A car contained automotive speed control system is described. Electrical signals generated by a speedometer operated switch are amplified by a transistor controlling a solenoid valve. This valve modulates manifold vacuum supply to a diaphragm which controls the engine throttle, maintaining a precisely preselected speed. Components and system operation are outlined, with a description of driver operated controls and circuitry.
The AC Electro-Cruise concept has resulted in a constan speed throttle control which can be economically produced to fill today's super highway cruising needs. There is considerable design flexibility for adapting to the individual desires of various car manufacturers and for filling future needs.