A step on a journey. Significant gains over prior systems and and indication of what might be achieved in future. Power transfer efficiencies are 'nasty' as range increases. Significantly better than the 2007 MIT MIT CMRS system. FWIW, I saw systems being demonstrated in the early 1970s (1973 I think) that transferred several hundred Watts "wirelessly" by resonant inductive power transfer ("IPT") while operating at (AFAIR) only 400 Hz. Enough power transfer to drive a small (one person, "go kart" sized) vehicle along a university corridor. I had a brief ride in it. To achieve this power transfer would have needed to be in the hundreds of Watts range. That predates the more recent "discoveries" of IPT by almost two decades. Notes somewhere. ______________ They say: *With a maximum output power of 209 W at 20 kHz, the Dipole Coil Resonant System can charge 40 smart phones simultaneously, even if the power source is 5 meters away* *&* The system has a low Q factor of 100, showing 20 times stronger against the environment changes, and works well at a low frequency of 100 kHz. The team conducted several experiments and achieved promising results: for instance, under the operation of 20 kHz, the maximum output power was 1,403 W at a 3-meter distance, 471 W at 4-meter, and 209 W at 5-meter. For 100 W of electric power transfer, the overall system power efficiency was 36.9 percent at 3 meters, 18.7 percent at 4 meters, and 9.2 percent at 5 meters. On 19 April 2014 07:01, YES NOPE9 wrote: > > http://www.wirelessdesignmag.com/news/2014/04/wireless-power-transfer-ach= ieved-5-meter-distance?et_cid=3D3891160&et_rid=3D486007905&location=3Dtop --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .