EMMC Value Drift
I seem to be noticing a very slight capacitance value drift in my EMMC
cap. It has 10 caps per string and has 5 strings of 1600 Volt 0.056uF
Panasonic high voltage pulse caps. The total value has gone from 27.9nF to
27.7nF. Each individual string seems to have drifted the same amount
(-0.7%). This is close to the limits of my LCR meter but the drift seems
real. After lasts week's run, it seemed to drop by about 0.3%. I ran it
very hard this 4th and it seems to have drifted another 0.4% with that use.
I run this 16000 volt cap at about 22000 volts so it is stressed in
voltage. The strings seem to be fine current wise. I wonder if the dv/dt
thing is degrading the internal connections?? Perhaps it will level out
with more use but it seems to be continuing in a linear way with the amount
of use. If it continues, eventually it will fail and I can dissect the
remaining caps to see what the cause is.