On 11/16/12 9:17 AM, plasticanvil wrote:
I would like to experiment with a Tesla coil for a Science Fair in mid-January. I can’t just do a show and tell. I need a hypothesis and a variable, data collection and something I can prove. I'd like to measure the performance of the Tesla coil and change some variable to increase it. This is kind of the idea I’m thinking of… varying the coil rotations or length, type of capacitor, or the gap length to produce different results.
A good quantitative experiment might be to experimentally validate John Freau's empirical "spark length in inches = 1.7*sqrt(input pwr in watts)" formula..
Build a coil with a breakout point and go to a ground point (something like a ring stand).. Use a variac to adjust the power. Carefully measure the AC power going into the coil. At each power setting, adjust the coil for peak performance.
The challenge is that for a given coil size, you don't get a lot of power range where it works. When you get too low, it stops breaking out.
Maybe another way is to vary the loss in the primary by using a variable resistor (salt water is easy, and will take the HV, and you can measure it with a standard meter with the power off)
You run at constant voltage into the system, so the only thing varying is the series resistance. You can measure current and voltage .. but to do it right, you'd really need to use an oscilloscope (but maybe you have one available or can borrow one).
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