computer grade elcaps - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 1st July 2007, 09:50 AM   #1
jarthel is offline jarthel  Australia
diyAudio Member
 
Join Date: Jan 2002
Location: somewhere in Australia
Default computer grade elcaps

I was looking at the mouser catalog and found this. I read the datasheet and they are advertised as long life, high CV and current filtering (which I assumed meant the ripple current rating for this cap is high).

I got no idea what CV meant so some searching led me to believe it means the charge of the capacitor.

Anyway, that's not the reason for this thread.

As I said I was looking at mouser and they seemed to be more expensive than the snap-in that I was looking at.

Can someone tell me what is so special with computer grade caps? I compared the specs of a snap-in cap VS a CG cap (both from Cornell Dubilier) and the snap-in cap has longer rated life and the ripple current rating is higher.

maybe they are not special at all?

thank you for the reply

ps. I did search the forums but all I cannot discussions comparing computer grade caps with other type of elcaps. I also searched the net but all I can find is some history on the name "computer grade" caps. The rest of the search results are mostly shops selling these caps.
  Reply With Quote
Old 3rd July 2007, 08:27 AM   #2
h_a is offline h_a  Europe
diyAudio Member
 
h_a's Avatar
 
Join Date: Sep 2006
Location: Graz, Austria
Honestly I don't know, but I think this is merely a term for cheap caps having quite ok quality.

Cheers, Hannes
  Reply With Quote
Old 3rd July 2007, 08:41 AM   #3
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
BullS...
__________________
2015 : World Cup Cat Hacky Sack
  Reply With Quote
Old 3rd July 2007, 09:58 AM   #4
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
looks like we should ignore the names applied to cap types and instead read the specs for all models from each and every cap manufacturer.
__________________
regards Andrew T.
  Reply With Quote
Old 3rd July 2007, 10:10 AM   #5
mzzj is offline mzzj  Finland
diyAudio Member
 
Join Date: Jul 2005
Location: 65N 25E
CV= capacitance per volume.
  Reply With Quote
Old 3rd July 2007, 10:45 AM   #6
jarthel is offline jarthel  Australia
diyAudio Member
 
Join Date: Jan 2002
Location: somewhere in Australia
Quote:
Originally posted by mzzj
CV= capacitance per volume.

thank you.
==============
but those new Cornell-Dubilier 381LX are really small for the capacitance they carry.

maybe in te old days, "computer grade" caps = high quality but not these days?
  Reply With Quote
Old 3rd July 2007, 10:55 AM   #7
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Computer grades have high ripple values, low leakage current values, generally have high voltage surge values.
Ultimately boils down to high reliability and a long life expectancy.
Some capacitor manufacturers did/do not use the term Computer Grade, but label their electrolytics as Long Life grade, the ones by Rifa and Siemens/Epcos for instance.
Most buy NOS big can CG's at really affordable rates, if you check the retail prices of the big bottles you'll find out they're pretty steep, $125 for a single big boy cap is not uncommon.
A couple of years ago i bought a large number of factory fresh 12-can CG boxes, turned out they couldn't handle the surge values of the big computer powersupplies they were ordered for.
The company had to dump a containerload of these caps because of the design mis-judgement.
Downside is that those CG's measure 9" in length, 3" diameter and weigh 2lbs each, good for constructing very sizeable amplifiers only.
__________________
2015 : World Cup Cat Hacky Sack
  Reply With Quote
Old 3rd July 2007, 11:08 AM   #8
Luke is offline Luke  New Zealand
diyAudio Member
 
Join Date: Sep 2001
Location: Wellington NZ
Send a message via AIM to Luke
Is it ok to use these big Computer Grade Caps if they are like 10 years old?
  Reply With Quote
Old 3rd July 2007, 12:04 PM   #9
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
the least you should do is reform them.
It would take a fair bit of kit and knowledge to test whether the ESR has deteriorated.
I believe reforming does not bring back ESR, only restores spec leakage.
__________________
regards Andrew T.
  Reply With Quote
Old 3rd July 2007, 12:07 PM   #10
ssmith is offline ssmith  France
diyAudio Member
 
Join Date: Aug 2005
Location: Paris
Quote:
Originally posted by Luke
Is it ok to use these big Computer Grade Caps if they are like 10 years old?
depends if they're used, and how they have been used. Once you figure this out you can refer to the datasheet for that particular cap and compare against the lifespan specs.

do a search also here to look for reforming caps that have been sitting on the shelf unused for a long time. This is a subject that has been addressed here before.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Rebuilding a DAC Audio grade or Computer grade caps? gto127 Digital Source 0 28th January 2009 08:17 PM
Computer Grade Capacitors Witchdoctor Tubes / Valves 14 6th January 2006 03:12 AM
Computer Grade/Inverter Grade Cap TunaFish Parts 2 11th March 2005 02:51 PM
Computer Grade Cap or Inverter Grade Cap??? TunaFish Tubes / Valves 10 11th March 2005 07:48 AM
Computer grade caps joke Pass Labs 19 19th September 2002 11:21 AM


New To Site? Need Help?

All times are GMT. The time now is 03:33 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2