Patents by Inventor Randolph D. Coleman

Randolph D. Coleman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Pulse width modulated power amplifier for direct current motor control
    Patent number: 4204143
    Abstract: A solid state electronic circuit for controlling a reversible direct curr motor from a voltage source such that it may be rotated in either direction. The reversible direct current motor is connected into a bridge circuit with semiconductor switching elements which provide that the full supply voltage is available for starting in either direction. A pair of comparators receives input signals from a triangular wave generator and a signal source and in conjunction with a cross-fire protection circuit generates the drive pulses which control the semiconductor switching elements.
    Type: Grant
    Filed: September 26, 1978
    Date of Patent: May 20, 1980
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Randolph D. Coleman