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Veritasium "How Electricity Actually Works"
electrodacus:
--- Quote from: snarkysparky on May 25, 2022, 04:14:48 pm ---
How does IanB's middle capacitor get charged if no energy can flow through the outer capacitors.
--- End quote ---
Two or more capacitors in series are no different from a single capacitor.
You can imagine a two parallel plates capacitor and you insert another plate in between those plates and that plate is not connected to anything and it will not affect the functionality or even capacity of that capacitor if plate is thin enough compared to the gap.
Inserting that unconnected plate will make that system a two capacitor in series setup and adding another plate will be equivalent with three capacitors in series.
a) -| |-
b) -| | |-
c) -| | | |-
a) 100pF single capacitor.
b) two 200pF capacitors in series.
c) three 300pF capacitors in series.
For the unconnected plates in the middle all that will happen is that free electrons already in those plates when capacitor is charged or discharged will move from one side of the plate to the other.
TimFox:
An interesting variation on case B is if you use double-sided aluminized Mylar for the center plate.
Back in grad school, when some of my buddies were building wire chambers for high-energy physics experiments, we considered using the tooling to build large electrostatic speakers, but the engineer in charge warned us that the double-sided Mylar film used in the chambers would burn out if we tried to use them for the membrane, since charge would have to flow through a very thin film to get from one side to the other as the membrane moved.
electrodacus:
--- Quote from: TimFox on May 25, 2022, 05:01:46 pm ---An interesting variation on case B is if you use double-sided aluminized Mylar for the center plate.
Back in grad school, when some of my buddies were building wire chambers for high-energy physics experiments, we considered using the tooling to build large electrostatic speakers, but the engineer in charge warned us that the double-sided Mylar film used in the chambers would burn out if we tried to use them for the membrane, since charge would have to flow through a very thin film to get from one side to the other as the membrane moved.
--- End quote ---
There will have been no reason for that not to work with low power. The wires mesh plates should have been fairly close to be an effective speaker but he should have allowed you to test this if nothing else will have been damaged other than worst case some inexpensive mylar tape.
snarkysparky:
""For the unconnected plates in the middle all that will happen is that free electrons already in those plates when capacitor is charged or discharged will move from one side of the plate to the other.""
Nope. Not the same. The unconnected plates will have no net change in charge levels.
The plates on the middle capacitor will gain charge on one side and lose charge on the other. The proof is that you can remove the middle capacitor after applying voltage to the series set and it will have a charge on it.
How did that energy get there.
electrodacus:
--- Quote from: snarkysparky on May 25, 2022, 05:27:56 pm ---""For the unconnected plates in the middle all that will happen is that free electrons already in those plates when capacitor is charged or discharged will move from one side of the plate to the other.""
Nope. Not the same. The unconnected plates will have no net change in charge levels.
The plates on the middle capacitor will gain charge on one side and lose charge on the other. The proof is that you can remove the middle capacitor after applying voltage to the series set and it will have a charge on it.
How did that energy get there.
--- End quote ---
Yes the unconnected plates will have no net charge but you can charge the setup c) and after you charged that you can connect a lamp between the two unconnected internal plates and discharge the middle capacitor.
So it is exactly the same thing the difference is that each unconnected plate is in case of capacitors made of two plates connected through a wire so charge moves from one plate to the other trough that wire instead of directly from one side of the plate to the other.
That group of two plates connected by a wire is the same as a single plate and there will be no net charge in either case.
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