Patent ID: 7207325
Filing Date: 2007-04-24
Classification: F02P

Abstract:
1. An ignition system for an internal combustion engine to be connected to an ignition coil and a circuit for providing an ignition signal, said ignition system comprising: a switch circuit connected to the ignition coil to switch on or off current supplied to the ignition coil; a control circuit, having an input terminal connected to said circuit for providing the ignition signal, for providing a control signal for controlling said switch circuit based on the ignition signal; a protection circuit including an input terminal that receives the ignition signal from the circuit for providing the ignition signal, a capacitor, a first NPN transistor having a collector connected to the input terminal of said protection circuit and the input terminal of said control circuit, an emitter connected to a ground, a base connected to the input terminal of said protection circuit via said capacitor and a parasitic diode between the collector and the emitter, wherein a prescribed capacitance is formed between the base and the collector of said first NPN transistor.