Patents by Inventor David C. Croft

David C. Croft 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).

  • Electronic switch with automatic protective turn-off followed by automatic reset
    Patent number: 4686383
    Abstract: A switch transistor (V1) has a controlled pathconnected in a circuit (P-Q) to be switched, and Control signals are supplied (ID) to its control electrode to switch it on. If, in the ON state the potential difference across the switch exceeds a threshold value, trip means (T1) are actuated to turn the switch transistor off. To prevent premature tripping, delay means R2, C3 disable the trip means (by holding off T3) for a short period following switch on, but is arranged so as not to delay the trip action once that period has expired.
    Type: Grant
    Filed: August 10, 1984
    Date of Patent: August 11, 1987
    Assignee: British Telecommunications Public Limited Company
    Inventor: David C. Croft