Abstract:
A power transmitting device according to one embodiment includes a power transmitting antenna, an oscillator, control circuitry, and a communication circuit. The control circuitry sets an initial value of a phase shift amount, causes the oscillator to output preliminary AC power of a voltage corresponding to the initial value, reduces the phase shift amount from the initial value at predetermined time intervals, causes the oscillator to output preliminary AC power of each voltage corresponding to each of the reduced phase shift amounts, fixes the phase shift amount upon activation of control circuitry in the power receiving device upon receipt of a first response signal indicating the activation of the control circuitry in the power receiving device from the power receiving device through the communication circuit, and transmits the AC power while maintaining the voltage corresponding to the fixed phase shift amount.