Cycle to cycle engine roughness sensor

Abstract From the Canadian patent

A roughness sensor for measuring cycle-to-cycle decreases in engine speed comprises engine-event responsive flip flop means for controlling the alternate store-up and subsequent count-down of contents into a first storage means simultaneously with the alternate count-down and the store-up of contents into a second storage means. The storage means feed respective first and second comparators that produce respective first and second output pulses the widths of which are determined by the interval between the time a corresponding storage means is counted down to its starting value and the time of the next flip flop transition. A raw roughness output pulse in the form of just one but not both …