catman Posted June 25 Share Posted June 25 (edited) G'day all, why strange? Because it was unused straight of my spare parts box, a 2200 uf 25v working. It clearly looks visibly 'bulged', and on the capacitance meter it measures around 1440 uf (varying). Kind of weird! I'm really getting to dislike large value electrolytic capacitors more every day! Regards, Felix. Edited June 25 by catman Grammar. 1 Link to comment Share on other sites More sharing options...
andyr Posted June 25 Share Posted June 25 1 hour ago, catman said: G'day all, why strange? Because it was unused straight of my spare parts box, a 2200 uf 25v working. It clearly looks visibly 'bulged', and on the capacitance meter it measures around 1440 uf (varying). Kind of weird! I'm really getting to dislike large value electrolytic capacitors more every day! Regards, Felix. Hah, Felix - you call "2200uF" a large value?? This is a large value cap!!: 1 1 Link to comment Share on other sites More sharing options...
catman Posted June 25 Author Share Posted June 25 G'day mate, yes I get your point, but 2200 uf capacitors are frequently used as the main filter capacitors in power supplies, so that's still 'large' in a manner of speaking anyway! Regards, Felix. Link to comment Share on other sites More sharing options...
surprisetech Posted June 25 Share Posted June 25 1 hour ago, catman said: G'day all, why strange? Because it was unused straight of my spare parts box, a 2200 uf 25v working. It clearly looks visibly 'bulged', and on the capacitance meter it measures around 1440 uf (varying). Kind of weird! I'm really getting to dislike large value electrolytic capacitors more every day! Regards, Felix. Gday Felix. Electrolytics do have a limited shelf life. Some brands are much better than others and caps from some brands at certain times have had issues with the electrolyte composition. How old do you think that cap might have been? I know that our parts store staff have to keep records and scrap electrolytics that are held in stock for too long. They give the best longevity when they are installed soon after manufacture and then the equipment is kept in regular use. 1 Link to comment Share on other sites More sharing options...
muon* Posted June 25 Share Posted June 25 (edited) 3 hours ago, catman said: G'day all, why strange? Because it was unused straight of my spare parts box, a 2200 uf 25v working. It clearly looks visibly 'bulged', and on the capacitance meter it measures around 1440 uf (varying). Kind of weird! I'm really getting to dislike large value electrolytic capacitors more every day! Regards, Felix. What brand and what's the manufacture date? Electrolytic drys out over time just sitting unused. I have 35v/1000uf Elna Silmic ll's dated 2018 and still within 10% of spec. The data sheet allows +/- 20% This one from 2021 measured near the same. Edited June 25 by muon* Link to comment Share on other sites More sharing options...
Addicted to music Posted July 13 Share Posted July 13 It's not just the capacitor value being within spec is important, a very important measurement comes into play: ESR, ESR rises as it age as the the internal chemicals degrade due to age and use, once that's out of spec the cap is useless, even though the capacitance is within specs hence you'll notice overheating and then it bulge(physically out of shape) The other interesting measurement is leakage. 1 Link to comment Share on other sites More sharing options...
Ian McP Posted July 13 Share Posted July 13 Link to comment Share on other sites More sharing options...
rocky500 Posted July 13 Share Posted July 13 Maybe replace it with a similar spec 2200uf 50V capacitor this time to give a little head room? 1 Link to comment Share on other sites More sharing options...
Recommended Posts