JPH0378651A - Carbon monoxide detector - Google Patents

Abstract

PURPOSE:To shorten a voltage applying time to a CO-gas sensor and to reduce power consumption by repeating operation such that the CO-gas sensor is operated fro a predetermined time after a definite time is elapsed from the point of time when the temp. of a combustion device rises and subsequently stopped. CONSTITUTION:When the temp. sensor 1 mounted on a combustion device detects definite temp. or more, the first timer 2 starts counting and outputs a signal to the second timer 3 after a definite time is elapsed. The timer 3 applies voltage to a CO gas sensor 4 and starts counting. When the detection signal of the sensor 4 does not exceed a predetermined time within a certain preset time, the application of voltage to the sensor is stopped and, at the same time, the timer 3 stops counting while the timer 2 starts counting and, thereafter, these operations are repeated. When the sensor 4 during operation detects CO exceeding the set value of the second judging circuit 8, a buzzer 7 is sounded.

Description

[Detailed description of the invention] [Objective of the invention] (Industrial application field) This invention detects carbon monoxide gas (hereinafter referred to as CO gas) generated during incomplete combustion from a combustor such as a water heater. The present invention relates to a CO gas detector, and particularly to a CO gas detector that can reduce power consumption.

(Prior Art) Gas leak alarms using catalytic combustion sensors have conventionally used an ACq source. Also, among these gas leak alarms, some CO gas detectors are portable, and in this case, the power source is a Ni-Cd battery, etc., and the battery is charged and used, or the dry cell battery is replaced. Was.

(Problem to be solved by the invention) When selectively detecting CO gas with a catalytic combustion sensor, the heater installed in the sensor must be used at a relatively low temperature compared to when detecting hydrogen gas or methane gas. However, it still needs to be used at about 200°C all the time. For this reason, it is possible to use an AC 100V power source as a power source for heating the heater, but if a Ni-Cd battery or a dry battery is used, it cannot be used for a long time.

On the other hand, since combustors such as water heaters do not normally use AC 100V power, it has not been easy to connect a CO gas detector to AC 100V power.

The present invention has been made in view of the above points, and an object of the present invention is to provide a CO gas detector that consumes less power and can be used for a long time with a power source such as a dry battery.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a CO gas detector for detecting CO gas generated from a combustor, including a temperature detection means for detecting the temperature of the combustor; a gas detection means for detecting CO gas generated near the combustor; a first timer for measuring time after the temperature detected by the temperature detection means reaches a predetermined temperature; and the first timer. a second timer that starts operating after a predetermined time period measured by the gas detection means and controls the power supply circuit of the gas detection means;
The present invention is characterized in that it includes a first determination circuit that outputs a signal to stop a timer, and a second determination circuit that simultaneously sounds a buzzer.

(Function) According to the above configuration, after the temperature of the combustor reaches a certain temperature, a voltage is applied to the CO gas sensor, which is the gas detection means, after a certain period of time has elapsed, and the CO gas sensor starts operating. If the sensor does not detect CO gas within a predetermined time, the voltage applied to the sensor is turned off, and after the predetermined time elapses, the voltage is applied to the sensor again to repeat the above operation.

During this time, if the sensor detects CO gas and the value exceeds the value set in the first determination circuit, a voltage is continuously applied to the sensor and the monitoring state continues. Further, if the value exceeds the value set in the second determination circuit, a buzzer sounds. If the output of the sensor becomes less than the value set in the first judgment circuit,
The voltage applied to the sensor is turned off and the above-described operation is repeated. Further, if the temperature of the combustor is below a certain temperature, all circuits are turned off.

As described above, since the time during which voltage is applied to the sensor is short, power consumption is low and batteries or the like can be used as a power source for a long time.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment.

A temperature sensor 1, which is a temperature detection means such as a thermistor, is attached to a combustor (not shown) such as a water heater.
A first timer 2 and a second timer 3 are connected in series to the temperature sensor 1. The first timer 2 is the temperature sensor 1
starts counting when the signal detects a predetermined temperature,
Counting is stopped when a preset time has elapsed, and a signal is output to the second timer 3 at the same time.

A sensor power supply circuit 5 that applies voltage to the CO gas sensor 4 is connected to the second timer 3, and the sensor 4 is turned ON via the sensor power supply circuit 5 by the output signal from the first timer 2, and the sensor 4 is simultaneously counted. The counting is started, and when a preset time has elapsed, the counting is stopped, and at the same time, the sensor 4 is turned off via the sensor power supply circuit 5.

The CO gas sensor 4 includes a first determination circuit 6 that outputs a signal to stop counting of the second timer 3 when the output of the sensor 4 exceeds a first set level, and a A second determination circuit 8 is connected which causes a buzzer 7 to sound when the set level is exceeded.

Next, the operation of this embodiment will be explained with reference to the time chart shown in FIG.

For example, the gas supplied to a combustor such as a water heater is combusted,
When the temperature sensor (P) 1 attached to the combustor reaches 50° C. or higher, the first timer (T1) 2 starts counting. For a preset 10 minutes after the first timer (T1) 2 starts counting, the second timer (T2) 3 does not operate and the CO gas sensor ( No voltage is applied to C). When 10 minutes have elapsed, the first timer (T1)2 switches to the second timer (T2).
3, a signal is simultaneously output to the sensor power supply circuit (H) 5 as shown in FIG. 2(b), and a voltage is applied to the CO gas sensor (C) 4 from a dry cell or the like (not shown). At this time, the counting of the first timer (T+)2 is stopped.

The second timer (T2) 3 starts counting by the signal from the first timer (T1) 2, and the detection signal of the CO sensor (C) is sent to the first determination circuit 6 within a preset 4 minutes. If the set value SIa is not exceeded, the count will be stopped after 4 minutes, and at the same time the sensor power supply circuit (H) will be turned off.
Apply voltage to the CO gas sensor (C) 4 via O
FF.

Then, the first timer (T+) 2 starts counting for 10 minutes again, and the above operation is repeated thereafter.

Note that the initial 30 seconds of the 4 minutes during which voltage is applied to the CO gas sensor (C) 4 are used for heating up and initial stabilization period to stabilize the sensor output, and the actual sensor operation time is 3 minutes and 30 seconds. becomes.

As shown in Fig. 2 (C), when CO gas with a value exceeding the value 51a set in the first judgment circuit (Sl) 6 is detected during the operating time of the CO gas sensor (C) 4. teeth,
The 4-minute time setting of the second timer (T2) 3 is canceled, and a voltage is continued to be applied to the CO gas sensor (C) 4, resulting in a continuous monitoring state. In addition, a CO gas sensor (
C) If 4 detects CO gas having a value exceeding the value S2a set in the second determination circuit (S2) 8, the buzzer 7 sounds.

The output of the CO gas sensor (C) 4 is determined by the first judgment circuit (S+
)6, the second timer (T2)3 stops counting, the voltage application to the CO gas sensor (C)4 is also turned off, and the first timer (T2)3 stops counting again. T+)2 starts counting, returns to the state shown in FIG. 2(b), and repeats the above operation.

In addition, regardless of the above state, the temperature sensor (P) 1
When the output falls below the set temperature of 50°C, all circuits are turned off. For this reason, it is desirable to set the temperature to about 50° C. so that the circuit does not turn off immediately after extinguishing a combustor such as a water heater.

According to the present embodiment, the value of CO gas detected by the CO gas sensor 4 is the set value 31 a set in the first determination circuit 6.
If it is below, the CO gas sensor 4 is used only for 4 out of 14 minutes.
Since voltage is applied to the combustor and voltage is not applied except when the combustor is in use, unnecessary power consumption can be eliminated. In addition, since the power consumed in each circuit other than the CO gas sensor 4 is small, dry batteries or Ni-C can be used as a power source.
D batteries can be used for long periods of time.

The set temperature and each set time shown in the above embodiments are merely examples, and the present invention is not limited to these values.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to eliminate unnecessary power consumption of the CO gas sensor when the combustor is not used, so that it can be used for a long period of time even if a dry battery or the like is used as a power source.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
FIG. 2 is a time chart similarly explaining the effect. 1... Temperature detection means (temperature sensor) 2... First timer 3... Second timer 4... Gas detection means (CO gas sensor) 5... Power supply circuit 6... First Judgment circuit 7...Buzzer 8...Second judgment circuit

Claims (1)

[Scope of Claims] A carbon monoxide gas detector for detecting carbon monoxide gas generated from a combustor, comprising: temperature detection means for detecting the temperature of the combustor; and carbon monoxide gas generated near the combustor. a first timer that measures the time after the temperature detected by the temperature detection means reaches a predetermined temperature; and a first timer that is activated after the predetermined time measured by the first timer has elapsed. a second timer that starts the gas detection means and controls the power supply circuit of the gas detection means; and a first timer that outputs a signal to stop the second timer when the output of the gas detection means exceeds a predetermined value. A carbon monoxide gas detector comprising a determination circuit and a second determination circuit that simultaneously sounds a buzzer.