| 摘要 |
PURPOSE:To assure a prescribed spark time and cause stable ignition even in the rapid rotation of an engine, by providing a turn-off time control circuit to interrupt the starting of energization of an ignition coil, for a prescribed time after ignition. CONSTITUTION:The output of a rectangular wave shaping circuit 2, which produces a rectangular wave signal synchronously with an internal combustion to determine the degree of opening and closing in a low-speed range, is applied to an OR circuit 5. A pulse signal, which is generated by a turn-off time control circuit 4 through an F-I conversion circuit 3 in response to the rectangular wave signal after a prescribed quiescence time represented as Ao(Fo-F)/F where Ao denotes a constant, Fo denotes a variable and F denotes rotational frequency, is also applied to the OR circuit 5 to drive a transistor 8. According to this constitution, the duty factor Ti/T in the constant current time T1 of the transistor is controlled constant and the current of an ignition coil is reached a prescribed constant level ico in any rotation range. This results in attaining stable spark performance. |
