This one is the most used in the house.
I also found this one in a dustbin a while back. It did not work, but when I opened it up it looked like it was someone's incomplete project that they got fed up with and consequently threw it away. I completed it and it works well. I don't know what make it is supposed to be (Velleman perhaps), but it's about 40W (20V 2A) with adjustable current limit, course and fine voltage adjustment. It's perfect little handy power supply to use when you are cosy in the house and just want to check something out without having to run out to the workshops in the freezing snow.
I can tell you all about that one...
That was made at the BBC's engineering training site at Wood Norton, and it's my design (I work there). It's nothing clever; just an industry-standard floating regulator that everyone uses, but it's proved to be reliable and many have been made over the last few years. It was designed to be easy to build, which is why the PCB is TH and single-sided, and why connectors have been used where possible. The enclosure was chosen by someone else, and it did impose some mechanical and thermal constraints, but it's not bad overall.
It has adjustable current limiting (limit shown on meter when DC output is switched off, just like the TTi units) and an over-temperature cut-out. Regulation is done by a dual op-amp. The maximum voltage should be set (with PR1) to 18V with fine-volts at min, and about 0.4V higher with the fine-volts at max. Current should go to 1.2 or 1.3 amps, although I only used a 1N4148 as the reference for that, so it's not terribly stable with temperature (decided that didn't matter - you have to draw the line somewhere!). You should find that the voltage stability is pretty good for such a simple design.
No-one on the course has ever left with a partially-completed unit - we always make sure they are finished and tested - so I'm intrigued to know what you needed to do with it. I'm also curious about where you found it. I wonder who would want to throw away such a useful thing? Of course, not all broadcast engineers need to work with electronics these days...
I can send you comprehensive details if you like - drop me an email.
All the best,
Mark