Self chargeing capacitors?

[[email protected]]

I recently finished building my Zagi 400, a remote controlled airplane.
I used a "12" volt 300 ma charger to charge the battery. I took my volt
meter to make sure of the polarity before hooking up an expensive
battery. I know by taking a charger apart that there is a capacitor
inside. When i unpluged the transformer, the capacitor would slowly
discherge. I would short the two leads, the voltage would drop to zero,
but as soon as i unshorted them the voltage would slowly climb into the
tenths of volts range, if i had been more patient it might Have reached
a whole volt. Whats going on here?

 

[The Phantom]

I recently finished building my Zagi 400, a remote controlled airplane.
I used a "12" volt 300 ma charger to charge the battery. I took my volt
meter to make sure of the polarity before hooking up an expensive
battery. I know by taking a charger apart that there is a capacitor
inside. When i unpluged the transformer, the capacitor would slowly
discherge. I would short the two leads, the voltage would drop to zero,
but as soon as i unshorted them the voltage would slowly climb into the
tenths of volts range, if i had been more patient it might Have reached
a whole volt. Whats going on here?

It's a phenomenon known as dielectric absorption. Go have a look at:

http://www.tpub.com/celec/55.htm


and

http://www.sencore.com/custsup/pdf/TT105.pdf

 

[JeffM]

It's a phenomenon known as dielectric absorption. Go have a look at:

http---tpub---
The Phantom

I am amazed that you actually directed someone to that spammer's site.

 

[Tom MacIntyre]

I am amazed that you actually directed someone to that spammer's site.

Maybe he didn't know (I didn't). I do know that they once provided a
lot of stuff for free that now requires payment. The page in question
is at least informative, or so it appears.

Tom

 

[JeffM]

Go have a look at: http---tpub---

The page in question is at least informative, or so it appears.
Tom MacIntyre

That's the 1st time I've seen a link to that domain that was useful.

The site owner has been trolling these groups
trying to stir up traffic for his site
but not being helpful in any way.
All he gives are vague links. Once at his site,
you have to give him at least 2 more page hits
to actually get to anything useful.

He's just a self-serving jerk.