Wireless inductive power transfer

A power transmitter for inductively transferring power to a power receiver, the power transmitter comprising:

• a resonance circuit comprising a transmitter coil for generating a power transfer signal for wirelessly transferring power to the power receiver;
• a driver for generating a drive signal for the resonance circuit, the drive signal having a drive frequency;
• an error unit arranged to determine a coil current error indication being indicative of a difference between a measured current for the transmitter coil and a target current for the transmitter coil;
• a receiver for receiving messages load modulated onto the power transfer signal by the power receiver during communication time intervals;
• and
• a control loop arranged to control the current through the transmitter coil in response to the coil current error indication, the control loop being arranged to be active during communication time intervals;
• and
• wherein, at least during communication time intervals, a loop response of the control loop is attenuated for coil current error indications in a reduced control range relative to coil current error indications outside the reduced control range, the reduced control range comprising a coil current error indication value corresponding to zero coil current error.