POWER DESIGNS PRECISION POWER SUPPLIES

[nanofrog]

FWIW, I suspect it would survive load testing (these things are built like tanks IME). 

If not, there's surely someone that can post a proper schematic (I've a TP343B if that'll help; bit different obviously, but the offer stands should you need it).

[mtdoc]

FWIW, I suspect it would survive load testing (these things are built like tanks IME). 

If not, there's surely someone that can post a proper schematic (I've a TP343B if that'll help; bit different obviously, but the offer stands should you need it).

Oh it did pass load testing just fine - even before I replaced the burnt resistor. I just don’t like not understanding why that resistor blew.

[bitseeker]

Unfortunately, I don't have a better schematic. Perhaps someone did something funky with tracking since source A was affected.

[nanofrog]

FWIW, I suspect it would survive load testing (these things are built like tanks IME). 

If not, there's surely someone that can post a proper schematic (I've a TP343B if that'll help; bit different obviously, but the offer stands should you need it).

Oh it did pass load testing just fine - even before I replaced the burnt resistor. I just don’t like not understanding why that resistor blew.

I get it.

I'd be in the same boat should something happen to mine (would do my darnedest to figure out the issue and fix it, even if it ended up being more expensive than just replacing it with a working unit). 

They're just way too pretty to let go to a landfill IMHO.

[JonM]

About 36 years ago I saved a Power Designs 2005 from a dumpster and gave it to my father who had it hanging under a cabinet in his shop since then. After becoming an EEVblog fanboy I was surprised to see a 2005 on Dave's shelf and the video about it.

I recently recovered this power supply and did a bit of testing. The first problem was that the voltage was high by almost a full volt. That turned out to be due to the 0.1 v dial reading zero but actually being set to 9. With some difficulty I got it set properly. I did mess with the calibration pots before I noticed what was causing the 0.9 volt offset, so the 5.00018 v is not from a 40+ year old calibration.

The power cord is in very bad shape but before changing it I would like to loosen the 0.1 v dial shaft to make this supply be actually useful. If anyone has a recommendation please let me know. I was going to try some contact cleaner / lubricant spray but I suspect that it will not be enough of a lubricant.

[KrudyZ]

I'm not sure if you noticed, but the vernier on your unit in the photo is set to 8.
So if you want to calibrate this to better than 1 mV then make sure to take that into account.
I have one of these and they have incredibly low drift and great repeatability once the heater has stabilized.

[JonM]

I'm not sure if you noticed, but the vernier on your unit in the photo is set to 8.
So if you want to calibrate this to better than 1 mV then make sure to take that into account.
I have one of these and they have incredibly low drift and great repeatability once the heater has stabilized.

Thanks, I did notice the vernier position just after I posted (actually I thought that some dirt in the photo was the knob mark and then looked at the unit and saw the vernier was cranked up).

The first task is to get that 0.1 v position to move reasonably.

[nanofrog]

The first task is to get that 0.1 v position to move reasonably.

I recommend going with Caig Deoxit products. It's not cheap, but works extremely well. The K-2C sampler kit would take care of your 2005.

They do sell spray cans, but you'd be better off disassembling the pots and clean them that way IME.

[mtdoc]

Decided to do further noise testing of my recently acquired TP340A.  When I attached my scope to the output of source C the fault light lit up.  Tested and there was about 6 kohms between the negative output and ground. Not right! It is supposed to be an isolated supply.  Nothing obvious on inspection of the boards. The only connection between ground and the negative output is supposed to be via a couple of ceramic caps which I checked and were fine. After some tracing I isolated the problem to an orange wire leading to the V - A switch. Looking closer and aha!  The orange wire had been pinched between the frame and front panel - presumably when someone had taken it apart or loosened those screws.  I'd missed it on my earlier inspection. Easy fix.  

It's a testament to how well these things are built that even with this 6kohm connection between the negative output and ground, source C still passed preliminary load testing.

[bitseeker]

That's a sneaky fault. Good sleuthing, mtdoc.

[exe]

2mtdoc: are these wires, soldering and cable ties original? It all looks very well and tidy for such an old piece of equipment.

[mtdoc]

Yep, all orginal AFAIK. The PD supplies are like that.

[nanofrog]

Yep, all orginal AFAIK. The PD supplies are like that.

They are. 

I noticed a date code in one of your photos (RCA TO-3) of 8501. I suspect it's original, but do you recall if '85 is right based on other components?

[Barbouri]

2mtdoc: are these wires, soldering and cable ties original? It all looks very well and tidy for such an old piece of equipment.

I have always been impressed with the quality of the wiring and attention to detail in the Power Designs Inc. supplies.
Here is a picture of the bottom view of a PD 6150 hand laced wiring harness.

[mtdoc]

Yep, all orginal AFAIK. The PD supplies are like that.

They are. 

I noticed a date code in one of your photos (RCA TO-3) of 8501. I suspect it's original, but do you recall if '85 is right based on other components?

Yes, I think it is. If you compare my photos to Bitseekers in his repair thread (link in my earlier post), you can see there were several part changes in later models.

[exe]

Hello power designs lovers,

Do you think it's possible to convert 2005A to accept 230V input? I'm trying to figure this out from tear down photos: https://www.barbouri.com/2018/01/13/power-designs-2005a-precision-power-source/ . Looks like a new transformer is needed .

BTW, what power designs suplies have ovenized references? I know about 2005A, but I wonder if oven is used in their other models.

PS I see "Warning: this topic has not been posted in for at least 120 days. Unless you're sure you want to reply, please consider starting a new topic." Should I start a new topic, or keep it contained in this one?

[bitseeker]

Your post is relevant since the 2005A is a precision supply.

As far as I know, you'd need a different transformer for 220V operation.

Of the precision models, the 2005, 2005A, 2020A, and 4010 (not very common) use an ovenized reference. Note that there are also non-precision 4010 models (fairly common). They don't use an oven.

[Barbouri]

It looks like the 2005A was only built with a single 115V transformer primary winding.
The transformer part number is TTN-56 built by Power Designs, Inc.
Terminals 1, 2 are the primary.
Terminals 3, 4, 5 secondary #1 and 6, (7), 8 secondary #2 with terminal 9 transformer ground.

Most likely your least expensive option would be a 230 to 115V external step-down transformer, 50VA or larger.

[exe]

Thanks for the information! I'm thinking which one I'd like to get: 2005A or 2020A .

Are 2005A and 2020A different in width and height? The specs say so, but looking at photos they seem to be fairly identical. At least the front panel.

What model would you recommend? 2020A seems to be quite more powerful.

2005A seems can be fairly easy "upgraded" to 230V just by replacing a transformer. 2020A has a third winding with quite high voltage. This can complicate replacement.

[bitseeker]

They do look like they're the same height/width, but I don't have both, so I don't know for sure. My collection currently consists of all non-ovenized models (precision ones in bold): 2010, 2020B, 5020, 2015R, 3650-S, 6050A, TP340A, TP343B.

If you specifically want a precision version with oven, then the 2020A. Otherwise, the 5020 covers the 20V, 2A of the 2020 plus has the capability to go up to 50V at 1A.

[Johnboy]

Sorry to revive such an old thread, but I read this today and was interested enough to do a little research on these mystery boxes on my own.
I found this picture of a PD catalog someone is selling on ebay. I've attached a picture from the cover, as well as the link to the item if anyone is actually interested enough to buy it (I am not the seller and have no affiliation). I also tried to find a scan of this floating around on the 'net somewhere and came up emptyhanded.

What I thought was interesting about this picture is that it shows the "newer" digital models along with the older precision supplies, although I can't make out which one it is. This was at one point in time at least, their lineup prior to the acquisition of their branding and the change that followed. An interesting time for a PD catalog, and I'd like to see what's inside if anyone else has found a scan of it somewhere.

https://www.ebay.com/itm/Power-Designs-Regulated-DC-Power-Sources-Product-Catalog/323203742840?hash=item4b4071bc78:g:i0gAAOSwZ-Zazm~L

[Barbouri]

What I thought was interesting about this picture is that it shows the "newer" digital models along with the older precision supplies, although I can't make out which one it is.

Hi Johnboy,
Power Designs Inc. never did make a true digital control model power supply.
After the acquisition they came out with the plastic cased models: 5020A, 2040A, and 1001A Precision DC Power Source units, which I believe were considered their digital models.
These were basically repackaged existing power supplies with a push-button decade switch on the front panel that selected a combination of different resistors vs. turning a potentiometer.
I have never owned one of these so called digital units, but I have read that these were built to a price point, hence the plastic case.

Greg (Barbouri)

[bitseeker]

Sorry to revive such an old thread, but I read this today and was interested enough to do a little research on these mystery boxes on my own.
I found this picture of a PD catalog someone is selling on ebay. I've attached a picture from the cover, as well as the link to the item if anyone is actually interested enough to buy it (I am not the seller and have no affiliation). I also tried to find a scan of this floating around on the 'net somewhere and came up emptyhanded.

What I thought was interesting about this picture is that it shows the "newer" digital models along with the older precision supplies, although I can't make out which one it is. This was at one point in time at least, their lineup prior to the acquisition of their branding and the change that followed. An interesting time for a PD catalog, and I'd like to see what's inside if anyone else has found a scan of it somewhere.

Cool find, Johnboy. The models on the cover, as far as I can tell given the low resolution and excessive compression of the seller's image (clockwise beginning at the top-left):

1. TP340 or TP343A, triple-channel. It looks like there may be an 'A' designator at the end, so it may be a 343A. The TP340A has positive and negative binding posts for Source A and B, whereas the non-A is positive for Source A and negative for Source B (as in the image). The TP325 has a single line of lettering at the top, whereas the 340 and 343 have two-line lettering.
2. TW347?, dual-channel. I've only seen the 'D', digital, version of this.
3. 2020B or 2010, precision supply. By contrast, the 5020 doesn't have a range toggle between the amber/yellow lamps and the 2005A has an additional oven lamp.
4. 6010(A/B/C/D)?. I've never seen the digital version of this, but the range table on the left side of the panel looks like the one on the analog 6010.
5. 3K10, high-voltage supply (3000 V, 10 mA)
6. 6050C. The 6050D has lamps on either side of the display, like #4, but with four ranges instead of the three in #4.

Corrections welcome.

[Johnboy]

I am curious as to whether there is an MSRP included alongside the various models, as there is only one mention in this thread of what that might have originally been for only one model. If the cover is indicative of the main models they were offering at the time, which appear to be from the New York factory, it might be interesting to see what demographic they were aiming for in terms of marketing. Who was this flashy catalog for? Posters in this thread have reported finding stickers by big-leaguers like Grumman, Boeing (IIRC) and I have even seen a unit that was marked as property of Sandia National Laboratories. PDI seems to have been at one time making high-end test gear for military contract, a rather solid gig if you don't get greedy and start counting beans (which does not seem to be the MO of this company, at least until manufacturing left New York, and it's not clear why that happened either). I find it exceedingly strange that there were so many people who posted in this thread, over several years, and only a very few were able to find much information about this company at all. Surely PDI held some patents and someone had to take personal credit for the designs, at least at some point? This company was churning out rather unusual, visually-striking products for multiple decades. It seems very odd that there was so little left to find.

Unless, of course, they were aliens. 

[Barbouri]

4. 6010(A/B/C/D)?. I've never seen the digital version of this, but the range table on the left side of the panel looks like the one on the analog 6010.

Power Designs Inc.  6010D  Universal DC Source
Greg (Barbouri)