Adding polys to power supply

[370forlife]

I was just pondering (zoiks, narf,) about this. Say if you had a power supply that had two 3300uf, 10v caps filtering the 5v rail. Could you do something like take out both caps and put in one 5600uf, 10v cap with something like a 820uf or 560uf, 16v poly?

Would there be any benefits, would the solid help reduce ripple? Of coarse price would be pretty high, a 5600uf 10v nichicon HE is about $1.40 and a 16v, 330uf oscon is $.43, where as 2 3300uf 10v samxon's are $1.01 each. Cost would actually be less

[ratdude747]

Re: Adding polys to power supply

hmm... seems like overkill to me. not unless you are talking gutless wonder with few filter caps. then it might be worthwhile...

[370forlife]

Re: Adding polys to power supply

http://search.digikey.com/scripts/Dk...me=493-3115-ND

If I was going to get poly's for one to do this, I would probably get these. Cost just skyrocketed.

http://search.digikey.com/scripts/Dk...me=493-3112-ND

oooo, 1200uf for the 10v. That might be a little more feasible.

[Toasty]

Re: Adding polys to power supply

See PCBONEZ's post in the Nichicon HN HM thread:

Post #29
https://www.badcaps.net/forum/showth...?t=8454&page=2

Toast

[i4004]

Re: Adding polys to power supply

>Would there be any benefits, would the solid help reduce ripple?

nobody can really answer that prior to testing it first.
except perhaps somebody that actually designs these PI filters and knows his job.

he, then, perhaps would say "ripple goes somewhere eventually, and with lower esr more ripple goes to ground, and that means you have more ripple on the output, as ground is the same for psu and mobo".
<wink>

in other words what if that esr actually "sponges" some of the ripple(converts it into heat, just like normal resistor would?), and deacresing it brings ripple up...
offcourse too much esr has effect of diverting most ripple to output...and capacitance goes down when esr goes up, so cap is really not doing much of stuff it should.
(in that aspect it's amazing how totally blown caps with esr of 20 and more still work in psu....psu shuts off only when things go extremely bad....to that extent you don't need to think about extra good caps there, just put "good" caps and it'll probably extend life of psu to more than you'll use it...ie other components of the pc will be outdated by then)

oh yeah, toasty, you can link particular posts.....that "#29" is actually a link too..ie
https://www.badcaps.net/forum/showpo...0&postcount=29

[yanz]

Re: Adding polys to power supply

in other words what if that esr actually "sponges" some of the ripple(converts it into heat, just like normal resistor would?), and deacresing it brings ripple up...

i've been thinking about that for long.. good that you mentioned it.. though not much of answer..