I tried posting this in the main Power Designs Power Supply thread and didn't get a response, so I thought I'd have better luck here.
Just out of curiosity, is this a 2005 or a TP340A?
FWIW, I doubt it's all that critical (doesn't appear to be part of the ovenized circuit in a 2005 to me at any rate).
I've purchased some used test equipment to set up a learning lab, with the assumption that any broken equipment I end up with will be a learning opportunity. The circa 1996 Power Designs TP340A I got seems to fit in the learning opportunity category.
I know they were around in the '60's & '70's (design style of the front panels matches up to this IMHO), but I seem to recall they died well before 1996 (replacement part from a repair perhaps
Registered in CA in 1952 (source
), and trademark "PD" filed for in NY in 1964 (source
). Resigned in 1991, but it's not active, nor is there anything after that.
According to the .pdf scans of manuals I have saved (from the filing dates on the schematic & engineering drawings in the back):
- The original 2005 was designed in 1964.
- 2005A in 1969.
- TP340 & TP343A (same manual), is from 1983.
- TP340A & TP343B (same manual), appears to be from 1988 to my eyes, as the scans aren't that clear. But they seemed to have been consistent with a 5 year update/redesign cycle, so the timeframe fits.
Don't think they made it much past 1988 before they failed though, given it's registered agent resigned in 1991, and no filings were ever made after that. Trademarked PD expired in 2008, and wasn't renewed either (unlikely for a dissolved company).
Sad IMHO, as they're nice PSU's.
BTW, if you've a 2005, Power Designs model 2005 precision dc power source
might be of interest.
When I received it, before powering it up, I opened it up and checked it for obvious component failures. I found one, a sprague capacitor with a deteriorated rubber seal that pushed out its epoxy(?) seal.
I know from the users manual and googling that they are 100uF 25v polarized DC caps. I find plenty meeting that general description on digkey, etc, but don't really know what else to look for besides operating temp range and rated life, and I haven't been able to figure out those specs for the original parts. Is there anything else I should consider in picking replacements?
Nichicon VX series (TVX1E101MAD
) should do, as they're just general purpose axial aluminum electrolytic capacitors. And they're only $0.86 in singles.
If you want to go nutz, a Vishay 118AHT series might be of interest (MAL211836101E3
). Longer lifespan, but at ~4x the cost (rated for 4000hrs @ 125C; usable lifespan @ 40C is 500k hrs). Downside, is they cost $3.47 each in singles.
I also plan to recap my circa 1988 5020 Precision Power Supply. It has a number of caps that the datasheet describes as "tantalytic." Are these worth proactive replacement as well?
Unless there's visible evidence of leakage or scorching, I'd leave those alone (not necessary).