[A3rd.Zero]

i have recently scavenged some computer power supplies and I am trying to figure out what the bridge Diodes are rated for. Is there a way to identify this? Their labels seem useless by I wouldnt know. Also is there any way to find out if they are high speed soft recovery diodes?

thanks

milo

 

[ofb]

funny, i'm in the middle of tearing down some of those psu's myself.

most of the AT supplies have PBL605. the only info i can find is the datasheet for diotec's equivalent.
Diotec Cross Reference

the old apple supplies i've opened are all quite different from the ATs and each other.

i can't comment if the PBL605's are any good at all. since i have enough i figure on trying them in a scrapbox gainclone circuit.

 

[A3rd.Zero]

actually thats exactly what I was going to use them for, but unfortunatly I am having trouble finding a matching pair.

milo

 

[ofb]

humble opinion: if you don't have matching ones, don't bother. the gc seems pretty sensitive to all parts variation.

using matching pbl605's as an experiment is one thing, but to mix ones of different manufacture... eh, i think that's likely asking too much. one too many variables.

if you dig through the gc threads you'll find a few people didn't like the sound of the fairchild MUR860 compared to on-semi. me, i would have figured a MUR860 was a MUR860 till then.

 

[A3rd.Zero]

I just found a really cheap surplus store that makes the time spent desoldering look expensive.

www.goldmine-elec.com

They may not be the best out there but I can test a bunch on a budget.

milo

 

[JohnFerrier]

If you are tearing apart power supplies, you might look at the X Y (leakage) capacitors on the AC input. Because of their function they have to be high quality. For example, I scavenged some nice 20uF 250V polypropolyenes out of a couple of power units. Don't know how prevalent such nice caps are, but worth looking. They are easy to locate (right at the AC input). Think that the capacitors are in there in the first place to meet EMC (conducted immunity/emissions) and they have to be good quality to meet electrical safety requirements (so that someone doesn't electrocute themselves because the leakage current is too high if there is no earth ground connection...).


JF

 

[A3rd.Zero]

I have noticed some polypros but assumed that they were crap, thanks for the advice. I am really pleased however with the ammount of power resistors I can get out of them. It seems that most powersupplies use the same resistor values regardless of weather they are for regulated or switching.

Milo

 

[ofb]

there was a short comp psu cap quality discussion on Amp Chip Diy.

the thread

i'm no expert, but some of them do seem to have nice caps, especially the apples. so i'm yanking the parts out of curiousity to try, and because i hate to see useful things going into the dumpster.

but "cost effective"? pft! no. decent caps aren't expensive. i've just got spare computers that have moved from obsolescent to obsolete. a little desoldering is no-brainer relaxation like tv and fishing, and yields a nice collection of free parts to experiment with.

 

[A3rd.Zero]

" a little desoldering is no-brainer relaxation like tv and fishing"

much agreed! I tried recently to take apart an old (and broken) yoyo adaptor and it was a real pain in the ass. I have another broken one and I dont know if I want to go through that again.

Milo