Ignition system for internal combustion engines

摘要

In order to reduce the amount of ignition energy supplied to an ignition coil during low speed operation of the engine, an electronic circuit is provided to regulate the open time of the ignition circuit to be constant in an upper engine speed domain and to then obey a predetermined characteristic in the mid-range. The mid-range control is gradually made ineffective at lower engine speeds where the open ignition interval is determined by speed as measured by the duty cycle of the engine ignition transducer. The change of characteristics is obtained with the aid of a control voltage source which generates a speed dependent control voltage causing the discharge time of a capacitor to be extended at low engine speeds and causing the termination of the open time of the ignition to be determined by the transducer output signal.