POWER SUPPLY DEVICE, POWER RECEIVING DEVICE, CHARGING SYSTEM AND OBSTACLE DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a power supply device, a power receiving device, a charging system and an obstacle detection method capable of ensuring satisfactory obstacle detection sensitivity even when the obstacle is small.SOLUTION: A modulation section 202 modulates the amplitude or the phase of a test data row output from a test data row storage 201. Receiving an instruction from a determination section 204, a power control section 203 generates a power control signal for increasing the power level for the test data row every time when the power control section 203 receives a test data row. The determination section 204 determines whether the test data row output from the test data row storage 201 and a test data row output from a transmitting side receiving circuit 124 coincide with each other. The determination section 204 also stores a previous power level at which the transmission and reception of a test data row is successfully made in a state free from any obstacle to determine existence or absence of an obstacle on the basis of a relationship between the power level at which the determination results coincide and the stored power level.