Has anyone measured capacitance on any of these in larger sizes (eg. 22,000 or 33,000uF)? I know tolerance varies but there's usually a trend.
I have a few applications which all need 51mm diameter, and one in particular which needs a 22000uF in 75V or greater rating (which mandates 100V in most options). Most brands will jump up to 63mm for this, but the new Kemet ALS70 comes in 20000uF 100V at 51mm. I'm wondering what Kemet's measured capacitances are usually like, if they are on the higher side I'd give it a shot.
It looks like the Kemet/BHC have the best specs - higher ripple than the Epcos/TDK and longer life. Both are much better than Nichicon and United Chemicon for this application it seems.
I attached some datasheets just for interest, first two showing the 22000 and 33000uF in 63V for Kemet and Epcos, and another two showing the new ALS70 in 33000uF/63V and the 20000uF/100V which I'm interested in.
I'm open to other options as long as they are 52mm max, 75V+, and have ripple current comparable to these.
I have a few applications which all need 51mm diameter, and one in particular which needs a 22000uF in 75V or greater rating (which mandates 100V in most options). Most brands will jump up to 63mm for this, but the new Kemet ALS70 comes in 20000uF 100V at 51mm. I'm wondering what Kemet's measured capacitances are usually like, if they are on the higher side I'd give it a shot.
It looks like the Kemet/BHC have the best specs - higher ripple than the Epcos/TDK and longer life. Both are much better than Nichicon and United Chemicon for this application it seems.
I attached some datasheets just for interest, first two showing the 22000 and 33000uF in 63V for Kemet and Epcos, and another two showing the new ALS70 in 33000uF/63V and the 20000uF/100V which I'm interested in.
I'm open to other options as long as they are 52mm max, 75V+, and have ripple current comparable to these.
Attachments
I think kendeil makes some that are the smaller diameter like that also. I am not sure how they stack up against what you are looking at however.
Thanks, yes I did look at kendeil also, looks like a great option, though they are a little expensive for my liking (have a few amps to feed).
I wonder if anyone here has measured capacitance on Epcos/TDK B41456/458 or Kemet/BHC ALS30/40?
Certainly do!
Though the best spec (current) caps in this voltage/capacitance are still the larger 63mm diameter, I have less options in the 51mm format. Perhaps the future will bring more, the ALS70 is a new option this year. 🙂
I wonder if anyone here has measured capacitance on Epcos/TDK B41456/458 or Kemet/BHC ALS30/40?
Certainly do!
Though the best spec (current) caps in this voltage/capacitance are still the larger 63mm diameter, I have less options in the 51mm format. Perhaps the future will bring more, the ALS70 is a new option this year. 🙂
From what I have seen with some high voltage wet Al caps, smaller than these, higher height to diameter usually correlates with longer life, at least according to the manufacturers' specs. HF impedance might be higher with a taller cap, but with such large caps like this, that parameter is probably not important.
I'd pick the higher height to diameter ratio too.
I'd pick the higher height to diameter ratio too.
In this CV, d=51mm generally gives the highest height:diameter ratio anyway. The other common size is d=63mm which won't fit.
I was more concerned about finding a good (high ripple) capacitor that'll actually work for one particular application where I need that 50-51mm diameter and a slightly higher voltage (factory is 69V, 22000uF).
I know you shouldn't go lower in voltage but I did wonder if it's worth measuring what voltage they're actually seeing, and deciding if I could get away with something like a Kemet/Rifa PEH200 in 22000uF / 63V (which meets the 51mm criteria).
I'm guessing the factory 69V had some safety margin, surely at least 10%? I suppose there's only one way to know for sure - how would I measure the input voltage - positive lead on + terminal of cap and negative lead to power/chassis ground?
I was more concerned about finding a good (high ripple) capacitor that'll actually work for one particular application where I need that 50-51mm diameter and a slightly higher voltage (factory is 69V, 22000uF).
I know you shouldn't go lower in voltage but I did wonder if it's worth measuring what voltage they're actually seeing, and deciding if I could get away with something like a Kemet/Rifa PEH200 in 22000uF / 63V (which meets the 51mm criteria).
I'm guessing the factory 69V had some safety margin, surely at least 10%? I suppose there's only one way to know for sure - how would I measure the input voltage - positive lead on + terminal of cap and negative lead to power/chassis ground?
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