Patents by Inventor William W. Kiffmeyer

William W. Kiffmeyer 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).

  • Digital input circuit with fault detection means
    Patent number: 3992636
    Abstract: The state of a sensing device such as a switch is indicated as a logic signal at a circuit output terminal and a malfunction is indicated at another circuit output when the connections to the sensing device open circuit or short circuit. The input circuit employs a pair of LED photo-isolators which conduct during alternate half cycles of an a-c current which is applied through the sensing device when it is closed. A diode connects in shunt with the sensing device and when the device is open, only one of the photo-isolators conducts. If a malfunction occurs, neither photo-isolator conducts.
    Type: Grant
    Filed: February 5, 1976
    Date of Patent: November 16, 1976
    Assignee: Allen-Bradley Company
    Inventor: William W. Kiffmeyer