I made a simple so-called "Tesla Coil", the secondary is a pancake coil without top electrode and has a resonant frequency of 760khz, the primary circuit is a NST and I have used microwave diodes to rectify it so the coil is run on DC.
Most of the time I have the Variac set to severely limit the output voltage/power and I keep the gap small. Anyway I was tuning the primary tap point and I was drawing an arc to a screwdriver and I had decided that at the modest power levels I'd be Ok touching it, after all with the inductive field put out there would be a displacement current in my body for sure anyway if I touched it or not. So I drew arcs and I noted that as the arc hit there was a stinging sensation and the muscles in my hand would contract, of course this shouldn't really be the case when the coil is oscillating near a megahertz. I also found that the arc wouldn't create a stinging sensation if it landed on the tip of a screwdriver, indeed I tried many objects to draw the arc and it never worked if the arc hit an edge or a point. It is worth noting that the primary circuit does not have (much) high voltage on it and can be touched with relative safety since I have caps on either side although the impedance of the primary and possible imbalance between the home made caps stops this from being strictly true. I would wonder if it could be a static capacitive discharge as a VDG terminal can pack a bit on a punch however there is no terminal only a wire. So how is .75mhz from a Tesla Coil without any top loading causing muscle contractions and a shocking sensation? My leading theory *would* be capacitive coupling from the primary but as stated above it's not possible, the end of the primary coil that the secondary would be influenced by happens to be at zero volts and I can touch it without any sensation, the other end is at a slight voltage but very little and can be touched with no issues. I have used wires to conduct this current to my hand and as long as the arc doesn't fall on a point/wire it can be conducted by a wire just fine so it is current and not something along the lines of Teslas radiant stinging effect he observed. If anyone can think of a test, or a way to eliminate different possibilities I'd be interested, also I'd be interested in any way to measure this besides my hand getting shocked if anyone has and ideas.
