| 摘要 |
PURPOSE:To provide always a constant primary current supplying time by providing an ignition position determining circuit having a capacitor charged and discharged by constant current and another capacitor charged and discharged by different constant current. CONSTITUTION:A current supply starting position determining circuit 8 has a first integrating circuit 81 charged by constant current and a second integrating circuit 82 charged by constant current having a different size, and when the potentials of both circuits are equal to each other, a comparating circuit 85 generates the output of current supply starting signal. While a pulse signal generating circuit 83 generates a first pulse, the position determining circuit 8 makes a first capacitor C1 discharge, and when said circuit 83 generates a second signal, it charges the capacitor with constant current. Also, a second capacitor C2 discharges instantaneously according to the first pulse signal and is charged by first charging current until ignition position and by second small charging current until a second pulse is generated. Thus, ignition coil energizing current can be maintained constant irrespective of the rotational frequency and ignition position of an engine. |
