Patents by Inventor Alan W. Crawford

Alan W. Crawford 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).

  • Alternating current activated firing circuit for EBW detonators
    Patent number: 5533454
    Abstract: The invention is a firing circuit for an exploding bridgewire explosive detonator which is activated only by application of an alternating current of a preselected frequency. The firing circuit comprises a bandpass filter, a voltage multiplier, and a discharge circuit.The invention can be configured to selectively detonate a plurality of exploding bridgewire detonators by assembling a plurality of firing circuits for each exploding bridgewire, each firing circuit having a bandpass filter with a different preselected frequency.
    Type: Grant
    Filed: September 18, 1995
    Date of Patent: July 9, 1996
    Assignee: Western Atlas International, Inc.
    Inventors: James Ellis, Alan W. Crawford