Elektor Electronics - Page 2

"S Roby"



**  What make you sure they were faulty then ??





**  So they were electrically OK  -  but visual reasons existed to replace
them .





.............  Phil

The tech at work pulled them out(replaced them) to fix power supplies.

"S Roby"
"Phil Allison"



**  I repeat:

What make you sure they were faulty then ??

The tech may have replaced them as a precaution or because they were of a
certain age etc.



...........  Phil

   ESR meters aren't some kind of mystical  box which magically tell
you with 100% accuracy which capacitors are defective. They're just
one more test instrument which tells an experienced user with a good
knowledge of electronics about another characteristic of capacitors
which is very relevant to how well they're doing their job. ESR meter
readings have to be intelligently combined with other factors
including the physical state of the capacitor being tested.
   I never cease to be amazed by how little electrical knowledge many
ESR meter users have. The DSE meter was designed specifically for
service technicians, but many of them have been bought by hobbisyts
and "amatures", a lot of whom still seem to think that ESR equates to
leakage and/or that the higher the ESR the better.
   I agree with Phil's comments... he understands and appreciates
where ESR meters fit into the overall scheme of things. :)
   That's my 2c worth.

Cheers
Bob


On Fri, 16 Sep 2005 17:43:49 +1000, "Phil Allison"

I repeat
The tech at work pulled them out(replaced them) to fix power supplies.

The power supplies had spikes on the output (clearly seen on the scope) ,
fixed by replacing caps.

"S Roby" <




**  So the new caps simply had a lower ESR than the old ones.

The variation in ESR values for electro caps of the same nominal value is
quite wide.

 Did you bother to compare the old and new to see the difference ???




........  Phil