electroformer

I wish to build a small electroforming machine. low volts. amp and voltage controls. this is for jewelry making. plate copper to stones, build it up to desired thickness and plate with silver. my plater will not work as electroformer. no amp control. hope to build this with readily available components. Any ideas? need schematic and tech advise.
thanks krautschmidt :roll:

The easyest way is to feed PWM (Pulse Width Modulation) in to an power MOSFET