A power converter includes a full-bridge circuit, power converting circuit, transformer, and controller. The full-bridge circuit includes a series-connected unit made of first and second switches and a series-connected unit made of third and fourth switches and is connected to power transmitting terminals. The power converting circuit is connected to power receiving terminals. The transformer includes power transmitting coil and power receiving coil. The power transmitting coil is connected to full-bridge circuit. The power receiving coil is connected to power converting circuit. The controller turns on the first and second switches alternately and also the third and fourth switches alternately. A resistive load is connected to the power receiving terminals. The controller serves to determine a phase difference between the time when first switch is turned on and the time when third switch is turned on to decrease with a decrease in measured voltage developed at the power receiving terminals.