I have a nice 24V SMPS from a printer, that I want to use to power a pass BJT supply, for as wide a range as possible. I only want a few hundred milliamps, just for little quick breadboard use, and it will fit on a 5x7cm pref-board.
Should I heatsink a 2n3055 for say 0.5A at say 22V ?
So I could use a TL431 or overkill LM317 to drive the BJT. Should I use 2N3055 or the PNP version ?
And should I have a small resistor, from the regulator output, to the BJT base ? I assume I should put a small cap on the base. So that would make an RC filter.