. A text-book of radiology . he primary again with the alternating current we willfind that another alternating current is formed in thesecondary coil. This is, in fact, an experimental trans-former and differs in no essential particular from thoseused for the distribution of electrical energy whereveralternating currents are used. The primary coilimpresses a magnetism on the core which is constantlyvarying. As the core is continuous and passes throughboth coils, the secondary coil is thus exposed to a con-stantly varying magnetic field. We have already seen 14 TEXT-BOOK OF RADIOLOGY. that the
. A text-book of radiology . he primary again with the alternating current we willfind that another alternating current is formed in thesecondary coil. This is, in fact, an experimental trans-former and differs in no essential particular from thoseused for the distribution of electrical energy whereveralternating currents are used. The primary coilimpresses a magnetism on the core which is constantlyvarying. As the core is continuous and passes throughboth coils, the secondary coil is thus exposed to a con-stantly varying magnetic field. We have already seen 14 TEXT-BOOK OF RADIOLOGY. that the effect of this on a conductor is to set up currentsof electricity in it. It will also be found that we canvary the voltage or pressure of this secondary current toany extent we please. It is simply a question of thenumber of turns wound on the secondary as compared tothe number of turns on the primary. This will be bestexplained by an example. Suppose our primary coil hasone hundred turns of wire and the alternating current. IWCtt** 7 Secondary Coil Fig. 2. Diagram of Transformer. supplied to it has a mean pressure of 100 volts, and wewish to obtain a current to heat a cautery which requiresa pressure of say five volts. The primary has one turnper volt and theoretically the same will be right for thesecondary—in this case five turns. It will be found thatthis will come out about right, and if the wire of thesecondary has been chosen sufficiently thick plenty ofcurrent will be available for even the largest cautery usedin surgery. A transformer regulates itself in a mostperfect manner. As we draw off current from the CONDENSERS. 15 secondary this relieves the primary of so much of its self-induction, and consequently more current flows in. In awell-designed transformer very nearly the same amountof energy is available from the secondary side as is sup-plied to the transformer on the primary side. Capacity.—It is known to most students that thepoles of an ordinary battery, o
Size: 1626px × 1536px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidtextbookofra, bookyear1915
