[ofb]

i'm muddling my way through parts for a meta42. doing fairly well for the lost, thanks to headwize/head-fi/tangentsoft/et al, but i've run into a stumbling block with parts selection where the needed caps are obsolete, like C1 through C8 for the SDS psu.

i'm fairly sure P4125-ND is the part to substitute for P4033-ND, C1-C4. specified is a 560pf ceramic 200v. nearest digikey seems to have is the 1000v P4125-ND. sound reasonable?

but for the rest i get jammed by many seeming similar items in the digikey selection. for example C7,8 is the obsolete 330uf 25v panasonic P5703-ND.

for "330uf 25v panasonic" digikey serves up 16 items. obviously i don't want SMD, but after that it gets muddy. P10272-ND and P10273-ND have identical descriptions. P1182-ND and P5542-ND might works too; i can't tell what's really the difference here and if all or none are suitable for this psu.

perhaps someone who's gone through this part of the learning curve recently could give me some pointers? what's the method here? what's the key terminology? [and is it simply to post "hey erix, what part #'s did you use?"

]

 

[erix]

Quote:

Originally posted by ofb "hey erix, what part #'s did you use?"

Heh, Don't aske me - I forgot.

But seriously folks..

For the elctrolytics, use Panasonic FC series. When you do your search on Digikey's website just select that series in the search tool.

For the little ceramics - I really can't remember. Any ceramic will work.

ok,
erix

 

[tangent]

They have hundreds of the P4033 in stock. The P4125 may be a better part -- better dielectric, but looser tolerance -- but it's probably a whole lot bigger than you want. I'd go with the originally spec'd part, personally, since it appears to be available.

Eric's right on the FCs -- they're the proper substitute for the HFQ series.

 

[ofb]

woohoo! thanks guys. i'm now much closer to slinging solder.

"They have hundreds of the P4033 in stock." ... oh, hang on. mayber this is where i'm screwing up.

P4033-ND comes back as obsolete. but if i search just P4033, digikey comes back with a P4033A-ND, which they do have hundreds of.

P4033-ND is "560 PF/100V DISC CAP GP"

P4033A-ND is "CAP 560PF 50V CER DISC GP 5%"

...except the "A" is 50V, not 100V. the caps are on the 120vac side of the SDS psu circuit. damn. confused again.

is what i should have done is when i hit P4033-ND as obsolete is i should have scrolled down to "Other Names: ECCF2A561JE, P4033" and tried those? but what about the voltage difference then?

sorry for these real basic questions. i've been trying to avoid doing that here. been lurking about a year and have a couple of binders of print outs. i'm rather keen to start making hardware mistakes instead of all these theory mistakes.

 

[tangent]

Sorry, I'm not familiar with that power supply. I have no idea if the lower-voltage cap will work or not. But if it won't, I still wouldn't use that 1000V part if you didn't have to. Like I said, it's likely to be very big, partly due to its higher voltage tolerance, and partly because it uses a better dielectric, which tends to make for bigger caps all on its own. I've seen two ceramics, same Farads value, but one a COG and the other a POS (ha!), one the diameter of a pea, the other the diameter of a nickel.

 

[ofb]

...actually, now that i have the clear head of evening, i can't believe what i wrote above. my apologies.

the cap is actually on the 15v side so the substitution of the 50v cap will be just fine.

thanks all.