Abstract: An ignition system for an internal combustion engine comprising a semiconductor switching device, which is controlled by a control unit, is disclosed. In response to an output from a device for detecting a shorting breakdown or a heat generation of a power switching device, the power switching device and the ignition coil are cut off from a power supply by a current cut-off device. Even when the power switching device is broken by shorting, the power generation due to continuous energization of the ignition coil is prevented, thereby preventing the ignition coil from being heated abnormally.

Abstract: An ignition apparatus of electronic distribution type for a multi-cylinder internal combustion engine, comprising a plurality of ignition circuits each having an ignition coil and a power switching element for one or two cylinders of a multi-cylinder internal combustion engine is disclosed in which the ignition circuits are arranged into a plurality of ignition systems each having at least two of the ignition circuits and a signal current-limiting circuit is provided for each of the ignition systems to control the currents flowing through the power switching elements of the associated ignition circuits.