Please suggest main caps from Digikey!

[Logistics]

Okay, I'm finally going to buy some caps to recap my PSU. I would order from Badcaps, but due to circumstances beyond my control I can't use my PayPal account. I'm ordering parts to build cMoy headphone amplifiers, anyway so I'll just order everything from Digikey.

Since Panasonic FM's are listed as a good cap, I'll just use them for my PSU. However, the 820uF 200V guys don't exist in an FM. Could someone please suggest a capacitor from Digikey which is a good replacement for these? They were originally Fuhjyuu LP caps.

[PeteS in CA]

Re: Please suggest main caps from Digikey!

The appropriately sized Panasonic or UCC snap-in series parts should do well.

[Logistics]

Re: Please suggest main caps from Digikey!

On Fuhjyuu's site, they don't actually list the ESR or each cap, but the LP is suppose to be a low esr, low impedance, high ripple, 85C. I decided on the Panasonic TSED because it has almost exactly the same ripple rating and is a 105C. It's ESR is 0.182Ohms. Does that sound okay for a cap like this? There were some Nichicon's with a tan of .15 like the Fuhjyuu LP's, but the ripple was only around 2A on the 105C whereas the LP and this Panny are about 2.6A and the Nichicons are around a dollar more.

Question, I removed and am replacing ALL the electrolytics in my PSU so I ended up removing two 50V 1uF caps, but one of them was non-polarized and on the board, the two spots where these caps would have gone are both silk-screened to accomodate polarized caps so I can't tell which one was non-polar. They are also exactly the same physical size so that doesn't help. Any idea on what I should do? hehe!

[starfury1]

Re: Please suggest main caps from Digikey!

Well someone will correct me if I am wrong on this

but I dont think you have to get hyper critical about ESR with the mains filter caps.
a lot of the time they will be 85C too
I would just use good quality ones as PeteS said
(of course better specs for the job won't hurt)

As to your other problem
bit hard to tell without knowing the circuit so maybe
post make model and a photo of the pcb
and maybe a close up of the area.

chances are someone will have one and be able to tell you.
Alternatively maybe the naked PSU thread has the same supply
in the photos somewhere.

Again may depend on the circuit
but why not use 2 non polarized,
that way it don't matter what went were.

Generally speaking
Its usually best if you don't know to replace
with what was there thought.

anyway just my thoughts on it

[Logistics]

Re: Please suggest main caps from Digikey!

Well, I can't do anything about pics atm, but it's an Antec SL350 and the caps in question are C34 and C33. Again, they are both 50V 1uF, but one is non-polarized. They are on opposing sides of the PCB next to the outgoing wiring.

[PeteS in CA]

Re: Please suggest main caps from Digikey!

You're over-thinking this, Logistics. The high voltage primary-side 'lytics are what they are. "Low impedance" isn't the main concern, and impedance isn't even specified. The key specs for this application are capacitance, voltage, case size, ripple current and (sometimes) rated max. temperature. 85C rated parts are usually used in that application. Here are the D-K parts from which you can, hopefully, select the replacement parts you need. They are all rated for 820uF, 200V, 85C and, ironically, are all rated for the same ripple current, 2.93A.

Panasonic
P6126-ND 25mmD x 45mmH, TSUP series
P6127-ND 30mmD x 25mmH, TSUP series

P11862-ND 25mmD x 30mmH, TSUQ series
P11862-ND 30mmD x 25mmH, TSUQ series

UCC
565-2735-ND 22mmD x 40mmH, SMQ series

So get out your ruler and measure the diameter ("D") and height ("H") of the parts you want to replace. D is the most important, and the H of what you install is limited by your case and airflow (i.e., 5mm taller is probably OK).

[Logistics]

Re: Please suggest main caps from Digikey!

Again may depend on the circuit
but why not use 2 non polarized,
that way it don't matter what went were.

Generally speaking
Its usually best if you don't know to replace
with what was there thought.

anyway just my thoughts on it

Umm, I never gave this any thought, but in general can you use a non-polarized electrolytic as a power cap? I suppose a cap can do a couple things in this case, it acts as a filter cap and a smoothing cap, correct? People bypass with small films before IC's for this purpose all the time, but in the case of something large like a 100uF electrolytic, I have never seen a non-polarized used. Little help, here! I'm imagining that this is because in DC, you don't need to pass voltage back the other direction, and a non-polarized cap is usually more expensive, larger and doesn't come in as large of a capacitance, but if you wanted to use a non-polarized version, could you?

[starfury1]

Re: Please suggest main caps from Digikey!

the main reason a non polar cap would be used is if the DC voltage would at some point be reversed across the cap.

So I am guessing its part of some feedback circuit

as I don't know how they are really being used I don't know what the effects would be
but suspect you would get away with it
I could be wrong on this thought!

The other thing you could possibly look at with the caps is
"if one of the caps sits across a DC rail then it can only go one way"
So therefore that has to be your normal electro
its a small value 1uf so I suspect they are only
being used for bypass or coupling/decoupling.

you can actually make non polar or Bi polar electro's by use two in series
connect the 2 negatives(or positives) together
but you will find augments for and against this.
If want 1uf you could use 2 x 2.2uf
I am not telling you to do this thought just as an example K

hopefully just to make it easier for you
someone will post what the caps are in those positions

I did a search but couldn't find a photo here.

cheers
and its just my opinion please remember
I am not the Guru of smpsu's either

if you want to fry your brain you can have a read here on caps construction and properties Here
is heavy going and not overly relevant