2009/6/24 Kyle Mcallister <[email protected]> > > --- On Tue, 6/23/09, Michel Jullian <[email protected]> wrote: > > > Kyle, nice work as always. Couldn't the plate (the support > > of the net > > charge) be simply the inside surface of the glass tube, and > > the plasma > > be just the conducting "wire" leading to that plate? In > > this case, > > suppressing the "wire" would also stop your oscillator > > wouldn't it? > > But it wouldn't change the ch > > Might be, but the 'plate' must be some conductive material, perhaps a thin > layer of the plasma, > in order to act as a capacitor. AFAIK, there's no way to make a conductorless > capacitor simply > by having opposite charges on sides of a chargeable material. Or is there? > It'd certainly be interesting.
I trust someone will correct me if I am wrong, but indeed I don't think one can distinguish a disconnected capacitor plate from the same charge evenly "sprayed" on the dielectric. > > I did a follow up test, pulling the filament 6V supply and letting the plasma > slowly die; the frequency of the relaxation oscillation slowly > *decreased*...as if the capacitance of the tube were increasing. There were, > however, interspersed low-level oscillations of a much higher frequency. > Could this be evidence that the plasma 'wire' as you call it was no longer > effectively allowing for charge to accumulate and be withdrawn from the inner > surface of the glass? > > Further test: replacing the 15k limiter with a 47k limiter cut the > oscillation frequency in half. Again, as if the capacitance were increased. > 100k barely lit the tube, the oscillation was very noisy and unsteady...but > lower in frequency still. What do you think? Is the effective capacitance > being increased in some way, or is something else happening? > Or it could be that in both cases the capacitance remains constant (defined by the dielectric material, area and thickness), and the decrease in frequency is due to the increase in resistance of the resistor + plasma series arrangement feeding the capacitor. > > Michel "the static" > > Hehe, I'd never call you that in a bad way. Hmm... matter of fact, it sounds > like something from the 'days of old, when knights were bold.' > > "And so it came to pass that Michel the Static did journey forth to bring > knowledge to denizens of the land... and there was much rejoicing." > Nah, it wasn't knowledge, it was a cow he brought them: http://www.youtube.com/watch?v=7FJVAcvVcPQ Michel
