Patent ID: 7812481

Claim:
A power transmission control device provided in a power transmission device included in 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: a drive clock signal generation circuit that generates a drive clock signal that specifies a drive frequency of the primary coil; a driver control circuit that generates and outputs a driver control signal based on the drive clock signal, and outputs the driver control signal to a transmission driver that drives the primary coil; a waveform detection circuit that detects a change in waveform of an induced voltage signal of the primary coil; and a control circuit that performs foreign object detection based on a detection result of the waveform detection circuit, the drive clock signal generation circuit outputting the drive clock signal set at a foreign object detection frequency during foreign object detection, the foreign object detection frequency being a frequency differing from a normal power transmission frequency.