A power supply system is provided that can synchronize a primary circuit and a secondary circuit with high accuracy and are advantageous in downsizing and simplification. The system includes a first circuit including: a battery device; transistor elements to which a voltage is supplied; coil units to which a feeding current is supplied in an on state of the transistor elements; a capacitor that changes a flow direction of the feeding current; and a driving coil that turns on/off the transistor elements, and a second circuit including: coil units and a driving coil in which induced electromotive force is generated; transistor elements that are turned on/off by the induced electromotive force; and a battery device that receives supply of power in an on state of the transistor elements.