Abstract: A three phase DC motor (10) including a rotor portion (12) and a stator portion (16). The rotor portion (12) includes 6N.+-.2 permanent magnet poles (32), and the stator portion(16) includes 6N electromagnet poles where N in an integer. The motor (10) is characterized in that it has a high pole density, thus enabling improved efficiency, while retaining acceptable non constant torque characteristics. Since the inventive motor configuration provides for a symmetrical winding pattern, no assymetrical radial forces are produced. The inventive configuration further allows for small motor size in the height dimension. A first preferred embodiment of the motor (10) is adapted for three phase power to be connected to the motor windings (50), (56) and (58) in a "Y" fashion. An alternate preferred embodiment of the invention (610) has coil windings (650), (656) and (658) connected in delta configuration.

Abstract: The subject dynamoelectric machine comprises an armature between two field assemblies. The armature may rotate between the field assemblies or vice versa. The armature has three two-coil windings with the coils of each winding located diametrically opposite each other on the armature and wound in opposite directions. Each field assembly comprises a field ring, winding cores (or permanent magnets) and pole faces which span essentially 180.degree., there being a north face and a south face for each field assembly. The field assemblies are positioned with like faces facing each other. The commutation apparatus energizes each armature winding just as it is positioned completely between the field pole faces and de-energizes it just before it starts to move out from between the faces because of the relative motion between the armature and field assemblies. The machine concept is adaptable to pancake and cylindrical configuration.

Abstract: Lower coils (5b) and upper coils (5a) are inserted to slots (12) of a cylindrical armature core (4). The upper coils are used as crossover lines (102a) at the side of commutator (10) and form commutator segments. The crossover lines are approximately deviated by a pole pitch (yf) at the commutator and inserted to other slots as lower coils. The lower coils are used again as crossover lines and deviated approximately by the pole pitch at the opposite side of the commutator so as to be inserted again to the slots as the lower coils. An insulating resin (11) are forced to push into inner peripheral sides of the armature core, and the crossover lines forming a squirrel cage type shape and extending cylindrically from the core.

Abstract: There is provided an alternating current generator comprising: a rotatably supported field rotor having a pair of opposed rotor pole cores, each being provided with P/2 claw poles wherein P is an even number, and a field winding wound on the rotor pole cores; an armature core located around the outer periphery of the field rotor and having axially extending 3nP slots wherein n is an integer more than one; n independent sets of three-phase windings, each being wound on the armature core by being inserted in the slots so that the n sets of three-phase windings are shifted from each other by electrical angle of .pi./(3n) radians; and three-phase rectifiers connected with the n sets of three-phase windings to rectify output voltages generated by the three-phase windings.

Abstract: A direct - current electric machine includes a rotor rotatable about an axis of rotation and a stator formed with a plurality of locations angularly equispaced thereon and provided with a respective array of horseshoe magnets extending over 180.degree. about a respective helical coil wounded on a coil axis defined by a respective pair of arms mounted on the rotor and coinciding with a tangent to a circle centered in the axis of rotation.

Abstract: Coils for electric appliances such as motor or generator are made with a superconducting material, and the width of the coil and the gap between the coils are so adjusted that the passage of magnetic flux generated by a magnetic flux generating member in the electric appliance is not influenced by the magnetic repulsion of the superconducting material.

Abstract: A direct current machine is characterized in that each of field poles and an armature are formed to satisfy a condition that an internal peripheral width Wa of each auxiliary pole is equal to or greater than a distal end width Wt of each tooth and equal to or less than twice a distal end width Ws of each slot plus the distal end width of each tooth (Wt.ltoreq.Wa.ltoreq.2Ws+Wt). The D.C. machine also is characterized in that each of the field poles and the armature are formed to satisfy a condition that an inner peripheral width Wm of the permanent magnet is equal to or greater than twice a slot pitch Wp of the armature core and equal to or less than twice the slot pitch Wp plus the distal end width Wt of each tooth (2Wp.ltoreq.Wm.ltoreq.2Wp+Wt).

Abstract: A starter apparatus comprising an electric motor including an armature rotary shaft (35) made hollow so that power transmission mechanism (40) can be internally positioned and an armature core (36) mounted to the rotary shaft (35) and having in the periphery thereof a large number of slots (37) for winding therein an armature coil (38, 39). The armature coil of the electric motor (34) is composed by winding a single wave-winding coil (38) and a double wave-winding coil (39) in combination so that three coil conductor sections are positioned per one slot (37) for majority of the slots.

Abstract: A superconducting motor (1) comprises a stator (3) and a rotor (5), both of which employ superconductive windings. The rotor includes two sets of windings, a large rotor winding (13) and a small rotor winding (15). The windings are connected to form a current loop (16) which is exposed to a magnetic field. Switches (S1,S2) or diodes (D1,D2) are employed to trap a maximum number of magnetic flux lines in the loop when the magnetic field is impressed on the loop. Thereafter, the trapped flux is transferred from the small to the large winding to run the motor. When the switches are closed, the loop acts as a perfect conductor whereby no flux change occurs within the loop.

Abstract: A high start/stop cyclic capability connector to interconnect the field coil poles in a rotating electric machine. The connector includes a U-shaped intermediate portion with parallel jaws which include extensions perpendicular to the faces of the jaws a distance significantly greater than the width of the jaws, and with connecting pads configured for matching connection to the field coils and orienting the connector such that start/stop inertial forces are applied in the radial direction which causes circumferential flexure of the connector, and flexure due to thermal cycling is in the circumferential direction.

Abstract: An improved connector for the main field coil of a rotating electric machine having high start/stop cyclic duty capability. The connector is generally L-shaped with the field coil connection portion being parallel to the axis of the machine and the centrifugal forces of the start/stop cycles being applied perpendicular to the field coil connection portion. Enlarged connection portions integral with the L-shaped central region are configured for connection to the field coil and a terminal including a cylindrical post.

Abstract: A superconducting DC machine includes a superconductive field winding housed in a cryostat. A magnetic shield is arranged outside the cryostat. An armature drum is rotatably supported between the cryostat and the magnetic shield. The armature drum of the machine is divided into a plurality of segments along the length thereof, and has arranged thereon current-collecting brushes not more than one half of the segments. Each brush is electrically connected to the opposed one at the other longitudinal end of the same segment of the armature drum and also to the one at the longitudinal opposed end of an adjacent segment in diagonal fashion progressively.

Abstract: A superconducting rotating electric machine has superconducting rotor windings made from a high-temperature superconductor having a critical temperature of at least 78.degree. K. The rotor windings are cooled by a liquid coolant such as liquid nitrogen which is sprayed from the stator directly at the outer surface of the rotor.

Abstract: In a cylindrical rotary transducer having a stator core cylindrically formed from a high permeability material, a rotary core disposed coaxially with the stator core and cylindrically formed from a high permeability material, and a stator coil and rotor coil disposed respectively on the stator core and the rotary core so as to confront each other; the cylindrical rotary transducer comprises a disk-shaped terminal member mounted on one of the stator and rotary cores, having a plurality of projections radially formed on an outer peripheral edge thereof, and terminals connectd to one of the stator and rotor coils being fastened to the projections; and a supporting element for supporting one of the stator and rotary cores from the other in a rotatable relationship.

Abstract: The present invention relates to armature windings. Individual coils (100) of a group of coils (105) are disposed in slots (203) of an armature such that a first sub-group of coils (100a) are wound in a first direction and second sub-group of coils (100b) are wound in a second direction opposite the first direction.

Abstract: An armature of a three-phase magneto for generating three-phase AC output has a core having a plurality of magnetic poles arranged in an annular array on the periphery thereof. The armature has three series winding circuits corresponding to the respective phases, each series winding circuit including series-connected windings wound on every three magnetic poles. The winding direction of the windings of one of the three series winding circuits is opposite to the winding direction of the windings of the other two series winding circuits. The armature also has three connection conductors for connecting ends of the three series winding circuits into a delta connection and providing output terminals of the three-phase AC output.

Abstract: A three-phase direct-current motor has a field magnet having P field poles positioned as a circular array at angularly equally spaced intervals, and an armature having cores providing N slots with three-phase coils disposed therein, either the field magnet or the armature being rotatable with respect to the other. P and N are defined by P=2(4n+3) and N=3(2n+1) where n is an integer of 1 or more, and being selected such that the least common multiple of N and P is equal to N.times.P. Alternatively, P and N are defined by P=2(3n.+-.1) and N=6n where n is an integer of 2 or more.

Abstract: In an image-forming apparatus (1), such as an electro-graphic printer, in which an electro-static latent image formed on an photoconductive drum (5) is reproduced by a toner (15), having a pulse motor (M) for driving an agitator (13) built-in to a developer unit (8), the agitator (13) is controlled during an initialization process of the apparatus (1) by setting the rotational speed of the motor (M) at a lower level (P) upon a start-up thereof, and converting the same to a higher level (N) corresponding to the normal operational speed after a predetermined period (T1) has passed from the start-up, whereby a larger torque is generated from the motor (M) at the start-up stage of the initialization so that the agitator (13) can be smoothly rotated even if the toner (15) has solidified in the developer unit (8).

Abstract: Radial loop coils are wound in radial planes partly in the conventional slots of the stator and/or rotor core at right angles to the planes of the conventional drum coils. No conventional drum coils are wound. A cylindrical body of nonmagnetic material is fixedly interposed between the rotor core and the shaft and/or between the stator core and the yoke so that the flux of the stator and the rotor core flows in opposite side portions of the stator and rotor core, not through the shaft or the yoke, to generate e.m.f. in the radial loop coils by the transformer action. The flux which is produced by the transformer m.m.f. of the radial loop coils is constrained to flow into the air gap by virtue of the presence of the cylindrical body of nonmagnetic material where it acts to eliminate changes in the main magnetic field flux density distribution in the air gap.

Abstract: A D.C. rotary electric machine comprises an armature winding having a plurality of unit coils shifted from each other by a predetermined electrical angle and a commutator having a plurality of commutator segments. Each unit coil includes a pair of coil sides and is connected between two commutator segments. The unit coils are positioned with respect to the commutator segments so that an axial line passing through the midpoint between the pair of coil sides of each unit coil is circumferentially advanced by a predetermined angle with respect to an axial line passing through the midpoint between the commutator segments to which the coil unit is connected.

Abstract: An armature of an AC generator includes a plurality of polyphase windings. Each of the polyphase windings is a wave winding passing about substantially the entire circumference of the armature. In one embodiment, four three-phase windings are wave wound in the armature. External connection to each of the phases and the neutral of each three-phase winding is made through four connector quadrants disposed in four parallel planes. Connection to the remaining nine phases and three neutrals are made through further connector quadrants sharing respective planes with the first-mentioned connector quadrants.

Abstract: A self-excited brushless alternator having a rotating field winding excited by an alternating current exciter whose rotating armature rotates with the rotating field winding and is permanently connected to the field winding via a field rectifier also mounted to rotate with the field winding. The exciter has an exciter stator primary winding and a rotary exciter secondary winding connected via a rotray field rectifier to the rotary main field winding of the alternator. The primary excitation for the exciter is derived, via magnetic coupling, from a rotary auxiliary magnetic field produced by a feedback winding in series with the main field winding and rotating herewith. A common magnetic circuit couples the rotary feedback winding with an auxiliary stator secondary winding and the exciter primary and secondary windings.

Abstract: A dynamoelectric machine has a brushless, substantially ironless stator coil of a long electrical wire conductor which comprises a large number of straight legs which are grouped into spaced bundles to form a thin-walled structure that may be cylindrical as in FIG. 1 or flat as in FIG. 6. The thin-walled structure may be supported by a plastic framework or may be adhered to a thin, correspondingly cylindrical or flat, ferromagnetic sheet. A ferromagnetic sheet not only supports the coil, but also enhances efficiency by providing a return path for electromagnetic flux. A plastic framework is lighter in weight.

Abstract: A 5-phase dc motor which can be mass-produced readily at a reduced cost. The motor comprises a field magnet having four alternate north and south magnetic poles of an equal angular width, a rotor including a rotor armature core having five rotor pole shoes formed in an angularly equidistantly spaced relationship by an electrical angle of 144 degrees, a commutator including ten commutator segments provided successively on the rotor, and a pair of brushes disposed in a spaced relationship by an angular distance of 180.degree. electrical and for sliding contact with the commutator. A single conductor is electrically connected to the commutator segments and wound on the rotor pole shoes in a predetermined specific sequence to form armature windings which do not overlap with any other armature windings.

Abstract: Stator slots are skewed relative to rotor slots with a skew amount comprising an integer multiple of a stator electrical angle of 60.degree., thereby minimizing a torque ripple which is an integer multiple of six times of a primary frequency of electrical energy.

Abstract: The end turn portions of the saddle-shaped coils of a superconducting field winding in the rotor of an electric machine are clamped in an axial direction by a wedge device positioned in an annular recess between its wall and the nearest end turn portion. The wedge device comprises two rings mounted coaxially with the recess and having their sides facing each other bevelled so that the distance therebetween increases toward the axis of the rings. These sides are provided with radial depressions. Bolts with heads tapering toward the threaded portions are positioned in the depressions. When the bolts are radially shifted the rings are forced apart thus pressing the end turn portions one to another and to the wall of the recess.

Abstract: A winding pattern for a motor rotor comprising an armature mounted on a rotary shaft and provided with a plurality of longitudinal slots defined a plurality of core teeth; a commutator mounted on the rotary shaft at a longitudinally spaced relationship to the armature and provided with circumferentially divided segments; and one or more sets of coils wound around the core teeth through the core slots. The very first starting lead of the set of coils comprises a first span which extends from a first commutator segment into a first core slot, a second span which extends out of the first core slot and is wrapped around the rotary shaft at a part opposite to the commutator with respect to the armature, a third span which is passed through a second core slot from the second span towards the commutator, a fourth span which extends out of the second core slot and is wrapped around a part of the rotary shaft intermediate between the armature and the commutator over a certain angle.

Abstract: A compact, high-torque electric motor in which one motor element (either the stator or rotor) has magnetic poles whose effective magnetic width is substantially equal and which span equal center angles. The second motor element has a plurality of armature groups, each of which occupies a phase sector of the motor element formed by dividing the total periphery by a natural number. All of the armatures within an armature group are connected electrically in series and excited with a current of one phase (either an alternating current phase or an equivalent phase generated by commutator action). Within on pole group the poles may have equal widths or different widths.

Abstract: An improved alternating current machine having interdispersed armature windings is disclosed. The AC machine comprises an armature core having a plurality of generally longitudinal slots and a plurality of winding groups. Each of the winding groups comprises a plurality of one-turn coil windings which are series connected to electrically adjacent windings of the winding group. Each winding has two generally parallel side portions disposed in non-adjacent ones of the slots. The side portions are joined at one end by an end turn which extends axially outward from one end of the armature core and each of the side portions have an end connection extending a distance axially outward from the other end of the armature core for connecting to a respective electrically adjacent end connection of its electrically adjacent winding. The winding groups are interdispersed about the armature core such that there are a plurality of fixed distances between the electrically adjacent windings.

Abstract: A motor includes an armature and a field magnet which surrounds the armature. The armature includes a plurality of teeth being arranged at equal pitch, and the field magnet includes a plurality of magnetic poles being arranged at equal pitch. When the number of the magnetic poles of the field magnets is "2P" and the number of phases of divided armature windings is "Q", the number T of the teeth is determined in accordance with an equation T=(P.+-.N) Q (O<N<N<P-2P/Q). In addition, "phase" and "winding direction" of the divided armature windings to be wound on the respective teeth are determined through comparison of an actual angle in electrical degrees of respective one of teeth and an ideal angle in electrical degrees corresponding thereto.

Abstract: A compact three-phase permanent magnet rotary machine having minimal reluctance torque and electromagnetic torque ripple, and maximum energy efficiency and starting torque per unit volume of winding, comprises an armature having 3(2n+1) ferromagnetic poles and slots and a permanent magnet assembly having 3(2n+1).+-.1 permanent magnet poles, where n is an integer of 1 or more. Each of the three phases of the winding comprises multiple coils, each wound about a respective ferromagnetic pole and occupying a pair of slots located immediately on each side of a respective pole. The coils of a particular phase are located within a sector of the circular array of ferromagnetic poles encompassing 2n+1 poles.

Abstract: A three-phase induction motor includes winding slots and a stator winding. The number of winding slots per pole per phase is a noninteger. The stator winding is a three-phase balanced winding. A pitch s of the winding satisfies s=(r-t)/r or s=r/(r+t) (where t is an odd number and r is the order of a harmonic wave to be suppressed).

Abstract: A rotatory electromotor having a stator with stator poles and a rotor with rotor poles, permanent magnets being provided for the stator poles or for the rotor poles and electromagnets for the poles not provided with the permanent magnets, electronic switching means being provided for switching electromagnets in accordance with the relative positions of the electromagnets and permanent magnets in each case, and the permanent magnets and the electromagnets being arranged in such a way that only some of the electromagnets of the electromotor can be simultaneously switched in each case. Several adjacent electromagnets form a group of electromagnets belonging to one phase, this group cooperating with a number of permanent magnets located opposite, and adjacent groups of electromagnets belong to different phases.

Abstract: Winding arrangement of a stator and/or rotor of a three-phase generator or electromotor makes possible an improvement of all performances of these electric machines. The improvement is obtained in that to star-connected windings there are connected additional delta-connected windings, which in relation to the star-connected windings are spatially shifted for an angle of (.pi./2p).+-.(.pi./6p), p being the number of pole pairs. Such a winding arrangement is symbolically expressed by Y+j.DELTA.= .

Abstract: The present invention includes a rotary converter for converting direct current to altenating current. The rotary converter includes a rotor and a stator. The rotor includes a shaft, a commutator concentric with the shaft, and an armature core concentric with the shaft and adjacent the commutator, the core having slots in its outer circumference parallel to the axis of the shaft. At least one slip ring is mounted on the shaft adjacent the armature core. A first or direct current winding is electrically connected to the commutator and wound in a wave pattern through the armature cores slots. A second or alternating current winding is electrically connected to at least one slip ring and wound in a series of alternating clockwise and counterclockwise loops through the armature core slots. The rotary converter is particularly suitable for operation from a standard twelve volt battery to supply alternating current at a desired rating to electric tools and the like.

Abstract: A rotating electric motor has a permanent magnet member of a circular form and an armature core made of a magnetic material. The permanent magnet member has a plurality of N and S poles positioned alternately around the rotary axis of the motor, and the number of the poles is P which is an even number. The armature core has a plurality of teeth formed between two adjacent winding slots of the armature core, and the number of the teeth is T which is an integer not less than 2P. Overlapping winding coils of polyphase winding groups are wound in the winding slots of the armature core, and the number of the phases of the polyphase winding groups is H which is an integer not less than 2. The armature core has at least one short-block and one long-block, each of which consists of a group of teeth having at least two teeth positioned sequentially.

Abstract: A rotating electric motor has a permanent magnet member of a circular form and an armature core made of a magnetic material. The permanent magnet member has a plurality of N and S poles positioned alternately around the rotary shaft of the motor, and the number of the poles is P which is an even number. The armature core has a plurality of teeth formed between two adjacent winding slots of the armature core, and the number of the teeth is T which is an integer not less than 2P. Overlapping winding coils of polyphase winding groups are wound in the winding slots of the armature core, and the number of the phases of the polyphase winding groups is H which is an integer not less than 2. The armature core has at least a pair of short-blocks and long-blocks, each of which is a group of teeth having at least one tooth and positioned sequentially.

Abstract: An excitation system of a large dynamoelectric machine includes an excitation transformer having a liquid coolant system. The coolant system of the transformer is supplied with a liquid coolant, preferably from an existing source of de-ionized water, thereby permitting a smaller transformer to be used and/or the output rating of the transformer (and ultimately the output rating of the machine) to be increased, while using the same size transformer. The transformer may be disposed separate from, yet closely proximate, the machine.

Abstract: A multi-layer armature winding for large turbine generator is wound with individual diamond coils around to the point where the sides of initially wound diamond coils lying in upper armature slot positions interfer with the placement in lower slot positions of the coil side of additional diamond coils to complete the winding. To avoid having to "raise the jump" the winding is completed using bar coils, individual bars of which having been laid in those lower slot positions prior to the placement of any diamond coils. The remaining bars are laid in the vacent upper slot positions and then electrically joined with the initially laid bars to complete the individual bar coils.

Abstract: The alternating current motor stator of a polyphase motor has each coil wound of at least two separate conductors. The terminal ends of each conductor is encoded for separate circuit interconnection to other conductors of other coils of the motor stator. The coils are inserted into the stator with a single coil side per slot and appears as a conventional chain winding. The bi-filar wound coils have the encoded ends connected to obtain the benefits of double delta winding connections. The coils are paired and selectively connected to each other by speed responsive switches to define a double delta run winding with the phase windings connected in parallel and a double-delta start winding.

Abstract: A 3-phase, pole-changeable, phase-modulated winding providing alternative pole-number working by 6-terminal changeover switching. The winding provides 3-parallel, 3-phase, star-connected winding branches for both the alternative pole-number connections. In a preferred arrangement all the winding parts are energized for both the alternative pole-number connections.

Abstract: A cup-shaped winding for use in the rotor or stator of a motor such as a coreless motor or slotless motor makes use of leakage flux as well as magnetic flux in the main direction. The cup-shaped winding consists of wire bands which are lap wound such that they are successively shifted a given angle from one another about the rotating shaft of a core. The winding is shaped into a cylinder or cone. The portion of each wire band which is on the bottom of the cylinder or cone does not surround the rotating shaft and forms two sides that meet at a vertex lying on the periphery of the rotating shaft. The portion of each wire band which is on the curved surface of the cylinder or cone are inclined away from the rotating shaft.

Abstract: An electromechanical transducer comprises a fixed part and a part rotatable about an axis. One of these parts includes an assembly of aircore coils which are distributed about the axis. Each coil is divided into two parts, each of which comprises two active coil segments intersected by the magnetic field upon rotation of the transducer. The two parts of each coil are furthermore arranged so that the effects of mutual inductance of the active coil segments of one coil part upon the other are reversed relative to the effects of self-inductance in each part.

Abstract: A D.C. excited rotor winding arrangement for a dynamoelectric machine comprises at least one closed loop (1,2,3) of three or more series-connected winding sections (10,11,12,13,16,17,18,19,20,21,22,23) with at least three current-supply terminals (ABCD) at their interconnections. At least one pair of adjacent winding sections (10,13; 11,12) generate opposite magnetic poles when fed in parallel with current from their common supply terminal (such terminals are designated "odd", as opposed to "even" terminals which are each associated with two poles of the same sense) and the pole number is varied by switching the current supply from "odd" to "even" terminals or vice versa. Preferably the winding arrangement comprises a plurality of series-connected closed loops (1) of four winding sections interconnected at two odd (B5, D5) and two even (A5, C5) terminals. Preferably the winding arrangement is fed with current from one of a plurality of rotating rectifiers (4,6,7) according to the pole number required.

Abstract: The electric motor is of the type in which the speed of rotation as a function of the resisting torque is different in one direction of rotation than in the other, and comprises a pair of brushes (B1, B2) placed between field poles (P1, P2) and cooperative with an armature structure consisting of a commutator (14) rigid with an armature support (12) through which the shaft of the motor extends and in which are formed slots in which are wound wires connecting a series of strips (1,2 . . . ) of which the commutator (14) is formed, wherein each plane (L) containing the geometric axis (XX) of the motor and passing through the middle of a strip (1,2 . . . 8) of the commutator (14) halfway between two consecutive slots (15) of the commutator is offset by a given angle .beta. relative to the corresponding plane (K) passing through two diametrically opposed slots (B,F) of the armature support (12) in the direction of rotation (R) of the motor employed for the rising of the driven element.

Abstract: A winding arrangement for a twin winding set three-phase alternator having P rotor poles and 3nP stator slots, where P is an even integer and n is an integer greater than or equal to two, each set of three-phase windings comprising a group of P/2 interconnected winding components per phase. The stator coils each span an odd number of stator slots, and are connected such that circumferentially adjacent coils are connected in different of the sets of three-phase windings, and such that each winding component comprises one or more coils from each of two different pole pitches. As a result, a given stator slot contains winding elements belonging to only one of the sets of three-phase windings, and magnetic coupling between the sets of three-phase windings due to slot leakage is thereby avoided.

Abstract: This disclosure depicts a direct current machine having an armature, in which a plurality of coils are opposed to each of a plurality of field poles and coil-wound in a special wave winding. In this special wave winding, each of the coils is divided into two or more divided coil members for the coil-winding, and coil sides associated with each other of each of these divided coil members are wound into slots adjacent to each other.

Abstract: A power supply system for portable floodlighting equipment employing high-intensity electric discharge lamps comprises an alternating current generator having two independent armature windings, one for producing current at a standard voltage and the other for producing current at a voltage sufficiently high for starting a discharge lamp in series with a capacitor. The two windings are out of phase and interference with the operation of the lamps energized by the first winding and electric apparatus energized by the second is effectively eliminated. The use of the generator winding for starting and energizing the lamps eliminates the usual starting ballast and decreases the weight and cost of the portable floodlighting unit.

Abstract: A direct current motor comprising a field magnet with 2np magnetic poles, magnetized to N and S poles with equal angular intervals, where n is an integer of 1 or more and p is an integer of 2 or more; a magnetic member for closing the magnetic circuit of the magnetic circuit of the magnetic poles of the field magnet; n(py.+-.1) armature coils disposed in such a manner that the angular intervals of the electrically conductive portions of the armature coils, contributing to the generation of torque in the armature coils, are substantially equal to the magnetic pole width of the field magnet, where y is an integer of 3 or more; a wave-winding-type armature on which the armature coils are disposed, overlapping on each other, with an equal pitch, the wave-winding-type armature being directed towards the field magnet within the magnetic circuit; electric power supply control device for commutating the commutator current np(py.+-.1) times or 2np(py.+-.

Abstract: An improved magnetic core element for use in an electrodynamic rotary machine, and the method of making such a core element are disclosed. The core element, either a stator or rotor depending upon the design of the machine, is provided with a slot distribution such that when the rotor rotates with respect to the stator and a balanced energy field is provided therebetween, at least the lowest generated harmonics, will be substantially zero.