Patent ID: 8928182
Filing Date: 2015-01-06
Classification: H02J

Abstract:
1. A wireless power feeder which performs power feed by a non-contact method to a wireless power receiver having a power receive coil, the wireless power feeder comprising: a power feed coil to perform power feed from the power feed coil to the power receive coil on the basis of a magnetic coupling between the power feed coil and the power receive coil a power source section supplying AC power to the power feed coil; and a control section calculating a power transmission efficiency from the power feed coil to the power receive coil to control the power source section according to the power transmission efficiency, wherein the control section controls the power source section so that the power supply to the power feed coil is in a stopped state or in an intermittent supply state when the power transmission efficiency is lower than a first determination reference value, controls the power source section so that the power supply to the power feed coil is in a first power supply state when the power transmission efficiency is equal to or higher than the first determination reference value and lower than a second determination reference value, the second determination reference value being larger than the first determination reference value, and controls the power source section so that the power supply to the power feed coil is in a second power supply state when the power transmission efficiency is equal to or higher than the second determination reference value.