| 摘要 |
PURPOSE:To provide a small and convenient safety device by a method wherein a relay energized and operated in accordance with a gas concentration less than the desired value is arranged in an abnormal sensor circuit and its normal- open contact point is arranged in a driving circuit. CONSTITUTION:When CO concentration is at a normal value less than the desired valve and a burner 2 is operated under a normal combustion state, CO sensor 9 is held at a high resistance value less than the desired value of CO concentration, so that both of the transistors 8 and 8 are turned on, the relay 5 is energized and operated under an action of dry cell 7, resulting in closing the contact point 5a. During combustion in the burner 2, as CO concentration becomes an abnormal value more than the desired value, a thermocouple 4 is heated to generate a desired electro-motive force. However, both transistors 8 and 8 are turned off and the energization for the operating solenoid 1a is deenergized and the solenoid safety valve 1 is closed and then the combustion in the burner 2 is stopped to show a safe operation. |
