Identifier: practicalpointsi00judd (find matches)
Title: Practical points in the use of X-ray and high-frequency currents
Year: 1909 (1900s)
Authors: Judd, Aspinwall
Subjects: X-rays Electrotherapeutics Radiography X-Rays Radiography
Publisher: New York : Rebman Company
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
rom each other. When connected with a uni-direction high voltage current, the violet color appears on the negativerod C. The length of this color depends upon the number ofmilliamperes in the circuit. o 3= Fig. 14.—Shows an Oscilloscope indicating an alternating or oscillatingcurrent. This is indicated by the fact that the violet color showsequal length on each rod. IB- 0 ^A Fig. 15.—Shows an Oscilloscope indicating a small amount of inversewhich is shown by the short violet color on the other rod. metal rod. If the current is alternating, theviolet color will be equal on both rods. (SeeFigs. 13, 14 and 15.) Villard Valve Tube This is a device for cutting out inverse cur-rent. It consists of a vacuum bulb having aspiral electrode placed at one end of it anda small rod at the other end. As long as the 42 X-Ray and High-Frequency Currents spiral end is negative, the current flows freelyfrom the small rod at the positive end; but assoon as the spiral end is positive, it tends to hold
Text Appearing After Image:
Fig. 16.—Illustrates a self-regulating Villard Valve. When this isplaced in series with an Oscilloscope which, without the valve tube,will indicate, as shown on Fig. 14, when the valve is placed in circuitwith it, the Oscilloscope would indicate according to Fig. 15. Thisshould be used with every induction coil. back the current. As this device is commonlymade, it has a self-regulating attachment forkeeping its resistance constant. (See Fig. 16.) Tracing the Current through a Coil We will now proceed to trace the currentthrough the primary circuit. Starting with theinitial current, we have two wires. One of thesewill be attached to one end of the rheostat. Thecurrent will flow from there through the rheo-stat to a wire attached to the base of the handle.The quantity of current passing through willthus be regulated by the amount of the ribbonof metal which is included in the circuit, this inturn being controlled by the position of the han- The Coil and Accessories 43 die. The wire is

Note About Images