Method and system for transfer of power and data

The present invention relates to a method (400) for transfer of power and data, in an arrangement comprising a first circuit (102) comprising a first inductor (106) and a second circuit (104) comprising a second inductor (108), wherein the circuits (102, 104) are inductively coupled (110) to each other while being galvanically separated from each other, the method (400) comprising the steps of transferring (402) power between the first circuit (102) and the second circuit (104) by applying an alternating current to the inductor (106) of the first circuit (102) such that a current is built up in the inductor (108) of the second circuit (104), altering (404) a load condition in the second circuit (102) for modulating data to be transferred from the second circuit (102) to the first circuit (104), and detecting a change in current in the first circuit (102) resulting from the altered load condition in the second circuit (104), wherein the detected change in at least one of a current, a voltage or an impedance is demodulated for receiving the data at the first circuit (102). The present invention also relates to a corresponding system (100) and a lighting arrangement (200) comprising the system (100).