1. Practical aspects of development of Tesla's coil apparatus Marko Cvejić, mcveja@gmail.commcveja@gmail.com Milan Milošević, milan milosevic@gmail.commilan milosevic@gmail.com Prof. dr. Branko Kolundžija, kol@etf.bg.ac.yukol@etf.bg.ac.yu Prof. dr. Jovan Cvetić, cvetic_j@etf.bg.ac.yucvetic_j@etf.bg.ac.yu

2. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Motivation Project of making Tesla Coil at the Faculty of Electrical Engineering of Belgrade and scientific determination of its characteristic (resonant frequency) Attempt to use WIPL-D to determine Tesla coil resonant frequency Comparing obtained results with experimental results

3. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Basic facts of WIPL-D software WIPL-D is a powerful program for fast and accurate analysis of metallic and/or dielectric/magnetic structures (antennas, scatters, passive microwave circuits, etc.). The calculations are done in the frequency domain. As an output, WIPL-D provides the current distribution on the structure, radiation pattern, near-field distribution, admittance, impedance, and s-parameters at the predefined feed points. WIPL-D also provides 2-D and 3- D graphs of parameters of interest (admittance and impedance).

4. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Appearances Appearance of the splash screen Appearance of the file of simulation

5. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Secondary circuit modeling in WIPL-D Secondary circuit consists of two parts: - coil - top capacitance Main task is to create an appropriate geometrical model of the structure and to define distributed loadings for that model

6. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Secondary circuit modeling in WIPL-D: modeling the coil The secondary coil is geometrical modeled as a cylindrical surface with distributed loadings. Every curved surface is composed of n plane surfaces. Model accuracy depends on number of plane surfaces that make curved surface.

7. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Secondary circuit modeling in WIPL-D: modeling the top capacitance Top capacitance is made of toroid and two circles that close inside of toroid Toroid is modeled by BoR

8. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Secondary circuit modeling in WIPL-D: modeling the top capacitance Circles that close inside of toroid from the top and the bottom are approximated by 16 equal segments

9. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Secondary circuit modeling in WIPL-D: other Nodes, wires, junctions, generators Nodes and wires can be defined by user or they are predefined because they belong to other complex objects Each entity has its own number

10. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Distributed loadings Next very important task is to input correct distributed loadings Skin effect is included by putting σ parameter (conductivity for copper) RLC parameters for secondary coil and top capacitance

11. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Starting simulation For the determination of the self-resonant frequency of the secondary circuit, the generator is connected to cylinder. The last thing to do is to determine the frequency range of interest and the number of frequencies per range

12. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Results (1) Depending of complexity of structure results defer:

13. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Results (2)

14. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Results (3)

15. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Results (4) 107 kHz

16. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Results – comparing to experiment measured signal acquisitioned via GPIB 107.8 kHz Results obtained from simulation match the results from experiment

17. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Results – radiation patern

18. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Conclusion In this novel approach WIPL-D (developed at the Faculty of Electrical Engineering of Belgrade) is used. Although the software is designed to deal with the linear media and low voltages, it is applied here assuming that the effects of corona discharges at the top of the secondary are negligible compared to other parameters of the secondary coil. The results show more resonant frequencies with different values compared to the lumped element approach. The existence of the main resonant frequency of secondary coil at 107 KHz is confirmed.

19. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story References K.L.Corum, J.F.Corum: “Class Notes: Tesla Coils and the failure of Lumped-Element Circuit”, paper available at http://www.ttr.com/corum/. Accessed 1999. P. Nicholson “Tesla Secondary Simulation Project”, the study available at http://www.abelian.demon.co.uk/tssp, last revision 18th June 2002. WIPL-D Software, Help Manual.

20. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story Acknowledgments Prof. Branko Kolundžija Prof. Milan Savić Prof. Radivoje Đurić Prof. Acc. Aleksandar Maričić Vladimir Malić, Aleksandar Vacić, Marko Ćosic, Ivana Milovanović, Uroš Mitrović and Nebojša Malešević

21. Faculty of Electrical Engineering University of Belgrade, Serbia and Montenegro Laboratory for climatology and ecology Tesla - Neverending Story