Resonance - AAC ebook

Thread Starter

JStitzlein

Joined Dec 6, 2010
53
Hi All,

Question about this paragraph from the book -

If we assume that both components are subjected to a sudden application of voltage (say, from a momentarily connected battery), the capacitor will very quickly charge and the inductor will oppose change in current, leaving the capacitor in the charged state and the inductor in the discharged state

I'm confused why the cap can hold a charge while the inductor is discharged even if both are loads to the sudden pulse of battery source.

---EDIT
From what i've read, is it because the cap draws much more current, acting more of a "short"?


If the battery were kept there longer, charging both elements fully, would it just do nothing and not oscillate?
 

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beenthere

Joined Apr 20, 2004
15,819
I'm confused why the cap can hold a charge while the inductor is discharged even if both are loads to the sudden pulse of battery source.
The capacitor gets charged, but can't hold it once the battery is removed from circuit, as there is a discharge path through the inductor.
 

Wendy

Joined Mar 24, 2008
23,415
Caps charge fast, inductors don't. When you put a cap across power it acts like a dead short, surging several amps.

Coils on the other hand, resist current flow, in a mirror image to how caps act. When a coil is charge it is the one carrying several amps, but it takes time.
 

Thread Starter

JStitzlein

Joined Dec 6, 2010
53
Caps charge fast, inductors don't. When you put a cap across power it acts like a dead short, surging several amps.

Coils on the other hand, resist current flow, in a mirror image to how caps act. When a coil is charge it is the one carrying several amps, but it takes time.
This was my best guess, but i'm still curious to know what would happen if the battery were held there for a longer period of time. The cap would eventually charge, then the inductor would carry a magnetic field -

After the switch is released both elements would ideally hold their charge, but because of cap&inductive resistances, they would eventually lose charge.

I can't visualize what would happen next with both elements losing charge over time and supplying each other with energy, an oscillation with less amplitude?
 
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