NON-CONTACT POWER SUPPLY DEVICE, NON-CONTACT POWER-RECEIVING DEVICE, AND NON-CONTACT POWER SUPPLY SYSTEM

摘要

A power supply device (20), provided with an excitation circuit (22) and a power supply coil (23). The excitation circuit (22) inverts the polarity of an input voltage from a rectifying and smoothing circuit (21) in response to a PWM signal in which the duty ratio repeatedly increases and decreases at a period of an AC voltage to be applied from a power-receiving device (30) to a load (40), thereby generating an excitation current applied to the power supply coil (23). The power-receiving device (30) is provided with a power-receiving coil (31) and a filter circuit (32). The filter circuit (32) attenuates, from an AC waveform generated by electromagnetic induction in the power-receiving coil (31), frequency components corresponding to a frequency higher than that of the AC voltage to be applied to the load (40).