Remote control transmitter with an audible battery life indicator
AssigneeRCA Corporation
InventorDavid John Carlson
Life of this patent
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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.
Claims7
A remote control system comprising:
- means for selecting a function to be controlled;
- means for generating an ultrasonic frequency electrical signal in accordance with the function selected;
- means for supplying energy to said ultrasonic frequency electrical signal generating means;
- means for detecting when the energy available from said energy supplying means falls below a predetermined level;
- means for generating an audio frequency electrical signal when the energy available from said energy supplying means has fallen below said predetermined level;
- and
- ultrasonic transducer means for normally generating an inaudible acoustic signal in response to said ultrasonic frequency electrical signal, said audio frequency signal having a predetermined frequency selected so that said ultrasonic transducer means generates an audible acoustic signal in response to said audio frequency electrical signal.
Dependencies are inferred from the claim text.