| 摘要 |
<p>An apparatus for sensing the presence of an auxiliary battery connected to a cellular telephone is disclosed. An internal battery and a removable auxiliary battery are connected to the power system of the cellular telephone through first and second switches respectively. Connection of the auxiliary battery creates a current flow that is detected by a current sensing circuit which generates a current signal indicating the detection of current flow. A voltage sensing circuit determines whether the auxiliary battery can provide a predetermined voltage level and generates a voltage signal indicating the results of this test. A processor then utilizes the signals from the voltage sensing circuit and the current sensing circuit to control the pair of switches to connect the main and auxiliary batteries to the power circuitry of the cellular telephone.</p> |
