how positive & negative plates are decided in a cylindrical electrolytical capacitors

[rajaram04]

how positive & negative plates are decided in a cylindrical electrolytical capacitors

Hello sir
I how the positive & negative terminals are decided based on internal structure in an electrolytic type capacitors ? why no boundations are there incase of ceramic etc capacitors ?
In theory we didn't sudy about any of the exaplanations about how positive & negative terminals are made actually in practical

 

[chuckey]

Re: how positive & negative plates are decided in a cylindrical electrolytical capaci

Only electrolytic capacitors rely on a gel or wet solution the plate one conductive plate with a very thin layer of insulating material. All other capacitor types use a proper insulating material to start off with.
Frank

 

[rajaram04]

Re: how positive & negative plates are decided in a cylindrical electrolytical capaci

kk sir but negative & positive plates are made of ???????????

which one is using insulating material ? & what about another one ?

 

[BradtheRad]

Re: how positive & negative plates are decided in a cylindrical electrolytical capaci

I don't know all the details but from what I understand, when electricity is applied at the proper polarity and intensity, it causes a region of electrolyte next to one of the plates to turn into a microscopically thin insulating barrier.

Once it is 'formed', the capacitor only works at the same polarity. Bad things happen if you apply reverse polarity.

I don't know how they manage to prevent the plates from short-circuiting.

I suspect manufactures have to keep a few things a 'trade secret' as they must try to make electrolytics as reliable as possible.
Electrolytics are prone to become 'leaky', or to increase in ESR, or to drop in Farad value. In spite of that, they are a bargain with their high capacitance packed into a small package.