Dan's Conventional Tesla Coil

Solid State Tesla Coil PSPICE Simulation

Click here to download the PSPICE schematics

Introduction

My goal here is to create and simulate my High Power Solid State Tesla Coil using PSPICE. I will be

using Cadence PSPICE v9.2 for my simulations, however older versions of PSPICE will work as

well.

PSPICE Model of Tesla Coil Resonator

The following is a model of the actual tesla coil resonator which is being driven by the full-bridge power

supply circuit. This model is based on Terry Fritz's PSPICE coil model which can be found in his technical

paper here.

All coil parameters were calculated using MandK (Mutual Inductance Computational Program) written by Mark Rzeszotarski, Ph.D.

This program can be downloaded here. The value for corona loss (Rc) was basically copied over from Terry Fritz's model and for

our purpose works fine here.

The physical characteristics of this resonator are as follows:

Primary Coil

15 Turns

10 AWG stranded wire (0.1019 in. dia.)

3 inch winding length beginning approximately 1 inch above bottom plane of secondary coil

Secondary Coil

1200 Turns

24 AWG stranded wire (0.0201 in. dia.)

Toroid

12 in. x 3 in. Spun Aluminum Toroid (13pF)

Secondary/Toroid Resonant Frequency - 199 kHz

The following diagram depicts the frequency response of the tesla coil resonator model. Resonant frequency of the tesla

coil resonator is shown to be approximately 199 kHz.

AC Frequency response of tesla coil resonator model. (Resonant frequency is approximately 199 kHz)

PSPICE Model of Solid State Full-Bridge Converter

The following is a model of the full-bridge power supply I am using to excite my tesla coil resonator. With the exception of the

simplified gate driver circuitry seen here, the circuit is identical to what is actually being used in my system.

The gate drive signals are 12V squarewaves at 200kHz which is approximately the resonant frequency of my secondary coil.

PSPICE Model of Solid State Tesla Coil

The following is the top-level model of entire solid state tesla coil.

The full-bridge converter's input is half-rectified 120VAC at 60Hz. Again, the values for streamer loading (R6, C1) have been borrowed

from Terry Fritz's tesla coil model and have not been adjusted for this application use as of yet.

PSPICE Simulations

The following waveforms are from a simulation of the solid state tesla coil based on the following characteristics:

Input Power - 120VAC, 60Hz (half-rectified)

Full-Bridge Converter Frequency - 200 kHz

Simulated Full-Bridge Converter Output

The following waveforms illustrate the output (RF Envelope) of the full-bridge converter.

Notice that with 120VAC, 60Hz input half-rectified, the full bridge converter will only conduct current during the positive portion of the 60Hz wave. This is

important as any negative conduction of current would surely short out the MOSFETs through their internal body diodes.

Beginning portion of one RF Envelope cycle.

Midpoint portion of an RF Envelope cycle when amplitude is at a maximum. (approximately 330V peak-peak)

Simulated Tesla Coil Resonator Output

Here are the results of my initial PSPICE simulation of the tesla coil resonator output. I have not yet determined whether these results are valid

yet. I will run additional simulations at different frequencies to compare simulation outputs at non-resonant frequencies.

Tesla Coil Resonator Output (200kHz)

Tesla Coil Resonator Output - Single RF Envelope cycle

Tesla Coil Resonator Output - Midpoint of RF Envelope when output is at maximum.

More to come soon . . .

Last modified August 16, 2005 08:05:21 PM