Transactions of the American Institute of Electrical Engineers Volume . 19

Transactions of the American Institute of Electrical Engineers Volume . 19

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1903 edition. Excerpt: ...this form of signaling is sometimes called spark telegraphy. Hertz, who did more than any other man to elucidate the properties of these waves, cannot be considered the inventor of wireless telegraphy. Indeed it is difficult to ascribe the discovery to any one man, as, in its present form, so many inventors have contributed to the final result. The sending apparatus is very similar in most of the systems so far produced It consists essentially of an ordinary Ruhmkorff coil for generating sparks Specially designed apparatus is generally used for making and breaking the primary circuit. A battery of cells is sometimes used in connection with accumulators or storage batteries for supplying power, but when available and where greater distances of transmission are desirable, a dynamo, either with or without accumulators, is commonly employed to excite the primary of the coil. In its simplest form the battery or dynamo is placed in the circuit with the primary winding, in which also the sending key (ordinary make and break) is inserted. One pole of the secondary winding is then grounded, while the other is electrically connected to the aerial wire. These connections are shown in Fig. 1. These simple connections at the sending station are not now commonly used, but are somewhat complicated by employing an ordinary transformer and a condenser, a battery of Levden jars, in addition to the apparatus first used These are used in order to syntonize the apparatus. Fig. 2 shows one arrangement of connections when using the transformer and condenser. Different arrangements have been adopted by inventors for Kig. I.--Sketch of Sending Connections. (Non-syntonic.) A.--Induction Coil. B.--Spark Gap. C--Circuit Breaker. D.--Sending Key. E.--Earth. F.--Aerial more

Product details

  • Paperback | 406 pages
  • 189 x 246 x 21mm | 721g
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 123655583X
  • 9781236555830