Engine revolution rate computation arrangement which is not influenced by pulsed rotation of engine at low speeds

摘要

The arrangement measures time required to rotate through a defined angle each time the crankshaft rotates through the angle, and computes a corresponding engine revolution rate. A device determines whether the computed rate is lower than a predefined revolution rate. If the rate is lower than the defined rate a value is divided by a time required to rotate through a multiple of the defined angle to compute the engine speed. If the rate equals or exceeds the defined rate the value is divided by a value equal to a multiple of the time required to rotate through the defined angle.