Kohler Company

Jeffrey S Stueven

William T Volmary

An ignition system for an engine includes a position detector that generates a signal pulse while a segment of a member driven by the engine rotates past a given angular position. A first circuit produces a speed indicative voltage having a magnitude that is proportional to a duration of the signal pulse from the position detector. Upon termination of the signal pulse, a second circuit produces a second voltage the magnitude of which varies exponentially and an offset voltage is added to the second voltage at a node if the signal pulse is absent. A comparator has inputs coupled to the node and to the first circuit and produces an ignition signal when the voltage at the node and the speed indicative voltage are substantially equal.

Apparatus and method for controlling ignition of an internal combustion

A system for controlling the air/fuel ratio input to a small engine measures the oxygen level in the engine's exhaust and compares it with a reference level. A stepper motor controls the air/fuel ratio and it is advanced one step each time a clock pulse is produced in a direction determined by the level of exhaust oxygen. A fault detector circuit stops the engine if the sensed oxygen level is outside a preset range for more than a preset time interval.

Growing community of inventors

Howards Grove, WI, United States of America

Jeffrey S Stueven