Abstract: A contactless inductively coupled power transfer system includes a power supply device and a power receiving device. The power supply device includes a primary winding for generating an electromagnetic field (EMF) in response to an AC current flow having an operating frequency. The power receiving device includes a resonant circuit outputting an output voltage to a load and including a secondary winding and a reactance element. The reactance element is capable of forming a parallel resonant LC circuit with the secondary winding that resonates at the operating frequency, and forming a series resonant LC circuit that resonates at the operating frequency, and that is to be connected in series to the load.

Abstract: An inductively coupled power transfer (ICPT) system includes a primary winding for generating an electromagnetic field (EMF), and an ICPT device. The ICPT device includes a phase detecting winding which generates a detecting voltage according to the EMF, a resonant circuit which has an adjustable reactance and which generates an AC voltage according to the EMF and the adjustable reactance, and a control circuit which compares a phase of the AC voltage with a phase of the detecting voltage so as to determine whether said resonant circuit operates in an under-tuned or an over-tuned interval, and which varies the adjustable reactance according to the output voltage and one of the under-tuned and over-tuned intervals.

Abstract: A contactless inductively coupled power transfer system includes a power supply device and a power receiving device. The power supply device includes a primary winding for generating an electromagnetic field (EMF) in response to an AC current flow having an operating frequency. The power receiving device includes a resonant circuit outputting an output voltage to a load and including a secondary winding and a reactance element. The reactance element is capable of forming a parallel resonant LC circuit with the secondary winding that resonates at the operating frequency, and forming a series resonant LC circuit that resonates at the operating frequency, and that is to be connected in series to the load.

Abstract: An inductively coupled power transfer (ICPT) system includes a primary winding for generating an electromagnetic field (EMF), and an ICPT device. The ICPT device includes a phase detecting winding which generates a detecting voltage according to the EMF, a resonant circuit which has an adjustable reactance and which generates an AC voltage according to the EMF and the adjustable reactance, and a control circuit which compares a phase of the AC voltage with a phase of the detecting voltage so as to determine whether said resonant circuit operates in an under-tuned or an over-tuned interval, and which varies the adjustable reactance according to the output voltage and one of the under-tuned and over-tuned intervals.