Abstract: An engine control apparatus comprises a revolution speed sensor for detecting the number of revolutions of an internal combustion engine, an abnormality detecting means for detecting abnormality in the engine, and a control means for increasing or decreasing the number of misfire cylinders so that the revolution speed of the engine is brought down by a limited degree corresponding to a degree of abnormality of the engine when the abnormality is detected.

Abstract: A knock control apparatus of ignition timing control type according to the present invention comprises, as one aspect thereof, a knock control level increasing means for augmenting a knock phenomenon suppressing function, so that, when the knock interval is short, the output characteristic of the integrating means is increased to raise the control level for suppressing the knock generating element in each cylinder of the engine, and that the integrating means output characteristic is invalidated when the condition of the internal combustion engine reaches the normal operating state. The knock control apparatus comprises, as another aspect thereof, a reset pulse generation circuit for resetting the voltage from the above integrator to zero at the interval of more than a predetermined number of times the ignition cycle and in synchronism with the ignition signal.

Abstract: An engine-igniting signal generation apparatus comprises a flywheel rotatable with the crank shaft of an internal combustion engine, a field magnet attached to the flywheel, and a plurality of pickup devices provided facing the field magnet to produce ignition signals in synchronism with the rotation of the flywheel. The cores of the pickup devices are formed by a substrate body of one piece; each coil wound around the cores connects to a terminal, to output the ignition signals, and is covered with an insulating material.