POWER DESIGNS PRECISION POWER SUPPLIES

[timb]

Most likely the resistors have drifted over time. Above 1V the deviation seems consistent, so you should be able to calibrate it. I'll pull mine out tonight and figure out which pots you need to tweak.

The deviation below 1V is most likely your meter and not the unit. What kind of meter are you using?

Anyway, there's normally two pots you have to tweak, one for zero set and the other for cal. There may also be a pot to adjust the front panel meter.

[Ampere]

That is not unexpected, the lower ranges use less accurate voltage setting resistors.
Also: what is the accuracy of your meter below a volt.

It's a UT61E. The 220mV range is accurate to 0.1%+5 (at 0.01mV resolution) and the 2.2V and 22V ranges are accurate to 0.1%+2 (at 0.0001V and 0.001V resolution, respectively).

Most likely the resistors have drifted over time. Above 1V the deviation seems consistent, so you should be able to calibrate it. I'll pull mine out tonight and figure out which pots you need to tweak.

The deviation below 1V is most likely your meter and not the unit. What kind of meter are you using?

Anyway, there's normally two pots you have to tweak, one for zero set and the other for cal. There may also be a pot to adjust the front panel meter.

Thanks. That would be a big help! 

My meter is a UT61E. I know it's not the best meter, but the specs lead me to believe that it's accurate enough that what I'm reading can't entirely be blamed on meter accuracy. I also checked the results against a second (much less reliable) meter as a sanity check and the results were quite similar.

[bitseeker]

That meter is fine for this and other low-power electronics. Plus it has a pretty high resolution, which is nice for monitoring small changes. The major issue is safety if you're using it on high-energy circuits with the standard fuses. Although I've heard of some drift over time, you have a voltage reference to check it against. So, you should be just fine.

Carry on. 

[bitseeker]

Did a member happen to snag this 2005A today? It looked really clean (even had feet and tilting bail) and was very hard to resist rescuing it myself. $25 is quite the score and timb has parts for sale to finish restoring it.

http://www.ebay.com/itm/282122401045

[pelud]

Just a heads up: There's currently a 2020B listed on ebay for $75. eBay auction: #142105850722

[motocoder]

In case anyone is interested, I have an HP 6115A that I am selling.

https://www.eevblog.com/forum/buysellwanted/fs-hp-6115a-precision-power-supply-(us-only)/

[mtdoc]

OK fellow PD fans and TEA members. I just spotted a nice looking 2005A on the bay for $65 + $30 (US only- sorry). Link HERE.

 If i didn't have one already...

[motocoder]

I have a PD2005A I will give to anyone in the Seattle/Puget sound area that can come pick it up. I have repaired a broken heater thermostat on it with a small circuit of my own design, and converted the heater to run on the unused phase of the secondary transformer output (so I wasn't messing with mains). The supply works great, but it's just sitting on my shelf. I would rather someone get some use out of it. 

Please post here and PM me of you are interested. Again, only people who can pick it up locally to me. I live in Issaquah and work in Redmond, Washington.

[bitseeker]

Here's an interesting version of the 2020. All the 2010 and 2020 I've seen were in the horizontal enclosure.

[don.r]

Can any PD fans here enlighten me on the difference between the 5015-S and 5015-T models. I know that the A model was much older than these and the R is the newest one with a digital display. I can only find a schematic/ manual for the T and not the S so I was windering what the differences are since the appear to be identical from the outside and from the specs.

[bitseeker]

Hmm, I'm not really sure about those two variations in particular. Since the specs are the same, it may simply be architectural changes due to availability of parts or the like. Now that you've brought it up, I'd be curious to know more as well.

Unfortunately, there isn't a lot of info out there about the company or its products. I guess we, the PD product owners, need to start a wiki to consolidate whatever info we're able to find. I haven't even found documentation for all the supplies I already have.

[don.r]

Hmm, I'm not really sure about those two variations in particular. Since the specs are the same, it may simply be architectural changes due to availability of parts or the like. Now that you've brought it up, I'd be curious to know more as well.

Unfortunately, there isn't a lot of info out there about the company or its products. I guess we, the PD product owners, need to start a wiki to consolidate whatever info we're able to find. I haven't even found documentation for all the supplies I already have.

I just noticed a difference. There is probably something different in the error amplifier as the regulation specs are slightly different. 0.01% vs 0.05%.

[bitseeker]

Oh, OK. Which is which?

[don.r]

T has better regulation than S. I'm shopping for my son's home lab (3rd year EE) and thought a little old school PSU would fit the bill. 50V @ 1.5A should be plenty. No way he is touching my 2020B... no way. 

BTW, is there a Wiki on EEVblog? Seems to be almost no resources out there for PD collectors... which I guess I am now! 

[ez24]

...  Seems to be almost no resources out there for PD collectors... which I guess I am now! 

I know I am in the minority, but is it possible aliens made these?

[don.r]

...  Seems to be almost no resources out there for PD collectors... which I guess I am now! 

I know I am in the minority, but is it possible aliens made these?

I'm fairly certain of it.

[motocoder]

Most of us moved on to the HP 611x supplies 

[don.r]

Most of us moved on to the HO 611x supplies 

ewwwww!  Well, the HP (I assume you are talking about HP) precision supplies do have a certain... oh how shall I put this?.... functional "charm" about them. They do, however, lack copious amounts of aluminum and appear to be bathed in plastics of some kind. Only a face a mother could love, I think.

[bitseeker]

T has better regulation than S. I'm shopping for my son's home lab (3rd year EE) and thought a little old school PSU would fit the bill. 50V @ 1.5A should be plenty.

Yeah, even a 2015R should be fine unless he's making stuff that need more than 20V.

No way he is touching my 2020B... no way. 

LOL! It's hard to find a really nice 2020B. I have a 2010, thus far.

BTW, is there a Wiki on EEVblog? Seems to be almost no resources out there for PD collectors... which I guess I am now! 

Not that I'm aware of. I could start a thread just for collecting and organizing PD info if folks are interested in building such a resource.

Most of us moved on to the HO 611x supplies 

ewwwww!  Well, the HP (I assume you are talking about HP) precision supplies do have a certain... oh how shall I put this?.... functional "charm" about them. They do, however, lack copious amounts of aluminum and appear to be bathed in plastics of some kind. Only a face a mother could love, I think.

Although the HPs don't have the Art Deco/Streamline Moderne aesthetic of the PDs, they do have a lot of aluminum inside. If you haven't seen inside a 611xA or other instruments that use the "System I" enclosure, the beauty is inside (aluminum skeleton and gold traces/contacts). Here's my HP 3469A multimeter for a sampling.

[don.r]

Although the HPs don't have the Art Deco/Streamline Moderne aesthetic of the PDs, they do have a lot of aluminum inside. If you haven't seen inside a 611xA or other instruments that use the "System I" enclosure, the beauty is inside (aluminum skeleton and gold traces/contacts). Here's my HP 3469A multimeter for a sampling.

Inside, for sure, but I usually don't stare at the internals unless there is an issue or after initial purchase for curiosity sake. When my 5335A Counter died, I parted it out and still have a stack of aluminum left (PM me for parts!). HP is all about the specs and durability which is all well and good but not so much visual appeal, especially for a collector. At any rate, finding a decent HP supply for under $50 is tough but PDs do drop under this price frequently.

I know this thread was about the Precision designs but I posted here because it appears to be the only PD thread in the forum with traction. Would be nice to have some sort of manufacturer-based resource on EEVblog, especially for the defunct ones.

[nanofrog]

Would be nice to have some sort of manufacturer-based resource on EEVblog, especially for the defunct ones.

The entire company is defunct.   

There's precious little information on this as well, so I'm uncertain we'll be able to put a real date to it IMHO. I suspect the best source of information we could hope for are former employees (aside from .pdf scans of manuals).

[saturation]

Many forums have become the replacement 'manufacturer' support after they stop support even if they still exist.  K0BB and other volunteers maintain the service manuals etc.,  all are volunteers so its unlikely to be housed in a single location as they'll use whatever is easiest for them to use, support and work with.

As for PD, in this thread I think I traced the history some years ago, they were finally purchased by X and thereafter the name PD disappears, sometime early 2000.

[CatalinaWOW]

Although the HPs don't have the Art Deco/Streamline Moderne aesthetic of the PDs, they do have a lot of aluminum inside. If you haven't seen inside a 611xA or other instruments that use the "System I" enclosure, the beauty is inside (aluminum skeleton and gold traces/contacts). Here's my HP 3469A multimeter for a sampling.

Inside, for sure, but I usually don't stare at the internals unless there is an issue or after initial purchase for curiosity sake. When my 5335A Counter died, I parted it out and still have a stack of aluminum left (PM me for parts!). HP is all about the specs and durability which is all well and good but not so much visual appeal, especially for a collector. At any rate, finding a decent HP supply for under $50 is tough but PDs do drop under this price frequently.

I know this thread was about the Precision designs but I posted here because it appears to be the only PD thread in the forum with traction. Would be nice to have some sort of manufacturer-based resource on EEVblog, especially for the defunct ones.

To each his own.  I just sold my 2005A, for $40 because I don't find it visually that appealing and that interface is just nasty to use.  The center knob isn't too bad, but the ring dial gets old in a real hurry when you are changing settings. 

[don.r]

To each his own.  I just sold my 2005A, for $40 because I don't find it visually that appealing and that interface is just nasty to use.  The center knob isn't too bad, but the ring dial gets old in a real hurry when you are changing settings.

Truth be told, I use my HP 6205C more often just for that reason but I look at my 2020B first when I step into the "lab" and its the one piece of equipment that draws the most comments (that and my stack of Keithley browns). Yes its a bit of a museum piece now but its still highly functional and a darn sight cheaper than any new cheap Chinese unit and more stable and accurate to boot. If I was doing precision voltages all day the HP would be a better bet but personally I would rather look at the PD.

[mtdoc]

I just sold my 2005A, for $40 because I don't find it visually that appealing and that interface is just nasty to use.  The center knob isn't too bad, but the ring dial gets old in a real hurry when you are changing settings.

Whaaat?  Blasphemy!!   Who let this heathen into the church of the PD?   Cast thee out of  here demon, with thy digital PSU in hand...