Owen's Bridge, also known as Owen's Circuit, is a specific bridge circuit used for measuring the self-inductance of a coil (inductor) and the resistance of the coil's winding. It was developed by the English engineer William M. Owen. The Owen's Bridge is essentially a modification of the Wheatstone bridge, adapted for measuring inductance and resistance.
The bridge circuit consists of four arms, usually labeled P, Q, R, and S. These arms contain resistors and the coil whose self-inductance and resistance need to be measured. The basic principle behind the Owen's Bridge is to balance the bridge by adjusting the values of the resistors until there is no current flowing through the galvanometer (null condition).
The formula for calculating the self-inductance (
L) of the coil and the resistance (
R) of its winding using the Owen's Bridge is as follows:
=
(
/
)
−
1
L=
(P/Q)−1
R
Where:
L is the self-inductance of the coil,
R is the resistance of the coil's winding,
P and
Q are the resistances in the arms of the bridge.
It's important to note that Owen's Bridge is not commonly used nowadays, as more advanced techniques and equipment have been developed for measuring inductance and resistance. The bridge method is sensitive to variations in the bridge resistors and other components, which can lead to inaccuracies in measurements. Modern instrumentation often employs digital LCR (inductance, capacitance, and resistance) meters and network analyzers for more accurate and efficient measurements.