PURPOSE: To lengthen the life of a non-contact device by applying an AC or a pulsating current to a power supplying coil, rectifying the output of a power receiving coil electromagnetically coupled to the power supplying coil, and charging a storage battery.

CONSTITUTION: An oscillator is composed of inverters 2, 3, resistors 4, 5 and a capacitor 6, and the base of a switching transistor(Tr) 1 is controlled by the output of the inverter 3. If the emitter of the Tr 1 is connected to the positive electrode of a DC power source, a pulsating current synchronized with the oscillation period of the oscillator is generated at the collector of the Tr 1, and an alternating magnetic field is generated in a coil 7. The alternating magnetic field generated in the coil 8 electromagnetically coupled to the coil 7 is rectified by a diode 9 thereby to charge a storage battery 10. The coils 8, the diode 9 and the battery 10 are contained in a housing 11. Thus, the circuit is composed without contact thereby to prevent the battery terminals from contaminating with dusts, thereby lengthening the life of the non-contact device.