| 摘要 |
PURPOSE:To permit to detect abnormality such as faulty parts, disconnection or the like by a method wherein monitoring whether the abnornality is generated in the control circuit is effected during a stationary operation after finishing pre-check. CONSTITUTION:A monitoring circuit 3 receives the output signal of an oscillating circuit 2 and outputs a monitoring signal, consisting of a high value signal of constant frequency and constant pulse width from terminals (1), (3). In a flame detecting circuit 4, a P channel FET41 is intercepted when the terminal 1 is low value while an N channel FET42 is conducted under a condition that the flame is not detected but is intercepted under a condition that the flame is detected. On the other hand, the channels FET41, FET42 are conducted when the terminal (1) is high value and the same condition as the condition that the flame is not detected is produced. In case the control circuit 1 is normal, the normal signal of a predetermined level is outputted to the base of a transistor 5 to intercept the circuit 1. According to this interception, the voltage of the transistor 5 becomes a high value and a normality detecting signal is inputted into the terminal (2) of the circuit 3. Existence of the abnormality in the circuit may be decided by deciding the existence of the normality detecting signal through a deciding circuit 31. |
