FS: Power Designs 4010 40V/1A Precision Power Supply

[timb]

Up for sale is a classic Power Designs precision supply from the mid-1970’s. The heart of the supply is double oven that contains a hand binned zener reference and discrete transistor amplifier. Two sets of custom inner-outer switches allow selection from 0 to 39.990 volts, with an additional 10-turn pot that acts as a 0 to 10mV vernier, which allows setting the full scale voltage at a microvolt level. Current limiting from 0 to 1A is provided by a 3/4 turn pot. Three status lamps indicate oven, power and current limit status. The oven runs full time when plugged into AC, allowing instant precision use with no warm up. Voltage and current is shown on a Yokogawa edgewise meter.

I’ve taken the entire unit apart, cleaned it, checked all the electrolytes, replaced all three lamps with brand new orange neon units. I also took apart the pots, scrubbed them clean and applied DeoxIT Fader Lube. The switch array had the same treatment, only with DeoxIT Shield applied to the contacts and white lithium grease to the ball bearings and moving parts. I also repainted the case inside and out then added brand new fasteners.

Finally, I performed a voltage and current calibration on it. This thing is super stable! I can actually slowly move the mV knob and change the voltage in uV steps. And once warmed up, the voltage holds perfectly steady, only varying a hundred nV up and down as the oven turns off and on. This would make a great supply for anyone wanting to add a little precision to their lab.

I’d like to get $175 shipped (to the US; I’ll ship international but buyer pays any additional shipping costs over the first $25).











During Restoration:

[eas]

Nice!  These higher power PD precision supplies in any condition don't come up for sale all that often!

[bitseeker]

Great job, Tim. Looks like new!

[timb]

Thanks guys! Yeah, I put a lot of work into these things during restoration; I'm a bit of a perfectionist.

This particular model seems to be very rare. I've been tracking PD supplies on eBay for the last year and I've only seen two of these models come up for sale and this is one of them!

I was unable to find a manual for it online, either. Construction and layout seems to be between the 2005A and 2020 series.

All component values are clearly visible so a schematic could be reverse engineered with a continuity tester over a weekend easily.


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[timb]

And... Sold! Going to a good home.


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[eas]

Yay!

[bitseeker]

Excellent! What's your next project, Tim? I enjoy seeing the restorations that you and Robrenz do.

[timb]

Wow, thanks! I've actually got a Tek TM 500 power mainframe I restored (along with three plugins; that was the real work) that I need to make a thread about. I've also got a couple more PD precision supplies on the way; one of which is a unique 0-6V 500ma unit I had never seen before until one popped up on eBay the other day.

Without going too much into it, I've also possibly found a source for inexpensive enamel "Appliance" paint in custom colors. My goal is to have some Tektronix Blue and HP Brown made. (Right now, I sand cases by hand and then apply multiple coats of Rustoleum color paint before applying a matte clear enamel seal. It works well, but I obviously can't get original colors.)


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[bitseeker]

Looking forward to those threads. Also make one about that enamel paint. Definitely sounds interesting for cases.