Patents by Inventor Sherrel C. Smith

Sherrel C. Smith 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).

  • Photoconductive instrument
    Patent number: 4331867
    Abstract: The invention is directed to an instrument control apparatus capable of regulating the flow of electric current by detecting relative movement between an indicator and a control zone. A light source is positioned close to the control zone so that illumination from the control zone will change responsive to movement of the indicator. Illumination from the control zone is sensed and electrical resistance is varied in response to relative movement between the indicator and control zone for varying an output voltage. A first predetermined reference voltage is generated and the output and reference voltages are compared and a first predetermined output current is generated when one of the voltages is greater than the other one. A first circuit supplies electric current to the instrument.
    Type: Grant
    Filed: June 19, 1980
    Date of Patent: May 25, 1982
    Assignee: Chromaco, Inc.
    Inventor: Sherrel C. Smith