SMPS Topologies

yes, fat traces going to to220s marked TR at each end of the heatsink a couple of to220s marked IC probably linear regulators also on the heatsink probably for other voltages

and the DIP14s are LM324 a quad opamp

And a 5V reference AD586. Old style linear supply, but makes sense if you are worried about noise

And the other dip is a RTC and reset manager.

Obviously some exotic devices. Transistors would be marked "Q" and ICs would be "U".

The photos are distorted in my browser so it's hard for me to zoom in to see the silk screened component labels. Lasse notes that at least some of the TO-220 devices are marked as "IC." It's possible that the remaining unmarked TO-220 devices are MJE3055Ts.

Thank you,

Only on a schematic; not the board.

Yep. There are some LM317Ts among them and some others I'm not familiar with and difficult to read the numbers of. I'll get out my geriatric's magnifying glass and have a better look.

I'm not a designer (obviously!) but that's what I would have gone with for a high -end signal generator. I was just put off the scent by the fact that it's a relatively modern piece of gear and so therefore would have used a switching PS. An assumption too far on my part.

Tom, as the first person to correctly identify this as a linear supply, you're the lucky winner of a 5 shilling postal order! Well done! ;)

Oh. Well, there's hundreds of pages, could you add which pages are relevant?

(I guess the relevancy isn't very high anyway, if as you say, it has no schematic? :-/ )

Tim

Ah, that's better!

I don't see any inductors, so I'd be very suprised if it were hybrid.

Shouldn't need that much heatsink either, if it were. Though, I have a DC-DC module laying around somewhere, with an impressive heatsink...

The module, despite its heatsink, is for making all of a few amps at 5V, or something like that. (Unfortunately I don't have it handy, or I'd take a picture...) It's an old discrete design (or it has one or two ICs, I forget), bipolar switch, BYV something diode. Probably, it runs very cool, even at full load.

IIRC, I removed the module from an HP line printer. The kind with the page-width, single row of pin drivers, that oscillates back and forth on a crank and counterweight. It had a nice big 36VCT transformer in it, so it could count as a hybrid supply of sorts. It was probably the supply for the couple cards of 74LS logic they stuffed inside the thing.

Actually, maybe it was something else I had taken apart that year. It's been so long I don't remember...

In any case, both things I'm remembering, were chock full of 74LS, dated mid to late '80s. Could very well have been towards the end of production, with the initial design dating to the late 70s. Or if the design was newer than that, the designers certainly weren't, given the baroque mix of linear supplies, bipolar motor drivers, TTL logic and 8-bit microprocessors (Z80 based) they chose to use.

Tim

Exactly. There's some half-arsed block diagram buried in there somewhere but IIRC it doesn't reference the PSU section anyway.

The IC date codes are from the Seattle Grunge era, but the design seems very Night Fever and polyester bell bottom.

Hey, if it ain't broke...

Your schematics and your boards have different reference designators?

We use "IC" for ICs. Don't ask me! I just work there!

Ha! And I bet you use "RV" for a pot.

Or even worse, "LED" for an LED.

I like how the first 20 pages are just various warnings and advisories in six different languages.

I don't see the point in worrying about notifications. The little shining LED will not be insulted to be called a LED, and production doesn't care either

Cheers

Klaus

"404 Not found."