Patents by Inventor Roger E. Southgate

Roger E. Southgate 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).

  • Audio chime-signal generating circuit
    Patent number: 4250496
    Abstract: A circuit for generating an audio chime signal, for use on a passenger aircraft, for example to attract the attention of the passengers prior to a public announcement. High and low frequency oscillators are switched on for respective time periods, the low frequency oscillator being switched on after the high frequency oscillator. Decay circuitry causes a progressive decay in the output of each oscillator and a sine shaper removes harmonics of the high and low frequencies.
    Type: Grant
    Filed: April 20, 1979
    Date of Patent: February 10, 1981
    Assignee: Fieldtech Limited
    Inventor: Roger E. Southgate