Internal combustion engine ignition device and igniter for same

Abstract

An internal combustion engine ignition device able to suppress misfires etc. at abnormal times and achieving smaller size and lower cost, provided with an IGBT (switching device SW), a current limiting circuit for limiting a primary current running through the IGBT to within a predetermined value, a fast gate voltage drop circuit for making the gate voltage of the IGBT fast drop to an extent where spark discharge occurs at the spark plug, an abnormality detecting circuit for detecting an abnormal state of an igniter or electronic control unit and outputting an abnormality detection signal, and a slow gate voltage drop circuit having a gate voltage feed cutoff circuit for cutting off the feed of the gate voltage at an abnormal time and a discharge circuit for discharging the gate capacitor charge of the IGBT to make the gate voltage slowly drop to an extent where no spark discharge will occur at the spark plug.