Power Transfer Across the Iron Core Gap

Wireless Power Transfer is in the focus of a wide range of elaborated topics that are subjected to diverse research. These are destined for various applications like charging of mobile devices, cardiac pacemakers, transferring electric power through thin walls when drilling is to be avoided, and others. In the following paper, as in most related studies, the transfer of power from the transmitting unit to a receiving unit is realized via the magnetic field. Significance of the present study is the bundling, hence the enhancement of the magnetic field by employing an iron core. A special, highly permeable amorphous metglas magnetic material is shaped to an oval rectangular core with gaps on the two long sides. A coil on the one core transfers power to a coil on the other core across the gaps, which represent the wireless distance of the transferred power. Experiments have reached a transfer of almost 1
$W$
at 5 % efficiency across a gap of 6 cm with a comparably small laboratory arrangement of total length 11 cm and 17
$W$
input. Preliminary measurements indicate an almost linear relation between windings, core, gap size and the appropriate power transfer, suggesting reasonable prospects for increased power transfer across a longer distance using bigger cores and coils.