Whatsa a Capacitor (Re: very confused coil results)

["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>

Tesla list wrote:

> Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>"

> <Gary.Lau-at-compaq-dot-com>
 
> A spark gap is nothing remotely like a capacitor.


	A non firing spark gap is exactly like a capacitor.
	A very tiny, tiny capacitor.
	Firing, it becomes something else, something unique
	to itself.

> A capacitor can store a charge, a gap cannot.


	A gap can, and does.  But it's a tiny, tiny amount.

> A spark relies on ionized air to conduct, a capacitor does

>not.  If there's no ionized air in a gap, there no light,
> sound, no conduction, and no primary operation.  
 	concur...


> I agree that the only way a bulb can light without the gap

>firing is if the bulb was connected between the primary and

>secondary.  Or if there is a short between the primary and

>secondary.

	concur.

	rereading the text at bottom:
	Is it possible that the current was flowing from a leak
	the NST secondary thru some path (possibly a spark?)
	and UP the secondary?

	12W/240v means 50 mA to light the lamp to full
	brilliance, less to visibility...

	(This implies that some of the grounds may not be
	ground....)

	best
	dwp


> Gary Lau
> MA, USA
> 
> Original poster: "David Thomson by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <dave-at-volantis-dot-org>
> 
> Hi Chris,
> 
> Nikola Tesla remarked in one of his papers that he could tune a coil so well
> that no action would be seen at the spark gap, even though the coil was
> fully operational.  You got to remember that a spark gap is essentially a
> capacitor with air dielectric.  When you run AC in the primary circuit,
> power will still be in the primary circuit even though the spark gap appears
> to be quiet.
> 
> What was the exact wattage of the bulb and was it incandescent or
> fluorescent?  Did you have it connected _between_ the secondary and ground?
> 
> I'll try replicating this experiment to see what I get.
> 
> Dave
> 
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Saturday, April 06, 2002 10:49 PM
> To: tesla-at-pupman-dot-com
> Subject: very confused coil results
> 
> 
> Original poster: "Chris Swinson by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <exxos-at-cps-games.co.uk>
> 
> Hi all,
> 
> I was doing some experimenting with some ground currents on the base of a
> Tesla coil today.  I had a low wattage bulb connected and when the coil ran
> it was just visible to see it light. I tried this about 10 times. Though
> the odd thing is on about 4 occasions the spark gap didn't fire and the bulb
> lite very bright. I did this a few more time and the coil started to spark
> again, bulb was dim. I think asked my father to press the on switch so I
> could watch the spark gap more closely. On pressing the switch the second
> time the spark gap did not fire at all and the bulb lite bright again.  This
> was very strange as the secondary can't get power if the gap does not fire!
> I checked and re-checked for possible shorts from the NST to anything and
> found nothing where it could "track" to ground. The NST sounded open
> circuit, I say this as they make a funny buzzing ( they do anyway but not
> this type of buzz) which I have heard before when the spark gaps were to
> wide. I adjusted the spark gaps as wide as I could ( about double what they
> were the first time ) and it still fired the spark gap.
> 
> If there was indeed a short to ground or something then it would have
> bypassed the spark gaps, but they still fired.  In any case the bulb was
> only connected to the secondary and ground nothing else, in which case if
> there was a current flowing then it would have had to short on the secondary
> coil to make contact.  I am at a total loss on why it did what it did. The
> odd thing now is the spark gap fires every time, before it was intermittent.
> my adjusting the gaps could have had something to do with this. I tried a
> few times to make the gaps not fire but I can't get it to do it now.  The
> question still remains on WHY the bulb lite when the gaps did not fire. I
> can only assume a short of some kind but the only thing connected to the
> bulb is the secondary coil and ground ( ground I talk of here is a ground
> rod in the garden ) nothing else is connected to that ground. So even if
> there was a short I doubt it would conduct though the soil outside.  I
> assume theres a short from the NST ground , which is mains ground, to the
> outside ground. There must be  a house earth point somewhere but even so
> current can't flow.
> 
> I am open to suggestions for this puzzle!
> 
> Chris
> 
> 
>