Rpm measuring device for IC engine

摘要

The rev measuring device uses a signal processor (15) for evaluation of a signal representing the internal pressure of the engine (10), provided by a pressure sensor (11), for determining the engine revs when the number of engine cylinders in known. The internal pressure of the engine (10) may be obtained by a sensor at the oil dip-stick opening, the oil filling point, or the air filter connection, coupled by a signal modification stage (13) and a comparator (14) to a signal processor, receiving a second input from the electrical generator (17) driven by the engine through a filter (19) and a comparator (20) and controlling a rev display (16).