an alarm buzzer outside the door, so that even if a family member is away or there is an act of self-injury, it can alert the people around them. This method requires an extra alarm buzzer outside the door, which increases the cost, and it also has the problem that it is not useful when there are no people nearby.

Still another method is a centralized monitoring method used in apartment complexes, but this method requires a lot of staff and is expensive, and is also useless when the manager is absent.

[Means for solving problems]

The present invention aims to solve the above-mentioned conventional problems and provide a gas leak alarm that can notify surrounding people of a gas leak without causing a significant increase in cost. A gas leak alarm device made to achieve this purpose includes a gas leak detection circuit, a control circuit that generates an alarm signal based on a gas leak detection signal from the gas leak detection circuit, and an alarm signal from the control circuit. an alarm means that generates an alarm based on the alarm, an output circuit that outputs an abnormal signal to the outside based on the alarm signal, and an abnormal signal from the output circuit of another gas leak alarm having the same configuration, and Based on the warning signal, the warning means may include a signal monitoring circuit that generates a warning different from the warning based on the warning signal.

[For production]

In the gas leak alarm configured as described above, when the gas leak detection circuit detects a gas leak and outputs a gas leak detection signal, the control circuit generates an alarm signal based on the gas leak detection signal, and transmits the signal to the alarm means. to generate an alarm. Further, an output circuit outputs an abnormal signal to the outside based on the alarm signal from the control circuit. Further, a signal monitoring circuit monitors an abnormal signal from the outside, and based on the abnormal signal causes the alarm means to generate an alarm different from the alarm based on the alarm signal.

Therefore, by interconnecting the output of the output circuit and the input of the signal monitoring circuit between the plurality of gas leak alarms, the plurality of gas leak alarms can be It is possible to generate an alarm at the alarm, and it is also possible to identify whether the alarm is based on gas leak detection in the alarm itself or another alarm.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an embodiment of a gas leak alarm according to the present invention. In the figure, a surge protection circuit 1 protects the alarm by cutting off noise and abnormal voltage that instantly enter from the commercial AC power line. . The commercial AC power source is stepped down by the transformer 2 and is applied to the first and second power circuits 3 and 4 through its secondary windings 2a and 2b. First power supply circuit 3
supplies a stabilized DC power supply for the gas leak detection circuit 5, and the second power supply circuit 3 supplies stabilized DC power for other circuits other than the gas leak detection circuit 5.

The gas leak detection circuit 5 includes a catalytic combustion type detection coil 5a and a dummy coil 5 connected between the outputs of the first power supply circuit 3.
It consists of a bridge circuit composed of a series circuit of b and a series circuit of resistors 5C and 5d, and the voltage obtained between the connection point of coils 5a and 5b and the connection point of resistors 5C and 5d is used as a detection output in the control circuit. 6.

The control circuit 6 consists of an integrated circuit element having the configuration shown in the block diagram, and includes coils 5a and 5 in the gas leak detection circuit 5.
A comparator 6a is connected to the connection point of b and the connection point of resistors 5c and 5d, respectively. When the gas leak detection circuit 5 detects a gas having a predetermined concentration or higher and the voltage at the connection point between the coils 5a and 5b becomes greater than the voltage at the connection point between the resistors 5C and 5d, the output of the comparator 6a changes from H to L level. It starts to fall.

The output of this comparator 6a is applied to one input of the controller 6b.

A clock signal from the clock generation circuit 7 is frequency-divided by a counter 6c and applied to the other input of the controller 6b. Controller 6b is comparator 6a
Based on the signals from the outputs a and b, these signals are applied to the LED drive circuit 6d and the signal drive circuit 6e, respectively, and the comparator 6
A signal is sent to the output C based on the signal from the counter 6C and the signal from the counter 6C, and is applied to the buzzer drive circuit 6f. The controller 6b also sends a signal to the output d that maintains the L level for a certain period of time in response to the rise of the power supply Vcc. The outputs of the above-mentioned LED drive circuit 6d, signal drive circuit 6e and buzzer drive circuit 6r are connected to the LED display circuit 8,
It is connected to the abnormality determination output circuit 9 and the buzzer circuit 10, respectively.

The output of the LED drive circuit 6d is at H level during gas leak monitoring, but when the gas leak detection circuit 5 detects gas with a predetermined concentration or higher and the output of the comparator 6a in the control circuit 6 becomes L level, the controller 6b controls. By L
be leveled. The LED display circuit 8 has a red LED 8a and a green LED 8b, and the anode of the red LED 8a is connected to the positive power supply of the power supply circuit 4 via a resistor 8C, and the cathode is connected to the output of the LED drive circuit 6d via a diode 8d. The anode of the green LED 8b is the resistor 8e.
The cathode is connected to the positive power supply of the power supply circuit 4 through the transistor 8f, and the cathode is connected to GND through the transistor 8f. The base of the transistor 8f is a diode 8 whose anodes are interconnected.
The interconnection point of the diodes 8g and 8h is connected to the positive power source of the power supply circuit 4 via a resistor 81.

In the above LED display circuit 8, when the output of the LED drive circuit 6a is at H level, that is, when gas leakage is being monitored, the transistor 8f is turned on, the green LED 8b is turned on, and the red LED 8a is turned off. However, when a gas leak is detected and the output of the LED drive circuit 6d becomes L level, the red LED 13a is turned on, the transistor 8f is turned off, and the green LED 8b is turned off, indicating that a gas leak has occurred. Ru.

The output of the signal drive circuit 6e is at the L level when monitoring a gas leak, but when gas is detected by the gas leak detection circuit 5, it is set to the H level. The abnormality determination output circuit 9 has transistors 9a and 9b, the collector of the transistor 9a is connected to the positive power supply of the power supply circuit 4 via a resistor 9C, and the base of the transistor 9b is connected via a resistor 9d.
The emitter is connected to GND, and the base is connected to the output of the signal drive circuit 6e via a resistor 9e, to the positive power supply of the power supply circuit 4 via a resistor 9f, and to GND via a resistor 9g.
each connected. The base of the transistor 9b is connected to C, ND through the resistor 9f, the emitter is connected to C, ND,
The collector serves as an output terminal OUT connected to the input terminal (terminal corresponding to IN) of the gas leak alarm on the other side.

In the abnormality determination output circuit 9 described above, when the output of the signal drive circuit 6e is at the L level, that is, when monitoring gas leakage, the transistor 9a is turned off, the transistor 9a is turned on, and a current flows through the output terminal OUT and the transistor 9b. However, when a gas leak is detected and the output of the signal drive circuit 6e becomes H level, the transistor 9a is turned on and the transistor 9b is turned off, and the output terminal OU is turned on.
The current path through T and transistor 9b is cut off.

The output of the buzzer drive circuit 6f is at the H level during gas leak monitoring, but when gas is detected by the gas leak detection circuit 5, the output is intermittently set to the L level.

The buzzer circuit 10 sounds when its control input becomes L level, and is interrupted by the intermittent L level output of the buzzer drive circuit 6f.

The LED display circuit 8 is connected to a signal monitoring circuit 13 through a diode 11 whose anode is connected to the cathode of the red LED 8a, and the buzzer circuit 10 is connected to a signal monitoring circuit 13 through a diode 12 whose anode is connected to a control input. The signal monitoring circuit 13 is connected to the output terminal (
Depending on whether the terminal (corresponding to OUT) is in a conductive state through the transistor (corresponding to 9b),
It determines whether the other party's alarm is in a gas leak alarm state or a power-off state, and if the determination is YES, it operates to put the LED display circuit 8 and buzzer circuit 10 into an alarm state after a certain delay time.

More specifically, the signal monitoring circuit 13 includes a programmable unijunction transistor (PUT) 13a,
The anode of the PUT 13a is connected to a positive power supply via a resistor 13b and to GND via a capacitor 13C, and is connected to a diode 13d and resistors 13e and 13f.
The gate is connected to the positive power supply through a resistor 13h, the base of the transistor 13j is connected through a resistor 13i, and the cathode is connected to GND.

The collector of the transistor 13g is connected to the interconnected cathodes of the diodes 11 and 12, and the emitter is connected to GND.
, and the base is connected to GND via a resistor 13k. The collector of the transistor 13j is connected to the connection point between the resistors 13e and 13f, and is further connected to the positive power supply via the resistor 13β.
m and a capacitor 13n, the emitter is connected to GND, and the base is connected to GND via a resistor 130. In addition, 13p is PUT
This is a diode that connects the anode of 13a to the positive power supply. The anode of the PUT 13a is connected to an input terminal IN via a resistor 13q and a diode 14, and the input terminal is connected to an output terminal (terminal corresponding to OUT) of the gas leak alarm on the other side.

In the signal monitoring circuit 13 described above, when the gas leak alarm on the other side does not detect a gas leak, the transistor (9b
) is on, so if the input terminal IN is connected to the output terminal of the other party, the anode of the PUT 13a in the signal monitoring circuit 13 is connected to GND, and its potential is is at L level and turned off. Therefore, the transistor 13j is turned on and the transistor 13g is turned off. However, if a gas leak is detected by the leak alarm on the other side, or the power is cut off, the transistor (9) in the abnormality determination output circuit (circuit corresponding to 9)
(corresponding to b) is turned off, the anode potential of the PUT 13a increases in accordance with the rise in the charging potential of the capacitor 13C, and after about 45 seconds it becomes higher than the gate potential and the PU
TI3a turns on. By turning on the PUT 13a, the transistors 13j and 13g are turned off and on, respectively, and the red LED 8a in the LED display circuit 8 is turned on.
The cathode of the buzzer circuit 10 is connected to GND through a diode 11 and a transistor 13g, and the control input of the buzzer circuit 10 is connected to GND through a diode 12 and a transistor 13g.
The red LED 8a lights up and the buzzer circuit 10 continuously sounds. At this time, the green LED 8b remains lit without turning off, so the lighting of both the red LED 8a and the green LED 8b and the continuous sounding of the buzzer circuit 10 indicate that the alarm is caused by the gas leak alarm on the other side. will be informed.

Note that the output d of the controller 6b is connected to the output of the LED drive circuit 6d via a diode 15, and is also connected to the output of the comparator 6a via a diode 16; The output of the LED drive circuit 6d and the output of the comparator 6a are set to L by the output d of the controller 16b which becomes the level.
By holding the gas leak detection circuit 5 at the level until the operation of the gas leak detection circuit 5 stabilizes after the power is turned on, the gas leak detection circuit 5
This is to disable the output of , and to indicate this by turning on the red LED 8a and turning off the green LED 8b, and at this time the buzzer circuit 10 is in a non-sounding state.

Although it is not clear from the illustrated configuration, the controller 6b also controls the output of the comparator 6a so that when the gas concentration detected by the gas leak detection circuit 5 fluctuates in a short period of time, an alarm will not be issued due to this detection. L over a certain period of time
Only when the level continues, a signal for alarm is sent to the outputs a''-c.

As shown in Figure 2, the gas leak alarm with the configuration described above can be used as a standalone gas leak alarm by connecting the input terminal IN to GND, or it can be used as a single gas leak alarm that is installed in two houses. Configuration of gas leak alarm A and B
As shown in Fig. 3, by connecting the input terminal IN to the output terminal OUT, the output terminal OUT to the input terminal IN, and GND to each other, the alarm of the neighboring house can be activated in response to the detection of gas leakage in alarm A. It is also possible to issue an alarm at point B.

The operation will be explained below with reference to the time chart of each part shown in FIG.

Now, when the power is turned on at time t1, the controller 6b in the control circuit 6 outputs a% d as shown in FIGS.
(Signals as shown in dl are sent out, and the outputs of the LED drive circuit 6d, signal drive circuit 6e, and buzzer drive circuit 6f become H, L, and H levels, respectively.

Due to the L level of the output d, the diode 15 becomes conductive and the red LED 3a is turned on as shown in FIG. 4(f).

At this time, transistor 8f is on and the green LED
8g is also lit. Furthermore, since the output d is at L level, the diode 16 is also conductive, and the comparator 6,
- Since the human power is at the L level, the output of the comparator 6a is at the L level even if the potential between the coils 5a and 5b is higher than the detection level at the comparator 6a immediately after the power is turned on, as shown in FIG. 4 (Ql). This prevents malfunctions immediately after the power is turned on.

The output d of the controller 6b is at time t2 after a certain period of time.
The voltage rises from L to H level, the diodes 15 and 16 become non-conductive, the red LED 8a turns off, and the voltage at the connection point X comes to be applied to the comparator 6a. At this time point t2, as is clear from FIG. 4<e>, the voltage at the connection point X has fallen to a steady state below the detection level.

Thereafter, at time t3, when the gas leakage detection circuit 5 detects a gas having such a concentration that the voltage at the connection point X exceeds the detection level, the output of the comparator 6a falls from H to L level.
In response to this, the controller 6b delays by a certain period of time T, at time t4.
Then, the output a is changed from L to H level, and the output A is changed from H to L level, and intermittent pulses of H level are intermittently sent to output C. The LED driver circuit 6d, the signal driver circuit 6e-, and the buzzer driver circuit 6f have output a.
``-c is inverted, the red LEDs 8a and 8b of the LED display circuit 8 are turned on and off, respectively, the transistors 9a and 9b of the abnormality determination output circuit 9 are turned on and off, and the buzzer circuit 10 sounds intermittently.

When the transistor 9b of the abnormality determination output circuit 9 is turned off, the signal monitoring circuit (corresponding to circuit 13) of the gas leak alarm B on the other side, which had been connected to GND through the transistor 9b, is turned off. Capacitor (13C
Charging of the transistor (corresponding to 13
13g respectively) are turned off and on,
When this transistor (corresponding to 13g) is turned on, the red LED (corresponding to 8a) of the gas leak alarm device B on the other side lights up, and the buzzer circuit (corresponding to 10) continuously sounds.

As described above, by the lighting of the red LED 8a, the non-lighting of the green LED 8b, and the intermittent sounding of the buzzer circuit 10, you can know that a gas leak has been detected by your gas leak alarm A and an alarm has been issued. The lighting of both the LED 8a and the green LED 8b and the continuous sounding of the buzzer circuit 10 make it possible to know that a gas leak has been detected by the gas leak alarm B on the other side and an alarm has been issued.

In addition, even if the signal line between yourself and the other party's gas leak alarm device A, B is disconnected, or if the power is turned off due to an act of self-damage, the abnormality determination output circuit 9 and signal monitoring of the other party's Since there is no current path between the circuits 13, the signal monitoring circuit 13
The PUT 13a and transistors 13j and 13g inside turn on, off and on, respectively, and the red LED 8a lights up.
An alarm is issued by the continuous ringing of the buzzer circuit 10.

Figure 5 shows the wiring when three gas leak alarm devices A-C are connected to each other, and a backflow prevention diode D is connected at the part where each input terminal and output terminal are connected to the two output terminals and the input terminal. It is inserted into the signal line between the input end and output end.

In the embodiment shown in FIG. 1, by turning off the switching transistor 9b of the abnormality determination output circuit 9, the current path of the current flowing from the signal monitoring circuit of the gas alarm on the other side is cut off.
By interrupting this current path, the signal monitoring circuit detects an abnormality and generates an alarm. However, as shown in FIG. An output circuit 20 and a voltage signal monitoring circuit 21 may be provided to output a voltage to the outside and monitor and determine the signal voltage from the outside.

Specifically, the voltage output circuit 20 receives the output of the signal drive circuit 1i5e in the control circuit 6, which is at L level during monitoring and at H level when a gas leak alarm occurs, and outputs a constant voltage generated by the Zener diode ZD+ during monitoring. A voltage of about 6 cm is output to the output terminal OUT in addition to the base of transistor Q1 and the collector of transistor Q2, and when a gas leak alarm occurs, a constant voltage generated by Zener diodes ZD+ and ZD2 is applied to the base of transistor Q+ and the collector of transistor Q2. A voltage of approximately 12V is output to the collector and output terminal OUT. Note that the voltage at this output terminal OUT becomes OV when the power to the gas leak alarm is cut off.

On the other hand, the voltage signal monitoring circuit 21 monitors the voltage signal received at the input terminal IN from the voltage output circuit of another gas leak alarm having the same configuration, and the voltage signal received at the input terminal IN is approximately 6V. When , transistor Q3 is turned on, and transistor Q4 is turned off by turning on transistor Q3. At this time, since the transistor Q5 is also off, the diodes 11 and 12 are both non-conductive.

In this state, when the voltage at the input terminal IN reaches approximately 12V, Zener diode ZD3 becomes conductive, which turns on transistor Q5, and the cathodes of diodes 11 and 12 are connected to GND through transistor Q5. The red LED 8 will be connected.
A is lit and the buzzer circuit 10 starts to sound continuously.

Also, if the voltage at the input terminal IN drops from approximately 6 to OV due to power cutoff of the gas leak alarm on the other side or disconnection of the signal line between it and the gas leak alarm on the other side, the transistor Q
3 is turned off, transistor Q4 is turned on, and the cathodes of diodes 11 and 12 are connected to GND through transistor Q4, so that the red LED 8a is turned on and the buzzer circuit 10 is continuously sounded. Become so.

The gas leak alarm described above with reference to FIG.
If T is connected to a central monitoring panel, it can also be used in a central monitoring system.

〔Effect of the invention〕

As explained above, the gas leak alarm according to the present invention monitors the abnormal signal from the output circuit of other gas leak alarms having the same configuration, and depending on the result, issues an alarm different from the alarm generated by the gas leak detection itself. Since the alarm is generated by the alarm means, it is possible to mutually monitor gas leaks in adjacent houses by simply interconnecting multiple gas leak alarm devices. This method has advantages such as lower cost than the monitoring method.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing one embodiment of the gas leak alarm according to the present invention, FIGS. 2 and 3 are wiring diagrams showing examples of usage of the gas leak alarm shown in FIG. 1, and FIG. is a time chart diagram of each part in Fig. 1 to explain the operation in the case of the usage pattern shown in Fig. 3, Fig. 5 is a wiring diagram showing another usage pattern, and Fig. 6 is a gas leakage diagram according to the present invention. FIG. 3 is a circuit block diagram showing another embodiment of the alarm device. 5... Gas leak detection circuit, 6... Control circuit, 8...
・LED display circuit, 9... Abnormality determination output circuit, 1o・
...Buzzer circuit, 13...Signal monitoring circuit, 2o...
Voltage output circuit, 21... Voltage signal monitoring circuit.

Claims (1)

[Scope of Claims] A gas leak detection circuit, a control circuit that generates an alarm signal based on the gas leak detection signal from the gas leak detection circuit, and an alarm means that generates an alarm based on the alarm signal from the control circuit. , monitors abnormal signals from an output circuit that outputs an abnormal signal to the outside based on the alarm signal and an output circuit of another gas leak alarm having the same configuration, and causes the alarm means to output the alarm signal based on the abnormal signal. What is claimed is: 1. A gas leak alarm, comprising: a signal monitoring circuit that generates a signal monitoring circuit that generates a different alarm based on the alarm.