Thanks Andy!
I've already measured hand | antenna mutual capacitance using this method for three different length antennas, so I have some data. Now I'm looking for a mathematical function for hand | antenna mutual capacitance that takes distance between them, the physical dimensions of the...
I'm confused. If I simply add the two self-capacitances there is no distance-between-them factor (mutual capacitance should increase with decreasing distance between them). Could you be more explicit or perhaps show me the formula you're thinking of?
OK, self-capacitance:
For a sphere, my physics book says:
V = Q / ( 4 * pi * epsilon0 * radius )
so:
C = Q / V = 4 * pi * epsilon0 * radius
For the antenna, that paper says:
C = 2 * pi * epsilon0 * Length / ( ln( 2 * Length / Diameter ) - 0.4 )
How do I combine these linearly so that I get...
Hmm, I'm not exactly seeing how the self-capacitance plays into capacitance between two objects?
The equation I'm using for hand capacitance seems to be way off (underestimated) in the near and mid field of the hand to the antenna (compared to capacitance data I've taken). Far field seems...
Thanks Drmarshall,
I was thinking sphere for the hand but maybe that makes the math more difficult? I assume the solution will be a double integral, but don't know the exact approach. My physics book says to assume the antenna and hand are oppositely charged with +/- Q, then find V between...
I've been working on a Theremin Excel simulation for the past couple of months. For those who don't know what a Theremin is, it was one of the very first electronic instruments to be invented, and has two "antennas" that independently change the pitch and amplitude of a tone via hand...