BigPatents India

A dc power supply circuit, for the control unit of a CDI Unit, deriving input power from an excitor coil of the alternator of an i.c. engine, from a single wire input during the positive wave of the excitor coil ac supply, comprising a transistor; a zener diode connected to the base of the transistor and a first capacitor connected to the emitter of the transistor, to form a switching circuit, such that whenever the sum of the voltages across the first capacitor and the base-emitter voltage equals the voltage across the zener diode, the transistor suddenly switches off, stopping the charging current flowing through the excitor coil, to produce an "inductive kick", thus boosting the input voltage itself and avoiding a drop in the voltage of the second capacitor, namely, the capacitor of the CDI Unit.