Ignition apparatus for an internal combustion engine

摘要

The ignition apparatus includes an electronic control unit and an igniter. The igniter detects ions resulting from ignition, and sends an ion current output signal to the electronic control unit. The igniter has a waveform shaping circuit and an ion current detecting/outputting circuit. The waveform shaping circuit is adapted such that a voltage at an input terminal thereof becomes higher than a predetermined reference voltage to turn the switching element ON when the ignition signal is caused to flow through an electric load. The ion current detecting/outputting circuit has an output terminal which is connected to the input terminal and outputs therefrom an ion current output signal obtained as a result of conversion of an ion current, and is adjusted such that the voltage at the input terminal at the time when the ion current output signal is outputted to the electronic control unit becomes lower than the reference voltage.