. Archives of physical medicine and rehabilitation . riation in the alter-nating voltage applied to a kenotron,while the perfect uni-directional, al-though intermittent, current is clearlyshown in the lower curve. For theloan of the original electrotype of thisfigure, as well as those of Figures 64,65, 66, 71, 72, 73 my gratefulthanks are due Dr. W. D. Coolidge,of the General Electric Company. 65. Now the Coolidge x-ray tube,for which we have to thank the geniusof Dr. W. D. Coolidge, is a directapplication of the principle of ther-mionic emission. It differs from thegas tube, not because x-ray
. Archives of physical medicine and rehabilitation . riation in the alter-nating voltage applied to a kenotron,while the perfect uni-directional, al-though intermittent, current is clearlyshown in the lower curve. For theloan of the original electrotype of thisfigure, as well as those of Figures 64,65, 66, 71, 72, 73 my gratefulthanks are due Dr. W. D. Coolidge,of the General Electric Company. 65. Now the Coolidge x-ray tube,for which we have to thank the geniusof Dr. W. D. Coolidge, is a directapplication of the principle of ther-mionic emission. It differs from thegas tube, not because x-rays originatefor any different reason but becausethe stream of high speed electrons hasits origin in an incandescent filamentof metal. To heat the filament, anindependent circuit, called the filamentcircuit, is necessary. In the originalarrangement (Fig. 60), a storage bat-tery B| and B, was used as the sourceof supply for this circuit. In the ar-rangement now on the market (), a branch from the A. C. mainssupplies a small filament X-RAY AXD X-RAY APPARATUS—ROBERTSOX — the secondary of which is connected in series with the filament. While thisarrangement is more convenient, it hasone disadvantage. Voltage fluctua-tion on the line will cause correspond-ing fluctuations in the filament andconsequently, as we shall see later,alter the milliamperage through thetube. To give the necessary high speedto the liberated electrons, the hightension voltage is applied to the tubein the usual way, the hot filamentbeing, of course, negative. Since thewhole filament circuit is raised to thehigh potential of the cathode, it isnecessary to insulate the storage bat-tery (or the filament transformer).The complete circuit for the ordinaryCoolidge tube, therefore, includes (1 )the usual high tension circuit, (2) thefilament circuit. In Figure 62 con-nections for the complete arrangement(minus the synchronous motor circuit)are shown. It will be seen that thehigh tension circuit,
Size: 1538px × 1624px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthoramerican, bookcentury1900, bookdecade1920, bookyear1920
