What is the role of the resistor in a Parallel Resonance Circuit?

[paul9619]

Hi all.

I have a Parallel Resonant circuit with a Capacitor in Parallel with an Inductor & Resistor in Series together. Capacitor on the left branch and Inductor & Resistor on the right branch.

The question I would like to ask is what effect does the resistor have on the circuit?

I believe it may have something to do with the leakage current? Not really sure though.

Anyone help out??

 

[marcusl]

Hi all.

I have a Parallel Resonant circuit with a Capacitor in Parallel with an Inductor & Resistor in Series together. Capacitor on the left branch and Inductor & Resistor on the right branch.

The question I would like to ask is what effect does the resistor have on the circuit?

I believe it may have something to do with the leakage current? Not really sure though.

Anyone help out??

It determines the "Q" (Quality Factor) of the resonance. If omega_0 is the resonance angular frequency,

Q = omega_0 * L / R.

The width of the resonance at the -3dB (half power) points is

delta_omega = omega_0 / Q