I should have said a point concentrates charge and electric field density, it does not concentrate voltage.
On Tue, Jul 21, 2009 at 2:45 PM, John Berry <[email protected]> wrote: > Actually I'm not sure it is silly, counter intuitive but *maybe* right. > > A point concentrates charges and voltage, it might depend very much on the > specifics. > > However my personal believe is that the capacity is not an issue merely > that it contracts a flat piece. > > I took a bayonet light bulb and put my thumb on one terminal and carefully > positioned the other terminal to be struck and sure enough a strong > discharge was felt. > > Putting a small bit of wire on the terminal to draw the arc killed the > effect. > > The capacitance there must be tiny. > > So I took a piece of AL foil and used that to draw the arc despite having a > larger capacitance it manifested the effect only weakly. > > > > On Tue, Jul 21, 2009 at 2:21 PM, Stephen A. Lawrence <[email protected]>wrote: > >> >> >> John Berry wrote: >> > I connected a signal generator to the secondary and hung the >> > oscilloscope lead in the air, that is how i found the 760-ish khz >> frequency, >> > >> > I am not willing to run my scope near or even while the TC is running >> > currently as I have no power line conditioners. >> >> Eh -- good point. You did say something that implies you're running the >> TC from the AC line, which I hadn't quite picked up on. >> >> Hmmm -- I don't suppose you've got a computer somewhere in the house >> which is on a UPS? I'd think any garden variety UPS could run a typical >> scope for a good useful length of time fully disconnected from the wall. >> (Of course you're not supposed to operate them that way -- should >> always be grounded, so the instructions say -- but what the hey, last >> time I tried yanking the plug out of the wall on a UPS it worked just >> fine.) >> >> > >> > The shocking sensation isn't constant however it is only on the initial >> > establishment of an arc. >> >> Ah hmmm..... Does that make sense? It seems like it might make sense. >> Initial arc establishment is when the voltage must be highest, and that >> means the capacitor between the two terminals is most fully charged. >> (Which may not have anything to do with it, of course.) >> >> >> > >> > I found this on nerve response: >> > >> > /Now, for the Great Insane Shocking Signal Generator Experiment of 1997: >> > >> > WARNING - I disclaim safety of repeating this experiment! Do at your >> > own risk!!! >> > I connected a variable frequency sinewave generator to an audio power >> > amplifier, which drove a step-up transformer. With one wet hand, I >> > touched the two high-voltage-side terminals of the transformer. With the >> > other hand (insulated), I varied the voltage and frequency the first >> > hand was getting. >> > >> > Results: >> > >> > Low audio frequencies 80 Hz and less seem most shocking.Now, for the >> > Great Insane Shocking Signal Generator Experiment of 1997: >> > >> > WARNING - I disclaim safety of repeating this experiment! Do at your >> > own risk!!! >> > I connected a variable frequency sinewave generator to an audio power >> > amplifier, which drove a step-up transformer. With one wet hand, I >> > touched the two high-voltage-side terminals of the transformer. With the >> > other hand (insulated), I varied the voltage and frequency the first >> > hand was getting. >> > >> > Results: >> > >> > Low audio frequencies 80 Hz and less seem most shocking. >> > As frequency was increased above about 80-100 Hz, the burning/pain >> > sensation decreased but the "tingly" shocking sensation did not lose >> > much of its intensity until the frequency reached 500 Hz. Roughly at >> > that point, the shock began to be less intense in all ways as the >> > frequency was increased further. It was noticeably less intense at 1 KHz >> > than at 500 Hz, and a fraction as intense at 5 KHz as at 500 Hz. At 20 >> > KHz, there was almost no sensation of shock at voltages where lower >> > frequencies are painful. >> > As frequency was increased above about 80-100 Hz, the burning/pain >> > sensation decreased but the "tingly" shocking sensation did not lose >> > much of its intensity until the frequency reached 500 Hz. Roughly at >> > that point, the shock began to be less intense in all ways as the >> > frequency was increased further. It was noticeably less intense at 1 KHz >> > than at 500 Hz, and a fraction as intense at 5 KHz as at 500 Hz. At 20 >> > KHz, there was almost no sensation of shock at voltages where lower >> > frequencies are painful./ >> > >> > Based on that I'd say my shocks were probably lower than 100hz and >> > certainly lower than 500hz >> > >> > Also while I am aware obviously that points have lower capacitance and >> > leak more ion wind it seems that the fact that the other end was a wire >> > point anyway and the distance between the TC and arc point would make it >> > seem unlikely that the tiny capacity difference could explain it >> > especially when the tests showed than the size of the grounding >> > electrode didn't change anything. >> >> And yet, I thought you had observed that the shape of the electrode did >> matter -- did I misunderstand that? >> >> I'm not sure the difference is tiny, in any case. Unfortunately when I >> attempted to figure it out using a quick trip to Griffiths followed by >> some careful reasoning I arrived at the conclusion that replacing a >> point-and-plate capacitor with one made of two points (same separation) >> would *INCREASE* the capacity which is just silly. Maybe this is >> Nature's way of telling me it's time to go to bed. >> >> >
