Hi Tom,

I certainly don’t have all the answers but a bit more info might help.  What is the core you are using for your coil?  Is it pure iron or some less effective material?  If it is pure iron it will need to be equal in diameter to the magnet and if it is just soft iron wire or lamination plate it will need to be bigger in cross section than the magnets to avoid magnetic saturation which will make your motor generator run very slow and not show OU effects.  I have not got a formula for the size of wire or number of turns but would suggest 26 gauge SWG wire with a 10 ohm resistance.  So you can work out how many meters of wire you will need like for 26 gauge you need 74.6 meters of wire to get 10 ohms.  Your voltage is probably too low for neos magnets and you will go far better at low voltages with ferrite magnets and use neos for higher voltages like 48 volts upwards.  You may need to build 2 or 3 coils to get a good result unless someone can give you very accurate information.  All the best as we are all just learning this stuff.

Regard Russel P.