Power supply arrangement and inductively coupled battery charger with wirelessly coupled control, and method for wirelessly controlling a power supply arrangement and an inductively coupled battery charger

A battery charger comprising:

• a primary winding of a power transformer,
• switching means that are arranged to repeatedly switch, at a certain frequency, an electric current coupled into the primary winding for cyclically transferring energy from the primary side to a secondary side, located elsewhere than within the battery charger, at said certain frequency,
• a wireless feedback receiving arrangement for receiving feedback pulses at a certain frequency from a secondary side located elsewhere than within the battery charger and
• means for utilizing the received feedback pulses in controlling the rate at which energy is transferred from the primary side to the secondary side located elsewhere than within the battery charger;
• wherein the wireless feedback receiving arrangement is arranged to receive feedback pulses at a frequency that is different from the frequency used by the switching means to repeatedly switch an electric current coupled into the primary winding.

A battery-powered portable electronic device, comprising:

• a secondary winding of a power transformer,
• rectifying and filtering means that are arranged to cyclically discharge electromagnetic energy coupled into the secondary winding at a certain frequency, and
• feedback pulse generating means for generating feedback pulses at a certain frequency to be transferred from the battery-powered portable electronic device to a primary side located elsewhere than within the battery-powered portable electronic device over a wireless feedback link,
• wherein the feedback pulse generating means are arranged to generate the feedback pulses at a frequency that is different from the frequency at which the rectifying and filtering means are arranged to cyclically discharge electromagnetic energy from the secondary winding.

A method for controlling the operation of a power supply arrangement, comprising the steps of:

• repeatedly switching, at a certain frequency, an electric current coupled into a power transformer for cyclically transferring energy from a primary side to a secondary side at said certain frequency,
• generating, within the secondary side, feedback pulses at a certain frequency to be transferred from the secondary side to the primary side over a wireless feedback link, and
• on the primary side utilizing the feedback pulses in controlling the rate at which energy is transferred from the primary side to the secondary side;
• wherein the feedback pulses are generated a frequency that is different from the frequency used to repeatedly switch an electric current coupled into the power transformer.