Ignition system for internal combustion engines

Abstract

Abstract In an ignition system for internal combustion engines having a magneto generator for charging a capacitor and a thyristor for discharging the capacitor through an ignition coil upon receiving an ignition signal, an auxiliary capacitor and an associated transformer are provided as a source of the ignition signal. The auxiliary capacitor is charged through the transformer by each half-cycle of the magneto generator output of the opposite polarity with respect to the charging half-cycle of the capacitor. The auxiliary capacitor is discharged through the gate-cathode path of the thyristor under control of an auxiliary switching element to which a timing signal generator provides a timing signal at a proper ignition time. Since a short circuiting switching element connected across the auxiliary capacitor has the control electrode connected to receive through a resistor each half-cycle of the magneto generator output following the half-cycle of the magneto generator output during which the auxiliary capacitor is charged, if no timing signal has been applied to the auxiliary switching element the auxiliary capacitor will necessarily be short circuited. When the engine is rotating in the normal direction, the timing signal is only required to be generated during a time period from the completion of charging of the auxiliary capacitor until the short-circuiting switching element is turned on and this allows a sufficient range of advance angle. In the reverse rotation of the engine, the auxiliary capacitor is short circuited before the timing generator generates the timing signal resulting in the termination of the reverse rotation.

Inventors

• 👤 Masahiro Asai

Bibliographic Details