Patents by Inventor James D. Sweetman

James D. Sweetman 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).

  • Battery powered motor drive with temperature-responsive battery heater
    Patent number: 4667140
    Abstract: An improved battery powered quartz timing control circuit that drives a stepper motor, featuring a battery heated by a temperature-responsive battery heater which is activated when the ambient temperature in the vicinity of the battery drops below a predetermined temperature.
    Type: Grant
    Filed: February 20, 1985
    Date of Patent: May 19, 1987
    Assignee: Paragon Electric Co., Inc.
    Inventor: James D. Sweetman
  • Defrost control system
    Patent number: 4395887
    Abstract: A defrost control system is provided for initiating one or more (defrost) timing cycles each at a different time and for terminating the cycles at the end of their respective predetermined (defrost) periods. The unit generally includes a solid-state, microprocessor based, programmable twenty-four hour timer, and a display panel. The system also includes a proportional defrost module which measures the absolute humidity of the atmosphere and adjusts the defrost initiate time(s) in accordance therewith.
    Type: Grant
    Filed: December 14, 1981
    Date of Patent: August 2, 1983
    Assignee: AMF Incorporated
    Inventor: James D. Sweetman