Control circuit for use with air-diverter valve of internal combustion engine

Abstract From the Canadian patent

Abstract An electronic control circuit for actuating a solenoid-operated air-diverter valve or valves connected with the exhaust manifold of an internal combustion engine, to supply supplemental air thereto. The supplemental air reacts with some of the hot exhaust gases producing other gases which are in general less toxic than those coming directly from the engine. The circuit responds to engine speed in such a manner that after a, predetermined period of operation has elapsed during which the speed was continuously above a predetermined value, the normally energized solenoids are shut off to thus close the diverter valves and thereby interrupt the flow of supplemental air to the exhaust …