Non-contact power supply device and non-contact power supply method

A non-contact power supply method, comprising:

• converting direct current (DC) power supplied from a power supply into alternating current (AC) power using an inverter circuit;
• supplying the AC power to an external power receiving device in a non-contact manner;
• detecting a voltage difference between a predetermined reference voltage and a voltage value of the AC power detected by a voltage sensor in the external power receiving device;
• detecting a current difference between a predetermined reference current and a current value of the AC power as detected by a current sensor;
• and
• controlling the inverter circuit to reduce the voltage difference and the current difference when the voltage is outside a predetermined range.

A non-contact power supply device, comprising:

• an inverter circuit configured to convert power supplied from a direct current (DC) power supply into alternating current (AC) power;
• a resonant circuit configured to supply the AC power to an external power receiving device in a non-contact manner;
• a current sensor electrically connected the inverter circuit;
• a voltage subtractor circuit configured to detect a voltage difference between a predetermined reference voltage and a voltage value of the AC power as detected by a voltage sensor in the external power receiving device;
• a current subtractor circuit configured to detect a current difference between a predetermined reference current and a current value of the AC power as detected by the current sensor;
• and
• a controller configured to control the inverter circuit to reduce the voltage difference and the current difference when the voltage is outside a predetermined range, wherein
• the resonant circuit comprises a capacitor and a coil.