. An elementary manual of radiotelegraphy and radiotelephony for students and operators . be a dead-beat discharge of extremely uniform fre-quency, and should consist wholly of electricity winch has beendrawn from tlie condenser, and not be mixed up with a truealternatin*; current arc discharue which is due to current coming 272 RA DIO TELEGRA PHY directly out of the transformer. Marconi, however, found bycareful experiments that between metal surfaces in exceedinglyrapid relative motion it is very difficult to produce a true electricarc, but, nevertheless, an oscillatory discharge Irom a cond
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . be a dead-beat discharge of extremely uniform fre-quency, and should consist wholly of electricity winch has beendrawn from tlie condenser, and not be mixed up with a truealternatin*; current arc discharue which is due to current coming 272 RA DIO TELEGRA PHY directly out of the transformer. Marconi, however, found bycareful experiments that between metal surfaces in exceedinglyrapid relative motion it is very difficult to produce a true electricarc, but, nevertheless, an oscillatory discharge Irom a condensercan pass between these surfaces. Hence he has devised forms ofhigh speed rotating discharger made as follows:— In one form there are a pair of metal discs, C, C (see Fig. 21),which are caused to rotate rapidly by electric motors or othermeans. Between these, and insulated from them, another disc, A,rotates at a high speed, with its plane at right angles to theother two. The terminals of a dynamo machine are connectedwith the terminals of a pair of condensers, K, in series, and. Fig. 21.—Marconi High-speed Disc Discharger. through inductances, L, L, with the discs C, C. The middle pointof the condensers is connected to another condenser, E, and thisthrough one coil of the jigger F with disc A. If a key in thedynamo circuit is closed, it charges the condensers, K, and thenat a certain potential the condenser E discharges with oscillationsacross one or other of the air gaps between the rapidly revolvingwheels. The arc discharge which attempts to follow in the trackof the oscillations is, however, prevented by the rotation of thediscs from taking place. In another arrangement (see Fig. 22) the disc A has studs onits circumference at intervals placed transversely to its plane. The action of the discharger as shown in Fig. 21 is as follows: HA DIG TEL PIIIC S TA T/ONS 273 The ilyiiamo chiir»ies the two hirj^t? coudeiisers. K. and then at somejtoteiitial that }>hite
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
