Nikola Tesla Books
QUENCHED GAP APPARATUS 109 the full number of turns is in use, the instrument operates at its rated capacity. The secondary winding consists of 3,454 turns of No. 23 enameled wire wound in two sections. This winding is also done upon a round form, the air-space between winding and core serving to keep them both cool through the medium of the extra radiation surface provided. Each section of the secondary winding may be wound upon oiled paper 1½ in. wide. The winding may be carried out to within ½ in. of either edge of the paper, which makes the actual width of winding 14 inch. The two secondary sections are separated by a disc of fibre or, preferably, micanite sheeting, the edges of which may be bent around to lap over the pieces inserted between the secondary sections and the core. For specific instructions on the winding of a twosection secondary, see the transformer directions in later chapters. The magnetic leakage tongue may well consist of a bundle of pieces of the core iron cut 3 by 4 inch. The thickness of the bundle will depend upon the condenser capacity used with the transformer and also upon the type of gap employed. The correct amount can readily be determined by experiment, however, after the instrument has been finished and put in operation. Caution. The secondary winding of this transformer is of low resistance and it delivers a high potential current that would most likely prove fatal if taken through the body. For this reason, more than ordinary care should be exercised in the handling of the instrument. If one takes the precaution always to make sure that the main switch controlling the primary current is quite open and so located that it cannot by any possibility fall shut while the operator is working with the transformer, no accident can happen. In the experience of the author, but one serious accident
