| 摘要 |
A portable electronic device 10 including a battery 18 coupled to an accessory circuit 26, a battery monitoring circuit 14, and a processor 22. The battery monitoring circuit determines an output current of the battery, and the processor receives an indication of the output current. The processor determines, based on the indication of the output current of the battery, a power characteristic of the accessory circuit which may be impedance and/or power consumption, and controls a power that is to be provided to the accessory circuit based on the power characteristic of the accessory circuit. The processor may be configured to send an activation signal to the accessory circuit to change the state of the circuit from a first, inactive state, to a second active state. The test signal may have a predetermined voltage level and time duration. The accessory circuit may contain an external circuit 90 and may include an external speaker circuit wherein the activation signal has an infrasonic component. The processor may be configured to determine the manufacturer of the portable electronic device and supply less power to accessory circuits with a different manufacturer than that of the portable electronic device. |
