This standalone TET system accommodates the power conditions applicable for an implantable
heart pump. A half-bridge resonant converter was used to drive the power transfer coils, and power
°ow control was performed on the external primary side via feedback through wireless communi-cation. The system was able to provide 15W of power across a coil separation of 10mm to 20mm
corresponding to a coupling change of k = 0:3 to 0.15; with a maximum end to end e±ciency of
82.2% and a minimum e±ciency of 78.7%. It has also been demonstrated that the energy injection
converter retains it e±ciency across a control range of 100% to 25% energy injection, making it
ideal for TET systems which need to operate across a wide range of coupling. The presented power
transfer coils and circuitry are also su±ciently compact for implantation.