| 摘要 |
PURPOSE:To operate a combustion control circuit into safe direction when the circuit is faulty by a method wherein a means to detect the non-operation of a reset circuit and another means to control the safety operation of the combustion control circuit in accordance with the detection of non-operation effected by the detecting means for the reset circuit are provided in the device. CONSTITUTION:When a reset signal is not outputted upon throwing electric source in due to the fault of the reset circuit 11, the initial clear of a program counter in a micro-computer 10 is not effected, therefore, run away of program is caused. Accordingly, the program is not started from a head address, therefore, an INS flag will never be set at 1H. However, INS flag not equal to 1H is decided by a check after passing a main control process and, accordingly, the output level of an output terminal D1 is set to and held in a low level forcibly. A relay Ly is held impossible to operate by the low level whereby a solenoid pump, an ignitor and a fan motor are prohibited to operate and the safety of the device may be kept. |
