opened up an antique (60s-era) high-voltage power supply at work to fix a loose connector, and that thing had the biggest flyback transformer we've ever seen in it--like the size of a box of tissues

which explains the periodic clicking it makes when in use--it must be operating that thing at extremely low frequency, for it to need such a large transformer. Probably around 2-5 Hz judging by the clicking.

It's from that era when "fully transistorized" was a selling point
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and characteristic of that era, there were only maybe three transistors in the thing, along with a bunch of diodes

front panel was two galvanometers for showing the voltage and current, a single-turn potentiometer for setting the current limit, and most interestingly of all, four potentiometers driven by *gears* to rotary displays on the front, with a window to show through the number they're set to

the ones digit could spin freely, while the other three had rollers for ten detents in each
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I should open that thing up again and get some pictures, I can think of some people here who'd probably find it fascinating

this was back when HP made stuff to last, and last it has--everything in there seems to be original, and all we needed to do was screw down a panel nut to fix a loose output connector and it works perfectly, still in calibration even as far as we can tell with the equipment we have
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speaking of people who'd find it fascinating, ping @starkatt, @lorxus, and @Kyresti

and maybe @chr too
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@starkatt @lorxus @Kyresti @chr if anyone wants to see the photos i took today, look downthread from here! they will be coming as soon as we can get them off our phone
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