Nikola Tesla Books
CHAPTER XIX. LARGE TESLA AND OUDIN COILS FOR THE STAGE. In the present chapter, the specifications for two of the most popular types of high frequency transformers are given. The coils are complete in themselves and for their operation, the exciting apparatus described in the preceding chapter, or else the quenched gap apparatus covered in the former chapters, may be used. The proportions of these coils are excellent for transformers of larger or smaller size. The Tesla transformer illustrated in Fig. 1 is capable of throwing a 50 inch spark between terminals if made in the size shown in the detailed drawings, Fig. 2. This spark can be produced through the use of a two kilowatt transformer in the exciting circuit if the apparatus is tuned properly. The resonator shown in Fig. 3 is designed for the production of a comparatively short, but very heavy spark and it is capable of remarkable performances in the hands of an ingenious manipulator. The various experiments such as lighting lamps with current taken through the body and igniting cotton or paper with sparks taken from the fingertip are well within its scope and this on a big scale. The coil is also excellent for the generation of a very high frequency current at high voltage for the production of a bluish halo or glow which seems to come from the extremities of the body when the performer operates in the dark. 204
