Control circuit for electric motors

Claim 1

A control circuit for an electric motor having a plurality of driving coils and a rotor driven by the successive energization of said coils, said control circuit comprising: a plurality of switching means, each arranged to control the energization of a different one of said coils, a plurality of tranducers, each arranged to produce output control signals for actuation of an associated one of said switching means during the turning of said rotor through a different sector, said transducers being arranged such that their respective control signal producing sectors overlap whereby, at different intervals of rotor movement, output control signals are produced simultaneously by two transducers whose switchiNg means produce successive coil energization, and gating means having two inputs connected respectively to receive signals indicative of the outputs of each of said two transducers to prevent actuation of the switching means associated with one of said two transducers in response to control signal outputs from the other of said two transducers, said gating means having an output connected to the switching means associated with said one transducer to permit actuation of said switching means by control signal outputs from said one transducer in the absence of control signal outputs from said other transducer whereby a uniform and continuous energization, in succession, of said coils is presented to said rotor.