Another source of high power constant current power supplies are WELDERS. Specifically welders that are set up for Stick and TIG welding. Not MIG (wire feeders). As far as regulation, no guarantee of any precision. Be aware that normal open circuit voltage is typically 80 volts. Under load, the voltage drops down to around 15 to 30 volts. TIG based machines have the added advantage that they usually have an input for external current control, AKA the foot pedal.
A poor mans dropping resistor includes such wonderous items as garage door springs, electric elevator cast iron resistor banks, and water rheostats.
Larry C
