Objective: To determine the capacitance of an unknown capacitor.
Fig. 1. Wien Series Bridge Circuit .
C1= Capacitor whose capacitance is to be measured,
R1= a series resistance representing the loss in the capacitor C1,
C4 = a standard capacitance with series resistance of R4,
R2 and R3 = non-inductive resistances.
Equating the real and imaginary terms, we obtain
Two independent balance equations are obtained if C4 and R4 are chosen as the variable elements.
The dissipation factor of capacitance C1 is defined as,