POWER DESIGNS PRECISION POWER SUPPLIES

[timb]

The meter may be a replacement. The standard edgewise meter used in these supplies is a GE Type 185 with 1mA movement. You can find them on eBay as new old stock. (If you buy one, make sure it's 0-1mA as they also made 500-0-500uA versions with the needle in the center of the scale instead of at the bottom. The one you want will say "RTG 1MA" on the label of the meter.)

Just pop the scale out of your old meter and pop it in the new one.

(Also, ask the seller for a picture of the meter in question if he just has a shot of the box; they made needles in white, black and orange.)


Sent from my Tablet

[The Doktor]

I just received a 4010 restored by timb. It's exactly what he said it was, in case you're considering his offer.

Ed

I hope you're happy with the unit! It's a very nice little box.


Sent from my Smartphone

Yes, I am quite satisfied with it. I was pleasantly surprised when I took it out of the box, I was kind of expecting the packaging material to be stuck to the fresh paint. Based on my experience with other peoples repaints, I was seriously hesitant to purchase the supply at all. I have seen a lot of repainted equipment at hamfests, the paint is usually sticky or at least so soft you can leave fingerprints in. Your paint job was very nicely done, you would be doing many people hear a favor if you explain your technique and what materials you use.

As for function, I was expecting it to work perfectly, and it does. Can't really say too much more than that. I turned on the supply and my HP 34401a and let them warm-up for a few hours, then I sent the supply to 5.00V and noted that it was less than 150 µV low. I set the meter to min/max mode and have monitored it at this setting for 24 hours three times, each time the total variation over that period is less than 200 µV, I did not record the actual numbers each time, but I believe it was probably actually within that tolerance over the entire three days. The meter and power supply were both close to a wall, and most of the voltage variation occurred the first time the central air cycled on and off. Not bad at all for a 40-year-old power supply.

This little supply should have a long and happy life with me, it will only be getting used where I want a very stable and accurate voltage source, such as when I am playing with high-resolution analog sensors. It will be a rare occasion when it needs to supply more than a few tens of milliamps. Its first use will come sometime over this winter, when I attempt to repair/restore a Fluke 301E power supply which I purchased about 25 years ago at a farm auction, I believe for the princely sum of $5 :-) it is also a high precision power supply, but a pure tube design looking like it was built sometime in the 50s or 60s. It is a rather impressive beast, delivering 1.02-512V at 300ma, and claiming .1% accuracy. The 4010 will be standing in for an Eppley miniature standard cell until I am sure the Fluke is in good enough condition to be worth repairing, then I will need to design a permanent replacement for the standard cell.

Now if I could only find a PD 6150 that was not rackmount...


Ed

[ez24]

(Also, ask the seller for a picture of the meter in question if he just has a shot of the box; they made needles in white, black and orange.)

I do not understand what you mean.

Just in case here is the listing:

http://www.ebay.com/itm/252087857361?_trksid=p2055359.m1431.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Someone talked about how confusing the dials can be.  I missed a unit one time because I could not understand how they worked and the seller did not know either.

What ever short comings this has does not matter to me.  This thing is just too sexy.
I'll probably put it on the fireplace mantle.  It would make me feel like I am living in the Outer Limits. 

[The Doktor]

(Also, ask the seller for a picture of the meter in question if he just has a shot of the box; they made needles in white, black and orange.)

I do not understand what you mean.

Just in case here is the listing:

http://www.ebay.com/itm/252087857361?_trksid=p2055359.m1431.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Someone talked about how confusing the dials can be.  I missed a unit one time because I could not understand how they worked and the seller did not know either.

What ever short comings this has does not matter to me.  This thing is just too sexy.
I'll probably put it on the fireplace mantle.  It would make me feel like I am living in the Outer Limits. 

The dials are not confusing at all, each dial sets one digit in the output voltage. It is just like entering it on a keyboard, except you do it with four dials. The numbers are read from left to right, just like any other number. In the listing you referred to, it is set to 03.30V, note how those numbers show up in the little "window" in the piece of plastic.

The little knob below the center of this window is a fine voltage adjustment, it adds anywhere from 0 to 10 mV to the output voltage.

The little knob to the left of that, marked "Current Limit"sets the maximum current the supply will deliver. If you turn this all the way to the right, current limit will occur at the supplies maximum rating, you cannot damage these applied by turning it up too high. As you turn to the left, the supply will begin current limiting at the lower level, operating in constant current mode. IOW, it will raise or lower the output voltage until the current is at the set level, but under no circumstance will it exceed the voltage set by the knobs above.

Besides the constant current feature being useful in some situations, you should understand that the supply is designed in such a way that it can be connected to a short-circuit indefinitely without being damaged.

And yes, it is a very sweet looking supply. If you need something with a bit more power, consider a 6050 or a 6150.


Happy shopping 
Ed

[bitseeker]

(Also, ask the seller for a picture of the meter in question if he just has a shot of the box; they made needles in white, black and orange.)

I do not understand what you mean.

He's referring to the color of the needle in the volt/amp meter. Notice how the needle is black on that 5020, as compared to the orange/red one on this 2005:

http://www.ebay.com/itm/Power-Designs-MODEL-2005-Precision-Power-Supply-LOC1112-/291535984529

[bitseeker]

The dials are not confusing at all, each dial sets one digit in the output voltage. It is just like entering it on a keyboard, except you do it with four dials. The numbers are read from left to right, just like any other number. In the listing you referred to, it is set to 03.30V, note how those numbers show up in the little "window" in the piece of plastic.

The part that might cause some confusion after acclimating to the general operation of the dials is the rightmost value, since it goes from 0-(10) instead of 0-9. Since the maximum value that could be reached under normal circumstances would be 49.99, that last digit goes to 10, instead of 9.

49.9(10) = 49.99 + 0.01 = 50.00

[ez24]

The dials are not confusing at all, each dial sets one digit in the output voltage. It is just like entering it on a keyboard, except you do it with four dials. The numbers are read from left to right, just like any other number. In the listing you referred to, it is set to 03.30V, note how those numbers show up in the little "window" in the piece of plastic.

The part that might cause some confusion after acclimating to the general operation of the dials is the rightmost value, since it goes from 0-(10) instead of 0-9. Since the maximum value that could be reached under normal circumstances would be 49.99, that last digit goes to 10, instead of 9.

49.9(10) = 49.99 + 0.01 = 50.00

This is what happened to me  - thanks

[bitseeker]

The part that might cause some confusion after acclimating to the general operation of the dials is the rightmost value, since it goes from 0-(10) instead of 0-9. Since the maximum value that could be reached under normal circumstances would be 49.99, that last digit goes to 10, instead of 9.

49.9(10) = 49.99 + 0.01 = 50.00

This is what happened to me  - thanks

Glad that helped. It may seem weird to do it that way, but if PD made the leftmost digit go to 5 instead of 4, then people might expect the supply to go up to 59.99, which it can't since it's a 50V supply.

[timb]

I just received a 4010 restored by timb. It's exactly what he said it was, in case you're considering his offer.

Ed

I hope you're happy with the unit! It's a very nice little box.


Sent from my Smartphone

Yes, I am quite satisfied with it. I was pleasantly surprised when I took it out of the box, I was kind of expecting the packaging material to be stuck to the fresh paint. Based on my experience with other peoples repaints, I was seriously hesitant to purchase the supply at all. I have seen a lot of repainted equipment at hamfests, the paint is usually sticky or at least so soft you can leave fingerprints in. Your paint job was very nicely done, you would be doing many people hear a favor if you explain your technique and what materials you use.

As for function, I was expecting it to work perfectly, and it does. Can't really say too much more than that. I turned on the supply and my HP 34401a and let them warm-up for a few hours, then I sent the supply to 5.00V and noted that it was less than 150 µV low. I set the meter to min/max mode and have monitored it at this setting for 24 hours three times, each time the total variation over that period is less than 200 µV, I did not record the actual numbers each time, but I believe it was probably actually within that tolerance over the entire three days. The meter and power supply were both close to a wall, and most of the voltage variation occurred the first time the central air cycled on and off. Not bad at all for a 40-year-old power supply.

Wow, I really appreciate the compliment! These are the first ones I've sold, so it's really, I dunno, validating.

My cousin is a professional  auto-body painter and taught me a good deal last year. These cases were originally done in some type of heavy duty enamel with a textured impression. To preserve that texture, I use ultra fine grit sanding blocks to *evenly* remove a thin layer of the existing paint. Then I use Rustoleum (Lagoon Blue is the best off the shelf match, it's a bit more blue than the original blue-green) and apply it from about 24" away. The trick is to just "mist" the paint on in broad, even strokes.

I do at least 3 coats like that, letting each dry under a heat lamp for 24 hours (don't place the heat lamp too close or the paint will bubble up; I keep my lamp about 5' above the counter). After the last coat I do a single coat on the inside and let it dry naturally for 48-hours. Finally, I use a clear matte enamel overcoat for extra scuff protection and solvent resistance. (Though, your case was one of the first ones I did, and I think I used a Krylon brand clear overcoat; I'm not sure if it's enamel or not.)

Finally, I leave it under a heat lamp for about a week to fully cure.

Patience is the biggest key to painting. That and preparation.

If anyone is interested, I can do a short video showing the spray technique and the ins and outs of various off the shelf paints. Plus how to prepare the surface, etc.




Sent from my Tablet

[bitseeker]

If anyone is interested, I can do a short video showing the spray technique and the ins and outs of various off the shelf paints. Plus how to prepare the surface, etc.

+1 for timb vintage equipment restoration videos (cleaning, painting, and more)!

[robrenz]

+2 

[ez24]

+3     Maybe on the next one I get

[nanofrog]

+4 

[eas]

The dials are not confusing at all, each dial sets one digit in the output voltage. It is just like entering it on a keyboard, except you do it with four dials. The numbers are read from left to right, just like any other number. In the listing you referred to, it is set to 03.30V, note how those numbers show up in the little "window" in the piece of plastic.

The part that might cause some confusion after acclimating to the general operation of the dials is the rightmost value, since it goes from 0-(10) instead of 0-9. Since the maximum value that could be reached under normal circumstances would be 49.99, that last digit goes to 10, instead of 9.

49.9(10) = 49.99 + 0.01 = 50.00

I'm the one who noted the potential for confusion. The issue I had in mind isn't that you need to turn the least significant digit up to 11 10 to get the full voltage range, nor is it a problem figuring out how to read the dials (though some people seem to have had that problem). The problem is in setting them.

The meaning of the inner knob and outer ring isn't consistent between the left and righthand controls. On the right, the inner knob sets the least significant digit. On the left, the inner knob sets the most significant digit. This is unlikely to be a problem when you set and forget. It could be a problem when incrementing through a range of voltages, perhaps while focusing on something else, like the response of a meter and you jump from 0.99v to 10.99v while intending to go to 1.99v. This confusion is much less likely with the dials on an HP precision supply, or the non-concentric decade knobs any number of devices, like a GenRad decade box.

Some people may never have a problem with it. Others will only have a problem now that I've pointed it out. I discovered the problem on my own, and because I care about human factors, considered whether there was something about the device that tripped me up. It isn't enough reason for me to sell off my PD precision supplies -- I only mentioned it because it might give ez24 a pretense for not kicking himself if he misses out on winning this auction.

Another +1 on a painting tutorial video. The paint on my PD 5020 is compromised by rust. I've cleaned it and oiled it, but its really going to need more than that.

[eas]

The first step is admitting you have a problem...

We're going to have house guests in a few days, so I've been moving stuff down to basement storage so I can convert my "lab" back to a dining room. I was  struck by how many PD supplies I've accumulated looking for deals on eBay over the past six months.



All but one of the precision supplies are nominally operational. The 5020 (lower left), and 2020a (top center) needed cleaning and adjustment. One of the 2005a (both 2005a are stacked in the lower right) needed a new cord and fuse, cleaning and adjustment. It is nominally functional, but may need more troubleshooting and repair to get stability and ripple in spec. The 2020 is functional but settings are out of wack after cleaning and adjustment. I want to replace caps and revise some earlier repairs and perhaps trim some of the resistors in the decade divider. The TP340a needed a lot of troubleshooting (described elsewhere in this forum and on my blog). It is now functional and stable, but I've seen some evidence that the crowbar on Source B may need attention. The 6010 (top right) needed a new fuse and pot, its now somewhat functional, but voltage tops out at 15v. I suspect something in the "uniply" solid-state tap-switching or one of the output transistors and need to do more troubleshooting and repair. I've spent some time on the non-functional 2005a and need to spend more, because it powers on, the oven cycles, but there is no output.

Once I've got them all tuned up, I'll probably keep the TP340a 5020, 2020a and the 2020 and sell the 6010 and one or both of the 2005a.

[bitseeker]

That's quite a collection, eas. Thanks to you, so far I've been able to hold steady at one TP340A. But those precision versions sure are purdy.

[ez24]

The first step is admitting you have a problem...

Glad to know I am not the only one.  PM when you start selling the 2005s

[bitseeker]

ez,

Looks like you got a good deal on the 5020. Looking forward to hearing all about it when it arrives.

[saturation]

@ eas, impressive 

[ez24]

ez,

Looks like you got a good deal on the 5020. Looking forward to hearing all about it when it arrives.

Thanks will do

[mtdoc]

The first step is admitting you have a problem...

You're a sick man eas! and I mean that in a good way...

I've only got 2 PD supplies.  So far..

[fcb]

I've hankered after one of these units for quite awhile now - I absolutely love US gear of that era.

Has anyone got a link that details the history & what happened to Power Designs Inc???

[bitseeker]

Has anyone got a link that details the history & what happened to Power Designs Inc???

A few months ago, I tried to find some info on PD, but their name is rather generic, which yielded a lot of irrelevant search results. I'd like to know more about their history too.

[SeanB]

Try Ambitrol, they seem to have taken over the PD business. I was bidding for one, but it went for $1.25 with $30 shipping.

[nanofrog]

Try Ambitrol, they seem to have taken over the PD business. I was bidding for one, but it went for $1.25 with $30 shipping.

Ambitrol seems to have been one of their trademarks, along with UNIPLY, REDULE, and PD (source). PD trademark expired in 2008, and on a previous search, there hasn't been any activity with the corporation (filing) since 1991.

Precious little information it seems (there is a NY Times article regarding share reacquisition, but it doesn't give a year; here).