. Practical wireless telegraphy; a complete text book for students of radio communication . onstant voltage terms of the ratio of transformation, they may be classified as: (1) Step-up transformer; (2) Step-down transformer. According to the design of the coils and the core or magnetic circuit, they may beclassified as: (1) Open core transformer; (2) Closed core transformer; (3) Auto transformer; (4) Air core transformer. Fig. 37 is an elementary diagram of a closed core, step-up, constant voltage primary and secondary windings P and S respectively, are supported
. Practical wireless telegraphy; a complete text book for students of radio communication . onstant voltage terms of the ratio of transformation, they may be classified as: (1) Step-up transformer; (2) Step-down transformer. According to the design of the coils and the core or magnetic circuit, they may beclassified as: (1) Open core transformer; (2) Closed core transformer; (3) Auto transformer; (4) Air core transformer. Fig. 37 is an elementary diagram of a closed core, step-up, constant voltage primary and secondary windings P and S respectively, are supported by a rectangulariron core built up of strips of sheet iron. The primary winding, for example, may consistof one or two layers of comparatively coarse wire such as No. 10 or No. 12 B. & S. secondary winding S may have several thousand turns of fine wire such as No. 30 orNo. 32. The process of transformation is as follows: The alternating current flowing from adynamo through the primary winding P magnetizes the iron core periodically, causing a ILectromagnetic induction. 35. 15000 VOLTS500CTCU5 t_ s rs-i varying flux to flow through the iron core in accordance with the alternations of varying flux induces an E. M. F. in the secondary which will cause a current to flow ifthe secondary circuit is closed. The current in the secondary circuit flows in the oppositedirection from that in the primary circuit and as it increases, it sets up a flux in oppositionto that already in the core, reducing its strength. This reduces the self-induction of theprimary, permitting more current to flowin the primary and in this way thetransformer becomes self-regulating—a rise of the secondary current causingan increase in the primary current. If, for example, current at 110volts, 500 cycles, flows throughwinding P, the flux will alternatethrough the core 1,000 times persecond, setting up 1,000 alterna-tions of current in winding S consists of a great number of turns,
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
