Nikola Tesla Books
THE HIGH POTENTIAL TRANSFORMER for wireless telegraphic work. The higher potential permits a smaller condenser to be used. For other high frequency work, however, there is no particular advantage to be derived from the high voltage secondary and its use involves certain electrical and mechanical difficulties that are expensive and annoying to surmount. The most satisfactory potentials, in the author's experience, have been from 4,000 up to 12,000 in transformers ranging in size from 4 k.w. to 3 k.w. This range of potential, with a .03 mfd. condenser has been found quite suitable in the construction of many sets of apparatus. With the quenched type of spark gap, a totally different condition is met. Secondary potentials as low as 900 to 1,000 volts are excellent in the case of small transformers of capacities ranging from ¼ to ½ k.w. For the larger sizes, the potentials may run up from 2,000 to 3,000 volts. The quenched gap, which will be specifically described later, is exceedingly short and a much lower potential is, accordingly, in order. Transformer Construction.-In each chapter of this book, wherein a set of apparatus is described, the complete specifications for the construction of the transformer are given. The object of this discussion will, therefore, be to cover only briefly the essential principles of the construction. LEAKAGE Fig. 7. Primary and secondary on short legs of core and widely separated to increase magnetic leakage. This construction renders external impedance coil unnecessary
