| 摘要 |
PURPOSE:To enable always an appropriate ignition timing control to be carried out, by providing an ignition angle setting means which holds the ignition angle at a fixed angle independent of an indicator signal indicating the internal pressure of a cylinder, when an engine is under a low-speed rotational operating condition. CONSTITUTION:An indicator signal, indicating the internal pressure of a cylinder, generating circuit 1, and a reference position signal, indicating that a crank-angle position has reached the reference position, generating circuit 3 are provided. And whenever the reference position signal is generated, the maximum value of the indicator signal is retained in a peak-hold circuit 4, and when the indicator signal itself becomes lower than this maximum value, the indicator signal is generated from a comparison circuit 5. Whenever this indicator signal is generated, the count value of a counter 6 is latched by a latch circuit 10, and when the relevant count value reaches a prescribed value, a read-command signal is supplied from a decoder 11 to an ignition angle setting circuit 8. The ignition angle setting circuit 8 is so constituted that when the number of revolutions of the engine is less than a prescribed value, the ignition angle is made to hold a fixed angle. |
