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Jim Yanik Jim Yanik is offline
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Default Why do some manufacturers wrap the electrolytic capacitor that gets the hottest in a switching power supply in shrink wrap?

Chuck wrote in

Extron has been doing this for years and of course it is the first
part to fail in their units. Smart Technologies Sympodium power
supplies, that they have contract built in China, fail in a year or so
for the same reason. Technicians and electronic engineers at my work
place can't think of a rational reason why these manufacturers do
this. This is pro gear where reliability is a great concern so it
doesn't seem to be planned failure mode. Thanks. Chuck

IMO,in a proper design,the caps should not be getting hot.
Caps should be sized and rated properly,with a fair amount of excess
capacity,not sized/rated right at the margins.
We have inexpensive thermal imaging available that can identify hot spots
so that they can be corrected before the design is finalized.

Jim Yanik
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