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Old 1st Dec 2017, 4:31 pm   #1
astral highway
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Join Date: Nov 2006
Location: London, UK.
Posts: 2,738
Default Electrolytic capacitor fails after 1 hour in service!

Hi folks,

I don't want this to turn into a 'aren't components poor quality compared to the good old days' rant, but...

I feel nevertheless surprised that a capacitor from what I thought was a reputable manufacturer (Mods am I allowed to say, or is this defamatory, albeit with a defence of justification??)failed in less than an hour in service.

It was a 63V 1,000uF rated item used as a decoupling capacitor straight across the Vcc-ground pins of a a gate driver chip, in parallel with a 100nF poly component. The supply voltage was just 18V.

I know this is a 'noisy', environment and the component is under great stress, but I was surprised. It failed catastrophically for no apparent reason. Fortunately I had S/c protected the power supply but it could have been very damaging.

On inspection of the item when I had isolated it from the circuit, it performed normally up to 12V and then became progressively leaky, until it was passing 4A at a supply voltage of 30V.

I don't know what I'm expecting by posting this, that isn't encouraging complaints and sharing similar stories, but it's so surprising to me that I want to put it out there.
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