[PSUBS-MAILIST] pressure test

[Alan via Personal_Submersibles]

Brian,
most of the led drivers, motor controllers or buck / boost units have 
those large cylindrical electrolytic capacitors which can crush under 
pressure. At the top of them most have a cross cut in them to weaken 
them at that point so if they blow they blow in a controlled direction. 
They would be particularly weak at that point with regard to crushing. 
   I am not sure how the capacitor would operate once it was crushed;
whether it wouldn't work at all, or partially work, & whether that would
result in the circuits failure or just reduce the life of the circuit.
I read about this on the Psub list & other web sites years ago, so they
must have a history of failing under pressure.
Alan


Sent from my iPad

> On 15/04/2018, at 6:34 PM, Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> Alan,                   What type of capacitor is good under pressure ?
>  
>  
> Brian
>  
> 
> 
> --- personal_submersibles at psubs.org wrote:
> 
> From: Alan via Personal_Submersibles <personal_submersibles at psubs.org>
> To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
> Subject: Re: [PSUBS-MAILIST] pressure test
> Date: Sun, 15 Apr 2018 14:07:17 +1200
> 
> Hank,
> probably me advising caution about pressurising the LED drivers
> as most I've seen have large electrolytic capacitors that can be
> crushed under pressure. 
> Alan
> 
> Sent from my iPad
> 
> On 15/04/2018, at 8:04 AM, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> Today I pressure tested my LED light circuit board to see if it can handle the pressures Scott's P6 will see.  I am happy to report the circuit board survived one hr at 3,000 psi soaking in oil.  I was very cautious, because I kept hearing Hugh yelling at me from NZ  at least I think it was Hugh.  I stayed in Gamma and the pressure chamber was under Gamma while I pressured it up.  
> Hank
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