Patent ID: 7889190

Claim:
An apparatus for supplying power source comprising: a boosting circuit configured to boost a battery voltage to a first voltage, and supply the first voltage to a first display device and a boosted voltage detecting circuit via an output terminal of the boosting circuit; the boosted voltage detecting circuit configured to detect magnitude of the first voltage boosted by the boosting circuit, and provide a detected result to a feedback terminal of the boosting circuit, wherein the boosted voltage detecting circuit includes a first resistor having one end coupled to the output terminal of the boosting circuit, a second resistor having one end selectively coupled to another end of the first resistor, and a first transistor coupled between another end of the second resistor and a ground terminal, wherein the feedback terminal of the boosting circuit is coupled to a connection node between the first resistor and the second resistor, the second resistor is coupled in serial to the first resistor when the first transistor is turned on, and the second resistor is disconnected from the first resistor when the first transistor is turned off; a voltage adjusting circuit configured to adjust the first voltage supplied from the boosting circuit to a second voltage different from the first voltage according to a first control signal, and supply the second voltage to a second display device; a first switching circuit configured to switch couple the boosting voltage detecting circuit and the first display device; and a second switching circuit configured to switch couple the voltage adjusting circuit and the second display device, wherein the boosting circuit analyzes the detected result supplied from the boosted voltage detecting circuit and adjusts a boosting ratio thereof in accordance with an analyzed result in order to boost the battery voltage to an adjusted first voltage, wherein the first switching circuit provides the adjusted first voltage to the first display device according to a second control signal, and wherein the second switching circuit provides the second voltage to the second display device according to the first control signal.