Constant tangential velocity motor control for a disc recording system

Abstract

Abstract A disc recording system includes a motor control system for energizing a DC motor utilized as the prime mover of a recording disc. A transducer attached to a carrier, movable along a radius of the disc, is utilized for reading data from the disc or recording data onto the disc. A linear potentiometer is fixedly mounted along a radius of the disc and includes a movable wiper connected for movement with the transducer carrier. The potentiometer is connected in the feedback loop of a high gain amplifier function generator which produces an output voltage that is hyperbolic with respect to the position of the wiper along the length of the linear potentiometer. This hyperbolic output voltage is applied to a DC motor for providing substantially constant tangential velocity of the portion of the disc adjacent to the transducer. In applications wherein the transducer mechanically contacts the disc, increased torque opposes motor rotation as the transducer is moved farther away from the center of the disc. In these applications, a compensating motor driver is inserted between the hyperbolic function generator and the motor to provide an increase in electrical energy supplied to the motor in response to increased torque in opposition to motor rotation.

Inventors

• 👤 C Bringol

Bibliographic Details