Patents by Inventor Charles D. Bishop

Charles D. Bishop 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: 6292010
    Abstract: A driver circuit for automatic test equipment provides high voltage range and high frequency. The driver circuit includes a voltage buffer that has high voltage swing and is capable of dynamically generating an output voltage that alternates between two statically established voltage levels. The driver circuit also includes a current buffer that has high speed and is capable of dynamically generating an output current that alternates between two statically established current levels. The voltage buffer and the current buffer each have an output, and the output of the voltage buffer is coupled to the output of the current buffer through a series impedance. The output of the current buffer is also coupled to a device under test (DUT). A control circuit directs the voltage buffer and the current buffer to generate either static or dynamic output signals.
    Type: Grant
    Filed: February 2, 2000
    Date of Patent: September 18, 2001
    Assignee: Teradyne, Inc.
    Inventors: Thomas W. Persons, Charles D. Bishop
  • Patent number: 6281699
    Abstract: A detector circuit for automatic test equipment samples and tests differential signals. The detector circuit includes a pair of impedances connected in series between first and second legs of a differential input signal. A signal is formed at the junction of the two impedances that equals the common mode voltage of the differential signal. The common mode signal is coupled to the input of a window comparator, which compares the common mode signal with predetermined thresholds. The window comparator generates an output indicative of whether the common mode signal is above, within, or below the predetermined thresholds. Using this approach, the detector circuit can detect errors in differential signals caused by mismatched amplitudes or by timing skew between the first and second input signals. According to one feature, the detector circuit also includes a differential mode detector that receives the first and second input signals.
    Type: Grant
    Filed: March 15, 2000
    Date of Patent: August 28, 2001
    Assignee: Teradyne, Inc.
    Inventor: Charles D. Bishop
  • Patent number: 4539898
    Abstract: Semiautomatic food frying apparatus is disclosed which provides apparatus which may be easily and safely operated to prepare small portions of various food products. In one embodiment, the food frying apparatus includes an upright cabinet with a fan assembly mounted to exhaust air through the top of the cabinet while drawing air in, through and from the lower portion of the cabinet. A removable one-piece filter unit is positioned in the path of air flow to remove odors, gases, smoke, etc. . . . from the air before the air is exhausted back into the room. The removable filter includes a paper filter together with activated charcoal particles configured as an integral unit. In another embodiment, the fan assembly and filter unit are replaced by a closed-loop air cleaning system which does not discharge the internal air of the apparatus into the room. A container for holding a supply of cooking oil is located in the lower portion of the cabinet.
    Type: Grant
    Filed: August 8, 1983
    Date of Patent: September 10, 1985
    Assignee: Alpaire, Inc.
    Inventors: Charles D. Bishop, Kenneth H. Stamps, David L. Turney
  • Patent number: 4505194
    Abstract: Automatic food frying and dispensing apparatus is disclosed which is housed in a supporting cabinet and includes a device for holding a supply of cooking oil and a heating device for maintaining the temperature of the cooking oil at a predetermined temperature. A fan assembly exhausts air through the top of the cabinet. A derated precipitator, a flame arrester and a charcoal filter are positioned upstream of the fan assembly and in the path of air flow. A switch device is positioned in the path of air flow and shuts off the heating device if the air flow drops below a predetermined value. Food handling apparatus automatically lowers the food to be cooked into the cooking oil when a customer selects a desired cooking time and automatically raises the food from the cooking oil and dumps the food into a container positioned at the food collection station at the end of the preselected cooking time.
    Type: Grant
    Filed: September 9, 1983
    Date of Patent: March 19, 1985
    Inventors: Charles D. Bishop, Joe R. Powell, Kenneth H. Stamps, Clifford A. Watson