Talk:Homopolar generator

message: Self-promotion is against wiki policy, and since it seemed bad form to have two separate link sections I removed them.  — Preceding unsigned comment added by 85.80.170.103 (talk) 01:22, 13 December 2013 (UTC)
thread_title:  A crank is inserting links to his relativity denial website by hiding them as 'external references' 

message: I think the explanation table is somewhat misleading, when it terms, that it if both disk and indicator are moving the result is undetermined. It is surely not undetermined. Like some strange explanation also tries to say:
The voltage is "undetermined" when both the indicator and the disk are rotated, regardless of whether the magnet is moving. There is an EMF and a nonuniform charge density, but no reaction of the indicator.[3] An electric field is generated, but no voltage is brought out for display. This differs from the different relative motions of the parts of a rectilinear homopolar generator (where the answer would be "No").
I think this is explanation is unnecessarily complex. Simply stated: 
If the magnet rotates or not doesn't make any difference. If both indicator and disk rotate only the relative difference in rotation is relevant for the voltage seen on the indicator, which means if both rotate at the same speed the indicator doesn't see any voltage. The reason for this is simple, if both rotate at the same speed, then also the wires of the indicator circuit will develop the same voltage as the disk itself (the wire behaves the same as a second disk), therefore the indicator wouldn't see any voltage difference. Peace 83.77.199.33 (talk) 19:01, 15 February 2010 (UTC)
thread_title:  Comments for the explanation table 

message: Nearly all cases of which wiki talks about electromagnets, could we add the direction of which the current flows? Seb-Gibbs (talk) 20:37, 12 July 2009 (UTC)
thread_title:  Current direction? 

message: Paragraph from the bottom of the page:
"The correct interpretation of the velocity of the electron is that it is relative to the static parts of the machine, which are the sliding contacts and the circuit to which they are connected. In the language of special relativity, these objects act as the 'observer'. It is the velocity of the electron relative to these components that causes it to experience the Lorentz force."
How can this be true, since the results of moving the whole machine conflicts with this statement.  Seb-Gibbs (talk) 20:37, 12 July 2009 (UTC)
thread_title:  How it works 

message: Is it certain that the earliest patent referenced (US238631) is really a homopolar generator? I'm certainly no expert, but it looks like an induction dynamo to me. See: US238631 at Google Patents
70.60.39.47 (talk) 23:25, 30 June 2008 (UTC)
thread_title:  Earliest Patent? 

message: Since Lorentz Force Law and not traditional induction is governing the generation of current in the Homopolar Generator isn't the section "How magnetism makes current" somewhat misplaced? --Enghoff 04:40, 14 September 2007 (UTC)
thread_title:  Misguided: How magnetism makes current 

message: Umm...a compulsator is a specialized type of alternator. It is not either a Faraday disk nor a drum HPG. I have built  and used both.  I can also tell you that without relative motion between the armature and the field, you get no voltage in an HPG.  This article needs to researched more rigorously
:Your first point is correct, so I fixed the article.  Your second point is not correct.  Relative motion between the circuit and the field is irrelevant, since the field is uniform.  What counts is relative motion of the rotor and stator, within the uniform field.  --Heron 20:10, 14 September 2005 (UTC)
thread_title: research

message: Why is there still/again a Gaypolar generator page (even if it is a redirect)? --Art Carlson 15:45, 13 January 2006 (UTC)
thread_title: Gaypolar

message: This is highly dubious ". However, there are no records of the performance of [Tesla's] machine, nor of anybody else having tried to build one". A citation is needed, or the sentence needs to be revised or removed. 204.56.7.1
:: removed the above sentence, till a citation is provided. 134.193.168.244 16:15, 7 April 2006 (UTC)
replies: text: That was me, and I admit that I can't provide a citation, since it was just a statement of my own inability to find any evidence that one was ever built. I was hoping that someone would find an example of one and prove me wrong!  While we're on the subject, does anybody know what a "Forbes dynamo", mentioned in the article, is or was, please? --Heron 17:15, 7 April 2006 (UTC)
replies: text:  G. Forbes, "U.S. Patent 338169 Dynamo electric machine". That'[s his patent. 134.193.168.244 17:40, 7 April 2006 (UTC)
replies: text:  I also just read from Valone's article that you can find info on the Forbes dynamo in an article in the Journal of the IEEE by Robert Belfield (Sept, 1976; pg., 344). 134.193.168.244 17:52, 7 April 2006 (UTC)

text: Thanks. I must go and check those out. --Heron 19:39, 7 April 2006 (UTC)
thread_title: Dubious material

message: Could someone make a List of homopolar generator patents and move the list there? 204.56.7.1 19:40, 6 April 2006 (UTC)
thread_title: Move?

message: Other names for HPG.
* Faraday disk
* HPG
Should they be added and if so where? DeleteThis 02:59, 23 May 2006 (UTC)
thread_title:  Other Names for Homopolar Generator 

message: Since the page did not exist, but unipolar generator and disk dynamo I added Acyclic Genertor and redirected it to this page. DeleteThis 02:58, 23 May 2006 (UTC)
thread_title:  Added redirect from acyclic generator to here 

message: From Dictionary.com
Alternator - An electric generator that produces alternating current. 
Dynamo - A generator, especially one for producing direct current.
DeleteThis 02:59, 23 May 2006 (UTC)
thread_title:  Definitions of Alternators and Dynamos 

message: Current structure of article...
1 History and development 
2 Description and operation 
2.1 How magnetism makes current 
2.2 Disk type generator 
2.3 Drum type generator 
3 Physics 
4 See also 
5 References and further reading 
6 External links and other articles 
Does this make sense.
How would the other pieces be added into this one.
DeleteThis 11:09, 26 May 2006 (UTC)
replies: text: 500MJ is around 140 kWh and that would translate to about 187hp/hr. One gallon of Gasoline contains ~121 MJ. This is around 4 gallons of gas. DeleteThis 04:49, 28 May 2006 (UTC)
thread_title:  Structure of article 

message: Am I correct to assume that the term "indicator" in the table is a meter used to measure the voltage generated across the disk?  This is not 100% clear to me.  --Jakohn 21:08, 15 June 2006 (UTC)
thread_title:  Indicator? 

message: "It produced 500 megajoules"
: What, over the course of its lifetime?  More context needed. — Omegatron 19:29, 25 November 2006 (UTC)
thread_title:  megajoules? 

message: The article says "There is an uncertain nature of the torque reaction in homopolar machines". What is uncertain about it? Equal and opposite forces occur on the two parts of the electrical circuit, the stator and rotor, and no force occurs on the magnet (unless it happens to be conductive and forms part of the electrical circuit). See "Sources of confusion" in homopolar motor. -- D.keenan 15:14, 4 December 2006 (UTC)
thread_title:  Uncertain torque reaction? 

message: User:JzG removed these applicable references:
* Mike Galloway, "N-1 Homopolar Generator".
* Bruce E. DePalma, "The Trombly-Kahn Homopolar Generator; Critique of the N-Machine Constructed by Trombly & Kahn". 11 October 1985.
* Bruce E. DePalma, "A review of: "The Homopolar Handbook", by Thomas Valone". 2 February 1995.
* "The Faraday Disk Dynamo as the original over-unity device". Archer Energy Systems, Inc., 2006
J. D. Redding 21:59, 11 April 2007 (UTC)
thread_title: Removed references

message: * Bruce DePalma and other assorted mad scientists. J. D. Redding
===Bruce DePalma===
Bruce DePalma (born Bruno James DePalma) (October 2, 1935–1997), son of noted orthopaedic surgeon Anthony DePalma and elder brother of film director Brian De Palma, was a well known figure in the Free energy suppression community. 
De Palma claimed that his N-machine Homopolar generator, a device based on the Faraday disc, could produce five times the energy required to run it.  According to mainstream physics, no such device is physically possible. De Palma studied electrical engineering at Harvard (1958) and taught physics at MIT for 15 years, working under Harold Eugene Edgerton.  He was also employed by Edwin H. Land of Polaroid fame.
Bruce De Palma's development of the N-machine concept in 1977, among his other anomalous devices (at least one of which, De Palma claimed, displayed anti-gravity characteristics) and the claims surrounding them, set him on a collision course with his more mainstream peers.  His claims of "free energy" were vigorously refuted over the course of twenty years, by conventional scientists and some members of the alternative energy community alike.
His search for financial backing for the construction of a marketable N-machine saw him relocate from Santa Barbara, California to Australia c. 1994, and then New Zealand in 1996. Probably his greatest ally in his conviction that the N-machine could solve the world's energy and environmental crisis was Paramahamsa Tewari, a Project Director with the Indian Nuclear Power Corporation, with whom he corresponded regularly over many years.  Tewari's Space Power Generator, claimed to be 200% efficient, is based on the same theoretical foundations as the N-machine.
De Palma's death in New Zealand in October 1997 put an end to his most ambitious free energy project, and occurred only weeks prior to the official testing of a device constructed over the course of 6 months in an Auckland workshop.  The test was attended by, among others, the project's financial backer, Bruce Bornholdt, a prominent Wellington barrister, as well as the pioneering developer of the Adams motor, Robert Adams (now deceased), who observed the operation of, and measured electrical output from, the N-machine.  This single test failed to demonstrate the over-unity potential of the N-machine - most of the output energy being lost as heat - and the project was immediately dissolved.
*Homopolar generator
*Perpetual motion
*History of perpetual motion machines
*Steorn
* THE HOME OF PRIMORDIAL ENERGY, De Palma's website with numerous articles.
* Free Energy - The N-Machine
J. D. Redding 22:03, 11 April 2007 (UTC)
thread_title: WikiProject Paranormal

message: Bruce DePalma (born Bruno James DePalma) (October 2, 1935–1997), son of noted orthopaedic surgeon Anthony DePalma and elder brother of film director Brian De Palma, was a well known figure in the Free energy suppression community. 
De Palma claimed that his N-machine Homopolar generator, a device based on the Faraday disc, could produce five times the energy required to run it.  According to mainstream physics, no such device is physically possible. De Palma studied electrical engineering at Harvard (1958) and taught physics at MIT for 15 years, working under Harold Eugene Edgerton.  He was also employed by Edwin H. Land of Polaroid fame.
Bruce De Palma's development of the N-machine concept in 1977, among his other anomalous devices (at least one of which, De Palma claimed, displayed anti-gravity characteristics) and the claims surrounding them, set him on a collision course with his more mainstream peers.  His claims of "free energy" were vigorously refuted over the course of twenty years, by conventional scientists and some members of the alternative energy community alike.
His search for financial backing for the construction of a marketable N-machine saw him relocate from Santa Barbara, California to Australia c. 1994, and then New Zealand in 1996. Probably his greatest ally in his conviction that the N-machine could solve the world's energy and environmental crisis was Paramahamsa Tewari, a Project Director with the Indian Nuclear Power Corporation, with whom he corresponded regularly over many years.  Tewari's Space Power Generator, claimed to be 200% efficient, is based on the same theoretical foundations as the N-machine.
De Palma's death in New Zealand in October 1997 put an end to his most ambitious free energy project, and occurred only weeks prior to the official testing of a device constructed over the course of 6 months in an Auckland workshop.  The test was attended by, among others, the project's financial backer, Bruce Bornholdt, a prominent Wellington barrister, as well as the pioneering developer of the Adams motor, Robert Adams (now deceased), who observed the operation of, and measured electrical output from, the N-machine.  This single test failed to demonstrate the over-unity potential of the N-machine - most of the output energy being lost as heat - and the project was immediately dissolved.
*Homopolar generator
*Perpetual motion
*History of perpetual motion machines
*Steorn
* THE HOME OF PRIMORDIAL ENERGY, De Palma's website with numerous articles.
* Free Energy - The N-Machine
J. D. Redding 22:03, 11 April 2007 (UTC)
thread_title: Bruce DePalma

message: Please check statement about flux being a vector above. Magnetic flux is a scalar quantity ( \int \vec{B} \cdot d\vec{A}), not a vector. Moreover, the Lorentz force law, mentioned below, is derived using Faraday's Law of electromagnetic induction.
In all honesty this section needs to be reviewed.
(Copied from article. --Art Carlson (talk) 17:17, 23 January 2008 (UTC)
thread_title:  Editorial comments by 97.100.194.145 

message: I recently realized that I do not truly understand how a Faraday disc (I use this spelling on purpose). I am getting on in years so I apologize that my mind may not be working as well Isould lie it to. I find problems with the entry on the Homopolar generator. The entire introductory paragraph is confusing and ambiguous. It really should be rewritten.
The disk does not have to be magnetic. It does not even have to bn conductive unless significant output is required.
The fundamental description arises out of the special theory of relativity (SR). In SR, the fundamental field is a tensor that combines the electric and magnetic vector fields we all know and love into one tensor field usually represented by an antisymmetric 4 x 4 matrix. See the Wikipedia entry for Special relativity.
Given the tensor field (in laboratory coordinates), local motion transforms the tensor to produce an electric field locally at a moving point from the magnetic field present in the laboratory coordinates. Surprise, surprise; this is just the Lorentz force law. I do not yet understand how that fits in with the definition of electric field  F = q E. Does magnetic force F = q v x B arise from F = q E merely  by requiring invariance of the field tensor under a Lorentz transformation?
The electric field produced by motion does not require conductivity. In principle, that electric field should be observable by means of the Stark effect or various electrooptical effects.
More later.
PEBill (talk) 04:50, 25 August 2008 (UTC)
thread_title:  Problems with the Homopolar Generator section 

message: Parts of the explanation of how it works, described in the Physics section, seem confusing to me. In particular, I find misleading the paragraph starting with "There is a subtle difficulty in this explanation". In my opinion, there is no problem with the Lorentz force explanation. If one raises the question, how can this be reconciled with special relativity, this is what I think. In a moving frame, the electric and magnetic forces get transformed (the transformation laws are described by the electromagnetic tensor). What appears as a homogeneous magnetic field and no electric field in the reference frame of the stationary machine, appears as a combination of an electric and a magnetic field in the reference frame of an electron moving with the rotating disk. In the reference frame of the electron, the electron responds to this electric field. Mateat (talk) 22:04, 24 October 2009 (UTC)
thread_title:  How it works 

message: From the section above, Talk:Homopolar_generator#Problems_with_the_Homopolar_Generator_section, we had an objection from an unregistered editor:
"and a vertical-axis generator could allow the entire rim of a disk to be "brushed" by liquid metal"
I think this should say horizontal axis.  —Preceding unsigned comment added by 70.88.177.137 (talk) 04:32, 12 September 2008 (UTC)
thread_title:  Liquid metal brushes and rotation axis orientation 

message: The United States Patent Office uses the clasification class 310 (Electrical generator or motor structure) and subclass 178 (Dynamoelectric; Rotary; D.C.; Homopolar) for these devices. Many of the homopolar patents were obtained prior to 1975. Below is a list of homopolar generator patents.
===American===
* G. D. Hathaway,  ", Direct current homopolar machine".
* W. F. Weldon, " Homopolar machine ". 
* Antonios Challita, " Electrical machine".
* W. F. Weldon, ", Method of constructing a rotor assembly for homopolar generator". 
* W. F. Weldon, " Rotor assembly for homopolar generator".
* W. F. Weldon, " Homopolar generator power supply system".
*  W. F. Weldon, " Removable brush mechanism for a homopolar generator ". 
* Esko Ensio hubta-Koivisto, " Electric unipolar motor".
* E. C. Ketchum and D. H. Andrews, " Dynamo electric machine". 
* A. Kingsbury, " Dynamo electric machine".
* W. A. Dick,  " Dynamo electric machine". 
*  J. E. Noeggerath, " Dynamo electric machine".
*  H. Hertz,  " Unipolar exciter for turbo-generators". 
*  D. W. Troy, " Dynamo electric machine". 
*  A. S. Hubbard, " Dynamo electric machine". 
*  B. Von Ugrimoff, " Cooling device for electrical sliding contacts". 
*  E. C. Ketchum, " Brush holders for dynamos".
*  J. E. Noeggerath, " Dynamo electric machine". 
*  J. E. Noeggerath, " Dynamo electric machine". 
*  J. E. Noeggerath, " Dynamo electric machine". 
*  J. E. Noeggerath, " Dynamo electric machine". 
*  J. E. Noeggerath,  " Armature for unipolar machines".
*  J. E. Noeggerath, " Unipolar dynamo electric machine". 
*  J. E. Noeggerath, " Acyclic machine".
*  J. E. Noeggerath, " Protective device for unipolar machine". 
*  A. C. Eastwood, " System of control for electric motors". 
*  J. E. Noeggerath, " Dynamo electric machine".  
*  W. Mathiesen, " Unipolar dynamo". 
*  E. Thomson, " Unipolar generator". 
*  J. E. Noeggerath, " Dynamo electric machine".  
*  C. Macmillan, " Power transmission mechanism". 
*  C. Macmillan, " Dynamo electric machine".  
*  J. E. Noeggerath, " Unipolar alternating current machine". 
*  E. C. Ketchum, " Dynamo". 
*  H. H. Wait, " Dynamo electric machine". 
*  J. E. Noeggerath, " Unipolar machine".  
*  C. P. Steinmetz, " Dynamo electric machine". 
*  J. E. Noeggerath, " Electric motor". 
*  E. R. Cox, Jr., " Dynamo electric machine or motor". 
*  B. Bjarnason, " Dynamo electric machine". 
*  F. W. Throop, " Dynamo electric machine". 
*  G. Dalen and A Hultovist, " Dynamo electric machine". 
*  F. G. Mayer, " Dynamo electric machine". 
*  E. Thomson and M. J. Wightman, " Dynamo electric machine".
*  G. Rennerfelt, " Dynamo electric machine". 
*  H. E. Dikeman, " Dynamo electric machine". 
*  J. E. Maynadier, " Dynamo electric machine".
*  T. L. Willson, " Dynamo electric machine". 
*  N. Tesla, " Dynamo electric machine". 
*  J. B. Entz, " Dynamo electric machine". 
*  R. Eickemeyer, " Unipolar dynamo electric machine".  
*  E. A. Sperry, " Dynamo electric machine".
*  R. Eickemeyer, " Electro magnetic and megneto electric machine". 
*  R. Eickemeyer, " Device for taking electric currents from or to moving surfaces". 
*  R. Eickemeyer, "  Magneto electric and electro magnetic machine". 
*  R. Eickemeyer, "  Magneto electric and electro magnetic machine".  
*  R. Eickemeyer, " Magneto electric and electro magnetic machine". 
*  R. Eickemeyer, " Dynamo electric and electro magnetic machine". 
*  R. Eickemeyer, " Dynamo electric and electro magnetic machine".
*  R. Eickemeyer, " Dynamo electric and electro magnetic machine". 
*  R. Eickemeyer, " Magneto electric and electro magnetic machine". 
*  S. Z. De Ferranti, " Unipolar dynamo electric machine".   
*  C. Batchelor and H. E. Walter" Dynamo electric machine".
*  C. Hering, " Unipolar dynamo electric machine".  
*  G. Forbes, " Dynamo electric machine". 
*  A. E. G. Lubke, " Dynamo electric machine". 
*  A. F. Delafield, " Dynamo electric machine". 
*  C. E. Ball, " Dynamo or magneto-electric machine".
--J. D. Redding 17:04, 3 August 2013 (UTC)
thread_title:  Patents 

message: * G. D. Hathaway,  ", Direct current homopolar machine".
* W. F. Weldon, " Homopolar machine ". 
* Antonios Challita, " Electrical machine".
* W. F. Weldon, ", Method of constructing a rotor assembly for homopolar generator". 
* W. F. Weldon, " Rotor assembly for homopolar generator".
* W. F. Weldon, " Homopolar generator power supply system".
*  W. F. Weldon, " Removable brush mechanism for a homopolar generator ". 
* Esko Ensio hubta-Koivisto, " Electric unipolar motor".
* E. C. Ketchum and D. H. Andrews, " Dynamo electric machine". 
* A. Kingsbury, " Dynamo electric machine".
* W. A. Dick,  " Dynamo electric machine". 
*  J. E. Noeggerath, " Dynamo electric machine".
*  H. Hertz,  " Unipolar exciter for turbo-generators". 
*  D. W. Troy, " Dynamo electric machine". 
*  A. S. Hubbard, " Dynamo electric machine". 
*  B. Von Ugrimoff, " Cooling device for electrical sliding contacts". 
*  E. C. Ketchum, " Brush holders for dynamos".
*  J. E. Noeggerath, " Dynamo electric machine". 
*  J. E. Noeggerath, " Dynamo electric machine". 
*  J. E. Noeggerath, " Dynamo electric machine". 
*  J. E. Noeggerath, " Dynamo electric machine". 
*  J. E. Noeggerath,  " Armature for unipolar machines".
*  J. E. Noeggerath, " Unipolar dynamo electric machine". 
*  J. E. Noeggerath, " Acyclic machine".
*  J. E. Noeggerath, " Protective device for unipolar machine". 
*  A. C. Eastwood, " System of control for electric motors". 
*  J. E. Noeggerath, " Dynamo electric machine".  
*  W. Mathiesen, " Unipolar dynamo". 
*  E. Thomson, " Unipolar generator". 
*  J. E. Noeggerath, " Dynamo electric machine".  
*  C. Macmillan, " Power transmission mechanism". 
*  C. Macmillan, " Dynamo electric machine".  
*  J. E. Noeggerath, " Unipolar alternating current machine". 
*  E. C. Ketchum, " Dynamo". 
*  H. H. Wait, " Dynamo electric machine". 
*  J. E. Noeggerath, " Unipolar machine".  
*  C. P. Steinmetz, " Dynamo electric machine". 
*  J. E. Noeggerath, " Electric motor". 
*  E. R. Cox, Jr., " Dynamo electric machine or motor". 
*  B. Bjarnason, " Dynamo electric machine". 
*  F. W. Throop, " Dynamo electric machine". 
*  G. Dalen and A Hultovist, " Dynamo electric machine". 
*  F. G. Mayer, " Dynamo electric machine". 
*  E. Thomson and M. J. Wightman, " Dynamo electric machine".
*  G. Rennerfelt, " Dynamo electric machine". 
*  H. E. Dikeman, " Dynamo electric machine". 
*  J. E. Maynadier, " Dynamo electric machine".
*  T. L. Willson, " Dynamo electric machine". 
*  N. Tesla, " Dynamo electric machine". 
*  J. B. Entz, " Dynamo electric machine". 
*  R. Eickemeyer, " Unipolar dynamo electric machine".  
*  E. A. Sperry, " Dynamo electric machine".
*  R. Eickemeyer, " Electro magnetic and megneto electric machine". 
*  R. Eickemeyer, " Device for taking electric currents from or to moving surfaces". 
*  R. Eickemeyer, "  Magneto electric and electro magnetic machine". 
*  R. Eickemeyer, "  Magneto electric and electro magnetic machine".  
*  R. Eickemeyer, " Magneto electric and electro magnetic machine". 
*  R. Eickemeyer, " Dynamo electric and electro magnetic machine". 
*  R. Eickemeyer, " Dynamo electric and electro magnetic machine".
*  R. Eickemeyer, " Dynamo electric and electro magnetic machine". 
*  R. Eickemeyer, " Magneto electric and electro magnetic machine". 
*  S. Z. De Ferranti, " Unipolar dynamo electric machine".   
*  C. Batchelor and H. E. Walter" Dynamo electric machine".
*  C. Hering, " Unipolar dynamo electric machine".  
*  G. Forbes, " Dynamo electric machine". 
*  A. E. G. Lubke, " Dynamo electric machine". 
*  A. F. Delafield, " Dynamo electric machine". 
*  C. E. Ball, " Dynamo or magneto-electric machine".
--J. D. Redding 17:04, 3 August 2013 (UTC)
thread_title: American

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