I spoke to my electronics teacher today regarding ways to protect my transformer and told him i needed a 2mH inductor. He recommende winding them on ferrite cores that were little more than 3/4" across, is this possible, they measured uo right but with only 30 turns and on such a small core are they going to saturate or do something else undesirable like melt or catch fire, the wire is about 20 swg so fairly heavy