Patent ID: 8204531

Claim:
A power transmission control device provided in a power transmission device of a non-contact power transmission system, the non-contact power transmission system transmitting power from the power transmission device to a power reception device by electromagnetically coupling a primary coil and a secondary coil to transmit the power to a load of the power reception device, the power transmission control device comprising: an amplitude detection circuit that detects amplitude information relating to an induced voltage signal of the primary coil; an A/D conversion circuit that performs A/D conversion of the amplitude information; and a control circuit that controls the power transmission device, the A/D conversion circuit performing the A/D conversion of a detected voltage that has been detected by the amplitude detection circuit at a conversion timing and determining digital data relating to a reference threshold voltage, the conversion timing being a timing after a given period has expired from a timing when the detected voltage has exceeded a provisional voltage, by using the digital data relating to the reference threshold voltage, the control circuit performing at least one of data detection, foreign object detection, and detachment detection, the data detection detecting data that has been transmitted from the power reception device by means of load modulation, and the control circuit starting a count process using a counter from the timing when the detected voltage has exceeded the provisional voltage, and controlling the A/D conversion circuit to perform the A/D conversion at the conversion timing set based on a count value of the counter.