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Old 1st Dec 2017, 9:06 pm   #16
astral highway
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Join Date: Nov 2006
Location: London, UK.
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Default Re: Electrolytic capacitor fails after 1 hour in service!

Quote:
Originally Posted by David G4EBT View Post
I think that rippe current is rarely considered and rarely given by makers, which is why I tend to stick to Rubycon electrolytics from Farnel, because they're 105C and have high ripple ratings despite their compact physical size.

That's useful info, David. Thanks.

On closer inspection, the chip switches on even faster than I thought, in less than 10nS, pushing at least 2A pulses, in my case at around 300KHz. It would be unsurprising if even 1cm of lead length on the cap leads was a parasitic inductor. But sourcing a suitably robust replacement seems like a wise plan.

I might put a bi-directional TVS diode across the supply rail.
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