Electrical overspeed control for an engine

Claim 1

An overspeed control system for an internal combustion engine having an ignition circuit and throttle control means, said control system including a reversible electric motor adapted to be connected with said throttle control means, a speed signal circuit adapted to be connected with said ignition circuit for developing an analog voltage corresponding to engine speed, a level detector connected with said speed signal circuit for developing a speed logic signal having one logic state when the engine speed exceeds a predetermined value and another logic state when the engine speed is less than said predetermined value, a flip-flop having first and second inputs and first and second outputs, said first output being at logical high when said first input is at logical high and said second output being at logical high when said second input is at logical high, an inverter having its input connected with the output of the level detector and having its output connected with the first input of the flip-flop, the output of said level detector also being connected with the second input of the flip-flop, said reversible motor having a forward winding and a reverse winding, a first power transistor coupled between the first output of said flip-flop and one of said windings and a second power transistor coupled between the second output of said flip-flop and the other of said windings, whereby said windings are selectively energized one at a time in accordance with the logic state of the output of said level detector.