Hi to you oll ... I have one question about power suplay capacitors... I'am building Aleph 4 or 2 ( don't know jet ) ... The question is ...
What is Computer grade capacitor and what is the diference betwin normal electrolitic ones ???
I found Philips 26000uF/75V caps but it doesn't say it's computer grade for 6.95 USD and I found on RS-electronic BHC 22000/63V computer grade for like 30 USD ...( it's big diference in price so I'am confused , I know the normal price is like 20-30 USD)...so whats the diference ? ...can I use those Philips or should I go for computer grade capacitors ?
What is Computer grade capacitor and what is the diference betwin normal electrolitic ones ???
I found Philips 26000uF/75V caps but it doesn't say it's computer grade for 6.95 USD and I found on RS-electronic BHC 22000/63V computer grade for like 30 USD ...( it's big diference in price so I'am confused , I know the normal price is like 20-30 USD)...so whats the diference ? ...can I use those Philips or should I go for computer grade capacitors ?
Apex Jr.
Hi,
Those Phillips caps sound like the ones Apex Jr. has. They are cheap because Steve gets great deals on the surplus he buys up. I bought a boxfull a while ago and think that they should be great caps.
Cheers, Dan
Hi,
Those Phillips caps sound like the ones Apex Jr. has. They are cheap because Steve gets great deals on the surplus he buys up. I bought a boxfull a while ago and think that they should be great caps.
Cheers, Dan
Well as far as I remember (and I could VERY well be wrong) RIFA specifies shelf life of PEH169 (excellent cap) to 10 years. I think I have read the same numbers from Nichicon. Personally I am reluctant to buy anything older than 5 years if is not dirt cheap.
/UrSv
/UrSv
however...
I tested the 10,000uf caps in a 25+ year old SAE amp that I am rebuilding into a Leach amp, and they are still good. I charged the PSU up one day, and the next day the voltage was still pretty good (about 50% of full I recall), and I was able to spot-weld steel with them. 😀 The thick layer of dust in the amp probably contributed to the leakage.
I seem to recall reading (from Mr Pass?) that older big caps frequently stay good even if they dry up.
Cheers, Dan
I tested the 10,000uf caps in a 25+ year old SAE amp that I am rebuilding into a Leach amp, and they are still good. I charged the PSU up one day, and the next day the voltage was still pretty good (about 50% of full I recall), and I was able to spot-weld steel with them. 😀 The thick layer of dust in the amp probably contributed to the leakage.
I seem to recall reading (from Mr Pass?) that older big caps frequently stay good even if they dry up.
Cheers, Dan
Thanks for your replay people , but can you explain me what is computer grade capacitor ???
Thanks
Thanks
I just went to apex Jr page ... and there it is ... with the big letars... Computer Grade ... Philips 26000/75V ...
I didn't see it firs time ... only that it's great for solid state amps...
so thanks to you people out thare ones again ...
I didn't see it firs time ... only that it's great for solid state amps...
so thanks to you people out thare ones again ...
Capacitor types
FYI.......
Computer Grade are caps that look like beer cans,
either with the screw terminals or PC Leads, At one
time they were in the older computers.
There's also the snap in types that are a smaller version
of the computer grades: And than the Radial and Axial
Electrolytics.
I won't forget the Disc's, Poly types, HV, and the variations
from there.
BTW...The 26,000uf 75V caps date code is 9235
35th week of 1992.
Steve
FYI.......
Computer Grade are caps that look like beer cans,
either with the screw terminals or PC Leads, At one
time they were in the older computers.
There's also the snap in types that are a smaller version
of the computer grades: And than the Radial and Axial
Electrolytics.
I won't forget the Disc's, Poly types, HV, and the variations
from there.
BTW...The 26,000uf 75V caps date code is 9235
35th week of 1992.
Steve
Computer grade is a phrase left over from the good old
days of computing when they had linear supplies that
drew tons of amps all day long.
Nowadays they all seem to have switching supplies and
much smaller capacitors. The big cans are still readily
available, however industry in general has switched over
to PC mount snap in caps.
These work fine, but don't have the aesthetic appeal of
the big barrels.
😉
days of computing when they had linear supplies that
drew tons of amps all day long.
Nowadays they all seem to have switching supplies and
much smaller capacitors. The big cans are still readily
available, however industry in general has switched over
to PC mount snap in caps.
These work fine, but don't have the aesthetic appeal of
the big barrels.
😉
Is this what you are talkin' about?😀
I guess if today PC PSU used big dadies like this one they wouldn't crack up so often ( like mine, a week ago🙁)
Sprague on picture:
The 30,000uf 75V caps date code is 8008
8th week of 1980, and still has over 30.000uF capacity 🙂
best regards,
Leon
The 30,000uf 75V caps date code is 8008
8th week of 1980, and still has over 30.000uF capacity 🙂
best regards,
Leon
Computer Grade Caps
I see your picture; and the differance to think about is the
size. The older the date code the larger they will be.
I suspect your 30,000uf 75V cap is 3" Dia and about
5" high. My 26,000uf 75V are only 2" dia and 4 1/8" high
And there still making them smaller. Technology changes.
Steve
Apex Jr
I see your picture; and the differance to think about is the
size. The older the date code the larger they will be.
I suspect your 30,000uf 75V cap is 3" Dia and about
5" high. My 26,000uf 75V are only 2" dia and 4 1/8" high
And there still making them smaller. Technology changes.
Steve
Apex Jr
Small caps get hot. Not enough surface area on the can to get rid of the heat. The hotter they run the shorter the life. Check the specs for the ripple current ratings.
Has anyone held a RIFA (from Sweden of course!) cap in your hand? Shake them! What do you hear? Fluid inside which flows! The RIFA caps has lots of electrolythic fluid so they will last for a very long time.
To be short:
Computer grade:
Pros:
Can take very much current
Lasts long
Cons:
Expensive or very expensive
Big
Sonic properties, I have no idea.
To be short:
Computer grade:
Pros:
Can take very much current
Lasts long
Cons:
Expensive or very expensive
Big
Sonic properties, I have no idea.
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