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Electrolyitic Capacitor Ageing
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Glenn0010:
Hi All,
I need to calculate my expected lifetime for an Elec Cap.
I am looking at the https://www.mouser.co.uk/ProductDetail/Wurth-Elektronik/865080442004?qs=sGAEpiMZZMsh%252B1woXyUXj4jKQI6sNRw6szAjfBEpelo%3D
I can use Arrhenius’s Law to determine the liftime with regards to temprature. However what about DC operating point. Say you have a 25 V cap at 16 V. I remember hearing that that also improves life time.
Can anyone point me in the right direction
Thanks
Glenn
wraper:
Don't forget that lifetime figure is given under maximum ripple current spec. Voltage does not matter that much
MagicSmoker:
--- Quote from: Glenn0010 on February 25, 2020, 09:35:48 am ---...
I can use Arrhenius’s Law to determine the liftime with regards to temprature. However what about DC operating point. Say you have a 25 V cap at 16 V. I remember hearing that that also improves life time.
--- End quote ---
There's conflicting evidence (and mostly anecdotal at that, unfortunately) on how much longer an elko will last for a given percentage of voltage derating. Basically, there seems to be little benefit from operating at less than 75% of the WVDC rating, and if you need really a long (decades long) working life then you'd probably be better off with film capacitors.
edit - added missing "need" in last sentence.
splin:
See http://www.rubycon.co.jp/en/products/alumi/pdf/Life.pdf
[EDIT] It would be interesting to know why they only apply voltage derrating to the screw terminal capacitors - perhaps they aren't as well sealed?
[EDIT 2]: Also look at: https://www.illinoiscapacitor.com/tech-center/life-calculators.aspx
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