Abstract: In a system for controlling within a very tight tolerance the speed of a DC motor, a first servo loop servos the motor to a speed which is close to ideal but not perfect. A second servo loop, operating in concert with the first servo loop, acts as a vernier or fine tuning adjustment to add any necessary correction needed to bring the motor into substantially perfect positional alignment.The first servo loop utilizes ramp and velocity feedback techniques to achieve constant acceleration by tracking or following a speed command signal profiled to have a linear velocity ramp portion and a final constant velocity portion where acceleration terminates and speed remains constant. Once the motor has accelerated up to the desired speed the second servo loop begins to function in concert with the first servo loop.

Abstract: A three-terminal network which electrically senses the time at which the voltage applied to an AC induction motor is removed and concurrently therewith utilizes energy which was previously stored in a capacitor to effect eddy-current braking of the AC induction motor is disclosed.The disclosed system may be utilized to quickly, i.e., within two revolutions, brake a two-terminal shaded-pole induction motor, or a two-terminal unidirectional split-phase motor, or a three-terminal bidirectional split-phase motor.

Abstract: A speedometer-odometer apparatus is described comprising an encoding apparatus for generating pulses as a function of the distance a vehicle is moved, a calibrating apparatus and an indicating circuit means for visually indicating the distance and speed of the movement. Coupled between the encoding apparatus and the indicating circuit means, the calibrating apparatus is provided for controlling the number of pulses delivered to the indicating circuit means from the encoding apparatus so that the indicating circuit means will provide a predetermined output when the vehicle in which the apparatus is mounted is moved a predetermined distance. For providing a highly accurate and direct readout of the distance, there is provided, in the indicating circuit means and coupled to the output of the calibrating apparatus, a plurality of division circuits.