Perhaps, it is a cult, but I don't think so. Cult-ship
usually implies a blind following of a personality.
ESR meter users are just happy that the instruments
cut a lot of time and effort out of repairs. Failed
capacitors usually have very obvious ESR signatures: 10 to
1000x the expected ESR.
If you are looking at 1.5 ohm measured ESR vs 1.25 ohm,
expected ESR, as a sign of a failed capacitor, you are
using the ESR meter wrongly.
Capacitors have to get really bad before the circuitry
will fail, in most cases.
The dissipation factor is very useful for designing a
power supply, but a bit awkward to use for repair purposes.
Most meters that read DF need the capacitor out of circuit
to give any sort of useful reading. ESR meters measure
at such a low voltage that the semiconductor part of the
circuit is not activated.
The other thing I notice is the ESR meters generally work
at 50KHz, but bridges that measure DF are mostly 1KHz.
50KHz measurements usually mean a lot more to me when I am
repairing switching power supplies, than does 1KHz.
-Chuck Harris
On Wed, 24 Nov 2021 18:44:14 -0500 "Dave McGuire"
<mcguire@...> wrote:
On 11/24/21 6:40 PM, Richard Knoppow wrote:
?? It may prove more useful to use dissipation factor rather than
ESR even though both are a measure of the same thing. Since DF is a
ratio of reactance to resistance it varies with frequency and may
be more indicative of capacitor quality than plain ESR.
?? There is a good, short article on DF at:
<>
You know, I keep telling people that, and people keep telling me
I'm crazy. All converting DF to ESR does is introduce a frequency
dependency that gets in the way of deciding "good capacitor" or "bad
capacitor". There's almost a "cult of ESR" these days, it seems.
-Dave
