I built my first experimental cheap power supply for the 1800 Watt induction heater and it was a great success!
I have put together 12 old Lenovo 20V laptop chargers put together for to make a power supply that can output 40VDC at 51A. Two 20VDC power supplies is put in series for the 40VDC rating . Six of those series connected power supplies are then connected in parallel for the 41A rating.
See the induction heater here: https://kaizerpowerelectronics.dk/induction-heating/unboxing-a-chinese-1800-watt-induction-heater/