I built and use this
Induction brass annealer redux
My first annealer was built with the help of hollywood. He worked long and hard on finding the right coil size. He also came up with the water cooled coil and the radiator/pump system for it. I added the timer system, trap door, and voltage/current monitor meter. Together we came up with what...forum.accurateshooter.com
A lot less and works as good or better. Some basic electrical understanding is required to do it.