Re: Piezo HV Power Supply

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "David Thomson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>
> 
> Hi Ed,
> 
> How did you measure the volts, coulombs, and joules?

	Forgot to say, and meant to.  I discharged the 0.001 ufd capacitor into
a precision 10 ufd capacitor.  Charge (NOT energy) is preserved in the
process so the net charge on the paralleled capacitors is the same as
the original charge [V * 0.001 E-6].  Because the larger capacitor is
10,000 times as large as the original one, the voltage on it is 
1/10000 = 1E-4 times the original voltage.  For example, 10 clicks gave
a voltage of 0.75 volts across the 10 ufd capacitor, so the original
voltage was 0.75 times 10,000 = 7500. The energy stored was then
computed from the expression:

	E = (1/2) * C * V^2 = (1/2) * 0.001E-6 * 7500^2 = 0.028 joule

where C is the 0.001 ufd HV capacitor.  When the discharge is over and
the voltage across the 10 ufd capacitor is 0.75, the energy stored in it
is only 

	E = (1/2) * 10E-6 * 0.75^2 = 2.81E-6 joule.

The original energy is dissipated in the discharge process, some going
into heating (I^2 R) and some being radiated.

	Do a Google advanced search on "energy stored capacitor with the exact
phrase "joule".

Ed