Patent ID: 8134256

Claim:
A power receiving control device provided to a power receiving device included in a contactless power transmission system, the contactless power transmission system transmitting electric power from a power transmission device to the power receiving device by electromagnetically coupling a primary coil and a secondary coil so as to feed the electric power to a load serving as a power feeding object from a voltage output node of the power receiving device, the power receiving device including a rectifying circuit and a regulator; and transmitting a load modulation signal to the power transmission device by load modulation performed by a load modulation section included in the power receiving device, in a period of the power feeding to the load as the power feeding object, the power receiving control device comprising: a power receiving side control circuit that controls an operation of the power receiving device; and a power supply control signal output terminal that outputs a power supply control signal by which the power feeding to the load is temporarily stopped, the power receiving side control circuit turning on a switch circuit provided between an input node and an output node of the regulator, based on detection of lowering of power feeding capability to the load, so as to put a bypass path in an ON state, the bypass path directly connecting the input node and the output node of the regulator; the power receiving side control circuit turning off the switch circuit so as to forcibly put the bypass path in an OFF state, in a case where the power feeding to the load is temporarily stopped in a period during which the bypass path is formed, at one of timing at which a voltage level of the power supply control signal outputted from the power supply control signal output terminal is switched from a non-active level to an active level so as to temporarily stop the power feeding to the load and timing before the power feeding to the load is temporarily stopped, and the power receiving side control circuit turning on the switch circuit after releasing the temporary stop of the power feeding to the load so as to return the bypass path to the ON state.