# cap and ind back and so on

Discussion in 'General Electronics Chat' started by Lightfire, Apr 19, 2012.

1. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
OK. Capacitor charges and the Inductor don't want.... so how come they have alternating. or capacitor charges and then discharges to inductor and do the same thing again ang again

2. ### @android Member

Dec 15, 2011
178
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I didn't get. What are you implying? Please elaborate.

3. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
ok......

Capacitor chargesthen the charge there discharges and then the discharges charge will go the inductor and then the charge that has been charged in inductor will be disachage and then charge to capacitor again and so on.
LIKE CAP-->IND>>>CAP>>>>IND>>>CAP>>>IND ans so forth~

4. ### Bernard AAC Fanatic!

Aug 7, 2008
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Something like a parallel resonate ckt';

5. ### Ron H AAC Fanatic!

Apr 14, 2005
7,018
682
That's "parallel resonant ckt".

6. ### R!f@@ AAC Fanatic!

Apr 2, 2009
9,652
1,110
OP is talking about LC tank circuit
I bet he is having a hard time trying to figure out why the current circulates with in the tank circuit.

7. ### panic mode Senior Member

Oct 10, 2011
1,645
459
it is due nature of capacitor and inductor (the way they operate).
capacitor can store (and hold) charge.
inductor can store energy in form of magnetic field but only while current is flowing.
if the current is trying to change (increase or decrease) inductor opposes (like a flywheel).

when you connect L and C together and introduce charge to a capacitor, it will try to discharge because inductor provides current path. however, this is not mere short circuit, there is inductivity and this means that current cannot start (or stop) suddenly. when capacitor is discharged (potential across capacitor is zero), there is current flowing through inductor and it is "at full swing". this current charges capacitor the opposite way and to a nearly same voltage (there are slight losses in any real component, most notably due internal resistance of the inductor).
when the capacitor charge is at peak, current is zero, then the cycle reverses again. it continues until circuit is either disturbed (shorted for example) or some energy still remains.

one of the interesting properties of oscillatory circuits is equivalent impedance.

when two resistors are wired in parallel, equivalent resistance is smaller than either of resistors.
when two resistors are wired in series, equivalent resistance is greater than either of resistors.

counter-intuitively, LC circuits at resonance are behaving opposite:
parallel circuit acts as high impedance,
series circuit acts as low impedance.