Silly question about voltage and current

[MarkE]

Ok sounds plausible for water, tell me if alternating current is just current alternating through a conductor then why does this circuit build a negative ion cloud on one end and a positive ion cloud on the other.
If negative current were the only energy moving in the coil wouldnt we have a negative ion cloud only on one end of the circuit.

Capacitance

[Dave45]

Capacitance

comon Mark you can do better than that.

[Farmhand]

Ok sounds plausible for water, tell me if alternating current is just current alternating through a conductor then why does this circuit build a negative ion cloud on one end and a positive ion cloud on the other.
If negative current were the only energy moving in the coil wouldnt we have a negative ion cloud only on one end of the circuit.

Mark Is right, Dave we kinda need to think in a way that isn't so (positive-negative), not so (either-or) kind of thing. If one plate becomes more negative then the other plate becomes less negative in relation to it, or the same thing if one plate becomes more positive then the other plate becomes less positive and a potential difference occurs between them. Simple, the potential difference is between the two plates and they both share the charge differential.


Cheers

P.S. Dave maybe Mark is thinking, Come on Dave you can do better than that. I think you are getting ahead of yourself a bit, you're talking ion clouds, but you don't understand charge displacement. Maybe reading to too much Utikin, he is there to fill peoples heads with fallacies and make claims for Tesla he didn't make. Better to not read him, better to get a good basic understanding of electricity ect. However we all make our own choices. In that way we are free.

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[TinselKoala]

And that happens because the circuit pumps electrons into the capacity at the negative end. This could be a large shape or just a point, with the other "plate" being the Earth itself or the other end of the circuit if, again, a shape or point is provided. Voltage is charge pressure, which comes from packing like charges together into some _capacity_. If you have sharp points or edges, the _gradient_ of the electric field becomes large enough to break down the air molecules into ions - at the "negative" end, electrons are emitted, latch onto air molecules and give them a negative charge. Opposite on the other end, the depletion or holes "suck" electrons out of the air molecules leaving them positively charged. The diodes in the circuit prevent a discharge path that way. Just as with any capacitor, as you pack more charge into the region, it becomes harder and harder to put more charge in because the charge already there repels the charge you are trying to stuff in.

Really, if you want to understand current and voltage you need to think about the movement of and forces between like unit charges. Electrons and holes. Water doesn't exactly repel itself and there's no "water holes" like there are unit positively charged "holes" in conductors and semiconductors, so the hydraulic analogy breaks down if you try to take it too far.

Voltage is "relative charge pressure", which Farmhand is describing, aka potential difference. If you stick both your voltmeter leads to the same charged surface you won't measure any voltage, even though the charge pressure might be very high compared to the "ground" ... the Earth is essentially an infinite sink and source for electrons and so it is the usual "zero reference" to which higher voltages... charge pressures... are compared.
But charge itself isn't relative, it is conserved. You can pack a bunch of charge onto a capacitance, and it won't discharge if there is no path to a lower potential (charge pressure). But it still takes more and more work to pack more charge into the capacitance to raise its voltage. Eventually you get so much charge into or onto a capacitance that the very air breaks down into ions which are very conductive, and the charge leaks away. The voltage rating of capacitors is essentially the dielectric strength that can withstand the potential difference between the plates.

[Dave45]

Lets keep it simple
If current moves from neg to pos then current is moving through a diode in this direction