JPS6097497A - 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 FIELD OF INDUSTRIAL APPLICATION The present invention relates to a gas leak alarm that is installed in a kitchen or the like to detect and issue an alarm for gas leaks.

Conventional configuration and its problems A conventional example will be explained based on FIG.

1 is a power supply circuit for stabilizing the father current power supply to direct current.

Reference numeral 2 denotes a semiconductor type gas sensor whose resistance value changes depending on the gas concentration, and the resistance value decreases when gas leakage is detected. 3 is a processing circuit that calculates the resistance value of the semiconductor gas sensor 2 using a built-in comparator and issues a signal when the resistance value is less than a reference value. Reference numeral 4 denotes an alarm circuit that receives the signal from the processing circuit 3 and issues an alarm using means such as emitting an alarm sound.

In the above-mentioned conventional configuration, current always flows through the alarm circuit 4, and in particular, in a gas leak alarm that is continuously energized 24 hours a day, the consumption rate increases by 1k per month. It had the disadvantage that the alarm was small, and the alarm method was controlled by a piezoelectric buzzer or the like, which had low power consumption.

Purpose of the Invention The present invention eliminates the drawbacks of the conventional example, and minimizes the power consumption during the monitoring condition, which indicates the majority of the time the gas flash alarm is used, and only when the gas flash alarm is used. The object of the present invention is to provide a gas leak alarm that uses a large force and has an effective alarm function.

The gas deflection alarm of the present invention includes a power supply circuit that supplies a stabilized DC voltage, a semiconductor gas sensor whose resistance value changes depending on the gas concentration, and a resistance value of the semiconductor gas sensor. By receiving either a processing circuit that detects a change and issues a signal, and a signal from this processing circuit or a signal from an alarm circuit, the 14F
This is a gas leak alarm consisting of a switch circuit that switches A, and an alarm circuit that emits an audio signal while sending a signal to the switch circuit when there is a signal from the processing circuit described in niJ. In the state where it is not, the alarm circuit has all<': LL flow k fA? I made sure not to do that.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. A transformer 6 transforms the voltage into voltage, and a diode bridge 7 converts the voltage into DC, which is stabilized by a Zener diode 8.

9 is a semiconductor type gas sensor, and resistors R+ and Rz.

It consists of R3 and the Purinon circuit. This resistance R1~R
5 and voltage comparator 1Q constitute a processing circuit 11, and resistor R1
, R2, and the sensor voltage V2 f, which is divided by the semiconductor gas sensor 9 and the resistor R3, is compared.
Output. Normally, when no gas fluctuation occurs, the resistance value of the semiconductor gas sensor 9 is large, and the sensor voltage v2
is configured to be lower than the reference voltage v1, so the output voltage v3 is maintained at OV. If the semiconductor gas sensor 9 detects a gas leak, the sensor voltage v2 rises above the reference voltage v1, and the output voltage v3 rises to the circuit voltage v.
It becomes cC.

Then, a current limited by the limiting resistor R4 flows through the light emitting diode 12, lighting it up and notifying the light emitting diode 12 of a gas leak. Furthermore, 'the output voltage v3 of the voltage comparator 1o is
The switching transistor 14 is turned on. The OR circuit 13 and the switching transistor 14 constitute a switch circuit 16. When the switching transistor 14 is turned on, the power supply Vcc is also supplied to the subsequent circuits, so the microcomputer 16 becomes operational, but in this state it receives the gas leak signal from the voltage comparator 10, so the gas leak is detected. At the same time, a sound signal 7' is sent to the logical sum circuit 13.
−jSignals the meaning that is occurring.

A D/A converter 17 converts the digital signal of the microcomputer 16 into an analog signal, and outputs the analog signal. Reference numeral 18 is an operational amplifier for increasing the output signal of the D/A converter 1.1 The analog signal increased [1] by the operational amplifier 18 is turned into audio by the speaker 19 to notify gas leakage. lThis microcomputer 16° D/A converter 17. Operational amplifier 18. The speaker 19 constitutes an alarm circuit io.

Furthermore, even if the gas leakage disappears while the sound is being generated and the output voltage v3 of the voltage comparator 10 becomes OV, the signal from the microcomputer 16 is still supplied to the first logic circuit 13. Transistor 14 is ON
Since the state (3) continues and therefore the power supply continues thereafter, the series of alarm sounds is not interrupted.

At the end of the series of alarm sounds, the signal indicating that the sound is being generated from the microcomputer 16 is turned OFF, all inputs to the OR circuit 13 are turned OFF, and the switching transistor 14 is also turned OFF, preventing the subsequent circuits from being affected. Configured to stop supply.

Effects of the Invention As described above, the present invention minimizes the power consumption of the gas leak alarm when it is in the monitoring state, reducing the burden on the user. It is possible to carry out alarms, control, etc. using a voice with a large alarm effect, and it is extremely effective and economically advantageous in practical use.

[Brief explanation of the drawing]

J is a block diagram of a 12th conventional gas leak alarm device, and a 21st block diagram of an embodiment of a gas high W external device of the present invention. 5...'ili source circuit, 6...Transformer, 7...Diode bridge, 8...Zener diode, 9...Semiconductor gas sensor, R
1-R3...Resistor, 10...Voltage comparator, 11...Processing circuit, R4...Limiting resistor, 12...Light emitting diode, 13...OR circuit, 14...Swiss tink transistor, 1
6... Switch circuit, 16... Microcomputer, 17... D/A converter, 18...
・Operational amplifier, 19...Speaker, 2o...
・Alarm circuit. Name of agent: Toshio Nakao, Physician, and 1 other person Figure 1

Claims (1)

[Claims] A power supply circuit that supplies a stabilized DC'1u pressure, a semiconductor gas sensor whose resistance value changes depending on the gas concentration,
A processing circuit detects a change in the resistance value of this 17.4-unit gas sensor and issues a request, and the power supply of the alarm circuit is switched by receiving either a signal from this processing circuit or a signal from the alarm circuit. and an alarm circuit that emits an audio signal while emitting a signal to the switch circuit when there is a signal from the processing circuit (1).
A gas leak alarm consisting of 4 parts and 7 parts.