Using Polarized CAPs in AC - Electronic Circuits Projects Diagrams Free

joe_1 · 8th August 2007, 08:40 PM

Hi:

I am just wondering what will happen if I connect an electrolytic polarized cap to an AC line.
I know that connecting the wrong polarity to a polarized cap might cause it to explode, and in AC, the polarity is changing all the time.

Thanks.

dknguyen · 8th August 2007, 08:49 PM

Did you just not answer your own question?

joe_1 · 8th August 2007, 08:56 PM

I have very good "theoretical" idea about what will happen, so it is some sort of confirmation that I was looking for.

HarveyH42 · 8th August 2007, 10:58 PM

Explosion kind of depends on the voltage rating of the capacitor...

Leftyretro · 9th August 2007, 02:45 AM

There is a way.

By connecting two electrolytic polarized caps in series with + to + and input and output using the negative leads, one can use the resulting capacitor in a AC circuit. Of course the total capacitance will be less then either individual value. Two 10mfd caps in series will present a 5mfd value, calculated just like having two resistors in parallel.

Edit: You still have to spec the working voltage of the caps to the application voltage.

Lefty

9th August 2007, 05:14 AM

mfd? Do you mean uf (microfarad)? You have that posted as millifarad.

Hero999 · 9th August 2007, 08:36 PM

Some older publications use m to stand for micro which is pretty silly in my opinion, but it's only used for capacitors which aren't normally found it values as high as 1mF so it doesn't cause too much confusion. I never use mF, I normally use µF for values =<99,999µF and Farads for values >=0.1F, that way I never get confused.

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8th August 2007, 08:40 PM	(permalink)
joe_1	Using Polarized CAPs in AC Hi: I am just wondering what will happen if I connect an electrolytic polarized cap to an AC line. I know that connecting the wrong polarity to a polarized cap might cause it to explode, and in AC, the polarity is changing all the time. Thanks.

8th August 2007, 08:49 PM	(permalink)
dknguyen	Did you just not answer your own question?

8th August 2007, 08:56 PM	(permalink)
joe_1	I have very good "theoretical" idea about what will happen, so it is some sort of confirmation that I was looking for.

8th August 2007, 10:58 PM	(permalink)
HarveyH42	Explosion kind of depends on the voltage rating of the capacitor...

9th August 2007, 02:45 AM	(permalink)
Leftyretro	There is a way. By connecting two electrolytic polarized caps in series with + to + and input and output using the negative leads, one can use the resulting capacitor in a AC circuit. Of course the total capacitance will be less then either individual value. Two 10mfd caps in series will present a 5mfd value, calculated just like having two resistors in parallel. Edit: You still have to spec the working voltage of the caps to the application voltage. Lefty Last edited by Leftyretro; 9th August 2007 at 02:54 AM.

9th August 2007, 05:14 AM	(permalink)
Robot builder 101	mfd? Do you mean uf (microfarad)? You have that posted as millifarad.

9th August 2007, 08:36 PM	(permalink)
Hero999	Some older publications use m to stand for micro which is pretty silly in my opinion, but it's only used for capacitors which aren't normally found it values as high as 1mF so it doesn't cause too much confusion. I never use mF, I normally use µF for values =<99,999µF and Farads for values >=0.1F, that way I never get confused. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez And http://www.silicontronics.com, same screen name as here.