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US 5,313,661 AGranted
Method and circuit arrangement for adjusting the volume in a mobile telephone
AssigneeNokia Mobile Phones Ltd.
InventorsKalevi Malmi, Ari-Pekka Lajunen
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AssigneeNokia Mobile Phones Ltd.
InventorsKalevi Malmi, Ari-Pekka Lajunen
Estimating the term…
Method and circuit arrangement for adjusting the volume in a mobile telephone. The telephone comprises a transceiver unit and on the other hand a physically separate operating device. A dc voltage level (DC) corresponding to the desired volume is adjusted with a potentiometer (1) in the operating device and the level is converted with an A/D-converter (2) into a corresponding digital control signal. The control signal is read with a microprocessor (3) in the transceiver unit, which further through the hold circuit (4) controls the gain of the audio amplifier (7). A multiplexer (5) may be provided for controlling and selecting a suitable feedback resistor (6) for the amplifier. The A/D-converter can be located in the operating device or in the transceiver unit. When it is located in the transceiver unit the dc voltage level (DC) is transmitted to the transceiver unit, preferably superimposed on the AC-signal received from the microphone, which then is filtered off before the A/D-converter. The connection between the operating device and the transceiver unit may be realized with a cable or a wireless infrared or radio connection.
Method for user adjustment of the volume of a mobile telephone including a transceiver unit and a physically separated operating device, comprising the steps of:
Circuit arrangement for user adjustment of the volume in a mobile telephone, comprising:
Method for adjusting the volume in a mobile telephone comprising a transceiver unit and a physically separated operating device, characterized by the steps of
Dependencies are inferred from the claim text.