Patents by Inventor Samuel C. Caldwell

Samuel C. Caldwell 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).

  • Patent number: 4336585
    Abstract: A selective commutation technique used with an inverter eliminates one of the two commutation pulses at those points at which there is a particular relationship of inverter operating characteristics. The power factor angle .theta., the voltage phase angle .delta., and the voltage pattern notch angle .beta. are sensed to determine this particular relationship. Because at the switching point there is no current flowing through the gated thyristor, the gated thyristor can then be transitioned to the nonconducting state merely by the removal of its gate signal. A single makeup pulse is then rung through the system to initialize the commutation capacitors for the next switch point.
    Type: Grant
    Filed: December 23, 1980
    Date of Patent: June 22, 1982
    Assignee: United Technologies Corporation
    Inventors: Robert M. Moriarty, John W. Walton, Samuel C. Caldwell
  • Patent number: D278519
    Type: Grant
    Filed: August 2, 1982
    Date of Patent: April 23, 1985
    Assignee: Caldwell Corporation
    Inventor: Samuel C. Caldwell