I recently replaced a couple of electrolytics in a flat screen
TV for a customer. The caps were in the power supply and
were of course rated for 105 degrees C. So this brought to
mind a question. Could this possibly be an operating
temperature? Or is it a storage temperature?
Or perhaps it's an internal temperature?


** Its the actual temp of the cap itself - so it depends on the ambient
temp and any heat dissipation in the cap due to ripple current. The figure
gives the maximum allowable temp for a rated life in thousands of hours.

See any electro data sheet for the details.


It would seem like it would have to be a very high frequency
component to ever cause an electrolytic to ever approach
anything like this. Could one of these parts rated as such
actually get this hot and remain operational?


** The electros in many valve amp get very hot, especially if sited near the
output valves. Marshall guitar amps are a classic example - I have measured
the surface temp on the large can electros at 85C.

The ripple current in many SMPS is enough to heat electros significantly -
that is why you see fans in them.



..... Phil