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Magneto-Electric and Dynamo-Electric Machines: Their Construction and ..., Том 1
Попередній перегляд недоступний - 2018
action alternating current armature arms arrangement axis bars battery become bobbins brushes candles carried chine circuit closed coils collector commutator connected considered consists constant construction continuous convolutions core curve cylinder described desired diagram direction disks dynamo dynamo-electric machines effect electric electro-magnets electromotive force energy entire equal experiments external fastened field magnets flow force four give given Gramme Gramme machine greater heat horse-power illustrated increase induction insulated intensity iron lamps length light machine magnetic field manner material means measurements mechanical metal moved obtained ohms opposite pair parallel passing pieces placed plates points polarity poles portion position practical principle produced rent represented resistance ring rotation seen segments separate shaft shown in Fig shows side Siemens space spools springs stationary strength tension tion turned unit weight winding wire wound
Сторінка 137 - If now, while the circuit of the armature remains completed, the rheomotor be removed from the electro-magnet, on causing the armature to revolve, however rapidly, it will be found by the interposition of a galvanometer, or any other test, that but very slight effects take place. Though these...
Сторінка 139 - On bringing the primary coil of an inductorium (Ruhmkorff's coil) into the circuit formed by connecting the coils of the electro-magnet and rotating armature, no spark occurs in the secondary coil. On account of the great resistance of the circuit, which now also includes the primary coil of the inductorium, the current is not in sufficient quantity to produce any noticeable inductive effect.
Сторінка 136 - I have employed. The construction, it will be seen, is the same as that of the electro-magnetic part of Mr. Wilde's machine. The core of the electro-magnet is formed of a plate of soft iron 15 inches in length and •£ an inch in breadth, bent at the middle of its length into a horseshoe form.
Сторінка 139 - A very remarkable increase of all the effects, accompanied by a diminution in the resistance of the machine, is observed when a cross wire is placed so as to divert a great portion of the current from the electro-magnet.
Сторінка 137 - ... 0067 in diameter, by its making a powerful electromagnet, by its decomposing water, and by other tests. The explanation of these effects is as follows: — The electromagnet always retains a slight residual magnetism, and is therefore in the condition of a weak permanent magnet ; the motion of the armature occasions feeble currents in alternate directions in the coils thereof, which, after being reduced to the same direction, pass into the coil of the electromagnet in such...
Сторінка 1 - H. Magneto-Electric and DynamoElectric Machines : their Construction and Practical Application to Electric Lighting, and the Transmission of Power. Translated from the third German edition by NS Keith and Percy Neymann, Ph.D. With very large additions and notes relating to American Machines, by NS Keith. Vol. 1, with 353 illustrations. Second edition..
Сторінка 136 - The magneto-electric machines which have been hitherto described are actuated either by a permanent magnet or by an electro-magnet deriving its power from a rheomotor placed in the circuit of its coil. In the present note I intend to show that an electro-magnet, if it possess at the commencement the slightest polarity, may become a powerful magnet by the gradually augmenting currents which itself originates.
Сторінка 139 - ... but immediately afterwards the glow disappeared, and only about one inch of the wire could be permanently kept at a red heat. This diminution of effect was accompanied by a great increase of the resistance of the machine. The cause of the momentary strong effect was, that the machine from its acquired momentum continued its motion for a few seconds, though it required a stronger force than could be applied to maintain that motion. Each time the circuit is broken and recompleted, the same effect...
Сторінка 135 - ... it is not even necessary to give any external impulse upon restarting the machine, the residuary magnetism of the electro-magnetic arrangements employed being found sufficient for that purpose. "The mechanical arrangement best suited for the production of these currents is that originally prepared by Dr. Werner Siemens, in 1857...