Author Topic: Potting an electrolytic capacitor will make it last longer?  (Read 7135 times)

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Offline ogden

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #25 on: September 04, 2018, 07:45:46 pm »
:=\

Right. Potting electronics in high TC epoxy is good stuff unless you have forced air flow option.
 
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Offline Simon

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #26 on: September 04, 2018, 08:01:04 pm »
Thanks, but i assume that in a totally enclosed enclosure, the potting compound would always make it easier for heat to get out of the capacitor?
Yes i did think of the need-to-vent too....but philips potted over the can top......probably only about 5mm of potting covering the can top though....so could still explode out.....
presumably no 'lytic explosion would be enough to fracture the 1.5mm thinck plastic enclosure

Are you really an engineer? Which breakfast cereal did your degree come with?

Calm down, it's a valid question. Perhaps you can enlighten us all as judging from your reply you are quite the expert but have neglected to share such expertise that allows you to be so dismissive of the question.

Edit, having seen the rest of your sarky posts i have decided to give you a few days to reflect as well as calm down!
« Last Edit: September 04, 2018, 08:04:48 pm by Simon »
 
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Offline ocsetTopic starter

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #27 on: September 05, 2018, 05:14:52 am »
Quote
They are potted because they are outdoor drivers.
Thanks, i thought the same......but there are plenty of non potted outdoor drivers.
I assume potting prevents sulfur laden atmospheres from getting round the components and corroding them?
Also,  the potting stops moisture from  getting  round the components.
« Last Edit: September 05, 2018, 07:31:17 pm by treez »
 

Offline Kirkhaan

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #28 on: September 05, 2018, 05:47:03 am »
Another reason for potting a driver is that creepage and clearance distances can potentially be reduced in the design.

Such drivers are mostly mains isolated and the galvanic isolation barrier could become smaller if potting material is applied.
Don't get me wrong, its not just adding potting material and you're done. Careful circuit design and PCB layout is needed, but in the end it can lead to significant miniaturization.
 
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Offline Kjelt

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #29 on: September 05, 2018, 07:04:10 am »
Quote
They are potted because they are outdoor drivers.
Thanks, i thought the same......but there are plenty of non potted outdoor drivers.
Show me one Extreme outdoor driver from Philips that is not potted ?
That other chinese manufacturers do not pot their outdoor drivers is their (bad) business, I can show you products designed that will not last 1 year after power is connected. The extreme series of drivers have always had high requirements, should survive lighting strikes in the vicinity, bad mains, brown out etc. etc.
Outdoor environments can be hars, damp, heat, cold, ice, and so on.

 
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Offline Kjelt

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #30 on: September 08, 2018, 09:08:17 am »
 
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Offline ocsetTopic starter

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #31 on: September 08, 2018, 02:45:32 pm »
Thanks, i was at a radar company once...and they said they had problems with a certain potting compound, where it would put pressure on components as it cured, and damage them.
I hope  to avoid PSUs with that potting compound inside them.
« Last Edit: September 08, 2018, 02:51:53 pm by treez »
 

Offline Gyro

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #32 on: September 08, 2018, 05:59:56 pm »
According to nctnico in the following thread, Epoxy compound shrinks during curing, PU doesn't... https://www.eevblog.com/forum/projects/temperature-probe-failure-analysis/msg277766/#msg277766
Best Regards, Chris
 
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Offline coppercone2

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #33 on: September 08, 2018, 06:21:04 pm »
there will exist some kind of internal strain in the solid potted assembly that is not present in the nonpotted with any kind of surface contact. You can't compare free air to any kind of solid enclosure. Different geometries will be effected differently. The more gummy it is the more frictional losses of mechanical there will be to mechanical strain by temperature change. It's basically creating a bimetalic strip everyone is familiar of to a lesser degree.

I do wonder if there are any tricks, like putting a buncha straws to draw potting compound away (creating voids) from non populated PCB areas or something, so they can deform. It's too complicated for me to imagine.

I don't like the idea of potting myself. It seems like a brute force solution to a delicate problem.
« Last Edit: September 08, 2018, 06:33:19 pm by coppercone2 »
 
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Offline xani

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #34 on: September 08, 2018, 07:11:29 pm »
I do wonder if there are any tricks, like putting a buncha straws to draw potting compound away (creating voids) from non populated PCB areas or something, so they can deform. It's too complicated for me to imagine.

Mix a styrofoam granules with potting compound ? Would also make whole thing lighter and use less potting compound. And probably a lot worse for heat conduction
 
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Offline coppercone2

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Re: Potting an electrolytic capacitor will make it last longer?
« Reply #35 on: September 08, 2018, 07:17:11 pm »
I thought you can put straws in strategic places though
 
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