Patents by Inventor David John Carlson

David John Carlson 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: 4067000
    Abstract: A battery powered ultrasonic remote control transmitter for controlling various functions associated with a television receiver, or the like, includes an arrangement for providing an audible indication that the battery voltage has fallen below a desired operating level. In one embodiment, when the battery voltage has fallen below the desired level, the electrical control signal for at least one control function is selectively amplitude modulated by an audio frequency signal before being coupled to the ultrasonic transducer. As a result, when the control function is selected, an operator is given an audible indication that the battery needs recharging or replacement.
    Type: Grant
    Filed: May 28, 1976
    Date of Patent: January 3, 1978
    Assignee: RCA Corporation
    Inventor: David John Carlson