Patents by Inventor Jeffery C. Callahan

Jeffery C. Callahan 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).

  • Automatic audio mixing selector device
    Patent number: 4306114
    Abstract: An automatic mixing selector device for use with an audio amplifier or tuner for automatic priority selection and digital fading of two or more audio sources using the amplifier and tuner controls. The circuit comprises a priority selector circuit which monitors the designated priority audio source for signal amplitude and duration, a micro-computer then operates a digital fader to phase in the priority signal and also to phase in the alternate signal in the absence of a sufficient priority signal.
    Type: Grant
    Filed: January 21, 1980
    Date of Patent: December 15, 1981
    Assignee: Summa-Nova Corporation
    Inventor: Jeffery C. Callahan