To provide a step up/down circuit and a power converter capable of improving power factor, with reduction in size and loss.
A step up/down circuit 56 steps up or down the input voltage applied from an AC power supply 201, and supplies it to a load. It includes a full wave rectification part 16 which rectifies the input voltage so that the input voltage comes to be a voltage of predetermined polarity, a winding part 11 which contains a winding L1 and a winding L2 which are magnetically connected each other, with a voltage having been rectified by the full wave rectification part 16 being applied to the winding L1, and a route switching part 12 which switches a route of the current that flows the step up/down circuit 56 for performing a step up operation in which the winding part 11 outputs a boosted voltage or a step down operation in which the winding part 11 outputs a voltage that has been stepped down. Since the route of a current is switched by the route switching part 12, the current flowing from the AC power source 201 flows the winding L1 during the step up operation and the step down operation.
AUTO NETWORK GIJUTSU KENKYUSHO
SUMITOMO WIRING SYSTEMS