Talk:Tesla coil/Archive 1

This is an archive of past discussions about Tesla coil. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

Archive 2

Tesla Purpose

What is the purpose of the Tesla coil?

It doesn't need a purpose; it's designed to look awesome. Wunderbear 21:12, 21 June 2007 (UTC)

tesla effect

The June 7th revision by 204.56.7.1 again refers to a "Tesla Effect". On the same date, the same author also provided a new Wiki page that defines the Tesla_effect. However, the newly listed "effect" does not appear to fit the definition of an accepted scientific phenomenon, nor does it appear to be defined as precisely as all of the other effects currently listed in Scientific_phenomena_named_after_people. And, the new Wiki page that explains the "Tesla Effect" is not much help since it initially seems to imply a high voltage/capacitive effect, but then refers to electromagnetic induction. A Google search indicates a number of conflicting definitions for the term "Tesla Effect". And, virtually all of these references come from non-scientific/pseudoscientific sources. Although I can appreciate the author's attempt to honor Tesla in this fashion, I still recommend deleting reference to the "Tesla Effect" since it's ill-defined and is not an accepted scientific phenomenon in the league of other named scientific phenomena. Thoughts? Bert

don't delete; debunk. :-) my philosophy. - Omegatron 16:33, Jun 8, 2005 (UTC)

I have been searching for a coherent description of the "Tesla effect", and as Bert says (above), there's a lot of nutty stuff out there. However, I found an interesting extract from a book called "Lost Science" by Gerry Vassilatos that occupies about the last two-thirds of this web page. I think I understand what the extract is trying to describe, before it veers off into "alternative" physics about halfway through. It seems to be saying that the Tesla effect is what Tesla saw happening to resonant objects that fell inside the field of his pulsed EM transmitter - they developed high-voltage discharges whose amplitudes did not fall off with distance from the transmitter. He though that he had discovered a new kind of electricity that disobeyed Maxwell's laws, and even conservation of energy by the sound of it. He also thought that unipolar pulses of current were qualitatively different from AC, so that what he was seeing could not have been EM induction. We now know that pulses are just bundles of different frequencies of AC, so EM induction applies to them too. A modern physicist, reading between the lines of this account, would conclude that what Tesla saw was straightforward voltage multiplication in resonant LC circuits (the metallic objects he used as targets). By modifying their shapes to increase the multiplication, he was actually tuning them in to the transmitter. He went on to use this effect to build the Tesla coil. You could define the "Tesla effect" as electromagnetic energy transfer from one resonant air-cored coil to another.

An important aspect of the effect is that the transmitter was driven by pulses and not continuous AC. I suspect that this was because Tesla could not generate AC at high enough frequencies, so instead he used the pulses to trigger resonance in his primary coil (the transmitter). The resulting output must have been close to a continuous wave. I wish I knew what frequency he was working at - it would remove so much of the guesswork - but I suppose he had no way of measuring it. --Heron 21:14, 31 July 2005 (UTC)

These sources cite the "high voltage/capacitive effect",

Norrie, H. S., "Induction Coils: How to make, use, and repair them". Norman H. Schneider, 1907, New York. 4th edition.
Electrical experimenter, Janaury 1919. pg. 615

I will be adding other citation (as there are others) when I can. Norrie make reference to it's use in electrothreapy and lighting. There is a really good article about Tesla's wireless lighting that has the digram of the effect, written in Tesla's time .... it talk about his lighting effect (2 plates and a HVHF generator or another AC source; take his wireless bulb between the plates and it lights up) .

As to it not being like the other effects currently listed in Scientific_phenomena_named_after_people, it is list just like Edison's effect is listed.

Wardenclyffe Tower

The qualified statement "This type of coil may have been used as the basis for the Wardenclyffe Tower project" seems timid; if you have a look at the tower it is obvious. Waveguy

violet wand

The violet wand edit appears to advertise an unrelated subject.

There is no link between violet wand (Erotic electrostimulation) and tesla coil (electronics), save for the fact that one uses the other. Many thousands of objects use wood in their construction, but wood does not direct a reader to each. I believe it would be unlikley that someone looking into this aspect of electronics would appreciate being directed into an unrelared field.

On the contrary, the violet wand was a Nikola Tesla invention: a handheld Tesla coil connected to a gas discharge tube intended to be applied to the skin. His invention was an electrotherapy device which today is regarded as quack medicine. Numerous companies began copying Tesla's design, prompting Tesla's financial adviser to complain that Tesla was losing millions of dollars by not defending his invention. Tesla refused to pursue the copycats.--Wjbeaty 10:35, Jan 1, 2005 (UTC)

Adjustments

quote "It is advisable to begin the adjustments with low-power and low-frequency oscillations" This sentence does not make sense. I agree with the low-power part. But the purpose of the adjustments (tuning) is to adjust the resonant frequency of the primary circuit to match the one of the secondary. Therefore, you don't run your coil at a lower frequency to make adjustments, but you run it at low-power to make frequency adjustments. Would you agree? (I open the discussion, and I'll change the sentence if I don't get a negative feedback...) Glaurung 12:58, 3 Nov 2004 (UTC)
While we build a tesla coil, calculation formulas is needed. But there was no formulas even the most simplest one.
Changed it Glaurung 07:22, 15 Nov 2004 (UTC)
Changed it again Glaurung 30 June 2005 10:07 (UTC)

For anyone, curious this article is horribly out of date. I think I am going to start a re write. Eric Urban 04:30, 19 Dec 2004 (UTC)

skin effect

Skin Effect Edit: I did some significant rewording to correct a potentially dangerous misconception that Tesla Coil sparks are not painful because "skin effect" causes most of the current flow on the outside of the expeimenter's skin. This is a very popular misconception, but it can easily be proved as being false. The misconceptin could lead to injury or even death of careless or unwary experimenters. --Bert 17:07, 6 Feb 2005 (UTC)

I also agree with Eric Urban that much of the text is out of date. Have added some verbiage about the nature of Tesla Coil discharges and did further edits to the Skin Effect area, making it a separate section. --Bert 15:00, 7 Feb 2005 (UTC)

This article (and derivatives) is the only place where I've encountered a Tesla Coil being called "self-regenerative resonant transformer". Today, this device is more accurately known as a "dual resonant air core transformer" to reflect the fact that there are two coupled LC circuits. The source for the "self-regenerative" term is probably from one of Tesla's patents, but the term is really no longer used to decribe resonant transformers today. Perhaps we could acknowledge Tesla's terminology, but I'd recommend also indicating that the modern-day term for this device is a "dual-resonant, air-core transformer". Using the more accurate/modern terminology would also help researchers find other modern-day applications. Thoughts?--Bert 15:00, 7 Feb 2005 (UTC)

I agree. This article needs major re-work and organization. I was expecting much from Eric Urban's rewrite, but he apparently disappeared from Wikipedia before changing anything important. With some work, and additional pictures, this could even become a featured article. Glaurung 07:16, 8 Feb 2005 (UTC)

Alternating current driven for transceiving

I removed this and placed a different explanation in its place. Tesla coils do not transceive. True, the secondary coil and its capacitor can be used in receive mode generally Tesla coils are not driven for such purpose given the poor radiation achieved.

Rewrite

I am beginning a rewrite as of 12/23/2004. Eric Urban 04:43, 24 Dec 2004 (UTC)

I think you should write something about it on the article. Something like {{inuse}}, but not sure if that's for full rewrites that take time — Kieff | Talk 14:03, Dec 24, 2004 (UTC)

I suggest that all references to Nikola Tesla in the Tesla coil article refer to him by his full name to avoid confusion with the discussion of the Tesla coil itself. I am doing so in my rewrite.Eric Urban 03:17, 26 Dec 2004 (UTC)

The template {{inuse}} should be used for a limited amount of time. You can put it while you are editing the page to avoid editing conflicts. But you put that warning two days ago and you haven't edited the page since. So I would suggest you remove it and put it back when you will really be ready to edit the page. Glaurung 08:14, 28 Dec 2004 (UTC)

Command and Conquer

Tesla coils feature in the Command and Conquer series of strategy computer games, as a weapon on the Soviet side. What sort of heading could be added to this article in order to mention this? Something like "In entertainment"? –– Constafrequent ^{(talk page)} 03:14, 31 Jan 2005 (UTC)

sure. - Omegatron 04:04, Jan 31, 2005 (UTC)

try putting it under the "Tesla coils in popular culture" heading... when someone makes it Cal 1234 15:10, Feb 7, 2005 (UTC)

waveform

i'd love to see a waveform of the output of a coil. I imagine it's a high frequency wave periodically decaying exponentially? triggered each time it sparks? - Omegatron 16:37, Feb 7, 2005 (UTC)

It's actually considerably more complex than that since the energy in the secondary builds over a number of cycles, and the output waveform is dependent on when the primary spark gap stops conducting ("quenches") and whether or not there are discharges that are also removing energy from the secondary. See the following sections of Richie Burnette's site for some of the gory details:

Happy reading, --Bert 18:10, 7 Feb 2005 (UTC)

So that's a Tesla coil!

There's a cool looking photo of a tesla coil in action somewhere in the middle of the article, but it should be on top of the page! Putting it on top, as happens with other articles with nice to-the-point images, makes the whole article more inviting and overall enjoying to read. So trust me, it'll look better once I put it on top! Kreachure 22:09, 13 September 2005 (UTC)

thumbs up!

Tesla's coils

Couldn't we get one of those pictures of actual Tesla's coils for the top of the article? What are their copyright status? ☢ Ҡieff⌇↯ 17:26, 10 December 2005 (UTC)

Transmission

The placement of the spark gap versus the capacitor in the tank circuit does not significantly alter the operation of a Tesla Coil. In either position, the capacitor is initially charged to the spark gap's breakdown voltage via the AC supply transformer. In either configuration, the gap will break down at the same voltage, and in either configuration, current will suddenly ("disruptively") begin flowing through the gap, discharging the tank capacitor through the primary winding. Tesla utilized both circuit configurations, but he also came to recognize that placing the spark gap across the AC supply transformer reduced high frequency voltage stress on its windings. Modern Tesla Coils use this same configuration, and many enthusiasts also add low pass RC filters between the gap and AC transformer so as to provide further protection. This is particularly important when using relatively fragile Neon Sign Transformers (NST's). The prior wording that discussed marked differences between the two circuit configurations is not borne out by experiment and is also poorly worded. The longitudinal wave and radiant energy material is unsupported and speculative. Bert March 19, 2006

The longitudinal wave and radiant energy material is unsupported? Have you read his patents and other writings? It's not speculative. Tesla repeatedly talks of "radiant energy". "The true wireless" was made possible by Tesla's concentrated attention on the production of a powerful induction coil and the invention of the oscillation transformer (eg., the Tesla Coil). Longitudinal waves are "non-Hertzian waves" or not traverse waves. 204.56.7.1 14:51, 13 April 2006 (UTC)

I don't believe Tesla ever refered to "Longitudinal waves". This term seems to be a latter day invention. In any event, my revisions of March 19, 2006 were directed towards wording that implied profound differences between having the spark gap, or the tank cap, across the HV supply transformer in a Tesla Coil. Tesla NEVER claimed anything like this and, in fact, he utilized both circuit configurations (and many others) during his research. The wording that I changed also had severe POV problems in addition to being outright wrong. Tesla did, in fact, propose using what we would now call electrostatic induction to change the voltage on Earth's self-C via the Wardenclyffe facility. What Tesla said, his patents, and the laws of physics are not always consistent. Bert 17:07, 13 April 2006 (UTC)

1st, I would lean to support your contention that Tesla claimed anything like that ... I'd have to look into it though to fully support that .... and, yes, he utilized both circuit configurations (and many others) ...

2nd, did Tesla propose using what we would now call electrostatic induction to change the voltage on Earth's self-C via the Wardenclyffe facility? Yes, for the most part ... but there was much more to it (what you state is a bit of simplification, IMHO) ....

Now, did Tesla ever talk about "Longitudinal waves"? Yes ...

In "Tesla see evidence radio and light are sound" ... "It is true that many scientific minds envisaged the theory of a gaseous aether, but it was rejected again and-again because in such a medium longitudinal waves would be propogated with infinite velocity. Lord Kelvin conceived the so-called contractile ether, possessing properties which would result in a finite velocity of longitudinal waves. In 1885, however, an academic dissertation was published by Prof. De Volson Wood, an American, at a Hoboken institution, which dealt with a gaseous ether in which the elasticity, density and specific heat were determined with rare academic elegance. But, so far, everything pertaining to the subject was purely theoretical."

In "Roentgen rays or streams" ... "It is significant that, with these and other facts before him, Roentgen inclined to the conviction that the rays he discovered were longitudinal waves of aether."

In "Nikola tesla tells of new radio theories; Does Not Believe in Hertz Waves and Heaviside Layer, Interview Discloses" ... "I had maintained for many years before that such a medium as supposed could not exist, and that we must rather accept the view that all space is filled with a gaseous substance. On repeating the Hertz experiments with much improved and very powerful apparatus, I satisfied myself that what he had observed was nothing else but effects of longitudinal waves in a gaseous medium, that is to say, waves, propagated by alternate compression and expansion. He had observed waves in the aether much of the nature of sound waves in the air."

These were done off a quick search ...

Lastly ... I agree that Tesla's experiments, his patents, Tesla's quotes, and the "laws" of physics are not always consistent (with that latter more in error with phenonomena) ...

134.193.168.243 19:55, 14 April 2006 (UTC)

The "alternate configuration" schematic really just confuses the article. If you would like to delete it and re-word the article around that deletion, be my guest. I just drew it up to illustrate the assertion that Bert has since debunked. --Jim, K7JEB 05:24, 20 March 2006 (UTC)

The "alternate configuration" schematic is applicable. Tesla utilized both circuit configurations, the precise one pending his application. 134.193.94.71 22:23, 11 July 2006 (UTC)

Tesla's purpose?

What is the purpose of the Tesla coil? —Preceding unsigned comment added by 88.155.46.32 (talk • contribs)

here and there, where a high voltage low current high frequency is required, a Tesla transformer (resonant, air core, double tuned) can be the easiest way to provide it, I have seen one example of an airborne pulsed radar using such a power supply. HOWEVER, 99.9% of the TCs in the world are built for the hell of it, because they can be built, for the wow factor and because they look pretty. If I want a kick and do it by buying a 42" home theatre system, anybody with money can do that. But to build a TC I need skill, and how many people have that?NeilUK 07:53, 23 June 2006 (UTC)

For what did Tesla use this invention? The present entry doesn't say. The TC wasn't created to be a spark generator, although that aspect did figure historically. Let's start a list:

1. power supply for physics research into high voltage at high frequencies. It competed with the Induction Coil in early physics labs at various universities.

2. high power radio transmitter. Tesla was trying to transmit around the entire Earth, and Marconi only succeeded transmitting over long distances when he started using the so-called "Tesla oscillator." All the early "spark transmitters" were tesla coils with a wire antenna connected to the output.

3. high-volt driver for wireless fluorescent lighting. Tesla lit his turn of the century NYC lab with fluorescent tubes.

4. power supply for x-ray tubes of extremely high output intensity.

5. induction heater

6. medical diathermy (heats flesh, Tesla's company sold these units)

—Preceding unsigned comment added by Wjbeaty (talk • contribs)

Unclear diagram of tesla coil and description

I find it difficult to understand the initial diagram of the Tesla coil and the description following it. First of all, the parts should be labeled, if not in words, with letters with references by the text. Second, a step-by-step description of what happens with each component at each stage of every cycle is necessary to understand how it works -- where current is flowing, where induction takes place, etc.

The section entitled "Description" needs diagrams to explain the text. I cannot understand using the text alone.

Responsible rewrite still needed

2007.1.6 Documented SSTC & VTTC. Some of this article is pretty neat and some is terrible, mainly at the beginning. It seems as though there's a lot of quoting from Tesla's communications or patents, and he wasn't trying too hard to be understood by most of the people who are going to read the article. Was the person who wrote that even a coiler, I wonder, or just for some reason moved to do some transcription? One vote for slash and burn, by anybody who's going to do it right.

There seems to be a lot of ambiguity about whether an "extra coil", or "magnifier", design is being discussed in the Tesla-ese, as opposed to a classical, two-winding setup. If we're going to talk about Tesla's work specifically, lets do it well.

And yes, Tesla was an ordinary man, he took out some patents on things that don't work (and on some that do), he was very histrionic, and let's continue to avoid pseudoscience.

72.72.37.51 02:04, 7 January 2007 (UTC)Packer

OK, I couldn't take it anymore. I started reading the top of the article again, and some of it's comprehensible, even though it needs lots of illustration and is a touch boring. However, some of it seemed to have been edited badly, producing nothing coherent. I worked it around and fleshed it out rather extravagantly, but what I removed was minimal; I think it had been added by somebody who hadn't read or understood what they were altering.

I left in language I didn't like, out of politeness, but at least somebody can read the thing now.

72.72.37.51 00:44, 14 January 2007 (UTC)Packer

The "current understanding" is that energy does not have charge? How far are we going to take this? The Earth is "currently believed" to be spheroidal? I'm an epistemological nihilist myself; I don't think I know my own name, but this kind of thing is taken as read, you don't incessantly say that we don't know this or that when it's as likely as the nose on your face. Before you challenge basic science, it could be preferable to study it.

72.72.37.51 07:15, 22 January 2007 (UTC)Packer

Added explanation of what a patent wasn't. I refrained from repeating what I have read, that the US Patent Office, specifically in response to Tesla taking out many patents of very dubious merit, instituted a requirement that a working model be submitted with each patent application, which requirement was rescinded some decades later.

WELCOME to the Wiki Physics folks!!! 72.72.103.19 06:37, 25 February 2007 (UTC)Packer

You know, the Tesla cultist(s) who keep transcribing stuff into this article that they don't understand are making the whole thing look like a joke. I suggest they build and operate whatever they want to talk about, then talk about it!

72.72.103.19 04:54, 26 February 2007 (UTC)Packer

Maybe we should abandon "Tesla Coil" to the cultist(s) who keep transcribing material that they don't understand, and that the vast majority of visitors won't understand, which has essentially ruined the article, and start a new article for all the other material; perhaps we could call it "Tesla Coiling", but something like "Tesla Coil, Modern" is also a possibility. In fact, calling it simply "Coiling" might help a lot to prevent unwanted edits. I just think that this article is a lost cause because of these transcriptions.

72.72.99.194 01:01, 1 March 2007 (UTC)Packer

Oops! Packer was legitimately registered to another user. I am now: FETSmoke 13:29, 4 July 2007 (UTC)

I just took a deep breath and read the article again, and it's not doing too badly. Looks like somebody kind of beat it into shape. I don't agree with everything, but I'm leaving well enough alone. I'm glad we've got this working reasonably well for the benefit of the public. I do, though, hope that over time we can come to better agreement about the Reception section. FETSmoke 06:29, 5 July 2007 (UTC)

Hi there, this article is way too patent-oriented rather than encyclopedic, i have rejigged some of the sentences/structure but would prefer 3/4 of the article ditched or moved to "Nicola tesla's inventions/patents" or similar. i will continue if there is no upset to cull a lot of extraneous theory etc. I'm an engineer and it's difficult for me to understand! anyway, looks like I'll try as much as possible to clean this up.--Read-write-services (talk) 01:29, 12 May 2008 (UTC)

"High frequency electrical current" ?

What are you guys, retarded? What would you measure that in, precisely? Hertz-amperes? Charges*cycles per second squared? Is it some form of acceleration, then?

Not that everyone doesn't already expect scientific illiteracy from Wikipedia. Thanks, Jimbo, for making a medium where any idiot can pretend to have 4 doctorates, or 40 doctorates, or whatever, and fleece you, and by extension, the rest of the unwashed masses that make this site their home pages. Obviously the best person to ask for information about Tesla Coils is the first person you meet on the street corner, because that's exactly who is contributing to Wikipedia. --76.209.58.121 06:10, 23 March 2007 (UTC)

I agree that this page is tragic, and it isn't unheard of on Wikipedia, but your criticism is unfounded and embarrassing to your fellow bad-tempered cranks such as myself. Consider a current probe around a conductor, with the probe connected to an oscilloscope. The oscilloscope shows a sine wave at 50 kHz. Presto! High-frequency electric current. How to get it? Anything wrong with a function generator connected to a resistor? Perhaps you were thrown by the omission of the word, "alternating," but when a nonzero frequency is specified, "alternating" may be omitted since it is unambiguously implied. Incidentally, I have worked, very successfully, in industry for many years as an electrical engineer, and some time ago I designed and build a solid-state Tesla coil, which is giving me about 16-inch sparks. In that, I presume I'm typical of some (BUT NOT ALL!!!) participants in this article. FETSmoke 13:29, 4 July 2007 (UTC)

What do you measure the voltage coming from a high frequency sinusoidal source in, smart ass?--Loodog 20:16, 3 August 2007 (UTC)

I'm not sure what you mean, but if you mean units used to state voltage, then VRMS is often used, although some might prefer dBVRMS, or dBuVRMS (RMS is normally omitted and understood) or, bending the rules as is common, dBmW, with resistance understood. I'm interested in why you're abusive, by the way. I assume you're having a bad life day, but I like to know when I'm messing up. FETSmoke (talk) 06:20, 24 December 2007 (UTC)

I have to say FETSmoke, I do believe you told him :-D VOLTS! (Thank you for your contribution to this page) —Preceding unsigned comment added by 71.206.23.209 (talk • contribs) 03:46, 4 June 2008

Atlanta Ga experiment on population?

This section:

"In Atlanta GA, USA, students at Morehouse College have constructed a 32ft tall, 4.5 gigawatt coil to demonstrate potential biological effects of high voltage current on human populations. It was designed by Dr.Andrew Hedrick, also of Atlanta, and funded by a grant from Harpo Productions. It is reported that during operation, people within a 20 block radius of the device can feel the hair on the back of their necks stand up, and small sparks can be seen jumping between the teeth of people."

Has to be absolutely untrue for several reasons. There's no way any college kids could have built a 4.5 GIGAWATT coil. That would be more power output than most nuclear power plants are capable of. Using the current standard equation for predicting tesla coil output, that would result in sparks 6700 feet long from the top of the coil. That probably would have been noticed, and made significant national and international news. Not to mention because of all the nearby people that would kill, both by lightning strikes, and anyone with a pacemaker.

I also call into question the idea that any university could get permission to do experiments on a human population, especially those that involve high voltage electricity flying through the air, and sparks jumping between people's teeth. And as noted above, anyone with a pacemaker would die after it malfunctioned due to the extreme radio transmissions from the coil.

Removed offending section* —The preceding unsigned comment was added by Hightek02 (talk • contribs) 19:11, 28 March 2007 (UTC).

Reception citations

Need citations. Putting them under each bullet. J. D. Redding

The secondary coil and its capacitor can be used in receive mode.
- Tesla, Nikola, "The True Wireless". Electrical Experimenter, May 1919. (Available at pbs.org)
- U.S. Patent 0685957 - Apparatus for the utilization of radiant energy - N. Tesla
- U.S. Patent 0685958 - Method of utilizing of radiant energy - N. Tesla
- "Apparatus for Transmitting Electrical Energy," Jan. 18, 1902, U.S. Patent 1,119,732, Dec. 1, 1914 (available at U.S. patent 1,119,732 and tfcbooks' Apparatus for Transmitting Electrical Energy)
The Tesla Coil can also be made to utilize atmospheric electricity.
- Plauson, U.S. Patent 1540998 , "Conversion of atmospheric electric energy". Jun. 1925.
- U.S. Patent 0685957 - Apparatus for the utilization of radiant energy - N. Tesla
- U.S. Patent 0685958 - Method of utilizing of radiant energy - N. Tesla
Tesla stated that the output power attained from these devices was low.
- Noted that this was only via Hertzian methods
There are, to date, no commercial power generation applications that use this technology.
- Noted that this was only via Hertzian methods
The power levels achieved by Tesla Coil receivers have, thus far, been a small fraction of the output power of the transmitters.
- Noted that this was only via Hertzian methods
Various public demonstration of such technology, by any individual, group, college or university, industrial concern, government agency or laboratory or other entity of various kind have been reported.
- Tesla power could have been world changing on the electrical grid, but electrical companies turned it down because the couldn't put a counter on it! Basically, they couldn't charge people for using tesla!

I wonder if most, or all, of this section shouldn't be moved to Wireless energy transfer? Bert 14:31, 3 April 2007 (UTC) Some could be, but the majority should be left here. J. D. Redding

OK... The discussions/references pertaining to Tesla's Radiant Energy patents in the "Reception" section have nothing to do with Tesla Coils. Their presence in an article about Tesla Coils is confusing and off topic. A Tesla Coil resonator can indeed serve as reception device to detect rapid changes in local electrostatic or magnetic fields, and coupling can be inductive, capacitive, or conductive (base driven), and energy transfer can be via near field and/or far field effects. However, Tesla's Radiant Energy patents describe relatively slow charge collection on electrically isolated plates via atmospheric electricity, charged particles, or other sources of ionizing radiation, with the charge being SLOWLY accumulated across a low leakage high voltage capacitor. These patents, and the associated radiant energy discussion, have nothing to do with the description, design, operation, or theory of Tesla Coils. The Radiant Energy patents/discussions have nothing to do with the "Tesla Antennas" either (which is an RF device). Tesla coils utilize energy transfer between two (or more) tuned resonant circuits. Tesla's Radiant Energy patents show a variety of simple capacitor storage circuits including some that switch the charged capacitor to drive loads (either directly, or via an _untuned_ transformer). The entire radiant energy references and discussion might better fit in [Wireless power]] or perhaps {Wardenclyffe Tower]]. In any event, it does not belong here. Bert 16:59, 6 April 2007 (UTC)

"Tesla coil receivers" were an application of Tesla coils. Their presence in an article about Tesla Coils is clarifying the uses of his coils and on topic. A Tesla Coil resonator can indeed serve as reception device. Tesla coils can slowly charge electrically. These patents, and the associated radiant energy discussion, have everything to do with the description, design, operation, or theory of Tesla Coils and "Tesla Antennas". J. D. Redding 17:57, 6 April 2007 (UTC) (BTW., the material was added due to "citation needed" fact tags. This rectifies the situation of needing the references. J. D. Redding)

OK... Please show WHERE (in the Radiant Energy patents) tuned circuits are employed? Explain just HOW can a base-grounded resonator (the definition of a Tesla Antenna) can "charge up" slowly? WHERE is the connection between the Radiant Energy patents (using isolated plates to slowly charge a HV capacitor (via charged particles from cosmic rays, x-rays, beta particles, etc.) and the theory/operation of Tesla Coils? I fail to grasp how a slow accumulation of DC on a HV capacitor bears ANY relationship to an RF-excited Tesla Antenna or a Tesla Coil. Adding citations that do not relate to Tesla Coils does NOT improve the accuracy and understandability of this article - it detracts and potentially confuses readers. Bert 18:35, 6 April 2007 (UTC)

The photoelectric work doesn't relate to Tesla coils, you're right. I can't tell whether radiant energy also meant electromagnetic or near-field electric radiation at a low enough frequency to be picked up by a realizable Tesla coil. If you commutate the current feeding the HV side of a Tesla coil (which you might or might not be able to do usefully with available technology), you should be able to run it backwards. FETSmoke 06:57, 5 July 2007 (UTC)

The U.S. Patent 0723188, Method of Signaling, and U.S. Patent 0725605, System of Signaling, call for a elevated transmitter capacitance and a corresponding receiver. There is a top node, a earth electrode, and a transformer (with the primary or secondary, depending on the use, connected to a condenser). Transmitting, it's a impulse generator. Receiving, it's a impulse accumulator. The phrase "vibrate in synchronism" is key in U.S. Patent 0685953, Apparatus for Utilizing Effects Transmitted from a Distance to a Receiving Device through Natural Media. The "effects" are "radiant energy effects".

In U.S. Patent 0685954, Method of Utilizing Effects Transmitted through Natural Media may be from an "independent source" at a distant transmitting electrical energy (say a transmitter or a natural source). The isolated plate is the top terminal consisting of a metallic frame in the shape of a toroid. It can slowly charge a capacitor after a step down transformation (lowering the voltage, increasing the current). Notice in U.S. Patent 1119732, you can have a capacitor ... and this structure can be used as a reciever instead of a transmitter.

I can go on ... but this will do for now ... J. D. Redding 18:53, 6 April 2007 (UTC) (ps.,Tesla also states that U.S. Patent 0685957, Apparatus for the Utilization of Radiant Energy, is related to U.S. Patent 0577671, Manufacture of Electrical Condensers, Coils and Similar Devices.)

Appendium:

U.S. patent 7,053,576 states this system in more complete terms. J. D. Redding 19:49, 6 April 2007 (UTC)
- Abstract "transmitter and a receiver both incorporating Tesla coils"
- Page 10 "The transmitter and receiver each preferably comprise a Tesla coil" ...
- Page 14, "Eventually, in his power transmission system, he would replace this transmit-ter with a Tesla coil, and place an identical receiving coil at the receiving [...]"

Not proven

RE CREDIBILITY: Tesla's radiant energy work would appear to be either photoelectric effect, which is significantly less effective than semiconductor photovoltaic cells, or possibly in some cases the mistaking of atmospheric electricity for a photoelectric effect. The photoelectric effect is regarded as due to the energy imparted to the surface by a photon, which is not charged, causing an electron to fly off. Current is obtained when the electron eventually finds its way to a pole of a utilization or storage device (Tesla's condenser) of which the other pole is connected to the irradiated surface. (Tesla's use of an "insulated" electrode is novel, but at the tiny currents he admitted that he was obtaining the insulation (whatever material it was) might have been conducting. Electrons can seem to get from anywhere to anywhere because each of them is everywhere at once; this is how tunnel diodes work. I don't know whether tunnelling could account for this. In any case, his experiment is no more supportive of "charged corpuscles" than of photoelectric effect. He admits, you may notice, that photoelectric effect was already known prior to his involvement. FETSmoke 15:16, 7 July 2007 (UTC))

Nobody is denying the atmospheric voltage gradient; the issue is the limited power available due to the limit on the current that may be drawn at any one point (air isn't very conductive). As I've noted in the article, the total amount of power available world-wide would appear to be only enough for less than one in a thousand households. Interestingly, at the turn of the century, when Tesla was working on this, world population was far less and per capita energy consumption was far less, so it would have been a bit more realistic, but not by a factor of a thousand.

I would prefer that Tesla's claims of a hundred years ago, when electricity was very little understood, not be used to justify language that implies that Tesla's interpretation of something is generally accepted. FETSmoke 05:23, 5 July 2007 (UTC)

In particular, Tesla makes it clear in his patent that the "charged corpuscles" are only his speculation to explain his photoelectric results, and their presence everywhere in space is also a speculation. Please identify these ideas as speculation, and don't present them as generally accepted fact.

You've scrambled two different things together, or three things: the photoelectric work, which has nothing to do with Tesla coils, the reception of electromagnetic radiation (alternating or time-varying) or near-field alternating current and the harvesting of direct current from atmospheric electricity. It's a pity you can't work with somebody who knows the science to get this stuff straight.

An ordinary Tesla coil does not "slowly charge up." To direct current, it's a dead short to ground. Harvesting DC requires turning it into AC, possibly with a capacitor and spark gap at the high-voltage end. (The source must be weak enough that the arc can clear.) FETSmoke 00:02, 6 July 2007 (UTC)

The drawings entitled "Magnifier Configurations" do show such spark gaps, which are not customary on transmitting Tesla coils, and the large hats might provide the capacitance. However, if that's what they're for, there's no text to indicate as much. FETSmoke 05:56, 6 July 2007 (UTC)

That upper spark gap is said to be a rectifier for producing, not utilizing, unipolar voltage. That might work because of the broad electric field from the large hat; I found a web page showing a low-pressure gas rectifier tube, just two terminals, that worked by having much more surface area on one electrode (a wire helix) than the other. Having the big hat surrounding the upper spark gap electrode should suffice. One possible reason Tesla might have cared about unipolar voltage is if he wanted to modulate it at a low frequency, 8 Hz or whatever, to utilize Earth and ionosphere as a waveguide (or whatever exactly he did along those lines). What I don't understand, off hand, is how he could ring up the resonator without a topload on the lower side of the upper spark gap. If anybody knows what this was about, please comment. FETSmoke 10:03, 10 July 2007 (UTC)

My grandmother's fortune teller told her that the Astabigian War Council planted the idea of Tesla coils in Tesla's mind by mind control. Once the number of Tesla coils exceeds 0.23175 per square mile, all human life on Earth will be obliterated at once by high-energy discharges, and the Astabigian Confederation will take over the Earth to grow mutant coconuts. How do you know this is false; are you a skeptic? FETSmoke 16:50, 7 July 2007 (UTC)

Telluric Currents

Removed statement about Telluric currents in entry paragraph since it does not pertain to actual Tesla Coil operation. Bert 23:53, 5 April 2007 (UTC)

What do they actually DO?!

I skimmed this entire article checking the introduction and contents twice, and was left with no idea

1) Why these things were/are built

2) What they actually do

I feel this should be rectified. Shockeroo 17:24, 22 June 2007 (UTC)

In a word, entertainment. Much like playing with firecrackers. There are also a very few serious uses.FETSmoke 15:22, 4 July 2007 (UTC)

I feel some of their practical uses should be put in the article. I was seconds away from asking this same question and I'm sure several people have come to the article for the exact same purpose. 68.166.65.221 22:30, 20 September 2007 (UTC)

I agree, this article is extremely inaccessible to those who didn't know already. I came here wondering what a Tesla coil does...and I still don't really know. I know its something to do with electrics that was invented by Nikola Tesla, and not much else. While I'm sure the technical information is very good, this article could seriously do with a much expanded "for the ignorant" section. 82.69.37.32 19:01, 15 October 2007 (UTC)

I believe that Tesla made these coils while working on wireless electricity. I read that if you put wood on top of it it causes the wood to either glow from the inside or burst into bits. As for practical uses, the EMF produced allows wireless electricity, and the magnetic fields will ionize fluorescent light bulbs and the like. X giva 00:39, 11 November 2007 (UTC)

Tesla coil video

I just wanted to share a link to a video I made of a pair of tesla coils that were on display at the MAKE/Dorkbot Fair at SXSW Interactive this past spring. The coils are connected to a computer, which has the coils shoot out sparks at specific frequencies, generating music. Thought it might be an interesting way to show a creative use of a Tesla coil in the external links section. Acarvin 13:17, 4 July 2007 (UTC)

Health claims

A number of companies sell Tesla machines for high prices to credulous individuals at MLM "Tuppleware party" type events. Expected health benefits are the sole argument for paying the inflated prices demanded, and the sellers move the merchandise by making health claims in direct and indirect ways (frequently seeking to use personal testimonials from someone saying "seemed to help me" as a way to circumvent the ban on making unjustified health claims). Some machine buyers market individual "sessions" on the Telsa to trusting "alternative health care clients" too poor to buy a machine outright.

There are no peer-reviewed placebo-controlled studies for the unauthorized claims, and the devices are not FDA approved for the making of any health claims, nor any convincing evidence that the health benefits touted by the unauthorized claims exist.

Anyone having information along these lines, adding it to the article may help some trusting folks avoid having their pockets emptied by the delusive hope that the health claims will come true, or that the placebo effects will continue. If you have further information or sources (such as FDA records, warning letters, injunctions, etc.), please add it here, and when this section is ready, please add it to the main article. —Preceding unsigned comment added by 67.101.68.81 (talk) 17:16, 28 October 2007 (UTC)

Solid state Tesla coil

I took care of an old proposal to merge in Solid state Tesla coil to here by merging the text into the discussion of SSTCs at the end of Tesla's later coils. Old talk page here. --Morrand 22:02, 10 November 2007 (UTC)

Added reference to 'City of Heroes'

Added a reference to 'Tesla Knights' and 'Tesla Cages' in the 'In Fiction' section from 'City of Heroes'. 74.197.90.65 (talk) 04:02, 21 December 2007 (UTC)

Atmospheric Electricity

It's acceptable to delete all reference to atmospheric electricity. When I was looking at the patents, it looked as though it was thinking done by others; I didn't notice Tesla working on atmospheric static electricity; he worked on alternating near voltage fields and electromagnetic radiation. But it's only acceptable to delete all of the mention of it, not just some of it.

The reason that it could stay is that if you interrupt the current from the atmospheric static electricity, it acquires an AC component, and I believe that other workers proposed to use a spark gap and capacitor similarly to Tesla's work.

Unless somebody can point to Tesla working with atmospheric static electricity, it would be more orderly to delete all such material; it relates to free energy (like hydro, wind and solar; where's the excitement?), but not much to Tesla coils.

You could speak of "atmospheric electrical disturbances" to clarify that you meant AC, but then the patents on atmospheric static electricity should go.

FETSmoke (talk) 10:32, 24 December 2007 (UTC)

Please read Tesla material before removal. Tesla used radiant energy, which includes atmospheric static electricity, a non-hertzian energy (eg., please read up on Tesla's material and longitudinal "static" electricity that is natural and abundant) and the hertzian electromagnetic radiation. Of the latter, he stated that it was near useless in transmission of power. Of the former (the so-called "static" electricity), it was not static and was most promising to be used for wireless power transmission. J. D. Redding 23:41, 24 December 2007 (UTC)

The patent, Hermann Plauson, U.S. Patent 1,540,998 , "Conversion of atmospheric electric energy". Jun. 1925, deals with vertical atmospheric static electricity, i.e. DC.

Please cite a single document and quote the part that says atmospheric static electricity is radiant energy, here, in the discussion.

By the way, Tesla's work with the so-called corpuscles flowing in light was DC.

Don't say to "read Tesla's material"; the collection of it I bought is over 600 pages. Please cite a document and quote a sentence, here, in the discussion, where the term "longitudinal static electricity" occurs.

FETSmoke (talk) 09:50, 25 December 2007 (UTC)

I will look around for more references.

I had a discussion with another user a bit ago about the longitudinal electrostatic waves. He stated Tesla never mentioned them ... and a quick g.search of Pepe's Tesla site show that patently untrue.

Read Tesla's materials. A result link for you to begin! [1]

J. D. Redding 01:21, 5 January 2008 (UTC)

I've added a definition of "Hertzian." It's no wonder Tesla found it disappointing; the near field provides much more power (as a few burns and a deceased wristwatch can attest), but you have to be near!

It pleases me to leave the discussion of atmospheric static electricity in, because it provides refutation of another idea people have for "free" energy. However, it has almost nothing to do with Tesla coils.

My purpose is to keep people from wasting time and resources, which could from time to time cause serious harm. These things fan out in society, such that one comforting fantasy may distort the actions of thousands or even millions of people. With a bit of bad luck, that could be a problem. Suppose people vote for a presidential candidate because she says that we don't need cellulosic ethanol and economical photovoltaics. That would be tragic.

FETSmoke (talk) 07:23, 26 December 2007 (UTC)

Reddi, the search you provided comes up with various documents (dangerous .doc documents, but which can be read as HTML) that appear to be about X-rays (seemingly unrelated to the titles; that site didn't impress me for organization). The word "longitudinal" appears several times, but never in close connection to "electrostatic" or "static electricity".

Merriam-Webster's 11th Collegiate Dictionary says that "electrostatic" and "static electricity" both refer to stationary charges (DC). However, Tesla used "electrostatic" to mean "electric". I'm not aware that he ever used the term "static electricity" to mean anything other than the M-W definition, granting that this might have been confusing when he spoke of a charge that had been static finally discharging as lightning. And again, you have not provided an occurrence in conjunction with "longitudinal".

I'm not aware that I ever denied the existence of longitudinally polarized electromagnetic radiation, although an informed glance at a TV antenna shows that there are other polarizations. Tesla may have also meant an electric field without appreciable magnetic field. When the energy sloshes between the electric field and the magnetic field, that makes it electromagnetic, and able to propagate arbitrary distances from the source until absorbed, but usually spreading out and thus weakening. In Tesla's work in which he said he electrified the Earth, he felt the Earth as a conductor was guiding the energy, and it was converging at a point on the earth opposite the transmitter, then passing back and converging again at the transmitter, where he believed he was adding a little more energy and then sending it off around the Earth again. He felt he was using the Earth as what we would call a waveguide, and I don't know enough to say he wasn't. I think he also said he was putting in 10,000 horsepower (7.46 megawatts), even when he wasn't receiving more than enough for a lightbulb. Or was it 10 million?

The above was transmission and reception, not reception of naturally-occurring power. Incidentally, Tesla's incentive to receive useful amounts of naturally-occurring power was astronomical; he would truly have been the hero of the age if he had done that, and if he'd held the patent on it, he would have been fabulously rich; but still he didn't do it. Not conclusive, but it certainly bears thinking about.

My point, which I blush to make again, is not so much all of these details, but your habit of taking a bit of Tesla langauge from one document, some from another, unrelated one, throwing it in the blender because you don't understand it at all anyway and sticking the resulting meaningless gibberish in the article (or discussion). You've failed to meet my challenges to prove that you didn't make up terms you were using.

We're not developing a new religious ritual or something here. The words are there so that people can do things. Nobody will be able to reproduce any of Tesla's work, and carry it forward, if they're compelled to rely on your accounts of it.

Tesla was a showman and I don't know what he would have thought of what you do. As for me, do me no favors. When I'm dead, don't even think of representing me or my work until you understand it completely; just let me rot unmolested.

Of course, I'm far from perfect; you can look at my edit history of this entry to see my weak performance.

FETSmoke (talk) 17:09, 7 January 2008 (UTC)

It has been experimentally proven that radiant energy does indeed work, so there is more than just the patent as evidence, if you use your brain instead of your encyclopedia for once, but i've said it a thousand times and I don't expect any of you to get it now or in the future, nor do I any longer care. stop arguing start experimenting. anon —Preceding unsigned comment added by 90.207.189.247 (talk) 16:30, 1 December 2009 (UTC)

Oudin vs Tesla

OUDIN COIL OR RESONATOR

Just what is the difference between an Oudin resonator and a Tesla Coil? In his book, HIGH FREQUENCY APPARATUS 1916 Thomas Stanley Curtis says "Oscillation transformers may be broadly classed under these two headings. The Oudin Coil is in reality an auto transformer, i.e., its primary and secondary are connected together at a neutral point which, in the case of High frequency apparatus, could be grounded. In the Tesla coil, the only connection between the primary and the secondary is an inductive one. The two windings are separate and distinct." (See figure.XX) There is also a third type which is any combination of all of the above.

Found this at http://www.plasma-art.com/goodbadsci.html J. D. Redding 15:14, 8 March 2008 (UTC) [and on not a completely unrelated thing, Utilization of Raidiant Energy 1901 Nikola Tesla youtube.com... thought it was neat, so putting it here ... ]

Yes, that was the initial distinction, an Oudin coil was an autotransformer, with the primary a part of the secondary, usually wound on the same cylinder with heavier wire Martin, p.187-192. The bottom of the primary was grounded. The current was applied to the primary coil with an adjustable tap so that it's frequency could be tuned to match the secondary, which varied with loading as the coil was used Jacoby, p.108. The output was taken across both coils in series. In a Tesla coil, although the two coils may be connected, the output was taken only across the secondary. Not a big difference. In electrotherapy machines, the major use for such coils, the Tesla circuit was used in America, and the Oudin was preferred in Europe, supposedly because it was safer Strong, p.80-86. Oudin coils supposedly produced less powerful sparks but longer streamers (or 'effluvia'). Unfortunately, by around 1920 the definition changed, and any high frequency coil that was unipolar, with one end grounded, was called an Oudin coil, while any bipolar coil, with both ends at high potential, was called a Tesla coil. Ironically, the 'Oudin' coils of that time usually had exactly the same circuit as modern Tesla coils Twining, p.97. Here's an excellent discussion of the differences] by Jeff Behary who owns the Electrotherapy Museum, where you can see dozens of examples of both types. --Chetvorno^TALK 22:23, 20 May 2008 (UTC)

Rm Howto tag? Rm safety disclaimers? Ok by IAR?

I've joined these related sections for a discussion. Milo 10:12, 18 October 2008 (UTC)

Man killed in Pasadena MD by coil

I live in the area, and I had heard a few months ago (early 2008), a man in Pasadena had been killed by his hobby tesla coil. Either way, if anyone happens to find a source for this... I haven't looked. —Preceding unsigned comment added by 71.206.23.209 (talk • contribs) 03:46, 4 June 2008

I searched your area's online newspapers and didn't find anything with the expected keywords.

The next step would be to ask the county coroner's office, but if anyone does so, please post the result back here to avoid that office getting too many unnecessary calls. Milo 02:21, 23 November 2008 (UTC)

Tagged for prescription

I've tagged this article with {{howto}} for the constant safety advice. Articles are not meant to contain such prescription. Our article on crocodiles does not tell readers how to avoid them; we should not be constantly telling people how to behave around electrical equipment. It is unbefitting an encyclopedia and spoils the tone of the article. Chris Cunningham (not at work) - talk 11:27, 10 September 2008 (UTC)

How-to content

This article uses "how-to" descriptions in two different ways: to quote original descriptions, mostly from patent applications, and to in a readable way visualize the quite counterintuitive ways in which one has to proceed to create a Tesla coil. This is not an instruction sheet, nor a manual for constructing a Tesla coil. The "how-to" style in the description of HV equipment is a necessary part of describing extreme high voltage equipment, to avoid fundamental misconceptions as to how such gear is designed.
One can quibble about quoting the gauges of wires used in original patent application, but they do carry meanings beyond the current carrying capacities usually used for choosing gauges, and carry the flavor of the down-to-earth and naive-patent-writer Tesla, who is the central character of the entry.
Removing either of these parts would reduce the theoretical understanding of a Tesla coil, and the personal connection to the man behind the idea.

Thus the "how-to" tag on the entry is incorrect and should be deleted. Niklasdellby (talk) 05:26, 8 October 2008 (UTC)

Safety info discussion

Niklasdellby, I don't think Chris Cunningham was concerned about antique howto, which doesn't much help Tesla coil builders today. I know because I tried to build one from scratch using an antique library book. I put a lot of work into coil winding, but got a lesson in retro unobtainium because I couldn't find a junked Model T Ford trembler coil (photo) (theory and schematic).

IIRC, a Ford trembler coil generates 20 kV at its buzzer interrupter frequency in the audio range with harmonics into the low RF range. I now think it was supposed to drive the primary coil with broad spectrum noise, and so excite RF resonances with with a capacitor built from a stack of cut glass squares interleaved with foil.

CC seems concerned with safety warnings, which I suggest calls for using the Disclaimers tag rather than the Howto tag.

By guiderule, CC is correct about avoiding Wikipedia safety disclaimers. There is nothing that is completely safe (Warning: Drinking too much water can kill you), so there's no certain limit to the number or detail of possible warning disclaimers.

But – maybe lightly informed Tesla coil experimenters make a good case for retaining the safety warning disclaimers under a Wikipedia:Ignore All Rules consensus. Use of WP:IAR must be explained as to why it's better for the readers of this article:

(1) Tesla coil hobbyists who aren't RF techs
Entertainment and technical mysticism attract a lot of non techs to Tesla subjects and closely-related Kirlian photography. I've occasionally read some of this literature and watched the PBS Tesla biography without encountering any of the Tesla coil risks discussed in this article. If someone really did die in a 2008 Pasadena Tesla coil accident, would reading the safety info in this article have prevented it?

(2) RF techs unaware of Tesla coil safety issues.
Am I the only one? I have safely modified conventional power transmitters, but until I read this article, I didn't know that Tesla coils had killed people, maybe recently. I wasn't aware of the random arc conductor effect that reportedly killed showman Henry Transtrom. It's probably a good thing I never found a Ford trembler coil for my Tesla project. I thought the skin effect was protective at all Tesla coil RF operating frequencies. But from this article I've learned that's probably not so at the lower frequencies of the antique Tesla coil I was trying to build. Milo 10:12, 18 October 2008 (UTC) Re-edited 02:21, 23 November 2008 (UTC) & 08:16, 1 February 2009 (UTC)

As interested as I am in Tesla coils as a hobby, this is an encyclopedia and we should work to keep the 'how to' descriptions out. This includes normal (primary circuit) high voltage safety warnings, they don't belong here. I think it needs a little more work so I support leaving the 'how-to' tag on. However, I agree that an exception could be made specifically for the safety discussion about the streamers. This is a (somewhat) unique, notable feature of Tesla coils, and the fact that touching them doesn't cause an electrical shock is interesting; it could be included on that basis. --Chetvorno^TALK 18:02, 22 November 2008 (UTC)

The tag was misapplied. Safety isn't a 'how to', but it might be a disclaimer if it was avoidable. An article subject issue shouldn't be avoided.

Readers know that automobiles can be dangerous, but they typically don't know that Tesla coils can be dangerous. Yet they build and play with Tesla coils (except for glassware testing they are toys). If they later learn the risks, who wouldn't prefer that they had known beforehand? Therefore Tesla coil safety is an article subject issue. Milo 02:21, 23 November 2008 (UTC)

'Safety' section - resistor-capacitor model erroneous?

The paragraph recently added by User:90.230.117.12 describing the flow of Tesla currents in the human body with a crude 'resistor-capacitor' model is erroneous and dangerous. The previous explanation was correct: flow of radio frequency current in the body is more complicated and must be analysed as an electromagnetic wave, with a 'skin effect' calculation. The added paragraph may give people the idea that Tesla streamers are not dangerous. I'm going to remove it. --Chetvorno^TALK 17:02, 22 November 2008 (UTC)

I agree with your removal of that passage [2]. It seems substantially misleading as written and needs a source. But...

Putting aside whether the cellular R-C model correctly applies to the whole body, 90.230.117.12's roundabout technical point is that capacitive current is not cell-heating current, and the higher the RF frequency, the greater the proportion of the current will be capacitive rather than resistive. But at any given frequency and power level, the absolute proportion of resistive cell-heating current may not be safe. Also, the absolute proportion of resistive current increases with higher power Tesla coils, so bigger coils at a given frequency are always less safe.

To be fair to 90.230.117.12, the cellular 'resistor-capacitor' model is not crude. See Gimsa, 1998, "A Unified Resistor-Capacitor Model for Impedance, Dielectrophoresis, Electrorotation, and Induced Transmembrane Potential." Skip the heavy text (which mentions early such research by Fricke, 1925) and find "Figure 2". This is a schematic RF techs will recognize; read the first two sentences of the adjacent figure text. Then find down to "Frequency-dependent properties of the model" and read the first two sentences. Note in the References: Beving, 1994 "Dielectric properties of human blood and erythrocytes at radio frequencies (0.2-10 Mhz)..."

The problem is that Gimsa and Beving are isolated blood cell studies. Unfortunately 90.230.117.12 didn't cite sources for whole body research using this cellular R-C model, so a whole-body R-C model may or not be correct. As you've suggested, this R-C model doesn't take account of the 'skin effect' which becomes whole-body most important with increasing frequency.

Since there are survivable Tesla coil lower frequencies at which there is no substantial skin effect (thanks contributors; I didn't know that), a whole-body R-C model of low-heating RF conduction may have a place in this article if it can be sourced. Milo 02:47, 23 November 2008 (UTC)

The RC model in your Gimsa citation was only used to model the bulk impedance properties of cells, not to suggest that RF current didn't damage cells. (1)The idea that ...capacitive current is not cell-heating current... is simplistic. The component of dissipation due to dielectric polarization occurs everywhere. And Joule heating occurring outside cells is conducted to the inside. At the cell level everything is in close thermal contact. (3)In the Gimsa experiment the applied RF power was a single pulse of 32Vpp, not the hundreds of kilovolts and many watts of dissipation that would be applied by a Tesla streamer. (4)Even if it were true that current did not flow through cells, it could cause damage to cell membranes and other structures. Heating may not be the only mechanism of damage. --Chetvorno^TALK 04:53, 23 November 2008 (UTC)

"The idea that ...capacitive current is not cell-heating current... is simplistic."

Most theories are simplified views. That's why they are distinguished from practice. In the R-C theory model, "capacitive current" means the strict sense of current leading the voltage by exactly 90 degrees. Such current is called "imaginary" because it can produce no heat or do any other work like bond-breaking that would result in known danger at the cellular level.

"The component of dissipation due to dielectric polarization occurs everywhere."

Dissipation is a heating loss observed in practice resulting from a resistive current which leads the voltage by less than 90 degrees - therefore, in the R-C model composed of perfect components, practical dissipation is not the result of "capacitive current" even though it occurs in imperfect physical capacitors.

Otherwise, you seem to be objecting to positions I didn't take. 90.230.117.12 was describing an accepted cellular conduction theory, and I cited Gimsa to prove that and nothing else. I also wrote (Milo 02:47): "at any given frequency and power level, the absolute proportion of resistive cell-heating current may not be safe", by which I referred to the current proportions of the perfect components in the R-C model, no matter where these occur in the body environment. Milo 11:22, 23 November 2008 (UTC)

Sorry, I didn't mean to object to positions you didn't take. I agree with most of your first post above. I was a little wigged out by that paragraph in the article, and the thought that hobbyists would read it and decide that streamers are safe. --Chetvorno^TALK 13:09, 23 November 2008 (UTC)

Tesla's nationality

The nationality of Tesla in the lead sentence has been repeatedly changed from "Serbian-American" to "Serbian" or "Croatian-Serbian". I feel this misrepresents the work and gives the impression the Tesla coil was invented in Croatia or Serbia. Tesla was an ethnic Serb who was born in Croatia, but emigrated and became a citizen of the US and did almost all his work there. The MoS (WP:NAMES) says the nationality should be: "...the country of which the person is a citizen or national, or was a citizen when the person became notable." That would be the US, but I think "Serbian-American" pays tribute to his background while making clear that he did the work in the US. I think it should be changed back. --Chetvorno^TALK 09:58, 3 January 2009 (UTC)

Amen to dialog! If you can't defend your edits, well... Of course, tonight is my annual folly. I don't believe in Wikipedia anymore, mainly because of this article, but it was just the canary in the coal mine. I must say, though, the beginning of it has been fixed up splendidly. At the moment(!)FETSmoke (talk) 08:36, 7 January 2009 (UTC)

Regarding Serbia vs Croatia:

At the time the place of birth was in Serbia, the location now being a part of Croatia:

Nikola Tesla, American scientist of Serbian origin, ... Nikola Tesla was born on July 10, 1856, at Smiljan, in the Military Border zone of Austro-Hungarian Empire, now in the Republic of Croatia. [3].

Leonard G. (talk)

Thanks for the quote. I've added it as a footnote to the article. Milo 20:06, 14 June 2009 (UTC)

Operation

The article states:

In a conventional transformer ... voltage gain is limited to the ratio of the numbers of turns in the windings. However, the voltage gain of a disruptive Tesla coil can be significantly greater, since it is instead proportional to the square root of the ratio of secondary and primary inductances.

The square root of a ratio (>1) is less than the ratio. This statement makes no sense. Must it perhaps be 'square' instead of square root?

82.197.193.84 (talk) 19:44, 5 January 2009 (UTC)

Well, in a non-resonant transformer it is correct to say that the voltage gain is proportional to the square root of the inductances. So for example, the equation for the inductance of a solenoid becomes inaccurate when the number of turns is low (it's lower than the solenoid equation predicts, and the wire diameter becomes significant, so a thicker wire gives an even lower inductance).

However, a Tesla Coil is a double-tuned resonant transformer, so turns ratio and even inductance ratio is almost meaningless. Take a look at [Murikami Equations].

jhallenworld (talk) 23:16, 24 February 2009 (UTC)

Yes! Would somebody please remove this "Square Root" gibberish Gutta Percha (talk) —Preceding undated comment added 22:34, 17 May 2010 (UTC).

Typical Wikipedia entry. Too vague with bad diagrams.

Didn't know how they operated from reading this wiki article so i did an internet search and came up with this other website. Tesla is a simple device really. Just a step up transformer actually.

links
http://www.rb59.com/tesla-coil/tesla-coil.html
http://tesladownunder.com/tesla_coil_4inch.htm
--Ericg33 (talk) 23:36, 29 January 2009 (UTC)

Not just a step up transformer

"Just a step up transformer actually."

Actually it isn't just that. If it was, it would be insignificantly different from a neon sign transformer which operates at a high voltage but a low power line frequency.

A Tesla Coil combines high voltage with high frequency. It took me a long time to figure that out for myself, and I see the intro to the article does not know that defining fact.

rb59.com/tesla-coil completely misses the point of high frequency alternating current resonance, with a description of "a single powerful burst or pulse." Not so. It's a continuous train of bursts of high frequency alternating damped waves, frequency resonant with the coils and capacitor selected, which waves are also transformed to high voltage. Milo 08:16, 1 February 2009 (UTC)

Explain the difference to me. High frequency = high voltage to me.

Frequency and voltage are not related, in general. In a Tesla coil, using high frequencies is part of what helps to get to high voltages, through resonances. Here are some books you can consult. Dicklyon (talk) 06:28, 8 March 2009 (UTC)

TESLA COIL ARTICLE GREAT!

There is needed a museum for Nikola tesla. (His birthdate is remembered in the US as Global Energy Independence Day on July 10th each year!) Maybe with a GIANT Tesla Coil too?! Shoreham Long island – where Tesla had his experimental Wireless Electric transmission station – is the brick building designed by famed Stanford White still standing? Attempts are being made to obtain this building and land to house such a GIANT TESLA COIL! Thanks!, Dr. Edison. —Andre' J. (decdam480921stcent.) Andreisme (talk) 23:59, 8 April 2009 (UTC)

Done! See Nikola Tesla Museum. Enjoy.

(I've taken the liberty of polishing your post for English structure, spelling, punctuation, and typographical errors, so that other editors can better understand and communicate with you. If you object, I or others will restore your original from the page history. Best regards,) Milo 05:09, 9 April 2009 (UTC)

TESLA COIL USED IN TRANSMITTERS ?

The claim that Tesla Coils were used in Radio Transmitters is dubious at best.

Certainly Rumkopf coils were used in early Spark Transmitters, and of course Resonant Transformers were used in later narrower band Tx's (and still are), but Tesla High Voltage coils have no meaningful role in radio transmitters. Induction coils (Rumkopf ) and Electrical Resonance (Lodge, Hertz, etc) clearly predate Tesla's work. Gutta Percha (talk)

I am not a starstruck fan of Tesla who believes he invented everything, as are many contributors to this page. However, Tesla coil circuits were definitely used in the early spark-gap wireless telegraphy transmitters as detailed in the references below. The high voltage, high turns ratio Tesla type coil was needed for an efficient impedance match with the low capacitance of the antenna.

Perhaps a more important point, however, is that although many of the wireless spark-gap transmitter circuits that were used in the early 20th century were invented by other people besides Tesla, such as Hertz, Lodge and Marconi, today all those designs could be called "Tesla coil circuits". They were all resonant transformers, excited by a spark gap, with the primary tuned by a capacitor and the secondary tuned to resonance by the parasitic capacitance of the antenna.--Chetvorno^TALK 07:53, 29 October 2009 (UTC)

You site some impressive references, but nowhere do you prove that the resonant transformers in spark transmitters were referred to as "Tesla Coils". Historically they were referred to as "jiggers", and more recently, simply as RF transformers or Tank Coils. The electrically short antennas used at VLF were brought to resonance by Loading Coils, and have a low impedance feed point. As before, high voltage Tesla coils have no place in driving a low impedance antenna. Gutta Percha (talk)

I think this is partly a semantic misunderstanding. The content in question says: "Tesla coil circuits were used commercially in spark-gap radio transmitters...", not that modern type Tesla coils themselves were used. The statement is sourced and I believe accurate, as confirmed by these sources 1 2 3 4 from the wireless telegraphy period. --Chetvorno^TALK 19:07, 17 May 2010 (UTC)

A "Tesla Coil" is a specific arrangement of standard components arranged to develop very high voltages at an elevated node. A Spark Gap transmitter is a similar collection of components but assembled in a different manner. It's purpose is to generate an high RF current in a long elevated wire. No knowledgeable engineer will refer to a Spark Gap Transmitter as a "Tesla Coil" because their functions are completely different and describe a different configuration. Gutta Percha (talk)

You make some good points which I agree with. As you say, the purpose of the circuits is different; the modern Tesla coil to produce maximum voltage, the spark-gap transmitter to produce maximum current in a long antenna. And I was wrong; the antenna and feed has low impedance, as you say. So the spark transmitter didn't have the large turns ratio the Tesla coil does, it had a smaller secondary to resonate with the larger capacitance of the antenna. But both use essentially the same circuits. Look at this 1 common spark transmitter circuit. Also 2 3 4. The coils in transmitters using Tesla type circuits, which Marconi called 'jiggers', were referred to as "Tesla transformers" by the radio researchers of the time; see refs above.

Here are supporting citations: "The spark gap transmitters used in the early days of radio development were essentially Tesla coils" Mitch Tilbury (2007) The Ultimate Tesla Coil Design and Construction Guide, "The principle of the Tesla coil is that of the oscillating transformer used in all spark transmitters..." Rolla Ramsey (1937) Experimental Radio, 4th Ed., "A Tesla coil is essentially a radio transmitter without the antenna" Julien Sprott (2006) Physics Demonstrations: A sourcebook for teachers, "Unfortunately, the common misunderstanding by most people today is that the Tesla coil is merely a device that produces a spectacular exhibit of sparks which tittilates audiences. Nevertheless, its circuitry is fundamental to all radio transmission" Peter Belohlavek (2008) Innovation: The Lessons of Nikola Tesla --Chetvorno^TALK 20:41, 18 May 2010 (UTC)

Resonant Transformers were well known before Tesla, so why call them Tesla Coils? Find me a reference from a contemporary (eg 1900's) engineering text and I'll believe you. Please don't waste our time with quotes from modern Pro-Tesla publications.

The point I am trying to make is that the coils in a Transmitter are merely high powered versions of those in a simple Crystal Set. A quick Google Book search on the term "Syntony" will give many early texts which describe how the need for resonant circuits in both RX and TX was understood very early on. Even Hertz understood (and demonstrated) the relationship between Wavelength and Frequency and L/C tuning.

Tesla did a wonderful job of demonstrating the huge voltage gain that can be achieved in unloaded resonant circuits, however almost nothing he developed was useful to those working in the field of Radio. Gutta Percha (talk)

I've already given 5 references from the early 1900s. For example "A type of transformer used specially in the so-called extra powerful [wireless] stations to transform to high potential the alternating currents furnished by one of the ordinary alternators is that of Tesla, as shown in fig.93." Domenico Mazzotto (1906) Wireless Telegraphy and Telephony, p.146 (Fig.93 shows a circuit identical to modern Tesla coils) Resonant transformers were not used in wireless transmitters before Tesla; that was his contribution, or at least he was the main contributor. The US Supreme Court in 1943 gave priority to Tesla's 1893 patents for resonant transformer wireless systems over Marconi's. I agree there are a lot of pro-Tesla publications that ridiculously exaggerate his accomplishments, but this seems to be the opinion of respectable, unbiased works like Sarkar's on Tesla's contributions to radio. --Chetvorno^TALK 18:31, 19 May 2010 (UTC)

The Mazzotto reference proves my points nicely: (1) That while Tesla did experiment with resonant transformers, so did many others, and a number of these predate Tesla. While a book may point to a specific coil and call it a "Tesla Coil", the term never came into general usage in this context. Marconi's term "Jigger" however did become universal. (2) That the modern style (High Voltage) Tesla Coil has no place in a Transmitter. Gutta Percha (talk)

The content you began this thread objecting to doesn't say any of that. It says "Tesla coil circuits were used commercially in spark-gap radio transmitters...". I think the truth of this sentence has been amply confirmed by our discussion. --Chetvorno^TALK 08:47, 20 May 2010 (UTC)

The sentence implies that (1) all Spark Gap Transmitters used Tesla coils (2) and that the modern form of Tesla coil was used. Both statements are clearly wrong.

To be acceptable the sentence should read something like "The coils in Tesla's designs could be called Tesla coils (but not those in other builder's designs) and the coils that Tesla used were not the ones we now call Tesla coils".

It would be simpler to abandon this nonsense altogether. Gutta Percha (talk)

Sorry, when was the earliest resonant transformer? Who invented that?- Wolfkeeper 15:35, 20 May 2010 (UTC)

Tesla. He patented an air-core spark-excited resonant transformer circuit in 1891 (US patent #454,622) 1, 2, p.268 --Chetvorno^TALK 18:14, 20 May 2010 (UTC)

Well, that's what I thought as well, but Gutta seems to be claiming there's prior art on that. Aren't Ruhmkorff coils non resonant? Isn't resonance the key idea of radio?- Wolfkeeper 18:29, 20 May 2010 (UTC)

Yes, Ruhmkorff coils are nonresonant. As Gutta says, other researchers besides Tesla such as Lodge and Braun introduced resonance (called "syntony" at the time). Tesla's contribution was applying resonance to transformers, which allowed the energy in a tuned circuit to be coupled efficiently into an antenna. 1 See the quotes from Tilbury, Ramsey, and Sprott above. --Chetvorno^TALK 18:55, 20 May 2010 (UTC)

Oh dear, where to start? It is not necessary for the transmitter output stage to be resonant. The earliest TXs and RXs were unashamedly broadband and were not resonant. Modern Transmitters also have broad-band output stages (Tuning and Loading controls have long disappeared). Certainly energy can be coupled efficiently into antennas without a resonant transformer.

Tesla needed resonant transformers because of his unique application. He needed an air-core to prevent high voltage breakdown. Resonant output transformers made early radio design easier, but they were not essential. They are not often used today.

Consider the TV Line-Output Transformer. Tesla fans have long claimed this as an application of the Tesla coil. But in fact the Line-Output Trans is broadband. It uses flyback pulses to generate the high voltage, not resonance. Nothing to do with Tesla.

Who invented Resonant Coils and Transformers? Henry and Savery did the ground work. Lodge was probably the first to use tuning in a transmitter. But most of the work was done in the early days of Telegraphy and Telephony where frequency division was used to enable long wire lines to carry multiple signals. As always, long-line telephony was way ahead of everybody else.

Even Hertz understood (and demonstrated) the effect of tuning on wavelength.

The bottom line is this: A simple crystal set uses Resonant Transformers. Why don't the Tesla Fans claim that Tesla invented the Crystal set? Gutta Percha (talk)

It's not always necessary for the output stage to be resonant; but it's always necessary for a transmitter to be resonant somewhere; otherwise it wouldn't have a carrier wave. Tesla was the first one to produce a practical system for producing strong carrier waves.- Wolfkeeper 13:26, 21 May 2010 (UTC)

Doing ground work is not the same as doing the work. Tesla invented the resonant transformer.

Tesla did invent a form of crystal set.- Wolfkeeper 13:26, 21 May 2010 (UTC)

And the article doesn't claim that Tesla circuits were the only ones or the first ones used in spark transmitters - they weren't, although they became the dominant type. It only claims they were used. --Chetvorno^TALK 15:09, 21 May 2010 (UTC)

" ...the article doesn't claim that Tesla circuits were the only ones or the first ones used in spark transmitters".

Hooray, at last! I'll edit the article to reflect that position.

And Wolfkeeper, I have a transmitter with a DDS generator and a Broad-band output stage. Not a tuned circuit in sight. And then there is TDMA, CDMA and UWB ... Gutta Percha (talk) —Preceding undated comment added 01:55, 22 May 2010 (UTC).

Yes, DDS = Direct Digital Synthesis = clocked digital logic, where the clock is usually a quartz crystal. You might like to remind yourself what a clock really is, and the significance of the term q-factor, and think about quartz crystals' notably high q! ;-)- Wolfkeeper 02:11, 22 May 2010 (UTC)

True, I got carried away, but we were clearly talking about Output Stages. Gutta Percha (talk) —Preceding undated comment added 03:28, 22 May 2010 (UTC).

Formatting issues

There are giant white textless areas in this article currently. The images should be reformatted somehow so that the text is uniform. 128.84.195.68 (talk) 18:38, 14 November 2009 (UTC)

Singing Tesla Coil merge

I think this article should be merged here, as it is simply a modification of a tesla coil and I don't think it appears notable enough for a separate article. Jhbuk (talk) 14:47, 4 January 2010 (UTC)

John Freshwater

Is the thing about John Freshwater really necessary in this article? I mean, I don't have a HUGE issue with it being in here, it just seems more like trivia as opposed to anything informative. 151.207.240.4 (talk) 17:17, 8 March 2010 (UTC)

Irrelevant reference

Reference 45 (to a Yahoo Groups discussion entry by a Konstantine Meyl) is irrelevant to the topic here, and is certainly not a publication in any meaningful sense. The section seems to have been put in only to provide a link to the reference rather than to contribute to or illuminate this article. I'll remove this for now if I can, but I encourage the regular maintainers of this article to follow up. 128.114.130.144 (talk) 02:08, 1 December 2010 (UTC)David Smith

removed by poster

Article too hard to understand

I gave the article template "Too technical" template, because I think this article is hard to understand for someone who is not an expert in this field. The article says its a type of 'resonant transformer' and I click the link to this article with the name 'Resonant inductive coupling' and that word means even less to me. Maybe we should change those hard-to-understand-words like 'resonant transformer' and 'Resonant inductive coupling' with the words which would get more clue to somebody reading it. 188.230.174.229 (talk) 19:56, 20 November 2011 (UTC)

The basic principle of capacitor-inductance resonance may help a layman's understanding

A capacitor is a device that can store electrostatic charge. It consists of two plates of electrical conducting material separated by insulating material. When a battery is connected to a capacitor it will become charged. A coil made of conducting material such as copper wire, will generate electricity when a magnetic field pass through it. When a charged capacitor is connected to a coil, the charge on the capacitor's plates flows as a current through the coil and a magnetic field develops around the coil until the capacitor loses its charge. At this time, the magnetic field around the coil begins to collapse and the collapsing field generates an electric current, but with reversed polarity. This current from the coil recharges the capacitor. Once the capacitor is charged, the cycle repeats until such time that the alternating current between capacitor and coil reduces to 'zero' due to losses in the circuit. The frequency of oscillation depends on the values of capacitance and inductance. The astute reader may ask: "When the current first flows through the coil, does it not create an electric field and hence generates an electric current?" Yes it does and this is known as "back-emf" but it is less than that of the capacitor driving the current. With this simple arrangement, the alternating current (AC) will in practice only last for a very short duration. Tesla's arrangement of coils and capacitors permit in effect a means of keeping the "primary capacitor" topped up with electrostatic charge so that the AC is maintained indefinitely. GeorgeHY (talk) 13:30, 18 December 2011 (UTC)

Popularity: MIDI & Microcontroller not significant to sound generation with Tesla Coils

This section mentions the tesla coil midi system that was built and shown on "America's got talent" (and by many others) and includes specific details such as the midi and microcontroller (Zeusaphone solution) which are not significant to the generation of sound with telsa coils, the wording here is very misleading implying that the midi protocol or microcontroller are significant. The note that the microcontroller takes digital data (i.e. midi signals) and outputs a PWM signal just shows that the tesla coil "speakers" are being driven by a pseudo-analog input. BrainSlugs83 (talk) 21:48, 9 February 2012 (UTC)

This article needs a complete rewrite

I am very unhappy with the current state of this article. It confusingly talks about several circuits which may or may not actually contain tesla coils, without ever stating what exactly a tesla coil is. It is woefully short on theory. It trivializes the device as mere entertainment. It is a hodgepodge of "fun" trivia that has little reason for being in an encyclopedia. It looks like what it is: a mishmash of remarks on an ill-defined subject.

It should start by stating unambiguously what a tesla coil actually is: two air-core coils, a long inner primary one and a short outer secondary one concentric around the inner one.

Then it should state what a tesla coil is used for: generating high voltages at high frequencies, when properly driven by a tuned circuit. Typically, output amperage is minimal in demonstration devices for safety sake, though this is not inherent in the device itself. (Experimenter Donald Lee Smith claims that positioning the secondary coil near the center of the primary instead of at the end results in high amperage.) Such high voltage, high frequency electrical potential can be used for broadcast and power transmission purposes, etc.

It might usefully state what similar or easily confused things are not tesla coils and how they fail to qualify as tesla coils, with references to articles for those other devices.

Then there should be a theory of operation section that employs suitable equations to relate the characteristics of the required input and the coil configuration parameters to produce a specific output.

A History section should include Tesla's own uses and proposed uses for the device as well as other notable later developments in experimentation and application (not mere demonstration and entertainment).

A Popular Culture section covering demonstration and entertainment uses should in no way be allowed to dominate the article. In no way should the importance of such a fundamental electrical device be trivialized.

Dlw20070716 (talk) 19:40, 7 March 2012 (UTC)

I agree it sure needs a rewrite. Just a heads-up: edits to this article attract long contentious arguments and edit wars. A lot if it was written by hobbyists who have strong opinions but not much theory, as well as Tesla groupies, and "alternative energy" and "broadcast power" fanatics who are convinced Tesla had the secret to transmitting power wirelessly around the world. BTW, current usage of the term "Tesla coil" refers to both the coil and the exciting circuit. --Chetvorno^TALK 20:00, 7 March 2012 (UTC)