| 摘要 |
PURPOSE:To restrain sudden increase in a current and reduce the consumption of current by providing a one-shot multiple circuit in the DC-DC convertor of an ignition device of an internal-combustion engine and feeding a primary current to an ignition coil later than a power switching element is turned off. CONSTITUTION:A one-shot multiple circuit 30 is provided in the timing control circuit of a DC-DC convertor 10. In a low speed range in which the OFF time of a power transistor 3e is longer than a one-shot time, the DC-DC convertor 20 operates only during the one-shot time. Conversely, in a high speed range in which the OFF time is shorter than the one-shot time, the DC-DC convertor 20 operates only during the OFF time. Thereby the sudden increase in a primary current in an ignition coil can be prevented reducing the consumption of current of the DC-DC convertor. |
