| 摘要 |
PURPOSE:To improve a safety and reliability of the combustion device when non-combustion gas is produced by a method wherein an alarm is produced by a voltage comparater which is operated under a low level of variation in resistance in the non-combustion gas sensor and a distingushing operation is performed by a voltage comparator having a high operation level. CONSTITUTION:When a lack of oxygen is produced, a resistance in a semiconductor gas sensor 25 is decreased by non-combustion reducing gas produced. With this reduction in resistance, at first the output of the operation amplifier 48 is made high and the alarm buzzer 50 is operated. Thus, the ventilation can be performed. Further the lack of oxygen is proceeded, a decrease in resistance of the gas sensor 25 is also proceeded, the output of the operation amplifier 40 is made low, the transistors 45 and 46 are turned off, the solenoid 6 is deenergized, the wick is lowered to perform a extingushihg operation and at the same time entire electric circuit is turned OFF. Thereby, when the oxygen is in short, the safety and reliability of the operation can be assured. |
