| 摘要 |
PROBLEM TO BE SOLVED: To provide a contactless power transmission system in which a power transmission device can accurately determine a request for power supply from a power reception device with a simple configuration.SOLUTION: A contactless power transmission system has a power transmission device and a first power reception device. The power transmission device contains an oscillation controller for making a transmission coil perform continuous oscillation or intermittent oscillation, and a current detector for detecting input current. The first power reception device has a coil state switching unit for performing a coil state switching operation between a first coil state where current flows in a power reception coil and a second coil state where no current flows in the power reception coil or current flowing in the power reception coil is not more than a predetermined value, and a coil state controller. The coil state controller sets the coil state to the first coil state during a first oscillation period of the transmission coil and sets the coil state to the second coil state during subsequent oscillation periods of N times of the transmission coil. When the oscillation controller determines that the input current is not less than a threshold value during the first oscillation period of the transmission coil and also the input current is less than the threshold value at least once oscillation period of the oscillation periods of N times of the transmission coil, the oscillation controller switches the oscillation of the transmission coil from the intermittent oscillation to the continuous oscillation.SELECTED DRAWING: Figure 1 |
