[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] "Means for increasing the intensity of electricaloscillations" The Tesla Superconductor of 1901

All true, except that I would disagree that the spark gap resistance is a major factor. The current in the primary of a moderate sized TC (mine, at 1600 watts, for example) is of the order of 100 amps. Going through a spark channel that is a fraction of a mm in dia gives a very high current density, not too different from lightning. A plasma at these current densities has a resistivity that is lower than any metal. A spark gap is a remarkably good switch for high currents.
The main source of resistance in the pri circuit is the coil wire, due to the very shallow skin depth. The bigger the better, stranded might help a little, the best would be a lot of small insulated wires bundled into Litz wire, but who wants to go to that much work?
There are calculators of resistance of wire at different frequencies on the web. Check this URL-- 

     http://ve3efc.ca/wire_ohms.html
The R of my primary (00 wire) from this table is about 0.07 ohms, and since the impedance of the coil is about 100 ohms, wire resistance is not a big factor. That means that without the secondary, the primary circuit ought to have a very high Q. I think I'll check that on my coil. By the way, let's forget Litz wire. Looks like I overspent on wire. But it sure is a pretty coil.
An interesting thing to be gleaned from the table is that the RF resistance of any reasonable wire used for the secondary will have hardly any increase of R at TC frequencies, so the ohmmeter resistance of the secondary is the RF resistance. The secondary coil Q should be high too. It seems that losses in the TC are small, and almost all the energy should be going into the coronas. If you look though them in the daytime, you can see quite a bit of heat distortion, even though it's hard to see the sparks themselves. 

---Carl





It might be worthwhile to put on our thinking caps before throwing liquid
nitrogen at our coils, and think about what's important.

Superconduction isn't possible with commonly available materials.  Any
claims made by Mr Tesla should be taken with a grain of salt.  As Dave
pointed out, some reduction in resistance might be achieved with cooling,
but you need to think about the relative impact in efficiency that might be
achieved.  It turns out that the secondary resistance does not have a large
impact in efficiency and performance.  Primary resistance IS very important
and any reduction there would be useful.  But the spark gap resistance is
still going to be the larger loss.

Consider also, the losses incurred through the mains wiring.  If your coil
is pulling 20A+ from the wall, you may find that gertting rid of wimpy
extension cords and beefing up the 120V wiring will have a measurable impact
in performance - an easy win.

Regards, Gary Lau
MA, USA

On Mon, Apr 11, 2011 at 10:02 PM, chris elfert<snotblossom66@xxxxxxxxx>wrote:


As it seems to be a law of physics that as a conductor's temerature is
lowered, the the resistance is lowered. The amount depends on the conductor
material of course, as can be seen in the experiments with superconductors.
In the scheme of things, copper is not nearly as good a conductor as many
other materials, so the cooling effect will have to be much greater than
just what can bew achieved with ice. Even Tesla said he used liquid air,
which was most likely liquid nitrogen to get the effect he described. Since
nitrogen doesn't liquify until at least -320 Deg. F, ice isn't even close.
For a home experiment, I might try starting with dry ice (frozen carbon
dioxide), which is about -110 Deg. and is easily found. I am sure this
should be sufficient to produce some significant improvements. For some
temperature/resistance formulas in different conductors, this link may be
helpful as an online calculator and explanation.
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html

From: Dr.Hankenstein<dr.hankenstein@xxxxxxxxxxxxx>
To: 'Tesla Coil Mailing List'<tesla@xxxxxxxxxx>
Sent: Monday, April 11, 2011 8:35 PM
Subject: RE: [TCML] "Means for increasing the intensity of
electricaloscillations" The Tesla Superconductor of 1901

Do it, dude! Fill that tesla coil up with ice and give it a try!

Hank

-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of Weinhold Shannon L
Sent: Monday, April 11, 2011 2:57 PM
To: Tesla Coil Mailing List
Subject: [TCML] "Means for increasing the intensity of
electricaloscillations" The Tesla Superconductor of 1901

While browsing through some of Tesla patents, I ran across this one,
patent number 685,012, in which he describes using artificially cooled
coils to obtain "a great increase in the intensity and duration of the
oscillations in a freely vibrating or resonating circuit". He describes
the utilization of liquid air to obtain these results.
He describes, as he has in all of his high potential patents, the
magnification of oscillations, the increase being directly proportionate
to the product of the frequency of the oscillations and the inductance
of the secondary coil, and inversely to the resistance in the secondary.
Other conditions remaining the same, the intensity of the oscillations
in the resonating secondary will be increased in the same proportion as
its resistance is reduced. He states that by using this technology, it
becomes viable to use a longer conductor, securing a much greater self
inductance, without the extra resistance that would normally be
encountered by such a change in length.

I'm wondering if anyone has done any experimenting with this phenomenon.

Sounds like it may be a viable way to obtain greater output without an
increase in input power...always a bonus.
He doesn't indicate a percentage in efficiency gain. I am curious as to
how well this works.
I'm thinking I might have to rig up a primary and a secondary coil, each
with an outer larger diameter pvc former, and try filling it with some
sort of freezing fluid to test this out.
Ideas anyone? Anyone else curious?

Shannon Weinhold
Klasdja Intelligent Innovations

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla