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 There is something good about esr meter because besides electrolytic
capacitor
ESR Meter - The Capabilities To Check Beyond Electrolytic Capacitor
There is something good about esr meter because besides electrolytic
capacitor it can be use to measure other type of capacitors such as the
non polarity capacitor. From esr meter specification, it is usually
mentioned only checking the electrolytic type. When i began to
experiment with the Dick Smith ESR Meter i found that it have the
capabilities to check other type of capacitors as well.
However
it is limited to checking capacitor in the higher value only such as
.1uf(104), .22uf(224), 1uf(105) and etc. Lower capacitance value don't
get any reading from the esr meter due to it can only read until 99
ohms. Perhaps other esr meter such as the B & K esr meter have the
range to check it.
You will even be surprised to see that the
dick smith esr meter can check the non-polarity capacitor in-circuit
(without removing the cap).
True case example-Monitor came in
with display jumping horizontally. You can see a bunch of horizontal
black lines across the top display (picture). From experienced it will
tell you that vertical section have problem. I begin to troubleshoot
the vertical section. Supply voltage checked ok, vertical driver and
oscillator IC replaced, all components connected or nearby vertical
driver and oscillator ic have been checked ok. By the way I used
digital capacitance meter to check the non-polarity cap and esr meter
to check the electrolytic cap. The problem is still there and can't be
solve!
When i use Dick Smith ESR Meter to compare the esr value
of a non-polarity capacitor located near the vertical driver ic, i
noticed that there is a big different in the esr value. The good esr
value for a .22uf non-polarity cap is between 6.5 to 7 ohm but the
spoilt one have a value of 14 ohm! Almost double the value, that's why
the display jump. The good thing is i discovered the culprit while the
capacitor still in the circuit which mean this esr meter can check
non-polarity cap in-circuit. However my recommendation for you is to
solder out one leg and check unless you already have the experienced in
checking components on board. Replacing the cap solved the display
problem.
Conclusion-In order to accurately test a non-polarity
capacitor, besides checking the capacitance value and using analog
meter to check the charge and discharge to see if it has develop any
short circuit when under load, you are also required to check the esr
value as well.
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