L-C Circuit

Topic Content:

Series L-C Circuit:

A series L-C circuit consists of an inductance and a capacitance connected in series, as shown:

As in all series circuits the current has the same value at all points. This means the current in the inductor is the same as, and therefore in phase with, the current in the capacitor.

The voltage across the inductor leads the current by 90 degrees, and voltage across the capacitor lags the current by 90 degrees. Since the current through both is the same, the voltage across the inductor leads the voltage across the capacitor by 180° (degrees).

Series L-C Circuit Phasor (Vector) Diagram:

• The current vector I is the common quantity and is drawn as a horizontal line.

• The voltage vector, V_L , is 90° ahead of I since the voltage leads the current