Contactless ignition system for internal combustion engine

Claim 1

An ignition system for an internal combustion engine comprising: a source of alternating current ignition signals produced in time relationship with the engine; a direct current power source; an ignition coil having a primary and a secondary winding; a switching transistor having a base and a collector-emitter path connected in series with said primary winding; means for connecting said primary winding and said collector-emitter path across said direct current power source; means responsive to each cycle of said alternating current ignition signals for operating said switching transistor conductive and nonconductive in timed relationship with the engine; and means, connected to said direct current power source, and said switching transistor, for bypassing a portion of the base current of said switching transistor when the voltage of said direct current power source exceeds a predetermined value thereby limiting the magnitude of primary current flowing through said primary winding to a predetermined magnitude, said bypassing means including a zener diode for sensing the predetermined value of said power source of voltage; and a bypassing transistor for bypassing a portion of the base current of said switching transistor; said zener diode being connected between said power source and the base of said bypassing transistor, and said bypassing transistor having a collector-emitter path connected across the base-emitter path of said switching transistor.