Brand? Model? Unknown PS, no markings, any ideas? - Page 1
Forum section: electronics / testgear

author: LeoTech
author_rank: Regular Contributor
timestamp: August 28, 2019, 03:34:21 pm
content: Hello,A couple of days ago, I bought an used power supply on the local used market, and it finally arrived today. It works perfectly, and although I originally thought I would disassemble it and use the case and parts for other stuff, I am now definitely gonna keep it this way.I have however no glue about the model, make, age or even brand. The info on it are a series of numbers and a calibration sticker, at least it looks like it, from 96. (See attached pictures)Anybody got any idea what this might be? Brand, model? Anything?Thanks,Leo

author: DaJMasta
author_rank: Super Contributor
timestamp: August 28, 2019, 03:39:04 pm
content: What's the construction inside? Any indicator on the board? Nothing telling on the back plate?If it weren't for the silkscreen on the front (and maybe even so), I'd believe you if you told me it was handmade by someone for a specific application. Is that even a silkscreen on the black numbers? The font seems to have slightly varying heights... in any case, if it's homemade, the internal construction would be fairly telling.

author: LeoTech
author_rank: Regular Contributor
timestamp: August 28, 2019, 03:41:59 pm
content: Quote from: DaJMasta on August 28, 2019, 03:39:04 pmHi,I figured about the same myself, but the numbers seem a bit odd for a homemade project. They appear to be more like typical markings found on school and public equipment here in Denmark.I will take a look inside ASAP.Thanks,Leo

author: Yansi
author_rank: Super Contributor
timestamp: August 28, 2019, 03:54:07 pm
content: Back in the days, when schools have actually done science and research, when laboratories were more than just for catching dust on both the old and newly gathered (for € fonds from EU) equipment, most of the schools had usually their own development laboratories, where they specialized in making custom test & lab gear.This could pretty much be and example of that.

author: LeoTech
author_rank: Regular Contributor
timestamp: August 28, 2019, 04:21:57 pm
content: So, I just took it apart, and it is definitely not a commercial project!I'd say that it was made by either a really skillful hobbyist or some RnD place/insitution with enough founding to make their own test equipment.Quote from: Yansi on August 28, 2019, 03:54:07 pmExactly this!It is quite interesting inside, I might try to reverse engineer it, or at least try to calibrate it, and learn from it.Although I am now far more curious to know which institution this came from.Thanks for the suggestions,Leo

author: Richard Crowley
author_rank: Super Contributor
timestamp: August 28, 2019, 06:14:52 pm
content: The lack of a brand name and model number is practically a dead giveaway of a DIY project vs. a commercial product.The interior PCB reminds me of HP style from the 1960s-1970s.And the use of comma for decimal indicator is a pretty strong indicator that it is European vs. US.It looks like a good job of using rub-on letters. Back in those days labs had sheets of rub-on text.You could get special sheets of electronics and scientific words, numbers, etc.We had an IBM 1620 computer which had several unused big lighted pushbuttons.Somebody (not me!) used the rub-on words to label one of the buttons: "WARHEAD ARMED"

author: LeoTech
author_rank: Regular Contributor
timestamp: August 28, 2019, 06:35:00 pm
content: Quote from: Richard Crowley on August 28, 2019, 06:14:52 pmSound like a really nice work setting.I contacted the seller, and it was indeed build and used by an University here in Denmark as far as he knew.Although I haven't heard about these rub-on letters before, but wouldn't they be flat? Because these are extruding out from the material.Any tips on reverse engineering this unit?Leo

author: Yansi
author_rank: Super Contributor
timestamp: August 28, 2019, 07:04:21 pm
content: Get a paper, pencil and start drawing the schematic of it

author: johnkenyon
author_rank: Regular Contributor
timestamp: August 28, 2019, 07:14:06 pm
content: Quote from: LeoTech on August 28, 2019, 06:35:00 pmBack in the day, the usual practice was to use the rub on letters, apply a spray lacquer/varnish over the top to encapsulate/protect, then mount the sockets/panel mounted components.Unless they had an art department somewhere that could create screen printing stencils etc, but that would require the engineers talking to artists...

author: Richard Crowley
author_rank: Super Contributor
timestamp: August 28, 2019, 07:35:50 pm
content: Quote from: LeoTech on August 28, 2019, 06:35:00 pmThe rub-on letters were relatively "thick" in order to survive the rubbing and transfer without breaking up.The result was much thicker than screen-printing as we would expect in modern commercial gear.They also sold small bottles of clear lacquer (or enamel?) to paint over the rub-on letters.The bottles were just like fingernail varnish with a little brush in the lid of the bottle.But many people just covered the entire panel with spray-lacquer (or whatever) after transferring the nomenclature.These days some people use laser (or inkjet) printed transfer sheets so you can design your entire panel and put marks where the holes should be, etc.Here are a couple of examples of the "Datak" dry-transfer sheets. Commonly availble back in the day in black or white: