Abstract: A position control system for controlling a motor-driven mechanism capable of occupying a plurality of specified positions comprises a plurality of switches for specifying a position to be occupied by the mechanism and an encoder for generating a specified position signal representative of the specified position and a loading circuit for providing a present position signal representative of the position presently occupied by the mechanism. A read-only memory circuit uses the specified and present position signals to provide a control signal for controlling the motor to move the mechanism to a particular position and a comparison signal and a particular position signal indicative of that particular position. A position detector responsive to the position of the mechanism provides a detection signal representative of the particular position when the mechanism reaches it.

Abstract: Apparatus for generating a signal corresponding to a reference phase of a reference rotor of a motor relative to the stator, includes a field magnet having a plurality of north and south poles mounted on the rotor; a Hall-effect element associated with the field magnet and mounted on the stator for generating a position signal corresponding to the position of the rotor relative to the stator for use in changing-over energization of coils on the stator; a plurality of equally spaced cut-out portions along the periphery of the rotor forming a plurality of equally spaced toothed portions; an optical detector associated with the toothed portions and mounted on the stator for generating a speed signal corresponding to the rotational speed of the rotor relative to the stator; a differentiating circuit for differentiating the position signal to produce a differentiated signal; and an AND gate supplied with the differentiated signal and the speed signal for producing the phase signal corresponding to a reference phas