Patent ID: 8004118

Claim:
A power transmission control device that controls power transmission of a power transmitting device of a non-contact power transmission system, the non-contact power transmission system transmitting power from the power transmitting device to a power receiving device by electromagnetically coupling a primary coil and a secondary coil and supplying the power to a load of the power receiving device, the power transmission control device comprising: a driver control circuit that controls a power transmitting driver that drives the primary coil; a load state detection circuit that detects a power-receiving-side load state; and a control circuit that controls the driver control circuit, the control circuit performing a foreign object detection process based on load state detection information from the load state detection circuit after receiving ID authentication information from the power receiving device, and starting normal power transmission to the power receiving device after performing the foreign object detection process, and the control circuit setting a drive frequency at a foreign object detection frequency when performing the foreign object detection process, the foreign object detection frequency being a frequency between the normal power transmission frequency and a coil resonance frequency.