Robison's Manual of radio telegraphy and telephony for the use of naval electricians (1918)
Robison, S. S. (Samuel Shelburne), b. 1867, United States Naval Institute, Todd, David Wooster, Hooper, Stanford Caldwell · Annapolis, Md. : The United States Naval Institute · leaf 28
called a closed-core trans-former; fig. 14b an open-core transformer or induction coil; fig. 14c anair-core transformer. Transformers are called step-up or step-down with reference towhether the turns in the coil C D are greater or less than those in A B.Fig. 14b is a step-down; fig. 14c a step-up… … =^ Fig. 13. 28. Keferring again to fig. 13: When the break at K is closed, acurrent is started, which progresses upward through the coil, the mov-ing charges composing it creating a magnetic field around the wire.The lines of force, as they expand from the current in the first turn ofthe spiral,…
