Patents by Inventor Richard A. Hoffmann

Richard A. Hoffmann 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).

  • Dry acoustic system preventing condensation
    Patent number: 5446249
    Abstract: An active noise control system is provided for cancellation of noise in a duct. A speaker is mounted over an opening in the duct. An enclosure is mounted the duct about the speaker. Air flow is generated through the enclosure in order to balance the diffusion of water vapor through the speaker such that the dew point of the air in the enclosure is always below the temperature of the air in the enclosure, thus avoiding condensation.
    Type: Grant
    Filed: July 13, 1993
    Date of Patent: August 29, 1995
    Assignee: Digisonix, Inc.
    Inventors: Seth D. Goodman, Richard A. Hoffmann