JPS63187395A - Gas 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 [Object of the Invention] (Industrial Application Field) The present invention relates to a gas alarm device in which the detection means is constituted by, for example, a semiconductor gas sensor.

(Conventional technology) In recent years, disaster prevention equipment has been increasingly installed in various buildings, but especially for gas, gas alarms have been installed to prevent explosions and gas poisoning. There are many. Due to recent developments in semiconductor engineering, gas alarms whose detection section is composed of a semiconductor gas sensor are often used.

Such a gas alarm has a configuration as shown in FIG. 3, for example. In the figure, 101 is a semiconductor gas sensor section that detects gas, and 103 is an alarm control section that controls alarm output based on a detection signal from the semiconductor gas sensor section 101. The alarm control unit 103 is a determination circuit that determines, based on the detection signal from the semiconductor gas sensor unit 101, that the gas moisture level at the location where the gas alarm is installed has exceeded a set value, and outputs an alarm signal to issue an alarm. 105
, a double cap section 107 that receives an alarm signal from the determination circuit 105 and outputs an alarm, and a power supply section 109 that supplies power to each component of the alarm control section 103 and the heater 102 of the semiconductor gas renovator section 101. , and a timer unit 111 that prohibits the determination operation of the determination circuit 105 for a predetermined period of time (about several minutes) after the power supply unit 109 starts supplying power. Note that the semiconductor gas sensor unit 101 has a generally known configuration, so a detailed explanation will be omitted here.
The heater 10 of the gas sensing part made of semiconductor
The change in resistance value that occurs in response to the degree of adsorption of gas during heating by No. 2 is output as a detection signal.

Next, the operation of the conventional gas alarm mentioned above will be explained using FIG. 4. In addition, in FIG. 4, (A) is the power supply section 1.
Figure J shows the status of power supply input to 09, (B) and (C)
(D) is a diagram showing the change in the power supply output voltage from the power supply unit 109 to each component a3 of the alarm ailJ control unit 103 and the power supply unit 102, (D) is a diagram showing the operating status of the U-timer unit 111, (E) is 5 is a diagram showing whether or not a determination can be made in the determination circuit 105. FIG.

First, when a commercial AC power supply starts to be supplied to the power supply unit 109 via the outlet 113, for example (see FIG. 4(A)
), the power supply unit 109 starts operating and starts supplying required voltages to each component of the alarm a1 control unit 103 and the heater 102 ((B) and (C) in FIG. 4). With the start of this power supply, the timer unit 111 starts counting a predetermined time period to required for the semiconductor gas sensor unit 101 to reach the required humidity due to the heating operation by energizing the heater 102 and to stabilize the detection operation. This prescribed 11. '
After the period J has elapsed, a determination permission signal is output to the determination circuit 105 (FIG. 4(D)). Therefore, determination circuit 1
05, after the start of power supply and the input of this judgment permission signal, it becomes possible to make a judgment based on the detection signal from the semiconductor gas sensor Pill 101 (see Fig. 4 (E).
)), the alarm i++ 107 will be activated as necessary.

(Problem to be Solved by the Invention) By the way, in the above-mentioned gas alarm, stable detection operation can be expected by setting a predetermined time period of 10 after the start of power supply. The power supply to the power supply unit 109 may be momentarily interrupted for some reason (for example, 2'Om sec
~100m sec)
(A)) The output voltage of the power supply section 109 is particularly high when the heater 102
When the power supply input is restored, the power consumption decreases drastically due to the large power consumption (Fig. 4 (B) and (C)).
teeth? There is a problem in that it is not possible to provide information ((D) and (E) in Figure 4). Regarding this problem, in consideration of the fact that gas alarms are spreading to general households, for example, the power supply section 1
It would be more convenient to use the commercial AC power supply 113 as the power supply input to 07, but it is known that instantaneous power outages like the ones mentioned above occur frequently in commercial AC power supplies. However, the occurrence of a warning failure period of a predetermined period of several minutes is a problem that requires improvement from the viewpoint of reliability as a type of disaster prevention equipment.

The present invention has been made in view of the above, and an object thereof is to provide a gas alarm device that eliminates unnecessary alarm failure time and is highly reliable.

"Structure of the Invention" (Means for Solving the Problems) In order to achieve the above object, a gas detection section that is equipped with a heating means and detects a required gas under a predetermined heating state is provided. Power is supplied to the heating means 2, -, after the power supply starts supplying power, after a predetermined semi-meter interval, it is determined that the gas has reached the setting ■ based on the detection signal from the gas detection unit, and an alarm is issued. In the control Δ+Fi device, the present invention provides a power supply that interrupts the power supply by the power supply unit when a stop 1 of the power supply for the operation of the power supply unit is detected after the start of the alarm control. and the preparation time by detecting that the output voltage of the power supply unit is not lower than the set voltage when the power supply for the operation of the power supply unit is restored, J:
The gist of the present invention is to have a restart control means for restarting alarm control after a short period of time has elapsed.

(Function) The gas alarm device according to the present invention has a gas detection section that is particularly equipped with a heating means and detects a required gas under a predetermined heating condition, and is connected to a power supply section during gas monitoring. When a momentary interruption of the power supply input occurs, the power supply output from this power supply is interrupted and the drop in the power supply output voltage is suppressed as much as possible, so that when the power supply input is restored, it takes less time than the preparation time required for the power supply to start supplying power. We are making it possible to resume gas monitoring.

(Example of the invention) Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a gas alarm according to an embodiment of the present invention. In the figure, 1 is a semiconductor gas sensor 1 that detects gas, and 3 is a semiconductor gas sensor 1 that detects gas.
Based on the detection signal from? This is an alarm control unit that controls τ alarm output.

Based on the detection signal from the semiconductor gas sensor section 1, the V-report control section 3 determines that the gas t and degree at the installation location of the gas alarm have become below the set value, and sends a zτ alarm signal to issue an alarm. A determination circuit 5 that outputs an alarm signal, an alarm section 7 that receives an alarm signal from the determination circuit 5 and outputs an alarm in response to a commercial AC power supply, and each component of the alarm control section 3 and the semiconductor gas sensor section 1.
The power source section 9 supplies power to the heater 2, and the stable operation monitoring section 11 monitors the operation status of the power source section 9 and monitors the operation of the determination circuit 5 and the power source section 9. Eve, as the judgment circuit 5 and the alarm section 7, n1
The determination circuit 105.+tj in FIG.
This is the same as the 1st and 7th report section 107.

The power supply section 9 includes a rectification section 15 that rectifies the commercial AC power supply voltage LF inputted via the current 13, and a rectification section 15 that rectifies the commercial AC power supply voltage LF inputted via the current 13, and a rectification section 15 that rectifies the commercial AC power supply voltage LF inputted via the current 13. It has a configuration including a constant voltage section 17 that generates and supplies voltage, and a switch 16, 18 of a closed type that is provided to be able to cut off a power supply path from the constant voltage section 17.

The stable operation monitoring section 11 includes a constant voltage section 17 to an alarm control section 3.
a first comparator 19 that detects the start of power supply by detecting that the power supply voltage to each component exceeds the first reference voltage V+;
In response to the signal from the first comparator 19, the determination circuit 5 performs a determination operation according to a predetermined time period to which it takes for the gas sensing part of the semiconductor gas sensor part 1 to rise to a predetermined temperature by energizing the heater 2 from the start of power supply. The first timer 21 is set to prohibit only the first timer 21. In addition, the stable operation monitoring unit 11 compares the output voltage of the rectifying unit 15 in the power supply unit 9 with the second reference voltage V2, thereby detecting the occurrence of a momentary power cut due to some cause in the commercial AC power supply and the commercial power supply after this moment r4Ji. The second comparator 23 detects the recovery of the AC power supply, and in response to the signal from the second comparator 23 indicating the occurrence of a momentary power outage, the switch 16.18 is turned off, and the second comparator 23 is turned off. Upon receiving a signal indicating that the power has been restored from It has a second timer 25 that prohibits the predetermined time j+(<jo) to return to The determination operation of the determination circuit 5 is prohibited under unstable operation conditions, and the power supply from the constant voltage section 17 is stopped in the event of a momentary interruption of the one-way AC power supply to prevent the output voltage of the constant voltage section 17 from decreasing. By suppressing d3 as much as possible and controlling it so that it can resume operation in a short time when recovering from a momentary power outage, an appropriate gas monitoring system is ensured and an unnecessarily long period of unmonitoring is prevented. It is something.

Next, the operation of this embodiment will be explained using (A) to (G) of FIG. 2. In addition, in FIG. 2, (A> is the power supply section 9
(B) is a diagram showing changes in the output voltage of the rectifier 15, (C) and (D> are diagrams showing the stable operation of the control unit 3 from the constant voltage unit 17, respectively) A diagram showing changes in the power supply voltage to the monitoring unit 11 and the heater 2, ([
) and (F) are the first timer 21 and the second timer 21, respectively.
A diagram showing changes in the operation of the timer 25, (G) is the determination circuit 5.
It is a diagram showing whether or not a judgment is possible.

First, when commercial AC power is started to be supplied to the power supply section 9 via the outlet 13 in order to activate the gas alarm, the constant voltage section 17 is activated by the alarm control section 3 based on the DC voltage from the rectification section 15.
The required voltages are started to be supplied to the stable operation monitoring unit 11 and the heater 2, respectively (<A) to (D) in the diagram M2). Along with this power supply U) 1, the first comparator 19
By detecting that the output voltage exceeds the first reference voltage ■1, it is detected that the gas alarm has started operating, and the first timer 21 is activated to perform heating operation by energizing the heater 2. The determination operation of the determination circuit 5 is prohibited for a predetermined time to (about several minutes) required for the semiconductor gas sensing unit 1 to rise to a predetermined temperature and the detection operation to become stable (second
(E) and (G) in the figure). As a result, the semiconductor gas sensor unit 1 is able to perform stable and accurate gas detection operations, and the determination circuit 5 uses the detection signal from the sensor unit 1 to determine the gas concentration by performing an appropriate determination operation. etc., and the alarm unit 7 can be activated as necessary.

Next, under such stable monitoring conditions, when a momentary interruption occurs in the commercial AC power supply (Fig. 2 (A)), the rectifier 15
The output voltage begins to drop rapidly (Fig. 2 (B)
). The second comparator 23 detects that the output voltage of the rectifier 15 is lower than the second reference voltage 2, and converts the signal to the second
Timer 25 appears. The second timer 25
When the signal from the comparator 23 is received, the switches 16 and 18 are turned off to suppress the drop in the output voltage of the constant voltage section 17 as much as possible, and power is supplied to the heater 2 and the judgment circuit 5 of the alarm control section 3 and the alarm section 7. to stop. That is, constant voltage section 1
7. The rectifying section 15 generally has a capacitive component in its circuit configuration, and by setting it in a no-load state, the voltage drop rate is suppressed by this capacitive component.

After this, when the instantaneous interruption of the commercial AC power supply ends and the voltage returns to a stable state (Fig. 2 (A)), the rectifying section 15 and the constant voltage section 1
7 returns to the voltage before the instantaneous interruption, so the second comparator 23 detects this and outputs a signal to the second timer 25 (Fig. 11-2<8). (C)). When the second timer 25 receives this signal, it returns the switch 16.18 to the OFF state and restarts the operation of the gas alarm. The determination operation of the determination circuit 5 is prohibited for the time i+(<jo) required to recover from the temperature drop (Fig. 2 (F), (G)).
). As a result, even if there is a momentary interruption of the commercial AC power supply, the gas alarm can restart the monitoring operation with the minimum necessary waiting time after recovery.

In this embodiment, the determination operation prohibition time after the instantaneous interruption of the commercial AC power supply is set to be constant (tl), but the w4 interruption time is relatively long and the output voltage of the constant voltage section 17 is set to the first reference voltage V.
1 or less and the first timer 21 is activated after the instantaneous interruption ends, causing a predetermined period of time 1o when the judgment operation is prohibited. Therefore, as a modification, the instantaneous interruption time is measured and the It is effective to make the determination operation prohibition time after @@14 variable depending on the result.

Further, in this embodiment, a case has been described in which a semiconductor gas sensor is used as the gas detection section, but the present invention can be similarly applied to a case where a so-called catalytic combustion method or a heat conduction method is used, for example.

[Effects of the Invention] According to the present invention described above, when Il# of the power supply input to the power supply section occurs during gas monitoring, the power supply output is interrupted by 1 to the power supply section, and the power supply output voltage is reduced. By suppressing the drop as much as possible, when the power supply input is restored, gas monitoring can be restarted in a shorter time than the preparation time J = required for starting power supply from the power supply unit, eliminating unnecessary alarm failure time. A highly reliable gas alarm device can be provided.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of an embodiment of the present invention, Fig. 2 is a diagram showing a timing chart for explaining the operation of Fig. 1, and Fig. 3 is a diagram showing the configuration of a conventional device. Figure 4 is the third
FIG. 3 is a diagram showing a timing chart for explaining the operation of the diagram. 1... Semiconductor gas sensor section 2... Heater 3... Alarm control section 5... Judgment circuit 7... Alarm section 9... Power supply section 11... Stable operation monitoring section 15... Rectification Section 16... Switch 17... Constant voltage section 18... Switch 19... First comparator 21... First timer 23... Second comparator 25... Second timer

Claims (1)

[Scope of Claims] A gas detection section that is equipped with a heating means and detects a required gas under a predetermined heating state, and at least after a predetermined preparation time has elapsed from the start of power supply by a power supply section that supplies power to the heating means. In a gas alarm device that starts alarm control that determines that gas has reached a set amount based on a detection signal from a gas detection unit and issues an alarm, after the start of the alarm control, the power supply for operating the power supply unit is stopped. A power supply stop means for interrupting the power supply by the power supply section when the detection is detected, and a power supply stop means for interrupting the power supply by the power supply section when the power supply for operation of the power supply section is restored, detecting that the output voltage of the power supply section has not fallen below the set voltage and performing the preparation described above. 1. A gas alarm device comprising: restart control means for restarting alarm control after a period of time shorter than the time period has elapsed.