Thought this might be interesting to some people. I've been building a high current variable DC power supply from scratch, and recently just got finished with it. It's variable from 8vDC - 24vDC and I've loaded it down with 20A and the transistor's, regulator, and transformer isn't even touched. It's made with (6) 4800uF powerlytic caps for the filtering, and (8) power transistors along with a .1ohm 25watt resistor to balance the current flow in each resistor. There are (2) meters that read voltage and current draw. The massive heat sink was taken off of a old car audio amplifier that no longer worked. There is a relay that closes when the ON/OFF switch is flipped that applies power to the transformer. Their is also a cooling fan that blows air up through the case and across all the transistor's. There are pictures in the uploaded attachments.
Thanks! 73's KD8RYP - Andrew