| 摘要 |
PURPOSE:To protect a spark plug and an engine from trouble due to too early ignition, by detecting the preignition caused on the spark plug and knocking, to delay ignition time. CONSTITUTION:Preignition on a spark plug P is detected by a preignition detection circuit 10 to generate an output signal corresponding to the occurrence time (interval) of the preignition, magnitude of current or voltage of the preignition, the frequency of the preignition occurrence or the like. The knocking of an engine is detected in terms of a signal from a knock sensor 3A made of a piezoelectric element or the like, so that a circuit 30 generates a knocking output signal. Both the output signals are applied to the base of a power transistor T which constitutes a spark delay control circuit 40. The circuit 40 produces a control signal to delay ignition time. The spark discharge time is thus adjusted. |
