Primary use for a ESR meter for me is testing all caps in a circuit because frequently I purchase a piece of equipment which has been out of service for a LONG time and the electrolytics in many cases have failed or dried out due to leakage.
Tek is (in)famous for switch mode power supplies which require low ESR caps to operate. Prior to ESR meter I would just replace all electrolytics and call it a day now i can replace only those which have failed so it's a moneysaver as well.
For HV low capacitance circuits it's pretty obvious when a cap has exceeded its useful life although ESR becomes critical again in HV high capacitance circuits like those found in RF amplifiers where a high ESR usually manifests itself with a bang and a flash of light and electrolyte sprayed all over the amp chassis.
Stefan Trethan wrote:
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That may be so, but when repairing relatively modern equipment with many
many caps that need to have low ESR for the circuit to work (e.g. switching
voltage converters) it is absolutely great to be able to test all caps in
circuit in a matter of seconds. Sure, one could add a good cap in parallel
and try the circuit, but that takes much longer.
OTOH i have no need for it when designing new equipment (power supplies).
But for industrial gear of say 5-10 years or more and consumer gear of 2
years of more the electrolytic cap has been the primary failure for me.
I have repaired a OS254P-U (which is very similar to a 7603) and found one
major fault with the esr meter, so i'd say it's definitely been useful
there. Sure i could have found the fault some other way.
ST
On Wed, Oct 1, 2008 at 6:39 PM, DEANE KIDD <dektyr@...> wrote:
ps: Add it all up and I have been around a long time. The ESR meter that
everyone seems to believe is required piece of test gear in the service kit
was never heard of until mid '90s when electrolytic caps of high values and
low voltages became the norm. I have never used an ESR meter and my normal
capacitors were 80 - 120 MFD at 350 - 450 volts.
Deane
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