Using an Un-Balanced AC Wheatstone Bridge to Measure Capacitance and Inductance

Abstract

The Wheatstone bridge is a very common and very important electric circuit, especially in the measurement of resistance/impedance corresponding to transducers and materials deformity. See Figure 1 . DC bridges are most often used for transducer measurements, both mechanical, material, and optical (1) , (2) , and (3) . AC bridges are often used to measure inductance or capacitance (4) , (5) . Both types of bridges require the voltage output of the bridge to be zero, and this is accomplished when the 4 arms of the bridge are balanced so as to pass the same current through the 2 left impedances as through the 2 right impedances, or in other words, the output voltage and current are zero.