In article , Nick Gorham
wrote:
Jim Lesurf wrote:
In article , Nick Gorham


I just measured it, somewhere around 65R, off load it was giving 8v RMS.
I said with the cap in place, it was producing about 5v P/P on a scope
trace, or about 2v RMS.


If I understand the ClarityCap papers correctly, you'd need to find
the mechanical resonance of each cap to get a peak level of vibration.
So 5k might not give as large a response as some other frequency.


Yes, but I was just trying to test the assumption that no cap would
produce any noise, having found that some do under simple to achieve
conditions, there is scope to perform more detailed tests.

OK. However the above makes clear that this is only likely to be a problem
in uses like a loudspeaker crossover where the current and power transfer
levels are relatively high. Even there, you needed to put your ear near the
cap to hear the sound - with an input signal of the order of 1 Watt.

I wonder if something like a strain gauge attached to the cap would be
the best way to measure any vibration.

The problem is that any sensor near the cap may respond suriously to the
E-fields or H-fields. So may not simply sense the sound/vibration. However
it may be an advantage here that that would tend to be at the drive
frequency, not the doubled frequency of sounds created by the forces you'd
expect.

Slainte,

Jim

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