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Playlist "26C3: Here be Dragons"

Wireless power transfer

Davor Emard

Wireless power is a most wanted technology. It has already been invented by Nikola Tesla in 1888. The speaker read the papers, reproduced the theoretical and practical results. The theoretical idea to get highly efficient wireless power transmission is to separate the electric from the magnetic field, because magnetic field lines are closed curves near the device, while the electric field lines reach to infinity and receiver only needs common ground (the earth). This is done by special requirements to the sender and receiver antennas (form of the coil). The antenna form has been modeled in the software nec2 (variant xnec2c on debian). A lowcost PET bottle serves as the hull of the coil. Around 200 windings of insulated copper wire are manually applied to the bottle. A transmission in the range of 10 meters was reached, the power used is 100mW, from signal generator amplitude 10V and 1 MHz frequency. This will be shown.