A TACHOMETER SYSTEM FOR AN INTERNAL COMBUSTION ENGINE WHICH SENSES AN ELECTROMAGNETIC SIGNAL PRODUCED BY A FIRING OF THE ENGINE

摘要

A tachometer system for an internal combustion engine. The tachometer system uses one of two electromagnetic pulse sensing means to detect an electromagnetic signal produced by a firing of the engine. The sensing device may be an antenna or an inductive pickup. One of the signals is chosen and processed. A parameter indicative of pulse timing in the output signal is determined. This parameter is most advantageously a time between different ones of the output signals. The parameter is then converted into a value indicative of revolutions per unit time of the engine. The converting structure is advantageously formed by a personal computer.