Nikola Tesla - The Founder of High-Frequency and Radio Engineering Page 9

alternating currents into weakly damped and undamped oscillations of various periods, voltages, and energies. This problem was solved using special oscillators for direct and alternating current, which include spark gaps, capacitors, Tesla coils, and transformers. Tesla developed various types of spark gaps with magnetic and electromagnetic quenching of the spark and electric arc, produced sparkers with multiple sparks in series, and developed rotary oscillators in which the interruption of the spark was performed in air, gases, vacuum, and liquid media. Using such constructions, Tesla was able to produce many thousands, even tens of thousands, of spark interruptions per second in the primary circuit and to transform tens and hundreds of kilowatts from the primary to the secondary circuit, where, by adjusting capacitors and coils, high-frequency currents of various voltages—from several hundred to several hundred thousand volts—and various periods—from several tens of thousands to several tens of millions per second—were produced. The efficiency of such conversion of low-frequency energy into high-frequency energy amounted to about 85%.

2) The problem of resonance in high-frequency circuits. Tesla solved this problem by using variable self-induction coils, rotary capacitors, and loosely coupled circuits.

3) The problem of producing free and amplified oscillations in the secondary circuit. This was achieved by using helical coils, capacitors, and transformers with cooling and insulation in oil, by reducing ohmic resistance through artificial cooling, and by utilizing larger self-inductances and smaller capacitances at a given frequency.

Parallel to this work, a method for producing high voltages was also developed. As early as 1891, Tesla produced voltages of several hundred thousand, and later several million volts. In his historical experiments in Colorado in 1899, Tesla produced 12 million volts.

This work of Tesla was carried out mainly from 1891 to 1899. It represents the creation of a new technique, and it can freely be said that it is unique in the history of technology, because, with the exception of the electron tube, which was discovered and perfected much later, all other apparatuses in the field of high-frequency technology are encompassed by Tesla’s inventions. Professor Zenneck therefore rightly calls Tesla the creator of high-frequency technology.¹

¹ “Hochfrequenztechnik und Elektroakustik”.
“Jahrbuch der drahtlosen Telegraphie und Telephonie”.