Re: [TCML] Speaking of bottle caps...

[bsneath@xxxxxxxxxxxxxxxx]

	Thanks heaps, the PDF was very helpful, the fromula for calculating
the power dissipation and reactive power draw is going to take alot of
guesswork out of calculating a cap's characteristics, that is if i can
work out how to use it  properly... 

	It was a little surprising to see that the dissipation factor was so
high for PVC, being 4 times that of glass. Perhaps i shouldn't of used
it as a dielectric in the last cap i made... 

	Well at least bottle caps are cheap, so i guess they're still useful
even though there is no way around the losses... 

	ben
	Hi Ben, Assuming the "lossiness" of the capacitor dielectric
(Dissipation Factor or DF) is constant with respect to voltage and
frequency (which it usually is not...), then the capacitor loss will
be proportional to the square of the applied voltage and directly
proportional to the operating frequency: 

	Power Loss = V^2*2*pi*f*C*(DF) Where V = RMS voltage       f -
Operating Frequency (Hz)       C = capacitance (in Farads)      DF =
capacitor dielectric system Dissipation Factor The DF for various
glasses range from about 0.0002 (fused silica) to 0.0036 for common
borosilicate glass. 

	Halving the applied voltage reduces losses by a factor of four.
Unfortunately, this also reduces your system's "Bang Size" by a
similar factor. Halving the frequency will halve the losses (again,
assuming that the DF stays constant). So, a workable strategy would be
to design your system with as large a capacitance as possible (for the
power supply) and operate the bank at a lower operating voltage and
frequency. 

	BTW, you can read more about capacitor losses in chapter 3 of Dr.
Gary Johnson's excellent write-up on Solid State Tesla Coils: 

	http://eece.ksu.edu/~gjohnson/tcchap3.pdf [1] Bert 


Links:
------
[1] http://eece.ksu.edu/~gjohnson/tcchap3.pdf
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla