Anderson Bridge for measuring inductance with large time constant

The Anderson bridge is a type of bridge circuit used for measuring the inductance of an unknown component. It is particularly useful for measuring inductors with a large time constant, which can be difficult to measure accurately using other bridge configurations.

Working principle

The Anderson bridge works by comparing the unknown inductor with a known reference inductor. The circuit consists of four arms, each containing an inductor and a resistor. The unknown inductor is connected between two of the arms, while the reference inductor is connected between the other two. The bridge is balanced when the voltage across the two parallel arms containing the inductors is zero.

Advantages

The Anderson bridge has several advantages over other bridge configurations. It is particularly useful for measuring inductors with a large time constant, since it allows the measurement to be made at a higher frequency than other bridges. This can improve the accuracy of the measurement by reducing the effects of stray capacitance and other parasitic effects.

Another advantage of the Anderson bridge is that it is less sensitive to changes in the resistance of the inductor being measured. This can be important when measuring inductors with a high Q factor, which can have a significant resistance component.

Conclusion

In conclusion, the Anderson bridge is a useful tool for measuring the inductance of an unknown component with a large time constant. Its ability to operate at higher frequencies and its reduced sensitivity to changes in resistance make it a valuable addition to any engineer's toolkit.