[duncanlowe]

I thought I recognised this. Many (many) years ago when I was in my first job, one of the other guys in the office was into amateur radio, but wasn't really into electronics construction. He had tried to build this design, but it didn't work. He asked me to look at it and after a bit of work (poorly soldered connections mostly) I got it working for him.

Some years later I inherited a rather dead heavy duty BNOS power supply with a pair of nice torroidals, a big case and space to mount a decent number of 2N3055s. I dug out the photocopy of the article from AR magazine he had given me to help fix his, and built it up. It can supply more than the 20A of the original design, and has adjustable voltage and current limit. And it's still working! Have to admit I've been thinking of getting rid of it, as it's so heavy and I have a nice Farnell AP 60-50 that's smaller, lighter and more powerful (as it's a switcher).

EDIT: oh and I've also found that original photocopy from more than 30 years ago!