Hi guys, here's a electronic newbie question: can we use polymer caps for a pc psu?
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Re: polymer caps for psu?
Short answer: no
It's hard to find polymer caps over 1000uf, with the decreased uf, the rails loose the umpf, or think of it as a truck, the uf as it's weight. When a large, sudden load increase comes along, such as the truck hitting a car, the truck is going to slow down more the less it weights. Basically, the less the uf rating, the lower the voltages may drop when confronted with a larger load. The drop would be so quick a multimeter wouldn't pick it up either.
The very low ESR of polymer caps can also make ripple worse, as the pi filters are "tuned" to the certain esr of the caps used originally. Lowering (or raising) this ESR can cause the ripple to increase.
There are some new psu's with polymers in them, they use them on the dc-dc daughter boards that generate the 5v and 3.3v from the 12v. They also use standard electrolytics, with some polymers thrown in on modular pcb's or after the pi filters as supplementary. Don't know if they really do anything, or if they just are more of a marketing gimmick.Last edited by 370forlife; 02-14-2010, 03:52 PM.
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Re: polymer caps for psu?
"the pi filters are "tuned" to the certain esr of the caps used originally."
Is that certain? That means that when recapping one should try to find same esr replacement caps and not lower esr ones?
And if the new caps have a bit lower esr than the original is that a problem?Comment
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Re: polymer caps for psu?
You want to try to stay as close as possible to the original ESR. If the psu is known to have a problem with ripple, you really need to stay close to the original ESR, but if it is a power supply known to have good ripple, putting something like rubycon MBZ in it may still be in spec but still raise the ripple.Originally posted by goodpsusearchComment
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Re: polymer caps for psu?
Originally posted by 370forlife
Enermax modu87 PSUs
Many sites recommend them
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Re: polymer caps for psu?
CWT and Superflower loves them too. I think superflower was one of the first to start doing it. Won't be surprised to see it in low watt psu's soon with the efficiency craze.Comment
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Hello,
First, I am a complete noob with high voltage stuff. I'm learning, but I need help by someone looking over my shoulder.
I recently came into posession of a Heathkit IO-4205 5MHz Dual Trace Oscilloscope. The documentation is copyright 1978. I'm told it works.
I opened it up to check the caps before I applied power, and found the following black caps and wanted to know what they were. They are on the power supply board. I was able to read the name and model and came up with, "Nytronics 162J-1, 0.1uF, 20% tolerance, 2000VDC."
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Hello!
I have two projects on my work bench. One is a friends dead JBL Xtreme speaker with a blown voltage regulator and corresponding bulged and shorted cap. That cap has clear markings so I know what replacement I need for it.
The other project however is a whole different deal. It's a Zoom 9000 guitar effect from the 90th that has developed a devil hound howl when there is no input from the guitar. I'm guessing caps problem. So, since I don't really use this effect anymore I thought it would be a perfect project to learn on.
I have studied the board and... -
I'm trying to repair two old VCRs, they both have bad caps. One has leaky ones, the other would barely run until I subbed in some caps from another power supply I had laying around (though they are the wrong values). This vcr works for an hour or two, but then the power supply starts whining and the picture gets lines in it. I didn't replace all the secondary caps, so another voltage might still be problematic, or the values I used are too far off.
I've been on mouser and digikey but the options are a bit overwhelming. I just need some new ones that will work. They don't need to be top quality,... -
Good evening
I recently aquired a rev 1.1 Gigabyte 60XT, and was suprised of the amount of leaking caps for a motherboard of the P3 era. Especially the way the 330µf caps seems like the housing discolored even.
Now, there are some 3300µF 6.3V KZG series around the CPU. Would it be OK to replace them with something like EEUFR1A332 ? (Panasonic FR 3300µF 10V). Or was this board designed around very low ESR caps?
But I was also suprised about the bigger boys, which are 330µF 25V.
Could it be they used 25V caps because they were cheaper / available at that time?... -
I know I've been a little scarce lately (like the last 2-3 years), but I'm still here and still doing my thing with fixing PSUs.
For today's considerations, I have a Seasonic B12 BC-550 [A551bcafh] 550 Watt ATX power supply for you (click on links for full size images).
https://www.badcaps.net/filedata/fetch?id=3591771
https://www.badcaps.net/filedata/fetch?id=3591772
It's a modern ATX unit with fixed (non-modular) cables and an 80-plus bronze certificate. Here's the label:
https://www.badcaps.net/filedata/fetch?id=359177...
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