This is my induction heater I built over a few weekends. It works surprisingly well, heating up metals to hundreds of degrees in relatively short periods of time (30 seconds @ 12 volts for a 50 gram iron peice maxes out my thermometer at above 200 degrees). There are a few aspects that I would improve in a future revision, namely that the main coil could be replaced with airconditioner tubing which can be water cooled. Not having the rig water cooled limited the output power I could reach without overheating. Furthermore, the large bank of capacitors is used simply because that is what I had on hand, however, this could be replaced with much fewer capacitors. It should be noted that with such a high current oscillator having a few capacitors in parallel reduces the strain on the single capacitor in terms of current per capacitor. I've uploaded my schematic/board files as well as gerber exports here.