Ciao
There are aspects in the homopolar generation that I think deserve to be investigated.
Certainly there has never been easier to experiment, experiment more interesting and more controversial since the beginning of 'electromagnetism, as the magnet of Faraday rotation and the disk.
Because of their simplicity and beauty have always captured the attention of the physical and many researchers.
According to Poincare "the most curious experiments in electrodynamics are those where there is a continuous rotation, called unipolar induction experiments."
Einstein, in his first paper "on the electrodynamics of moving bodies," says this: "it is clear that Maxwell's electrodynamics - as current interpretation - once applied to moving bodies, leads to asymmetries which do not appear to be related to phenomena .
The hypothesis of a hybrid config spiral, the turbine electrodynamics
The reversal of cause and effect in the classical description of electromagnetism, causes a misconception that is the basis of many paradoxes and exceptions. Currently, the curious fact that the induction unipolar or the disc is an exception to Faraday's law induction Faraday is generally accepted. When we establish a proper relationship between cause and effect is evidence of a link between mechanics and electromagnetism, as a new law of induction for which the paradoxes or exceptions do not occur. The difficulties in interpreting the disk flow directly from Faraday's law induction Faraday and the equation that defines and measures the magnetic induction. The electromagnetic force and torque generated in the disc Faraday unipolar dependent figure of the circuit that connects the hard drive, a provocative duality "absolute-relative" of emf and torque unipolar. This leads to different interpretations. The analogy with mechanics suggests that this duality derives from the dual nature of the inert and gravitational mass electromagnetic. You can describe some experiments paradoxical unipolar induction involving the unique geometry of the spiral that demonstrate this duality and reversal of cause and effect. L 'emf and the torque of the Faraday disk with a spiral of conduct is due to the continuous variation of the angular momentum of the electromagnetic current. These experiments confirm the strength of Lorentz and invalidate the law of induction Faraday. They show how an emf in a closed loop and a unipolar torque are not produced by the change in magnetic flux, which is constant, but with two variations in the electromagnetic angular momentum. The three possibilities of change in the electromagnetic angular momentum generated by the movement of charge causes different forms of electromagnetic induction.
http://arxiv.org/ftp/physics/papers/0012/0012009.pdf Tesla, from an article written for the electrical engineer in 1891
note entitled "The Unipolar Dynamo."
Here Tesla presents a detailed analysis of the Faraday disk generator, explains why it was an inefficient generator, describes its variations and improvements on the device of Faraday, in the bottom of the third page of the article, declares that he has invented a AGENER where " the current, once started, may then be enough to maintain itself even to 'increase the resistance. " Then, at the end of the article, states that "... several machines were built by the producer and ranging from two years." Two years before the writing of that article was 1889. All points show evidence of a unipolar dynamo model of Tesla's turbine being, first, the design of a machine that can continue to produce electricity after the separation from an external source of power.
CURRENT self-sustaining
Before going into the details of this invention would be interesting to have an idea of how all the generator, even in theory, could be capable of generating a current self-sustaining. This was clearly explained by Walter M. Elsasser in an article on scientific-american (May 1958) called "the land as a dynamo."
Elsasser models the earth-dynamo, conveniently for this explanation, the Faraday generator, as a metal disk spinning over a bar magnet placed on the edge of the disc. Note also that the bar magnet could be replaced by an electromagnet can get its power from the rotating disk, by attaching an electromagnet wire to the outside of the disk and the other wire through the center axis metallic disc .
Elsasser then specifies that an ordinary disk generator "could not maintain a current for very long because the current induced in the disk is so weak that he would soon be dissipated by the resistance of the conductor [the disk]." This convention provision does not explain "how currents could be developed and perpetuated to make the magnetic field of the earth proposes three options, although the model of the dynamics that explain the persistence of terrestrial magnetism.
If we had a material that could conduct electricity a thousand times better than copper, the system actually make a current self-sustaining. We could also make this feasible
Working rotating disk very fast ... A third possibility to make such a dynamo self-sustaining would increase the size of the system: the theory says that the bigger we make such a dynamo, better work. If we could build a device rotating disk of its kind in scale of many miles, we would have difficulty making the currents self-sustaining.
Tesla did not have a material a thousand times more conductive than copper, neither was able to rotate a disc at ultra-high speeds needed to produce such a current, or planned to use a metal disc rotating several miles in diameter. Tesla knew he had to use the energy normally wasted in a generator to transform it into a power source.
UNIPOLAR DYNAMO
Tesla's design varied from that of Faraday in two important ways. First, he used a magnet that was larger than the diameter of the disc so that the magnet completely covering the disc. Second, he divided the disk into sections with spiral curves radiating from the center toward the outer edge.
In the Faraday unipolar generator, known Tesla, the current can never come entirely to the external circuit ... e. .. by far the largest of the current produced will not appear externally ... not having full coverage of the magnetic disk.
Tesla used the entire surface of the disk in power generation instead of a small section directly adjacent to the bar magnet, as happened in the Faraday device. This not only increases the amount of power generated, but it will be all transferred from the center to the outer edge of the disc, making it available to the external circuit.
The most important changes made by Tesla to design Faraday is one that has removed one of the biggest problems in the physics world [the reaction to every action]. It is this reaction that works to cancel the force generated from the original. In an electrical system if there are two turns of wire wrapped below and a current is passed through the wire, the current passing through the first loop will install a magnetic field that will work against the passage of current through the second loop.
The divisions into sections in the spiral disk, lead the current to cross the full radius of the disk or, as in his alternative version of the generator, the current is forced to make a complete circle around the outer edge of the disc. Since the current is going into a big circle on the disc, the magnetic field generated by the current does not work against the field magnet above the circular plate, as in conventional generators, but actually strengthens the magnet. The disk cuts the magnetic lines to produce a current, the current that is detached from the disc reinforces the magnet, allowing a greater output current.
Like the conventional DC power generators, the unipolar dynamo also functions as a unit if the power is connected to the disc and this seems to be the last element that could make the device self-sustaining, that is, able to generate power after the detachment from a external source of power.
The rotation is started for example by a motor powered by line current. Is a generator that a disk drive motor are mounted in the magnetic circuit. Since the disks gain speed, the current produced reinforces the magnets, this causes the generation of more current. Current probably is primarily directed toward the disk motor which increases the speed of the system. At some point the speed of the disks is large enough that the magnetic field generated by the current balance of the resistance dynamotore that goes without saying.
You can make assumptions about what is the process that could maintain the unipolar dynamo operating after the start-up power, however, two characteristics of the generator are significant. First, when a resistive load, like a light bulb is added to the circuit, it lowers the voltage at the center of the disc. This lower voltage at the center, it means that there is a major difference in the tension between the core and the outer edge of the disc than before the bulb had been added. While the difference between the center and the outside increases, the generator increases and makes it more current. Secondly, however, the most important thing is that the generator loses very little, or nessun'energia be preserved because of the current that is detached from the generator is doing double duty. The current makes the bulb glow, but on its direction from the generator to the filament in the bulb, through a route that adds momentum to the dynamo and, therefore, energy consumption is at a very low rate.
The process continues, it would seem, until heat losses in the filament are not equal to the energy of rotation of the flywheel generator. In terms of Elsasser criteria for self-sustaining generator, the Tesla unipolar dynamo comes to meeting the condition of the electrical conductor better. This is not to use new materials, but a new geometry applied so that the current does not generate its own opposing forces. This is similar but not equivalent to having a better conductor.
Whether or not a dynamo "fuelless" This generation seems to be indeed a clever invention of engineering that takes one of the basic principles of nature, an equal and opposite reaction for every action and turns, through the use of a new geometry of the circuit, in a reaction that is cumulative action original. Instead the opposite reaction that slows the system that generated it, the reactions add energy to the system.
Patents:
http://v3.espacenet.com/searchResults?locale=en_EP&NUM=US406968&ST=number&compact=false&DB=EPODOC&submitted=true