The Engineer Volume 73

The Engineer Volume 73

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1892 edition. Excerpt: ...all the essential features of s shunt machine. The sentences which follow a pear to me to describe the series-shunt with equal accuracy. The commence with the statement that there are several ways of " oing this," that is, of obtaining a circuit of excitation and an electric lighting circuit from a single current, by dividing it into two portions. The method preferred is to make both circuits pass round the magnets, that of greater resistance being employed for excitation only, whilst that of lesser resistance excites the magnets, and also does the work of lighting. The series-shunt is evidently treated as a mere modification of the shunt system; and I think it might be reasonably regarded in that light by the patentee. The alteration in the mechanical arran ement of the apparatus is iii itself trivial; and the possibility of thereby obtaining such a constant potential as would, at a future date, suflice for flu purpose of incandescent lighting was not present to his mind. There might, as one of the witnesses suggests, still remain room for a patentable improvement upon the series--shunt as described by 'arle_v, consisting in an adjustment which would insure a high ilugree of constant potential. N o such ossibility is indicated either by Varley or in Brush's patent of 1 78. In the a men! addressed to your Lordships, counsel for the appellants lai mncli stress upon these words occurring in Varley's specification: --"The insulated wire composing the helices is connected to the insulated wire surrounding the soft iron magnets of the machine, and is usually inserted in the circuit of greater resistance." They mautained that the necessary result of giving effect to that direction would be to deprive the apparatus...
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Product details

  • Paperback
  • 189 x 246 x 58mm | 2,046g
  • United States
  • English
  • black & white illustrations
  • 1236952367
  • 9781236952363