Talk:Wireless power transfer/Archive 4

Thank you for consenting to the inclusion of "laser induced plasma channel" in the article.

The laser plasma channel technique . . . is not "coupling" . . .

Pardon me Sir, you are mistaken.  Coupling, in the present context, is the transfer of electrical energy from one circuit segment to another.  For example, electrical energy can be transferred from a power source to an electrical load by means of conductive coupling.  The laser induced plasma channel technique depends upon electrical conduction through plasma created by the ionization of air.  This means the transfer of electrical energy from a power source to an electrical load using the laser induced plasma channel technique is "coupling."  In fact, energy transfer from a transmitter to a receiver by means of far-field electromagnetic radiation is also "coupling" as defined by this encyclopedia (see Coupling (electronics)).

[The laser plasma channel technique] does depend on radiation, so it does not belong in a "Non radiative coupling" section.

While it is true that a laser is used to thermally ionize the air, creating a conducting channel, the actual transfer of electrical energy is by electrical conduction through plasma.  Electrical conduction is neither a near-field nor a far-field phenomenon.  It is the bound-mode propagation of electromagnetic field energy guided by an electrical transmission-line.

There is already a "Lasers" section, . . . [laser induced plasma channel] belongs there.

As for its placement in the "Lasers" section under "Far-field or radiative techniques," the laser induced plasma channel technique is neither far-field nor is it radiative, as explained above.  Neither is it near-field.  It is the propagation of electromagnetic field energy guided by a transmission-line.  With all of this in mind, do you consent to my creation of a new section under the "Near-field or non-radiative techniques" heading titled "Electrical conduction" and my placement of "Laser induced plasma channel" therein?

GPeterson (talk) 22:36, 25 October 2015 (UTC)

No.

• "Coupling, in the present context, is the transfer of electrical energy from one circuit segment to another"

No, in the context of electrical engineering and particularly the context of this article, "coupling" means inductive or capacitive coupling, not conduction. Would a person say "I coupled my extension cord to the wall socket"? "Connected" is the word. This entire article has carefully been written to use the word "coupling" for near-field induction effects, so that beginning readers can understand the correct usage. Placing a technology that doesn't have those limitations in the "Near field" section is going to destroy that work and confuse readers. It would make half the "Field regions" section erroneous. "Laser induced plasma channel" is not limited to the near field.

• "Electrical conduction is neither a near-field nor a far-field phenomenon."

Then why should it be put in the "Near field or nonradiative" section? Even if the actual transfer of energy is by conduction, the laser beam that creates the plasma channel is a "far field" electromagnetic wave, and it's range is limited by the same inverse square law as all the other beam technologies in the "Far field" section. The section can explain that the power transfer does not drop with distance like other beam technologies. Besides, we already have a "Lasers" section. Putting "Laser induced plasma channel" somewhere else is going to be confusing to readers.

--Chetvorno^TALK 01:37, 26 October 2015 (UTC)

Dear Sir,

This is the proposed section rearrangement.  It addresses many of the organizational issues that have been raised.

        3 Non-radiative techniques
                3.1 Near-field electromagnetic induction
                      3.1.1 Resonant magnetic coupling
                      3.1.2 Resonant capacitive coupling
                3.2 Electrical conduction
                      3.3.1 Plasma beam coupling [wireless transmission by electrical conduction through plasma]
                      3.2.2 Surface wave transmission line coupling [wireless transmission across planar conducting surface]
                3.3 Magnetodynamic coupling
        4 Far-field radiative techniques
                4.1 Microwaves
                4.2 Lasers .

In response to my comment that electrical conduction is neither a near-field nor a far-field phenomenon you wrote:

Then why should it be put in the "Near field or nonradiative" section?

"Electrical conduction" will not be placed in a "Near field or nonradiative" section.  The "Near field or nonradiative" heading will be changed to "Non-radiative techniques."  Under that will be placed the "Electrical conduction" sub-section in which will be placed "Plasma beam coupling" (wireless transmission by electrical conduction through plasma).

Even if the actual transfer of energy is by conduction, the laser beam that creates the plasma channel is a "far field" electromagnetic wave, and it's range is limited by the same inverse square law as all the other beam technologies in the "Far field" section.  The section can explain that the power transfer does not drop with distance like other beam technologies.

Wikipedia does not publish original thought: all material in Wikipedia must be attributable to a reliable, published source.  Articles may not contain any new analysis or synthesis of published material that serves to reach or imply a conclusion not clearly stated by the sources themselves.

Besides, we already have a "Lasers" section.  Putting "Laser induced plasma channel" somewhere else is going to be confusing to readers.

A hypothetical person being 'confused' is no justification for placement of the electrical-conduction-method "Plasma beam coupling" technique under the wrong section heading.  I'm mindful of a fellow editor's admonition that Wikipedia is a reference work and does not dumb down.  To do so is to enter on to a slippery slope that, even if inadvertently, can lead to the introduction of inaccuracies or worse, the alteration of facts.

In the context of electrical engineering and particularly the context of this article, "coupling" means inductive or capacitive coupling, not conduction.  Would a person say "I coupled my extension cord to the wall socket"?  "Connected" is the word.

It would be correct to say, "The electrical energy coming from one of the building's exterior wall outlets is being coupled to the distant circular saw through the hard-wire extension cord."

This entire article has carefully been written to use the word "coupling" for near-field induction effects, so that beginning readers can understand the correct usage.  Placing a technology that doesn't have those limitations in the "Near field" section is going to destroy that work and confuse readers. . . .

Once again, a hypothetical person being 'confused' is no justification for placement of the "Plasma beam coupling" technique in the wrong section, nor is it an excuse for the introduction of inaccuracies.

Remember, Wikipedia is a reference work and does not dumb down.

It would make half the "Field regions" section erroneous.  "Laser induced plasma channel" is not limited to the near field.

I'm sorry the structure of the rewritten article is based upon multiple faulty premises.  This particular one is a matter of global consistency.  Electronic coupling is clearly defined.  As Editors we should not modify well-established definitions to make them conform with our personal beliefs vis-à-vis the content of an article.

I'm willing to help you straighten things out, if you'll let me.  Please consider allowing me to resume full and unimpeded participation in the development of Wireless power.  We are close to having an encyclopedic article deserving of a B-Class or perhaps a GA-Class energy article rating, rather than the Category:C-Class rating that it presently holds. 

Most sincerely,
G. L. Peterson
GPeterson (talk) 04:12, 29 October 2015 (UTC)

No one is hindering your "full and unimpeded participation" in the article, but changes to the article need to be based on sources, not unsupported opinions. The article has not been "dumbed down" in any way. The division of wireless power technology into "far field" and "near field" regimes, and the division of the latter into "inductive coupling" and "capacitive coupling" is thoroughly sourced in the article; for example Sun and Valchev. There is no support in mainstream WP:RSs for an "Electrical conduction" or "Surface wave" section; they have been thoroughly discussed above on this page and have been rejected repeatedly by a consensus of editors. The many, many previous times you have inserted these sections they had to be removed because they contained your pseudoscientific WP:FRINGE WP:OR theories.

As I mentioned above, the source justification for inclusion of the "laser induced plasma channel" material in this article is marginal at best; it does not appear in mainstream wireless power texts, and none of the sources refer to it as a "wireless power" technology, only as a directed-energy weapon. It might be better moved to other articles. It certainly does not justify any change to the article's structure. --Chetvorno^TALK 14:09, 29 October 2015 (UTC)

I have to say writing this stuff is dirt simple, you look up some well regarded authors writing on this general topic that covers all these methods and cite him/her chapter and verse. Looking through this discussion I see zero citations by GLPeterson that could even be loosely be considered reliable secondary sources on this topic. The fact that only primary sources are being put forward and a debate is being pushed based on the perception that other editors are failing to divine their meaning points to a massive misunderstanding of Wikipedia somewhere. That sentiment is further reinforced by GLPeterson's statement "Wikipedia is a reference work and does not dumb down". errr...no. Wikipedia is a referenced work (it is based on references), it is not a "reference work" per WP:NOTTEXTBOOK. We do not pull together all these modes and say "I think that is wireless power, see this paper proves it"...... not our job. The citation has to be to that authoritative author who has pulled together information on all these modes and made the direct statement "this is a form of wireless power". Citing Wikipedia:Consensus is fine but you can never push consensus past the base consensus cited in every edit window that content must be verified to some other author that has a recognized valid overview of the topic. Fountains of Bryn Mawr (talk) 15:05, 29 October 2015 (UTC)

Yeah, that's right. Deleted the "Laser induced plasma channel" section. --Chetvorno^TALK 16:51, 29 October 2015 (UTC)

Wikipedia is not a reference work per WP:NOTTEXTBOOK.

Wikipedia is an encyclopedic reference (per WP:NOTTEXTBOOK).  A reference work is a book or periodical (or its electronic equivalent) to which one can refer for confirmed facts. [Farlex. "The Free Dictionary by Farlex". Retrieved 2 May 2012.]  Reference works include dictionaries, thesauruses, encyclopedias, almanacs, bibliographies, and catalogs (e.g. catalogs of libraries, museums or the works of individual artists). [The University of Santo Tomas Miguel de Benavides Library. "The Reference Materials". Retrieved 3 May 2012.]  Wikipedia is a reference work.

There is no support in mainstream WP:RSs for an "Electrical conduction" section.

Here is reliable source justification (per WP:RS) for inclusion of "Electrical conduction" and "Plasma beam coupling" in Wireless energy transmission:

ref name="Giulietti"
Giulietti, Antonio; Ledingham, Kenneth (2010). Progress in Ultrafast Intense Laser Science, Vol. 5. Springer Science and Business Media. pp. 111–114. ISBN 3642038603.

ref name="Rakov"
Rakov, Vladimir A.; Uman, Martin A. (2003). Lightning: Physics and Effects. Cambridge Univ. Press. pp. 296–298. ISBN 0521035414.

ref name="Franklin"
Franklin, Steve (2015). Non-Lethal Weapon Handbook. Digital Services. pp. 161–162.
 
ref name="WiseGeek"
"Electrolaser". WiseGeek website. Conjecture Corp. 2015. Retrieved October 25, 2015.

ref name="Kaneshiro"
Kaneshiro, Jason (June 21, 2012). "Picatinny engineers set phasers to 'fry'". News Archives. US Army official website www.mil.gov. Retrieved October 25, 2015.

ref name="Lawrence"
Lawrence, Jonathan R.; Waugh, D. (2014). Laser Surface Engineering: Processes and Applications. Elsevier. pp. 456–460. ISBN 1782420797.

ref name="Forestier" 
Forestier, B.; Houard1, A.; Revel, I.; et al. (2012). "Triggering, guiding and deviation of long air spark discharges with femtosecond laser filament". AIP Advances. 2. American Institute of Physics: 012151. doi:10.1063/1.3690961. Retrieved October 25, 2015. {{cite journal}}: Explicit use of et al. in: |first3= (help)CS1 maint: numeric names: authors list (link)

ref name="Clerici"
Clerici; et al. (June 19, 2015). "Laser-assisted guiding of electrical discharges around objects" (PDF). Science Advances. Amer. Assoc. for the Advancement of Science. doi:10.1126/sciadv.1400111. Retrieved October 25, 2015. {{cite journal}}: Explicit use of et al. in: |last1= (help)

GPeterson (talk) 14:42, 30 October 2015 (UTC)

Looked at the sources and they are about "laser lightning rods" and other methods of laser triggered electrical discharge. The reliable source about this being a system to deliver wireless power is where? Fountains of Bryn Mawr (talk) 15:31, 30 October 2015 (UTC)

(@Fountains of Bryn Mawr:, these are the sources I added to the "Laser induced plasma column" section to satisfy the requirement for secondary sources, some of them being secondary.) Yes, GLPeterson, none of these say anything about "wireless power". --Chetvorno^TALK 16:18, 30 October 2015 (UTC)

Still in "dirt simple" modes running through these sources ;). All that has to show up is a source on using these things in "wireless power" and we are golden, could even be an edit noting its a new process being explored. It may be there and I am missing it. Fountains of Bryn Mawr (talk) 19:04, 30 October 2015 (UTC)

All that has to show up is a source on using these things in "wireless power" and we are golden . . .

Wireless energy transmission technology can be intended either for wireiess power or wireless telecommunications. When a source states the technology is used for detonating unexploded ordinance, it becomes clear the author is not writing about its use for telecommunications.

Shooting lightning bolts down laser beams is just what a device being developed at the Picatinny Arsenal military research facility in New Jersey is designed to do. . . . When [the lightning] hits its target – an enemy vehicle, person or unexploded ordnance, for example – the current will flow through the target as it follows the path of least resistance to the ground, potentially disabling the vehicle or person and detonating the ordnance. The lightning will also deviate from the channel when it gets close to the target and finds a lower-resistance path to the ground."^[1]

1. [1]

   Kaneshiro, Jason (June 21, 2012). "Picatinny engineers set phasers to 'fry'". news Archives. US Army official website www.mil.gov. Retrieved October 25, 2015.

. . . could even be an edit noting its a new process being explored.

Done.

GPeterson (talk) 02:55, 17 January 2016 (UTC)

I have started to bring large contributions to a field I know quite well and teach but these contributions were deleted. To be honest I am a bit disappointed as my personal(patented and long published)work is also presently being used with unappropriated explanations, links and comments. I admit that a lot of references were missing in my recent contribution but if others didn't add them, I planned to do it soon. The main ideas that are missing according to me (and were deleted)are:

In the whole near-field section: - The simplest form of coupling for near and far field (in both cases electric and magnetic) is to consider two distant dipoles. For near-field not only longitudinal coupling is allowed but it also gives a coupling coefficient twice larger at the same distance. The longitudinal/transverse separation arises from general theoretical considerations. The transverse field is associated to wave propagation whereas the longitudinal one is associated to the Coulomb's force and can be shown to propagate instantaneously (however energy always propagates at the speed of light due to the transverse aspect of it, see for instance the QED book written by the Nobel Prize Claude Cohen Tannoudjy). A way to describe simply the situation is to consider the direction of the Energy flow and to compare it to the dipoles orientation.

- Another missing concept is the coupling coefficient importance (the represented situations only involved the perfect case k=1). If getting into details is not possible here, a small sentence such as "ideal coupling case" could be used. I also added an important explanation for the importance of Quality factors in general (for both magnetic and electric couplings) showing that they do not modify the link itself (that is described in both cases by a coupling matrix involving self and mutual coefficients), that section was also inappropriately deleted.

In the capacitive coupling section:

- Tranverse and longitudinal are indeed the right expressions to be used. - Same for the picture used for illustration in the k=1 case. - The "said" unipolar configuration is extracted from patents (mine and many others) with a very indirect reference made to Markus instead of the original sources (this is OK Markus article is fine).

- I also tried to remove health issues arguments that reminded me the times where Edison electrocuted elephants in public to show that Tesla's alternating currents were dangerous. I think this page is not the appropriate place for discussing such polemic content.

- In near-field non radiating situation, the use of words such as emitters, receivers should be removed and replaced by generators and loads (or primary and secondary coils for instance). The idea of evanescent field is also inadequate in situations where there is little power radiated away and only multi-poles field exist, unless you think that the Coulomb's field is an evanescent one !

In the rest of the page: - It will be better according to me to introduce resonant induction coupling without referring to the special MIT design that add air transformers only for impedance tuning reasons (an usual transformer could be used instead). A basic schematic only representing two serial LC circuits coupled via their mutual inductance would be a lot better. More generally, the difference between non resonant and resonant coupling is only a question of technology, as explained before the wireless link itself is unchanged (see what was deleted for more explanations). — Preceding unsigned comment added by Henri BONDAR (talk • contribs) 13:25, 18 January 2016 (UTC)

Sorry to be late answering this. I appreciate your expertise, it is great to have a researcher from the field working on the article. I was too hasty in reverting all your edits, sorry. But I have some issues with the changes you made.

Keep in mind that Wikipedia is a general-readership encyclopedia. Wikipedia guidelines say to keep specialized technical WP:JARGON down, explain jargon, and use terms consistently throughout the article. For example the terms "transmitter" and "receiver" are generally used in wireless power literature for the two parts of the system, these are explained in the introduction. If we change "transmitter" to "generator" as you suggest, I know from experience this will cause an enormous amount of reader confusion with electric generators. Similarly, if we replace the term "receiver" with "load", what do we call the electrical device which consumes the power? The term "dipole" is another piece of jargon that needs a few words of explanation. In the description of the scaling laws at the beginning of the "Near field" section, you replaced the more accurate expression D_range/D_ant which used parameters defined in the previous section, with an undefined variable r. Here are my feelings about your remarks above:

• I agree I was too hasty in reverting the terms "transverse" and "longitudinal" for the two types of capacitive coupling, but they are going to be confusing to general readers. You are using these terms in a somewhat different sense than they are used in the introduction to the "Near field" section, where they refer to the relation of the field direction to the axis between transmitter and receiver. In capacitive coupling I think the terms "bipolar" and "unipolar" are also used for these two circuits, and should be in there as a less confusing alternative to "transverse" and "longitudinal". From an engineering perspective, in the latter circuit the receiver has a single (unipolar) capacitive plate that must be interfaced with the transmitter; in the former two plates.
• On the health issue, electric fields have significantly different effects on living things than magnetic fields. In applying a technology, its safety and health effects certainly must be considered. Note the section does not say capacitive coupling has been abandoned, merely that it has not been used in high power applications (or really any applications) yet. BTW, the 1903 electrocution of Topsy the elephant had nothing to do with the Tesla/Edison War of the Currents, that is a myth.
• I agree that the MIT experiment is overemphasized in the "Resonant inductive coupling" section, although I'm not sure all mention of it should be eliminated. When I wrote this section I just happened to have a block diagram of the MIT experiment so I put it in. I agree a better illustration would be a generic circuit, I will try to draw one up. Are serial tuned circuits used more commonly than parallel in both transmitters and receivers?
• I agree about the importance of the coupling coefficient. The Wireless power#Inductive coupling section introduces it and notes that the link efficiency is proportional to k². I was going to include the equation for the general link efficiency as a function of coupling coefficient and tuned circuit Qs but didn't get around to it.
• The addition at the beginning of the "Near field" section on the coupling difference between longitudinal and transverse dipoles is interesting but pretty obvious as far as inductive coupling goes; that is why the transmitter and receiver coils' magnetic axes are always oriented collinearly, "longitudinally". Also at the proximity at which inductive and capacitive coupling operate, to generalize the fields as dipole fields is quite an oversimplification, isn't it? To calculate the coupling accurately, you need the actual fields of the coils or capacitor plates. Also the supporting citations are both research papers. These are not technically enough support; Wikipedia requires WP:PRIMARY SOURCEs to be backed up by secondary sources, see WP:PSTS.

--Chetvorno^TALK 19:29, 23 January 2016 (UTC)

In the non-radiative near-field section, I have planned to add soon some brief considerations concerning coupling coefficients and also to explain simply how resonance associated to large Q-factors improves the performances without modifying the link itself (the coupling coefficient depends only on geometric consideration or equivalently on self and mutal inductance or capacitance). I also think that the resonant induction could be introduced in a simpler manner (two distant coils in series with two capacitors), as it is used in most applications (Witricity uses a special patented design involving air transformers on both sides mainly for impedance adaptation reasons that can be presented as a sub-case). The same general schematic is used in many recent papers for coupled capacitors (whatever the physical implementation), the coupling coefficient "k" is figured between the two capacitors instead of between the two coils. By the way, the transverse capacitive configuration (not known as such), was introduced for power transfer by a New-Zealand guy a long time ago, but most recent articles do not even mention his name, can you help to clear that point. Finally they have been recently a few proposal based on radiative near-field techniques in the GHz frame (using for instance the phase conjugation technique to focus energy on loads), I think they deserve a section in the Wireless power page. Finally, I think that the best presentation should not separate induction and resonant induction, or the same classification should be applied to capacitive and resonant capacitive. A section Radiating near-field could be added instead, leading to a more satisfying classification of devices according to frequencies and sizes :

• Far-field (always radiative)
• Radiating near-Field
• Non-radiating near-fields (with electric and magnetic sub-cases)

Besides, I am thinking on a Galilean Electromagnetism page Draft:Galilean_electromagnetism that could be used for an elegant introduction for Quasi-Electrostatics and Quasi-Magnetostatics, your contributions will be appreciated.Henri BONDAR (talk)

Sounds interesting. I have never been satisfied with the explanation for resonance-enhanced power transfer currently in the article, which I got from the Kur paper: "...high Q factor resonators exchange energy at a much higher rate than they lose energy due to internal damping...". If you can come up with a better way to explain this to introductory readers, fantastic.

• On the tripartite (far-field, radiating near-field, non-radiating near-field) field model, isn't that only relevant to electrically large antennas? That would mean frequencies in the GHz. Are there any near-field applications that use such high frequencies? When I originally wrote the "Field regions" section I elected not to go into that model, in the interest of keeping the explanation simple, but I guess it could be added.
• I agree that resonance is a standard technique used in almost all wireless systems now, and it doesn't make sense to have a separate section for resonant inductive or capacitive coupling.
• Can you give a link to one of the papers that uses the "general schematic" for capacitive power transmission you mentioned? (you can add an external link by putting the URL in single square brackets).

My main interest is in keeping the article as understandable as possible for nonexpert readers. These, of course, are going to be the vast majority of readers coming to this page.

Cheers, Chetvorno^TALK 22:28, 23 January 2016 (UTC)

For the general aspects of the non-radiating near-fields see https://www.dropbox.com/sh/765ig8ksoqo0934/AAD54qcUgl6BvV3ralooQfvaa?dl=0

Be careful with Liu's work as it always avoid to cite its true sources (as many others) and they are many old works that use the same formalism to describe the capacitive coupling. In the Furukawa paper (they have recently reached 1kW in a transverse capacitive design) you will find the appropriate "T model" for inductive coupling in paralell with the also appropriate "PI model" for the capacitive coupling (both long known). I think the best way to introduce inductive and capacitive coupling technologies is the proposed schematics I used several times in the past (I do not pretend to be the first). A link to the article "Estimate of the maximum range......" could also be useful and appreciated. For the radiative near-field (the Cota technology is explained here: http://www.gizmag.com/cota-ossia-wireless-charging-microwave-phased-array/29217/), I am also reluctant to create a new section for that as for beams the limit between the near-field and the far field is around the focal point then quite far away in some cases. So may-be we may keep only the radiative/non-radiative distinction and add the somehow guided propagation as a sub-case of the radiative case.Henri BONDAR (talk)

I am still not comfortable with the use of unipolar/dipolar terms. In the electrical networks frame all components are dipoles, right ? Why not use instead the idea of symetrical/asymetrical dipoles ? Henri BONDAR (talk)

Unipolar and bipolar are common descriptive terms in electrical engineering. A device with a single terminal can be described as unipolar. A device with two terminals, particularly when driven out of phase, can be described as bipolar. I am not too comfortable with the article describing all near-field sources as "dipoles". We will need to explain this approximation in the article. Although at long distances the field approximates a dipole field, at the short distances used for most inductive and capacitive coupling, the field of typical sources differs significantly from a dipole field. I also don't see that term used for near field sources in mainstream wireless power references such as Agbinya, Sun, or Shinohara. Keep in mind that Wikipedia articles need to be supported by secondary sources like survey articles and textbooks (WP:PSTS), not just primary sources like research papers. --Chetvorno^TALK 15:35, 26 January 2016 (UTC)

Agreed that near-fields have a more complex structure at short distances than the dipolar model that dominates at relatively large ones. Higher order terms such a quadruple structures can be for instance involved. Agreed also on the fact that you may consider local unipolar interactions in some cases. For instance you may consider a single conductor interacting with the surrounding electric field and then derive the notion of self-capacitance for an electrode alone in the vacuum (this idea is well known and taught in some countries but seems to have some difficulties to cross the Atlantic where only the mutual capacitance seems to be known). However, when you consider distant unconnected structures (Wireless), the smallest order coupling term is always dipolar. So why not introduce the quadripolar and higher order idea before the unipolar one ? The unipolar idea focuses only on one side of the structure, whereas the whole thing is indeed dipolar. I think that this page must start to describe things as a whole (dipolar is according to me the best compromise) before going into details (local unipolar descriptions, global muti-polar coupling terms, asymetry, resonance,...). The present text is appropriately written according to me. Agreed also that en encyclopedic work is a matter of balance and should reflect current trends even if they are not always technically appropriate or even coherent (with appropriate warnings however). What about my preceding post just above ? Henri BONDAR (talk) —Preceding undated comment added 07:48, 27 January 2016 (UTC)

As explained in the current page, power transfer(for both types) depends on the square or the field level, the surface of the facing dipoles and frequency. At large frequencies, the requested field levels are usually quite low. This explains why capacitive systems can now match inductive ones (An old electrostatic influence machine rotating at 50tr/s (50 Hz) was able to deliver 1W of power at best, the same machine if allowed to run at 5Mhz, will produce around 100kW). In present technologies, the limit is not the field level but the dissipation involved in large reactive power elements, then mostly in coils. For instance, Furukawa in Japan succeeded to transfer 1kW with a transverse capacitive arrangement with voltages not exceeding 600Vpp (then equivalent to 220V RMS) because they are working at large frequencies and also use quite large electrodes. On the other side, it is false to believe that coupled coils do not involve large voltages. Here also it depends on the configuration, small section coils with large turn number working at quite low frequencies may involve hundreds of kV, note that a capacitive coupling term is difficult to avoid in such cases (as demonstrated by Nevada lab experiments on Tesla coils). Most inductive systems used in WPT power applications (for instance for the wireless charge of electric cars) involve tens of kV. So I suggest that health issues considerations should be treated accordingly. To avoid to attract dogmatism and polemics in this technical page, the best way according to me is to provide a link to an appropriate page (if existing). --Henri BONDAR (talk) 10:40, 29 January 2016 (UTC)

Existing:
Wireless power transfer (WPT)^[1] or wireless energy transmission is the transmission of electrical power from a power source to a consuming device without using discrete manmade conductors.^[2][3][4][5]

Proposed:
Wireless power transfer (WPT)^[1] or wireless energy transmission is the transmission of electrical energy^{[2][3][4][5][6][7][8]} from a power source to an electrical load or consuming device without the use of discrete man-made conductors.^{[9][10][11][12]}

GLPeterson (talk) 16:19, 14 February 2016 (UTC)

Electrical load is a bit WP:JARGON for the lead in an encyclopedia and was removed as such. Is there a reason for the added WP:REFBLOAT? Fountains of Bryn Mawr (talk) 19:45, 14 February 2016 (UTC)

The term "load" is a more general term than is "device."  Consider, for example, the case of a high power satellite microwave beam energy transmission system feeding an electrical power transmission and distribution grid, which is not a "consuming device."  The term is not truly jargon and is required in order for the article to be comprehensive.  If a hypothetical reader is confused by or unsure of the meaning of the term "load," such a person can easily receive immediate clarification simply by clicking on the word.

Back on 25 October 2015 () I added the words "or electric, magnetic or electromagnetic field energy" and "or an electrical load" without taking anything away.  My revision was promptly undone an editor who said, "This is not supported by sources."  Generally, I try to minimize the use of citations in an article's introduction (see WP:LEADCITE).  There is no need for citations there unless statements are made that are not made again in the body of the article and it's generally good practice to summarize in the introduction without references and then go into detail in the body of the article with appropriate sources.  However, in this case the citations seem to be required in order to justify the revisions. GLPeterson (talk) 21:21, 14 February 2016 (UTC)

• Support - It's technically a little more correct. Although electrical load is somewhat jargon, I think the fact that it's wikilinked provides an opportunity to educate readers. We should not, however, overwhelm the lead with citations per WP:CITELEAD. - MrX 21:45, 14 February 2016 (UTC)
• Oppose - mostly for basic policy and MOS reasons. The lead should generally not contain references, let alone massive amounts of REFBLOAT. References (and the explanatory material they support) go in the body of the article. Primary source papers should not be cited in the lead at all. The lead should be a much more accessible summary of secondary source material. If the material is not explainable or able to be referenced by a couple of good secondary sources then something is very wrong here. Links should not be used to teach words (specifically noted at WP:JARGON), a more common alternative should be used. Fountains of Bryn Mawr (talk) 16:27, 15 February 2016 (UTC)
• Comment - Looking at wording we could use re: "what do we mean here" I am struck by - why does this article exist? Everything notable in here has another article and it has been noted ever since this type of article was put forward that this may not be a term/article (and I see we have gone through a 9 year "full circle" naming/kicking this article around). Maybe this should be a DAB page? Fountains of Bryn Mawr (talk) 16:27, 15 February 2016 (UTC)

This article makes several citations to Nikola Tesla's writing hosted at tfcbooks.com. As a result, we have language such as "magnetic and capacitive induction coupling techniques" instead of "inductive and capacitive coupling"; "resonant electrostatic... coupling" instead of ,"resonant capacitive coupling"; "resonant magnetic inductive coupling" instead of "resonant inductive coupling"; "electrical condenser" instead of "capacitor"; "uppermost on Tesla's mind" instead of "Tesla's priority". We really should be using current secondary sources and nomenclature that is in use today. Thus I've marked the article with a primary sources tag.- MrX 14:23, 21 February 2016 (UTC)

I agree. I removed the most confusing construction "capacitive inductive coupling" from the article, but the others mentioned above should also be removed. I don't understand the purpose of these edits, and don't see any improvement to the article; I think they could all be reverted. --Chetvorno^TALK 21:29, 25 February 2016 (UTC)

The Lightning Foundry is a project to build two 10-story (108-foot) high Tesla Coils that can generate arcs 260 feet in length.  A fully functional 1:12 scale Lightning Foundry prototype is use to study the interactions between two matched [Tesla] coils.&nbsp: The two identical 1:12 prototype coils were made by first winding a length of secondary wire onto a cardboard tube.  The cardboard tube with the winding was then inserted into a corrugated plastic pipe and potted into place.  Once the potting had set, the cardboard tube was removed, leaving the winding exposed inside of the pipe.  The L_sec and F_o of the windings did not measurably change after potting.  The 9-foot high twin coils show a strong tendency to wirelessly couple electrical energy over large distances.  This ability is described in detail in a paper on wireless power transfer at the 2008 North American Power Symposium.

"Efficient Wireless Transmission of Power Using Resonators with Coupled Electric Fields," by G. E. Leyh and M. D. Kennan, Nevada Lightning Laboratory, http://lod.org/misc/Leyh/Papers/NAPS2008Final.pdf

“Tesla’s original patent [N. Tesla, "Apparatus for Transmission of Electrical Energy," U.S. Patent 649 621, May 15, 1900] resembles a far-field approach, given the large intended distance between stations compared to the station size.  However, Tesla’s system minimizes radiated fields and instead relies upon actual conduction, replacing the transmission line with two non-wire conductors.  In this case one conductor is the Earth, and the other appears to be either a capacitive path or a direct ionized path to the ionosphere according to different descriptions of the system.”

As it is described by U.S. Patent No. 649,621, APPARATUS FOR TRANSMISSION OF ELECTRICAL ENERGY, May 15, 1900, the Tesla wireless system relies upon electrical conduction, using two "non-wire" conductors.  One conductor is Earth, and the other involves a capacitive or ionized path between the two air terminal electrodes.

“Of the designs mentioned above, the approach outlined in this paper is perhaps most similar to Tesla’s system, since it does not rely upon far-field or radiated power, or magnetic coupling.  However this approach differs significantly from Tesla’s patented system in two important ways: A) There is no ionized path between the devices, and B) The receiver performs a synchronous detection of the received energy in order to optimize conversion efficiency.  The transfer of energy in this approach occurs primarily through the electric fields between the receiver and transmitter.”

In the exact same manner as the Tesla wireless system, set forth in APPARATUS FOR TRANSMISSION OF ELECTRICAL ENERGY, the approach outlined in the Leyh-Kennan paper depends upon electrical conduction through the earth.  It differs from the Tesla system as described in APPARATUS FOR TRANSMISSION OF ELECTRICAL ENERGY only in that, A) there is no highly ionized path between the Tesla coil transmitter and receiver, and B) the receiver performs a synchronous detection of the transmitted energy in order to optimize down-conversion efficiency.  Tesla’s patents, ART OF TRANSMITTING ELECTRICAL ENERGY THROUGH THE NATURAL MEDIUMS, May 16, 1900, U.S. Patent No. 787,412, Apr. 18, 1905 and ART OF TRANSMITTING ELECTRICAL ENERGY THROUGH THE NATURAL MEDIUMS, Apr. 17, 1906, Canadian Patent No. 142,352, Aug. 13, 1912 do describe a means by which the Tesla wireless system can be operated without the necessity of an ionized path between the two devices, and also a means for synchronous detection of the transmitted energy.

"A curious thing happened recently that you might find interesting.  We accidentally burned a grounding lead attached across the primary of one of the prototype twin coils, while running the 120L50k coil across the lab.  The interesting part is that the twin coil responsible for this misdeed was completely disconnected from any source of power.  I'd always thought capacitive coupling such as in Tesla's wireless scheme to be a very weak effect, at best.  However, faced with a burned grounding lead we set out to determine exactly how such amounts of power could be coupled across the room.  We are now completely convinced that the power flowed through the ambient electric fields and returned through Earth, similar to Tesla’s original concept from 1900.  Placing electric field shielding between the coils stopped 95% of the power flow."

Mike Kennan driving his 'Tesla Roadster', Published on Oct 30, 2011, Mike Kennan driving his 'Tesla Roadster,' powered completely from the ambient fields produced by the Lightning Foundry 1:12 scale prototype coils.  Note the sparking to the concrete, forming the return path.  Video by Josh Bailey.

"Mid-range [coupling] is defined as somewhere between one and ten times the diameter of the transmitting coil."  "Typically, an inductive coupled system can transmit roughly the diameter of the transmitter." [Baarman, David W.; Schwannecke, Joshua (December 2009). "White paper: Understanding Wireless Power" (PDF). Fulton Innovation. pp. 2, 4.] "Strongly coupled magnetic resonance can work over the mid-range distance, defined as several times the resonator size." Agbinya (2012) Wireless Power Transfer, p. 40.]

Lightning Foundry Twin Coil Prototype dimensions:
Overall height = 2.74 meters
Resonator (transmitting coil) height = 2.44 meters
Resonator (transmitting coil) diameter < 0.57 meters
Resonator spacing (transmission-reception distance) = 12 meters
Resonator spacing-to-diameter ratio > 21:1

"Mid-range [coupling] is defined as somewhere between one and ten times the diameter of the transmitting coil."
The Lightning Foundry Twin Coil Prototype coupling is greater than 21 times the diameter of the transmitting coil.^[1][2][3][4]

GLPeterson (talk) 15:25, 18 February 2016 (UTC)

(Unless I am missing something) this seems to be a series of primary sources and your interpretation of them. Such sourcing (and why its not allowed in Wikipedia) has been discussed many times. If I am wrong please point out the reliable secondary sources. Fountains of Bryn Mawr (talk) 17:05, 18 February 2016 (UTC)

(back from long absence) I agree with Fountains of Bryn Mawr:

• The Leyh-Kennan paper has already been discussed very thoroughly above on this page; see #Timeline of Wireless Power, 2008 Entry No. 3 and #Electrical Conduction. We don't need to rehash it.
• GLPeterson, with regard to the video of Mike Kennan driving his 'Tesla Roadster' you linked, your analysis of spacing-to-diameter ratio is wrong. As mentioned in the Leyh paper, power is transferred by capacitive coupling (do you see any inductive coils on the "roadster"?) The relevant size of the resonator is its height (the spacing between the capacitive top terminal and ground), 2.44 m, not its diameter. If the transmission distance is 12 m as you gave, the spacing-to-resonator-size ratio is 12 / 2.44 or 4.9:1, not 21:1. Typical for mid-range resonant capacitive coupling.
• As editors have pointed out many times, the Leyh-Kennan paper is a WP:PRIMARY source. The YouTube video is nowhere near a WP:RS. Drawing your own conclusions from these sources is WP:SYNTHESIS.

Tesla's limited contributions to wireless power are already acknowledged adequately in the article. --Chetvorno^TALK 22:46, 18 February 2016 (UTC)

This seems to be a series of primary sources.

The Leyh-Kennan paper is a WP:PRIMARY source. 

Wikipedia guidelines about sourcing apply only to articles, not article talk pages.

The cited paper ^[2] published in the NAPS 2008 40th North American Power Symposium proceedings is a secondary source, forming an analysis of Tesla's original research, referencing ^[3][4][5] and ^[6]. 

In addition to showing that the apparatus used by Leyh and Kennan in their replication of Tesla's original research is capable of wireless power transfer over greater than mid-range distances, there is a second point being made.  It is shown that, in the exact same manner as the Tesla wireless system set forth in APPARATUS FOR TRANSMISSION OF ELECTRICAL ENERGY, the performance of their apparatus depends upon electrical conduction through the earth; the electrical energy flows through the earth between the Tesla coil transmitter and Tesla coil receiver ground-terminal electrodes.

In the system devised by me a connection to earth, either directly or through a condenser is essential. The receiver, in the first case, {the Hertz wave system] is affected only by rays transmitted through the air, conduction being excluded; in the latter instance [the Tesla wireless system] there is no appreciable radiation and the receiver is energized through the earth while an equivalent electric displacement occurs in the atmosphere.^[7]

GLPeterson (talk) 18:45, 6 March 2016 (UTC)

All your statements above are contradicted by the source you gave:

• There is nothing in the Leyh-Kennan paper that says they achieved "greater than mid-range distances", as you claim. Mid-range wireless power transmission distance is defined as between 1 and 10 times the size of the transmitter. The transmitter coil was about 6 feet (2 meters) high. The power throughput (Table 3) was only 16.5% at 6 meters (3x size of transmitter) and dropped to almost nothing, 1.58% at 10 meters (5x size of transmitter). These are typical mid-range distances achieved by capacitive coupling.
• If you will remember, when you first brought up the Leyh-Kennan paper above on this page, it was pointed out that Tesla in his patent claimed that his wireless power system worked by a "flow of electrical energy, by conduction, through the earth and the air" In their paper, Leyh and Kennan themselves explicitly say that their system is not the same as Tesla's because it does not use conduction through the air as Tesla claimed his did: "...this approach differs significantly from Tesla’s patented system in two important ways: A) There is no ionized path between the devices...".
• The paper says the power transfer was not by Tesla's "electrical conduction through the earth", as you claim. The Leyh-Kennan paper distinguished three methods of power transmission in their experiment: "(1) Magnetic coupling between the two secondary cores, (2) Electric coupling between the two top electrodes, (3) Coupling through shared ground current paths". They found that "...transfer of energy in this approach occurs primarily through the electric fields between the receiver and transmitter.", not ground currents: "The conclusion from this experiment was that shared ground current paths provide negligible amounts of coupling..."

Finally, as Fountains of Bryn Mawr said, the Leyh paper is a primary source. On WP, primary sources require backup by secondary sources, which you have not given. If it cannot be used as a source in the article, there is not much point in bringing it up here. --Chetvorno^TALK 20:05, 14 March 2016 (UTC)