VI. The "N" MACHINES d) Trombly-/Kahn-"N"Machine The Trombly/-Kahn "N" Machine represents a new and improved version of classic "N" machine types. It is a departure from the past machines since it utilizes rotating electromagnets along with the central-"disc" rotating component. The improved operation of the Trombly/-Kahn "N" Machine is achieved by providing a low reluctance magnetic return path for the magnetic flux that passes through the central rotor-(disc) component. This low reluctance return path permits the electromagnets to produce a high electrical field with a relatively small input current. Since the input current is low, overheating is avoided and the full potential of the homopolar generator is achieved. The low reluctance magnetic return path is preferrably produced by providing a relatively high permeability corotating enclosure (having enclosure halves) of sufficient radial and axial dimensions to enclose the electromagnets and disc conductor of the rotor. The disc conductor is preferrably constructed from a high permeability, low resistivity material such as iron, and can be integral with the electromagnetic cores. An International Patent has been issued on this present art which is listed as:-X02K31/00, and fully describes the details and specifics of the new type of "N" machine. In the summary of this Patent, it is stated that this present invention provides a co-rotating homopolar generator that avoids the heating problems of prior machines and renders possible and convenient the generation of electricity at extremely high efficiency. The generator has a rotor comprising a disk conductor and co-rotating co-axial electromagnets on either side. The present invention achieves the improved operation by providing a low reluctance magnetic return path for the magnetic flux that passes through the disk conductor. The low reluctance path permits the electromagnets to produce a high field-(limited to 2.2 Teslas by the saturation of iron) with a relatively low value of coil excitation current. Thus overheating is avoided and the full potential of the homopolar generator is achieved. In the preferred embodiment, the low reluctance magnetic return path is provided by a relatively high permeability co-rotating enclosure,-(designated a "flux return enclosure") of sufficient radial and axial size to enclose the magnets and disk conductor of the rotor. Additionally, the disk conductor itself is preferrably constructed from a high permeability low resistivity material such as silicon iron, and can indeed be integral with the electromagnet cores. Output power is drawn between the periphery of the disk conductor (within the flux return enclosure) and the rotor shaft through fixed disk and shaft brushes. The disk brush protrudes through an annular slot in the flux return enclosure, and is geometrically configured so as not to add a large amount of reluctance to the flux return path. To this end, the disk brush is formed with a relatively thin web portion that passes through the enclosure gap. The web portion still has sufficient thickness so that the mechanical strength of the brush is not compromised. Moreover, the web portion has sufficient thickness, and hence conductance, that the saving in magnet power is not offset by excessive ohmic heating in the web portion. A quote from Bruce DePalma about this latest Trombly/-Kahn "N" Machine,:-"Trombly and Kahn are two of the brightest young physicists in America today.'' "Their work is of the very highest quality and is described in the subject Patent and report." Bruce DePalma believes that this new "N" Machine can be enlarged to handle more current by the application of a liquid metal brush system, such as he employs in his "N" Machine project work. e) Bruce DePalma
DePalma Institute, Santa Barbara, California
Although the concept of the "N" machine is not new, having been based on Faraday's disc of 1831, various researchers, including Bruce DePalma have made continuous performance improvements on these machines. It was Michael Faraday who first rotated a copper disc between poles of a horseshoe permanent magnet and discovered that a voltage is produced between the central shaft and the outer edge of the disc. The disc has become known as the Faraday Homopolar-Disc generator, and the EMF is drawn off by brushes in contact with the shaft and outer disc edge. The "N" machine basiclly consists of a high speed cylindrical permanent magnet from which electrical current (positive charge) with the circuit connection with brushes made in the same manner as the Homopolar Disc generators. These electrical generating units have been the first and simpliest machines which exhibit an over-unity output, but only at very high speed levels of approximately 7000 rpm, and higher. The "N" machines produce a uniform wattage flow at low voltage high current, which is a useful feature for many power applications. The requirement for the peripherial brush contacts has been, and to some extent remains a problem for these units due to the extremely high surface contact velocities. Bruce DePalma has been active in evolving solutions to the various problems of the "N" machines, including the safeguarding against bursting of the rotating magnet at high speeds. One of his machines is essentailly a hybrid design, 69