Capacitive coupling.

Does it depress the surface of oil?

See what I wrote on bodkin's thread, physics of the primary state, page 4.

@Inquorate

There is no need to complicate things. johnb003 held HV secondary. He was capacitively coupled with conductor and with ground. All the insulation in the world won't prevent that. And yes, what he felt was a simple very low current stimulation of his nerves. If he was to raise or lower the frequency the feeling of "toothbrush vibration" would change. It's as simple as that.

Chastened

@ lighty, point taken, the way I read it, the vibration was felt in the air, my mistake.

Actually I was holding the ground. I was moving the ground wire close to the hv terminal.

I originally tried the test with the negative terminal of the secondary (not the HV terminal), I know the transformer is oscillating so you could try to say either terminal can be HV, but in the flyback, there are diodes internally so it's only hv on the one terminal (the one I wasn't holding).

Since the original post I've done more tests. I connected secondary ground with the primary ground, and still I felt the effect.

You may be completely right about the capacitive couple, I just didn't expect it from the ground wire. I'm not trying to claim anything really, I just wanted to understand what was happening.

Also I thought a good way to test the capacitive coupling, would be to put some metal around the metal rod and see if I can get a voltage. I tried it, I used a 25' roll x 6" wide, grid (grid spacing is about 1/8 inch) it's a metal screen / mesh thing of galvanized steel. The inner diameter is about 4 inches. So the grid is surrounding the rod, separated by about 2 inches, and from this I get some small sparks back to the rod.

`John

Sounds interesting

Very interesting...

Any images of the arcing?

Diodes have nothing to do with the HV voltage on the secondary. They will regulate current flow polarity but both endings of secondary are producing HV. Simply put, when you put diodes on one end of secondary it doesn't mean the other end of secondary is dead.

I think I know what's bothering you. You're using inaccurate terminology. The wires you speak about are not Earth ground wires. One could rather call them Common potential wires. However Common wires still have floating potential in relation to Earth ground. In other words you have voltage between your Common and Earth (on which you stand and to which you're capacitively coupled).


[quote] I tried it, I used a 25' roll x 6" wide, grid (grid spacing is about 1/8 inch) it's a metal screen / mesh thing of galvanized steel. The inner diameter is about 4 inches. So the grid is surrounding the rod, separated by about 2 inches, and from this I get some small sparks back to the rod.[/qutoe]

Of course you're getting sparks. HV charge likes to jump to any body of sufficient self-capacitance. It doesn't really matter if we're talking about Earth or some metallic body. Try to imagine it in a very simplified way- conductors sitting on a HV potential would like nothing better then to get rid of some of the charge. So it seeks any conductive body in vicinity. Then it will relase some of it charge either through spark (current) or through capacitive coupling (E-field).


Sorry to say this mate, but this is a common effect when dealing with HV. What's bothering people is the fact that there is a heavy insulation around HV wires. They don't realise that insulation won't prevent capacitive coupling and transfer of energy. Only the lowering of mutual capacitance between HV conductor and other conductive body will lower energy flow between them. One of the reasons why so called "Avramenko plug" won't work over great distances without significant losses is capacitive coupling of various components of the system with Earth ground. There are methods of reducing those losses and raising efficiency but that is out of the scope of this particular discussion.

Diodes have nothing to do with the HV voltage on the secondary. They will regulate current flow polarity but both endings of secondary are producing HV. Simply put, when you put diodes on one end of secondary it doesn't mean the other end of secondary is dead.

I think I know what's bothering you. You're using inaccurate terminology. The wires you speak about are not Earth ground wires. One could rather call them Common potential wires. However Common wires still have floating potential in relation to Earth ground. In other words you have voltage between your Common and Earth (on which you stand and to which you're capacitively coupled).


Of course you're getting sparks. HV charge likes to jump to any body of sufficient self-capacitance. It doesn't really matter if we're talking about Earth or some metallic body. Try to imagine it in a very simplified way- conductors sitting on a HV potential would like nothing better then to get rid of some of the charge. So it seeks any conductive body in vicinity. Then it will relase some of it charge either through spark (current) or through capacitive coupling (E-field).


Sorry to say this mate, but this is a common effect when dealing with HV. What's bothering people is the fact that there is a heavy insulation around HV wires. They don't realise that insulation won't prevent capacitive coupling and transfer of energy. Only the lowering of mutual capacitance between HV conductor and other conductive body will lower energy flow between them. One of the reasons why so called "Avramenko plug" won't work over great distances without significant losses is capacitive coupling of various components of the system with Earth ground. There are methods of reducing those losses and raising efficiency but that is out of the scope of this particular discussion.