Noise immune crankshaft pulse position developing apparatus

摘要

A digital system for providing pulses that represent the position of an engine crankshaft that has a digital filter for filtering out pulses caused by noise. A square wave signal having voltage pulses that represent crankshaft position is applied to the input of the filter. The filter determines whether or not the high and low time periods of the square wave signal exceed a predetermined time period and based on this determination ignores or passes pulses of the square wave to the output of the filter.