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[Fwd: VAR]




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>> Thus the peak current which we might expect in the tank is based on the peak
>> capacitor voltage and the surge impedance.  Such that... I peak = 21,000/50 or
>> 420 amps   From this we compute peak impulse power = 420 X 21000 = 8.82
>> megawatts!!!!!


>Shouldn't that be MVARs (Mega-Volt Amps Reactive),
	I wouldn't say so.  I wouldn't say watts, either, tho.

>as the V and I aren't in phase?
	Probably not.  In conventional 'lectrical eng'g, Watts is reserved
	for Real Power, which means _knowing_ that the V and the I are In Phase.
	Here, we don;t know.

	Likewise, conventionally, VA is used for the product of Volts & Amps
	where the phasing of V and I is Unknown, OR is known & Specified.  Some
	times VA equals W.  Sometimes (most times) VA is greater than W, by some
	unknown amount.

	Conventionally, VAR (MVAR, if there are lots of them...  8)>>) Are
	DEFINED AS VA WITH A PHASE OF 90 Degrees.  That is, pure 'imaginary'
	power.  Pure inductive or pure capacitive load.  A tesla coil is
	neither.  (the technical term for such a load is 'complex'.
	OOOOOOOOOBoy is is complex...8)>>)

	It is tempting, as i said a few days ago, to think of the coil load
	(at the line side) as being 'highly inductive', i mean after all, we can
	SEE all those windings...  I Suspect the actual is a little different.
	The tank is resonant, so L and C balance, more or less, leaving the
	power transformer looking at a (largely) resistive load.  Likewise,
	the secondary is resonant, either physically, or lumped-parameter, or
	both, so THAT should 'look' resistive.  So i bet the input looks a whole
	lot more resistive than might appear.

	I'd be real interested in some measured values as to how reactive the
	coil looks at the AC line input.  I suspect that a coil 'just below
	breakout' is more resistive than expected.  Once it breaks out, hmmmmm,
	dunno.  Measure & see...  Beats the heck out of any amount of guesswork.

	regards
	dwp

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