Resonance

[Kevin Weddle]

What is the thory behind resonance. What is it about the capacitor and inductor that lends itself to the open and short at the resonant frequency? I know that in series, you subtract the reactances. I know in parallel they call it a tank. I am assuming in the tank, there is no current from the source. This is because the inductors voltage leads the current and because the source voltage lags the inductor voltage. What happens is that as the voltage rises, the inductors voltage is equal to the source. And the inductor draws no current. Now the capacitor will charge from the inductor and the inductors voltage is equal to the source. Hence there is no current from the source. As the capacitor charges from the inductor, since the impedances are equal all the power from the inductor is transferred to the capacitor. This is what happens when the voltage rises. When it falls, there is still no current delivered to the circuit because the capacitors voltage is equal to the source and all the power of the capacitor is transferred to the inductor.

So my conception is based on the voltage of the source with respect to the voltage on the tank. Since there is no voltage difference, there is no current that is delivered to or taken from the tank with respect to the source.