摘要 |
The contactless method of supplying power magnetically couples a portable device receiving coil with a power supply stand transmitting coil and transmits power by magnetic induction. The portable device sends power adjustment signals to the power supply stand, and the stand adjusts transmitting coil output based on the power adjustment signals. The portable device compares the power received from the stand to the required power, sends an increase-power-request signal if the received power is below the required power, and sends a decrease-power-request signal if the received power is above the required power. Power adjustment signals include increase-power-request weighting values that increase with the size of the request to increase power and/or rate-of-change weighting values that increase with the amount of change in the requested power. Weighting values output with a given period are added and a foreign object is judged to be present when the sum attains a set value. |