Popular science monthly . t higher than the velocities reachedby De Laval turbines and certain centrif-ugal machines) electromagnetic wavesof 100,000 alternations per second fre-quency can be generated. This corre-sponds to a wavelength of about 6,000meters. One set of circuits shown in the patentis given in the accompanying generating commutator is formed ofsegments 8 and 7 placed side by sideand insulated by the separating material9. A brush with flexible tip 5, balancedby the weight 6, is revolved by powertransmitted through the belt 5a. Theantenna I is connected through tuningc
Popular science monthly . t higher than the velocities reachedby De Laval turbines and certain centrif-ugal machines) electromagnetic wavesof 100,000 alternations per second fre-quency can be generated. This corre-sponds to a wavelength of about 6,000meters. One set of circuits shown in the patentis given in the accompanying generating commutator is formed ofsegments 8 and 7 placed side by sideand insulated by the separating material9. A brush with flexible tip 5, balancedby the weight 6, is revolved by powertransmitted through the belt 5a. Theantenna I is connected through tuningcondenser 3 and inductance 4 to the rotation contact; alternate commutatorbars are connected to the oppositeterminals of the charging source 13, 14(which may be either two high voltagegenerators, or batteries, as shown).The middle point of the power supply isgrounded for radio frequency currents,from 15 through the condenser 16 to additional tuning circuit consisting The revolving brush producesradio frequency current. of condenser 12 and coil 11 is shuntedacross the main power leads, and avariable inductive resistance is placedin circuit at 10. Assuming that the upper terminal of14 is of positive polarity, and the lowerend of 13 negative, the operation of thetransmitter may be outlined briefly bypointing out that each time the contactrests upon a bar or the group numbered8 the antenna system is charged with apositive pulse; when the brush passes tothe next contact this charge rushes toearth and the antenna assumes a nega-tive potential. By adjusting the tuningof the antenna circuit as a whole so asto agree with the rate of interruptions ofthe commutator, strong radio frequencycurrents can be set up in the aerial andcorrespondingly intense waves radiatedtherefrom. The diagram merely indicates thebasis of the method proposed. Difficul-ties of insulation would suggest the useof two commutators with separatebrushes contacting alternately, one foreach polarity of charge. Variou
Size: 2297px × 1088px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1872
