[Fwd: RE: TC Secondary Currents - was ( Experimental Help - Terry?)]

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

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>



>Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" ><couturejh-at-mgte-dot-com>

>I agree the incandescent lamp is an excelent way to measure the TC
>secondary current. The test is easy and accurate enough for coiler's
>use. Contrary to what some coilers have said the non linearity of the
>lamp is not a consideration if the test is done properly.

	As i said, the nonlinearity is 'covered; in the calibration.
	It occurs to me that this technique will be insensitive at low
	currents, (the bulb is dark...).  'low' will depend on the
	'size' of the bulb.

> The brightness of the lamp is exactly the same for both AC(RMS) and DC.
> The lamp has the advantage that with AC the frequency and waveform do
> not affect the measurement.

>I have done this test many times and often wondered just exactly what
>kind of current I was measuring.

	hmmmm?
	'current is current'.

	Over simplifying by using the transformer 'model' its the
	secondary current.  the magnitude varies with:
		breakout or nor
		Corona or no
		Magnitude of radiated field.
		Secondary in or out of resonance.

> Was the current a reactive current charging the toroid and self
> capacitance of the coil or was it an ohmic current that was
> producing corona and the streamers? And how about the Maxwell
> displacement currents?

	I suggest that, as it all flows thru the one point it is
	the sum of all.  The nature of the variation of current
	with operating conditions means one or another may dominate
	at various conditions...

(To save a post)
Someone suggested using two lamps, simultaneously matching the
brilliance of a DC, metered lamp with that of a 'sense' lamp,
then reading the current from the 'DC' lamp.  Seems admirable,
with the caveat that the lamps may not match exactly:  wiring
so that the two lamps could be switch from on 'role' to the other
would allow interchange, to take readings from either...

One might epoxy on a photocells (matched?) to allow better
matching of the two bulbs brightness.

(all of which is getting kind of elaborate...   8)>>)

best
	dwp