PURPOSE: To reduce the size and weight of a non-contacting power feeding transformer so as to prevent the production of electromagnetic noise from the transformer by connecting a series capacitor with a feeder line which is also acts as the primary winding of the transformer and creating a series resonance state with the capacitance of the capacitor, circuit inductance of the feeder, and the frequency of AC power.

CONSTITUTION: A series capacitor 21 is connected with a feeder 7 and the output frequency of AC power 20 is controlled so that a series resonance state can be created with the capacitance of the capacitor 21 and the circuit inductance 5 of the feeder 7. When a non-contacting power feeding transformer is constituted in such a way, no excessive power supplying capacity is required for supplying reactive power, because the circuit inductance 5 of the feeder 7 becomes nearly zero. Therefore, the size and weight of the transformer can be reduced and the production of unpleasant electromagnetic noise from the transformer can be prevented.