Patent ID: 9660699
Date: 2017-05-23
CPC Classifications: H02J,H04B

Claim:
1. A power transmission device comprising: a resonance circuit including a coil and a capacitor; communication circuitry configured to perform communication with a power reception device; detection circuitry configured to measure a first Q-value of the resonance circuit; control circuitry configured to supply an alternating current to the resonance circuit for the measurement of the Q-value and to control the detection circuitry to measure the first Q-value, in a state where the resonance circuit is not transmitting power; and determination circuitry configured to receive an information received from the power reception device in response to a request from the communication circuitry, wherein the determination circuitry is configured to compare the first Q-value with a threshold value to determine whether a foreign object is in a space affecting the power transmission, and the threshold value is a second Q-value that is based on the information received from the power reception device.