| 摘要 |
PURPOSE:To increase safety of firing operation by control of opening of a fuel valve depending on an ignition signal while an ignition timing in a device which controls opening of a fuel valve by detection for existence of a flame. CONSTITUTION:When a power-supply is on, an integrated circuit 1 inputs a time measuring clock pulse from a terminal 8 of a power circuit 5, and starts to measure a prepurging timing, and energizes a magnetic relay 12 for a fan to begin a prepurge. When the prepurging timing has passed, a magnetic relay 11 for a fuel valve is turned ON and fuel is supplied and operation of an ignition circuit 2 is ignited. A firing is detected by a flame detecting circuit 3 and an ignition signal operates a steady burning through the integrated circuit 1, while no ignition signal during an ignition timing results in OFF of magnetic relay 11, 12 and stops a firing operation. |
