Tesla's mysterious Phantom Streams

[barbosi]

Tesla's patent for the bifilar coil US512,340 (for me anyway) is way of producing an electromagnet without the self-induction that normally causes a back-emf arc at the contacts when the circuit is broken.

Jeff, although I greatly admire your dedication and work in the field:

Tesla intended (and stated) these coils will cancel the self-induction, which in common electrical science means the inductive impedance is canceled by capacitive inductance hence it is a self resonant device (it has its own resonant frequency).

From here one can see how little has this with a regular electromagnet (used to attract ferromagnetic materials) as stated in the title of patent.

Instead, assuming we could have a device which is capable of deliver extremely short pulses to this kind of coil, the coil will resonate to its own frequency no matter what. Like plucking the guitar string. Later in history, a mathematician called Dirac coined the term "Dirac pulse" used nowadays in the theory of systems to characterise the characteristic response in frequency domain of any system.

In other words, Tesla found in its time a way to have a resonant circuit which if properly calculated and constructed, no matter what excited it, it will resonate at the intended frequency. The efficiency of that, as stated in the calculation made within the patent is staggering and the only loss was the resistance of the wire. Less resistance, less loss. Simple.

Having said that, the arcing on the contacts occurs not because of the counter-emf (back-emf as many call it) but occurs also on pure resistive load. So it is not a consequence of a reactive load. And arcing is not only present on braking out the circuit but also in making on the circuit.

I think the bifilar coils need a new name. Tesla called them "Coil For Electromagnets". Maybe we could add "Bifilar" to the title...??

In my view, true Tesla bifilar spiral coil does not need a new name.
Twisted wires used in "bifilar" coils do not bring anything special to the science as long they cannot be easyly calculated with predictable effects. Unless I'm proven wrong, I'll call them perverted bifilar coils.

Regards and again I assure you of all my respect on the work you have done and proven in the field. Your documents exposed in your web site are invaluable, please hold them dear and make/keep them known to the public.

[jeff_behary]

Electromagnetics

I am curious in general regarding magnetic properties of various spirals. I know some studies were made as early as the 1850s by Daniel Davis.

I am also curious about a device Tesla invented called the "Static Eliminator". I wonder if any of our friends in Croatia have seen better photos of this device anywhere? (Tesla museum published some nice books over the last few years, a pity they are not so easy to get here!)

This Static Eliminator contained several flat (???) coils wound in a special fashion and arranged in a certain way inside of a case. I think the Tesla museum in Beograd has one or two. At least I remember one from a fantastic book I saw of Tesla's trunk contents.

[morpher44]

stuff

Jeff Behary
The Turn Of The Century Electrotherapy Museum

Jeff,
I thought you might be interested in this guy if you don't know about him:

Tom Kipgen's Sale Page

The honeycomb coil winder looks very nice.

[lighty]

@Jeff

If there is a copy of static eliminator in Tesla Museum in Belgrade I doubt it will be possible to examine it. There are two main reasons for that.

1. Hardly any museum will allow for outside people to disassemble their exhibits.
2. They got new management about year and half ago which is extremely uncooperative and greedy. If you want to scan or photograph one of the photographs in their collection it costs about 100EUR. Former management gave everything for free or almost for free using logic that it is the purpose of Tesla Museum spreading facts about his life and work.


As for the magnetic properties, I used precise laboratory gaussmeter to do a crude mapping of spiral coils and as it turns out net magnetic field strength is identical to the equivalent helical coil. Biggest difference is that magnetic field spreads far around the surface of the spiral coil in form of "bubble". Imagine magnetic field lines in helical coil and then turn that coil partially inside and out. What you will get is magnetic field topology which spread much further into the space above flat surfaces of spiral coil. Again, net magnetic field strength is the same as with helical coils, it's just that it has different geometry. Also, the field strength is highest at the center of the coil and it spreads into space perpendicular to the surface of the coil. In fact it spreads into space surprisingly far.

Of course I'm talking about DC, low repetition rate pulsed DC and low frequency AC where capacitance between windings don't play such big role.The behaviour of the magnetic field on high frequencies might (or might not) be significantly different.

I never got time to test bifilar spiral coils so they might be a bit different.

Hope this helps a bit.

[witsend]

Referring to Tesla's pancake coil 'US patent number 512,340 - COIL FOR ELECTROMAGNETS.

Has anyone tried this configuration using hollowed copper tubing? The optimum turning would be - if you can imagine this, a long copper tube - doubled, then turned from the centre out so that the two ends are 'in series' with each other and both ends on the outer circumference. Alternatively just electromagnetically coupled as per the second configuration.

A really interesting thread by the way. Thank you jeff for starting this.

[grizli]

Question for Jeff :


I tested my pancake coil a little today...

Freq used was about (presume close) to 1/4 wavelength is wire length : here 750 khz

This freq seems not to produce longer sparks , presume secondary is not in resonance ... At lower freq sparks are much longer for the same power level...

At larger spark gap distance coil GLOWS inside, I wonder why, outer sparks are not longer than diameter of coil , if I use lower freq and shorte spark gap there is no glow inside and sparks are the same length ....

whats wrong with my coil it has 3 layer per turn and each turn is at least 8mm apart from another

When I make spark gap shorter (at 750 khz) at some point sparks get VERY short and glow streamers can easly be seen in darkness, BUT I really cant see that phantom streamers go FROM surrounding to the coil ...

How can I actually know do I get phantom streamers or not ?

They like practicly exactly like this : I wonder can they charge capacitor to DC

http://www.electrotherapymuseum.com/...y/DSC06702.JPG

[Jetijs]

Grizli, I presume that your coil starts to glow because at increased spark gap, more voltage is needed for the spark to jump the gap, thus higher voltages are used in primary coil. This makes also the voltage of the secondary coil to increase and eventually reach the point where ionization between coil turns start. A bit more higher voltages and sparks will jump across the coil windings.

[lighty]

Has anyone tried this configuration using hollowed copper tubing?

It could be done, of course but only on larger coils and with very small number of turns- it's simply that there is some minimum diameter of tubing that can be used.

BTW- why would you want to use hollow copper tubing? It's great for high frequencies or very short impulses because of doubled skin effect but other than that tubes are pain in the ass to work with.

[witsend]

Hi Lighty. Do you know this effect because you've tried it? Or is this the obvious result? I'll tell you what interests me is the idea that the magnetic fields would no longer be 'extruded' from the piping - I imagine? I'm open to correction however. But if they do get 'drawn in' to the material of the tube itself - then how do they manifest? I'm actually wondering if this would induce the field into the pipe rather than outside.

Thanks for answering this btw.

[lighty]

Hm, that's an interesing question. Yes, I quite often used copper tubing for the primaries of large Tesla transformers. The only reason for doing that is that because of the fast rise times and short duration of the discharge impulses most of the current goes over the surface of the conductor. Well, when you have pipe then you have twice surface area then with solid core conductors and that means better conductivity and less losses.

Since magnetic field is formed radially around the conductor I suppose some of the magnetic field could be forming inside the tubing as well. That's really an interesting question and I never thought about it before. Give me some time to think it over.

[grizli]

Grizli, I presume that your coil starts to glow because at increased spark gap, more voltage is needed for the spark to jump the gap, thus higher voltages are used in primary coil. This makes also the voltage of the secondary coil to increase and eventually reach the point where ionization between coil turns start. A bit more higher voltages and sparks will jump across the coil windings.

Of course, thats logical, but I wonder does Jeff coil glow inside, when outer sparks are longer than pancake diameter : If not that would mean that there is something wrong with my coil construction...
maybe paraffine is pretty durable if there is glow inside...

maybe vacuum pump would do much benefit considering parrafine voltage breakdown..


Well but, after all it is made to see phantom sparks, which does not require too high voltage... ..

[grizli]

my images: please comment:

one with closer object near , one with object more distant:

http://img147.imageshack.us/img147/6402/p9130034.jpg

http://img406.imageshack.us/img406/7939/p9130035.jpg


So when metal not grounded object is NOT affected with main shiny sparks, only with phantom ones, and when i turn coil of this metal object when I close finger to it small spark occurs, so it implies that metal object is DC charged..

I dont know if it is positive or negative charged...

[jeff_behary]

Nice!

my images: please comment:

one with closer object near , one with object more distant:

http://img147.imageshack.us/img147/6402/p9130034.jpg

http://img406.imageshack.us/img406/7939/p9130035.jpg


So when metal not grounded object is NOT affected with main shiny sparks, only with phantom ones, and when i turn coil of this metal object when I close finger to it small spark occurs, so it implies that metal object is DC charged..

I dont know if it is positive or negative charged...

Can you send a picture of the coil with the lights on? Nice images!
The ungrounded metal is receiving positive charge from the Phantom streams, normally. Isn't it interesting to have an Oscillatory coil with static effects?

I don't know about the coil showing light inside, unless...:
If you use Paraffin wax, it has an interesting phosphorescent property. Not sure if Phosphorescent is the best word, but under much UV (esp. shorter wavelengths) it will appear to glow similar to pyrex glass under X-Rays, a light blue colour. If you see light from within the coil, its possible to be arcing somewhere internally. Sometimes this is arcing from the Tesla coil, but also sometimes there is static arcing from a strong static charge accumulating from the Phantoms.

If you change the spark gap slightly, or capacity slightly, or the input current or voltage, the Phantoms will change from straight lines to thick positive appearance sparks - like thick tree branches. It gets very interesting. Also a black room without lights (and a shielded spark gap) will really enhance these effects, because the eyes can better adjust to the darkness.

Thank you for trying some experiments everyone, I've waited forever for others to join in this fun!

Jeff

[jeff_behary]

Geissler Tube for Phantom Streams

@Jeff

If there is a copy of static eliminator in Tesla Museum in Belgrade I doubt it will be possible to examine it. There are two main reasons for that.

1. Hardly any museum will allow for outside people to disassemble their exhibits.
2. They got new management about year and half ago which is extremely uncooperative and greedy. If you want to scan or photograph one of the photographs in their collection it costs about 100EUR. Former management gave everything for free or almost for free using logic that it is the purpose of Tesla Museum spreading facts about his life and work.


As for the magnetic properties, I used precise laboratory gaussmeter to do a crude mapping of spiral coils and as it turns out net magnetic field strength is identical to the equivalent helical coil. Biggest difference is that magnetic field spreads far around the surface of the spiral coil in form of "bubble". Imagine magnetic field lines in helical coil and then turn that coil partially inside and out. What you will get is magnetic field topology which spread much further into the space above flat surfaces of spiral coil. Again, net magnetic field strength is the same as with helical coils, it's just that it has different geometry. Also, the field strength is highest at the center of the coil and it spreads into space perpendicular to the surface of the coil. In fact it spreads into space surprisingly far.

Of course I'm talking about DC, low repetition rate pulsed DC and low frequency AC where capacitance between windings don't play such big role.The behaviour of the magnetic field on high frequencies might (or might not) be significantly different.

I never got time to test bifilar spiral coils so they might be a bit different.

Hope this helps a bit.

Lighty:

I have developed a new form of Geissler Tube to show presence of Phantom Streams. It is being made now by a famous glass blower in Germany. It has a long filament to allow ionisation of neon to be confined in the centre of the tube, and a larger OD to allow phantoms striking the glass to show up as bright target spots on the wall. It is an interesting detector of these streams! More information when I receive them, probably in a month or two.

I have horrible news though. The store where I formerly bought Croatian, Russian, Ukraine, Latvian, and Lithuanian beer has now closed. I might die from drinking less important liquids. Fortunately I can still get some Czech and Polish, which are quite fine, but I have a limited selection. Fortunately we still have pigs, so I can still eat Smalec...



Jeff

[grizli]

I have horrible news though. The store where I formerly bought Croatian, Russian, Ukraine, Latvian, and Lithuanian beer has now closed. I might die from drinking less important liquids. Fortunately I can still get some Czech and Polish, which are quite fine, but I have a limited selection. Fortunately we still have pigs, so I can still eat Smalec...



Jeff

Don't you have American beer there ? Is there difference in taste or ? I have never drunk american ... hmm ?

There is no beer like Czech beer, or German beer etc...