A bit of TE now.
Had this old PSU I was given. It's very heavcey and ugly and looked like a home made project... so I stored it away and didn't think too much of it.
But I dug it out today and spent some time on it. After brushing off all the dust inside, and looking more closely.. it didn't look home made any more.
There is even a sticker on it... says it's made by ADTECH Power " PSU, model TAPS4-2, in the US of A.
Then as I was cleaning it, I noticed a piece of paper trapped between the chassis and the underside of the transformer... pulled it out and oh.... what do you know, a nice double sided A4 size original spec sheet for the thing ! Oh I just love old tech paper, I was over the moon.
Looking at that sheet, I now understand why it looks home made... it's not. But, it's a "budget" PSU, so comes bare bone... you just get a giant piece of folded thick sheet metal that serves both as a sturdy chasis, and a big heat sink. Then they put the circuit board ni place, bolt down the big filter caps... and that's about it. Then it's up to you to fit binding posts, and wire them up to the circuit board etc.
So in this case 4 rubber feet wre added, as well binding posts with markings using a sharpie... blac sharpy on a black chassis, how clever . That's all for a "front panel"... Then a metal bracket was added to support the power cable, power switch and fuse holder and earth connection. Also a piece of plexiglas was added to cover the side of the chassis where all the TO3 pass transistors are mounted.
So that gives it an uglty loook... but if you go past that anc just concentrate on the PSU itself, before it was "modded", then it's actually quite nice. Nice looking PCBs, nice rigid chassis. 3 output : 5V 12amps, and twin 12-15V 3 Amps. The "front panel" make sit look like it's a symmetrical / common ground +/- 12V supply but looking at the terminals on the board, and reading the datasheet... the 3 supplies are floating. There is no common ground. So I could potentially put the two 12V supplies sin series, say, so that's cool.
Wghat's cool as well, are the voltage regulator chips... we wxere just discussing these 723 chips from Tesla in that TO round metal can... AVG saying they are nice sealed units. Well... this PSU uses a 723 for each of the 3 outputs, and they are the TO can type.. aren't they beautiful, with gold plated legs as well !
Also... as AVG said, they are cool because sealed... and I guess it was cool even back in the day, because lookj at the spec sheet / marketing at the top of the first page... look what they proudly state : " ALL IC's and transistor HERMETICALLY SEALED, NO PLASTIC !!! "
Oh I just love it. I am now loving this PSU more and mode.
It's got to be useful in the lab.... 5V 12A and twiun floating 12V 3A outputs, adjustable up to 15V as well. So beefy 5V for your TTL and CP%U stuff, and twin 12/15V supllies for your analogy AOP fun.
Yes... I like this PSU a lot. I think I will strip it from all the ugly crap that was bolted to it, to "clean it up", then make a nice cabinet for it, so that the guts aren't exposed anymore/at risk, and so I can make a nice front panel for it, and integrate it more easily in the lab with the rest of the TE.
Yeah.... I think I have just added myself yet another project to the list !
Hi Vince,
That is not a "budget" power supply. It is a high performance professional "open Frame" PSU. It's intended to be built into a piece of equipment. They are a standardised basic design with interchangable models made by many manufacturers. Specification and quality is high They will run rated output 24/7 for years (some need a bit of fan cooling or heatsinking for full output). They are still made bu not not so common as SMPSs have become popular. Still used for low noise and legacy applications. A new replacement for yours will cost £200-300 depending how many you buy.
https://www.mouser.co.uk/ProductDetail/Bel-Power-Solutions/HDCC-150W-AG?qs=gCHJnwMCk7Ta3xAQtQTxFQ%3D%3D
They make great triple output bench power supplies but MUST be in a proper case for safety. Bringing the voltage trimmers out to pots on the panel will give some flexibility.
THanks. Wow so they ar still sold today, incredible... some standards do last then...
So my idea was the gonnd one then, put it in a cabinet and make a proper fornt panel for it. Will do that then... will take time though, as finding a suitable enclosure for such a bog and heavy piece... not gonna be simple nor cheap. Need to keep the budget under control... I guess I would need to add a fan in the enclosure to force some airflow over the chassis/heatsink, or maybe relocate the x5 TO3 pass transistor on a proper / finned heat sinks, at the back of the enclosure, like you find in any linear power supply.
Also, I called budget because... not me, but the manufacturer itself called it that on their spec sheet in the title, if you have a look. It says "
ADTECH POWER
Microprocessor power supplies
Triple output OEM
Economy general purpose power supplies
I can only guess that things went downhill over the years, and what they called "economy" PSU in 1977, 45 years later is now deemed "top quality" and expensive....
Still, as you say a nice PSU, so will definitely make a decent enclosure for it and proper front panel with access to the pots of course... but that will take money so it's way down on my priority list at the moment. Will get done... just not any time soon I think...
Forgot to mention yesterday, but the board the does the 5V supply, has TWO pots on it. One to fine adjust voltage, and is identified in the spec sheet. However the second pot is not mentioned in the spec sheet so I don't know what it does. It is user accessible just like the other pot, via a hole in the chassis/ heat sink, so I guess that means I am "allowed" to play with it... just would like to know WHAT it does !
I guess that's a fantastic excuse to pull that board out and reverse engineer it to see what's what.