| 摘要 |
A power adaptor to supply power for a portable device has an input circuit (21) for receiving mains input power, a power switch device (25), a power inductance (24) and an output circuit (22) coupled to the power inductance to provide the supply power for the portable device, and a controller (26) for controlling the power switch device according to a supply power requirement of the portable device. The adaptor has a measurement inductance (27) magnetically coupled to the power inductance, and the controller comprises a measurement input (28) for detecting a measurement signal indicative of a magnetic state of the power inductance. The controller detects the supply power requirement based on the magnetic state in response to said controlling the power switch device. Advantageously different portable devices can be supplied by appropriate power. |
