How a capacitor works

Explaining how a capacitor charges and stores energy. The effect of changing the area, the dielectric and the plate spacing.

Category:

Education

Tags:

• capacitor
• capacitance
• dielectric
• area
• spacing
• electric
• charge
• physics
• science

[fizzicsorg]

It depends what you want to test but you can't measure capacitance directly with a multimeter. The maximum voltage depends on the type of insulation between the plates/layers of foil. The max voltage is usually printed on larger capacitors. A capacitor fails when the insulation between the plates/layers of foil is too small for the applied voltage and a current leaks across.

[PhatQ45TT1]

what happens if u take capacitor out of PCB and put it back wrong way???

[fizzicsorg]

It depends what sort of capacitor it is. For some it won't matter, the two plates are the same with a simple layer of insulation between. However in an electrolytic capacitor the layer of insulation is a film of metal salt or oxide formed by chemical action on one of the plates. Reversing the plates will break down this layer and so the capacitor will fail. You can tell if the capacitor is electrolytic if it is marked with a plus and minus on the terminals.

[Mitsimad]

Thanks. What determines the voltage rating on the side of a capacitor?

[fizzicsorg]

The properties of the material used to insulate between the two plates and the thickness of that insulator.

[fizzicsorg]

Generally the thickness and properties of the insulating layer.

[rubikscubesolver17]

u helped me get an A on my science test thanks!

[8320884]

dude if u where one of my teachers i would totally pay attn. to u. 5/5

[MickLBrad]

Excellent tutorial, however the choice of music is horrible!

[baronvonsatanus]

Thanks. Just what I was looking for :-D

Please, please, please do one for inductors.

[Heriopasu]

Thanks. This is very helpful. +You have a good voice. You should do some professional narration.

[goaliedude32]

@katsumorymoto It is my understanding that capacitors are used in circumstances where voltage may drop too low. The capacitor will discharge when the voltage falls below a certain point and will recharge on the next peak cycle. I am also very new to this too and I had basically the same question so hopefully someone else will jump in on this and help us understand it a little better. For now i guess I am going to keep searching.

[AnnoyingXboxer]

Why is she taking her shirt off? O.o

[TheNickmazz]

cool man how about inductors.

[kipper09100]

@fizzicsorg

what would happen if i rip one out of my motherboard

for eg speakers i opened em up and it had those capicitors what wud happen if i rip 1 out

will it not work properly what wud happen??

[katsumorymoto]

this explains a lot.. BUT.. in terms of actually helping me to build something that might require a capacitor, i don't really know wtf i'm doing in that regard

i probably need a damn.. *thinks of the word.. resistor or some shit anyways instead