AC Applied to a capacitor and dielectric effects?

Click For Summary

Discussion Overview

The discussion revolves around the behavior of an electrolytic capacitor when subjected to two AC sources that are 180 degrees out of phase. Participants explore the unexpected voltage behavior observed at the capacitor's plates, which resembles the output of a bridge rectifier, despite the AC nature of the inputs.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes the scenario where an electrolytic capacitor has two AC sources connected to it, noting that the voltage at each plate appears identical to that of a bridge rectifier.
  • Another participant suggests that the behavior may be due to the nature of electrolytic capacitors, which are not designed for AC voltage and could act like a rectifier under certain conditions, particularly with limited current.
  • A request for further reading on the topic is made, indicating interest in understanding the phenomenon better.
  • A subsequent reply provides a link to a Wikipedia article on electrolytic capacitors, specifically mentioning the importance of polarity.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the explanation for the observed behavior of the capacitor. There are differing views on the implications of using an electrolytic capacitor with AC sources, and the discussion remains unresolved regarding the underlying mechanisms at play.

Contextual Notes

The discussion does not clarify the specific assumptions regarding the electrical characteristics of the AC sources or the exact nature of the capacitor's response to the applied voltages. There is also a lack of detailed exploration into the mathematical or physical principles governing the behavior of the capacitor in this scenario.

Who May Find This Useful

This discussion may be of interest to those studying electronics, particularly in the context of capacitors, AC circuits, and the effects of component limitations on circuit behavior.

HMS-776
Messages
63
Reaction score
0
Hi all,

An electrolytic capacitor has 2 AC sources connected to it, 1 at each plate. The AC sources are 180 degrees out of phase and have a high impedance which limits current in the nA range. Even though each plate should have AC on it which is 180 out of phase the voltage at each plate looks identical to the output of a bridge rectifier. One plate has all positive pulses while the other plate has all negative pusles.
Can anyone explain to me why this is happening or how it could even be possible?
 
Engineering news on Phys.org
The problem might be the electrolytic capacitor.

These are not built to take AC voltage and may act like a rectifier if the current through them is restricted.

Normally, if large currents can flow, applying AC to an electrolytic capacitor will destroy it.
 
Awesome, is there anywhere where I can find more information or read more about this effect?

-Thanks in advance!
 
Last edited:

Similar threads

Resistive heating power AC vs rectified AC/DC
  • · Replies 10 ·
Replies
10
Views
4K
How can I relate the electric field to potential in a parallel plate capacitor?
  • · Replies 22 ·
Replies
22
Views
3K
Need to use a rectifier.... but where to put it?
  • · Replies 7 ·
Replies
7
Views
2K
Exploring LRC AC Series Circuits
  • · Replies 25 ·
Replies
25
Views
3K
AC motor rotary capacitor soft start
  • · Replies 5 ·
Replies
5
Views
2K
Self excited induction generators and grid connected solar inverters?
  • · Replies 9 ·
Replies
9
Views
2K
AC to DC voltage doubler not working
  • · Replies 7 ·
Replies
7
Views
4K
Parallel plate capacitor question
  • · Replies 7 ·
Replies
7
Views
4K
"Flow through" electrolytic capacitor
  • · Replies 15 ·
Replies
15
Views
2K
How can I apply a variable phase shift to an AC signal generated by a VFD?
  • · Replies 9 ·
Replies
9
Views
2K