Computer Aided Design of Tesla Coils

Software for Tesla coil design has only recently become available. Computer Aided Engineering using appropriate software not only helps during the initial design but helps to refine system operating characteristics.

The TCTUTOR by James F. Corum and Kenneth L. Corum (1-6) is attractively and professionally packaged with three ring binder that contains program instructions and comprehensive dissertation. Because it is the only program that allows for Extra Coil design and analysis, we have used TCTUTOR to compare and contrast three of the largest Tesla coils built to date. The first, of course, was described by Nikola Tesla in Colorado Springs Notes (1-7). The second and third coils are those built in Colorado and Utah and described above. Using the measured and assumed values in Table I, print outs from TCTUTOR show the voltage induced from primary excitation, the Fourier Spectrum of the unduced voltage, and the final output voltage and extra coil characteristics for all three cases.

Table I

A (*) indicates that the quantity was not measured, the default program value was used in the analysis. R1 and R2 are AC resistances at the frequency of operation. Since minimal data was available for the Utah configuration (1-8), an assumption of values was based on the fact that the Colorado system had been built as close as possible to that used in Utah, which in turn had been electrically and physically as close to the Colorado Springs design as possible. The coil dimensions were the same and the length of wire used in the primary, secondary, and extra coil was the same. As a matter of fact, the same wire used for the Utah experiments was used for the recent experiments in Colorado.

In the initial summary, two reasons for poor coil performance were over loading and poor tuning. The fact that the secondary and extra coil are tuned so far apart contributes greatly to degraded coil performance. The supposition that the secondary and extra coil must be “detuned” (1-9) in order for the system to work cannot be explained by the author. Any explanations or suggestions to explain this oft-repeated statement would be appreciated.

In the future, more accurate measurements will be made and the coil will be properly tuned. All parameters will be measured and checked against the values given in the Colorado Springs Notes. The observation to be made here is the difference between the experiments of 1899 and those of Utah and Colorado. As can be seen in the comparisons, Tesla's coil was a masterpiece of fine tuning.

The primary objective of Project Tesla is to resonante the Schumann Cavity using the previously described method. A number of experiments with single electrode x-ray tubes were performed during the summer of 1988. The purpose of the experiments was to determine if an x-ray tube could be built to withstand the voltages present on the discharge of the extra coil. A paper in preparation will deal extensively with the methods to be used to overcome present difficulties and will present further evidence to indicate that the wireless transmission of power is not only feasible but can be a viable alternative to present transmission systems.

Footnotes

• 1-1 Singer, Paul, “Fusion Energy: will experiments in ball lightning provide the key?”, Design News, (4/20/'76)
• 1-2 Cox, Durlin, Modern Resonance Transformer Design Theory, PG. 98. Tesla Book Co., 1984, P.O. Box 1649, Greenville, TX 75401
• 1-3 Golka, R.K., personal communication based on discussions during the summer of 1987 and 1988
• 1-4 Drew, G.E., New SF6 Gas Improves Protection”, Electrical Digest, pp 53-58, September, 1958
• 1-5 Sulfur Hexaflouride, Application Note, Allied Chemical, Specialty Chemical Division, Morristown, NJ
• 1-6 TCTUTOR, Corum & Associates, 8551 State Route 534, Windsor, OH 44099 (216) 272-5722
• 1-7 Nikola Tesla, Colorado Springs Notes, 1899-1900, Nolit, Beograd, Yugoslavia 1978 (see Tesla Book Co.)
• 1-8 Golka, Bob, “Long Arc Simulated Attachment Testing Using A 150 kw Tesla Coil, Golka & Associates 400 Warren Ave., Brockton, MA 02403
• 1-9 Golka, 1987, 1988

Mr. Toby Grotz, President of Wireless Engineering, is an electrical engineer and has 15 years experience in field of geophysics, aerospace, and industrial research and design. Present work involves the design of industrial metal detection systems which have the ability to sense metal through metal. While working for the Geophysical Services Division of Texas Instruments and at the University of Texas at Dallas, Mr. Grotz was introduced to and worked with the geophyscial concepts which are of importance to the wireless transmission of electrical power. As a Senior Engineer at Martin Marietta, Mr. Grotz designed and supervised the construction of industrial process control systems and designed and built devices and equipment for use in research and development and for testing space flight hardware. Mr. Grotz organized and chaired the 1984 Tesla Centennial Symposium and the 1986 International Tesla Symposium and was president of the International Tesla society. As a Project Manager for Project Tesla, Mr. Grotz aided in the design and con- of a recreation of the equipment Nikola Tesla used for wireless transmission of power experiments in 1899. Mr. Grotz received his B.S.E.E. from the University of Connecticut in 1973. Anyone wishing to contact Mr. Grotz can do so by writing or calling him at the Theoretical Electromagnetic Studies and Learning Association, P.O. Box 277, Leadville, CO 80461. (719) 486-0133