Patents by Inventor Craig E. Tromborg

Craig E. Tromborg 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: 4701640
    Abstract: An electret transducer is comprised of a motor and signal processing apparatus, that may include an amplifier and/or impedance matching means, disposed within a sealed conductive housing. The motor is fabricated in place within a housing and the signal processing means is mounted on the underside of the cover for the housing so that each may be independently tested prior to combining into a unitary structure. The motor is comprised of easily fabricated and assembled components that include means for spacing a backplate from the walls of the conductive housing and a spacer intermediate the backplate and the center of a diaphragm. The backplate and the diaphragm are provided with registering apertures. The amplifier is mounted to the cover to conductively connect to the housing and to provide rigid outwardly extending terminals for ready connection to further electrical circuits, as in a hearing aid.
    Type: Grant
    Filed: March 11, 1985
    Date of Patent: October 20, 1987
    Assignee: Telex Communications, Inc.
    Inventors: Dean W. Flygstad, Craig E. Tromborg