Patent attributes
A power transmitting device determines transmitting power P(t1) at a beginning of a first unit time, and transmitting power P(t2) at an end of the first unit time, stores a control parameter Q(t3) that determines a voltage of the transmitting power at a beginning of a second unit time, and a control parameter Q(t4) that determines a voltage of the transmitting power at an end of the second unit time, determines a power difference ΔP=P(t2)−P(t1) and a difference ΔQ=Q(t4)−Q(t3) in the control parameter Q, and, if the ΔP is equal to or larger than a first threshold and an absolute value of the ΔQ is equal to or larger than a second threshold, determines that there is a foreign object between a receiver resonator and a transmitter resonator and decreases the transmitting power output from an inverter circuit.
