Separating Electric Charges by Hand - Voltage is the Potential to do Something

[Technoguy3]

I still don't understand voltage.

[koringles]

Once he builds the the flux, he'd be able to travel through time.

[wbeaty]

Years of thinking, and a couple of partial answers:

Voltage is Static Electricity. What we call static electricity is a high voltage phenomenon. Play with a VandeGraaff, and you're playing with voltage.

Voltage is a way to measure "e-fields," electric fields. Most of us know about magnetic fields, iron filings, lines of force. But another field exists too: electric fields. Voltage remains a mystery partly because we're taught magnets and b-fields, but not electrets and e-fields.

[Ken00001010]

Hi wbeaty,

I would not say that static electricity is voltage, but that static electricity has voltage. What you say about E-fields is close to the textbook definition of voltage as the work required to move a unit charge from point A to point B in a given E-field. You are right that we don't have a natural feel for what is going on, just a shock when we shuffle across the carpet and reach for that door knob.

[wbeaty]

Ah, but the main feature of commonly observed "static electricity" is not it's surface charge.

Instead, it's the extremely high voltage.

In your language, static electricity doesn't just "have voltage," instead it has extremely HIGH voltage.

Surface charge at low voltage is common in electronics. It does not produce sparks, or attract lint, or cause corona discharge, or make your hair stand on end. It's not like the common "static electricity" we experience in dry everyday conditions.

[Ken00001010]

I tried to simplify the explanation as much as I could, and so did not mention any electrical laws or equations. One of those is that the energy stored in a capacitor is equal to 1/2 the charge times the voltage. But when pulling the plates apart, energy has to go up as work is done against the force trying to pull the plates together. If charge is constant, for the equation to hold, voltage has to go up.

[Ken00001010]

@Matthiaswandel You bring up a good point. There is no charge gain in what I was trying to do, I just wanted to demonstrate voltage gain. I agree that the holding cap has to get more charge to keep going up in voltage, so without dropping its cap value at each step, something beyond the initial change has to be there to keep it going up. Thank you for your skepticism, I always like that in science. I will track this down and get back to you.

[Ken00001010]

@sturgeon333 It is true that the field falls off quickly, and you can feel that drop of force as you pull. However, it just means the rate of voltage boost goes down the farther you pull, but the voltage keeps going up as long as the charge carriers are moving apart.

[sturgeon333]

Ok, I agree with that. I wonder how far you need to separate the plates before you get 99% of the voltage. Maybe it's not that far.

[Matthiaswandel]

I'm skeptical about this. He's boosting voltage, but he keeps moving the same electrons back and forth between the rolled capacitor and his plate capacitor. So his net excess of electron isn't going to increase over time. Baiscally, he can multiply voltage, but not charge. To increase the voltage in the cap overall, you also need to increase the charge.

[Textra1]

Fascinating.