Abstract: Apparatus and method for detecting the direction of rotation of an internal combustion engine using a magnet wheel which moves past an electrical ignition coil. For each revolution, at least one current or voltage pulse is induced in the coil having a polarity dependent on the direction of rotation. The magnet poles and the coil have geometric relationships that, upon each magnet wheel revolution, the curve form of the current or voltage pulse has at least two prespecified extreme points with a curve characteristic which is substantially neither rising nor falling and at least one break point with a discontinuity. A direction of rotation signal is derived from these curve characteristics.

Abstract: A revolution threshold regulator and/or toggle switch has a first and a second fixed phase source of alternating current having a frequency proportional to the revolution speed of a rotor of an internal combustion engine. A trigger device scans the alternating currents to emit a control signal at a revolution threshold above or below a preset revolution threshold. The trigger device has a timer module which cooperates with one of the alternating current sources through a trigger charge element which can be discharged via at least one discharge path to create a control signal. The trigger charge element, as it discharges, sends a control current through a series Zener diode in a blocking direction to the control signal output.