# What kind of coil do I need for wireless power transmission?

My project: I am trying to design a system for a school project that will help with electrical safety. My idea is a wireless electrical socket/outlet. It will use a transformer to convert 120v to 6v, and the 6v is sent through a coil, producing an electromagnetic field that transfers power to an identical coil on the other side.

My Question: What kind of coil would I need? The inductance? The wiring gauge? And finally, would I actually have to get the coil to be rated at 300 amps?

Diagram:

simulate this circuit – Schematic created using CircuitLab

• Where did the 300A figure come from? – vofa Dec 12 '16 at 17:13
• Probably from the assumption that if the source outlet provides 15A at 120V, the out put should provide 300A at 6V.. – Eugene Sh. Dec 12 '16 at 17:20
• not defined are the requirements for safety. e.g. double insulation to 3kV and output voltage at 300A or total power out plus any switches. Air coupling (wireless) will not possible with 300A at 50/60Hz Also project function is not defined. – Sunnyskyguy EE75 Dec 12 '16 at 17:33
• I'm guessing here that you'd need a couple of facing silicon steel cores about a meter square and weighing several tons to get decent coupling with a 300mm separation at 50/60Hz. – Spehro Pefhany Dec 12 '16 at 17:58
• Refer to the Qi wireless charging standard. en.wikipedia.org/wiki/Qi_%28standard%29 en.wikipedia.org/wiki/Resonant_inductive_coupling – vofa Dec 12 '16 at 18:01