AC Bridge: Solve Unknown Inductance/Resistance

Thread starter Dhruv
Start date Feb 22, 2015
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Ac Bridges

In summary, an AC bridge is an electrical circuit used to measure unknown inductance and resistance values. It works by comparing the voltage across the unknown component to a known component while applying an AC signal. This method is preferred over using a DC bridge for high frequency measurements. The unknown values can be calculated using the formula L = R1R3/R2R4 and R = R2R3/R1R4. However, AC bridges are not suitable for measuring capacitance and have limitations such as accuracy at high frequencies and external factors affecting the results. The precision of components and skill of the operator can also impact the accuracy of measurements.

Feb 22, 2015

Dhruv

Homework Statement

I have given the T - bridged network figure and I have to calculate unknown inductance and resistance?

Homework Equations

I solved a lot of bridge problems using balanced bridge equation :-

(Z1)(Z4) = (Z2)(Z3)

But I have no idea how to proceed in this question , please help.

The Attempt at a Solution

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Feb 22, 2015

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http://en.wikipedia.org/wiki/Zobel_network

1. What is an AC bridge and how does it work?

An AC bridge is a type of electrical circuit that is used to measure unknown inductance and resistance values. It works by applying an alternating current (AC) signal to the circuit and comparing the voltage across the unknown component to the voltage across a known component. By adjusting the values of the known components, the unknown values can be determined.

2. Why is an AC bridge used instead of a DC bridge?

An AC bridge is used instead of a DC bridge because it is more accurate for measuring inductance and resistance at high frequencies. DC bridges are more suitable for measuring low frequency or steady-state values.

3. How do you calculate the unknown inductance or resistance using an AC bridge?

The unknown inductance or resistance can be calculated using the formula L = R₁R₃/R₂R₄ and R = R₂R₃/R₁R₄, where R₁, R₂, R₃, and R₄ are the known resistance values and L is the unknown inductance. The values of R₁ and R₂ are adjusted until the bridge is balanced, and then the values of R₃ and R₄ are used to calculate the unknown value.

4. Can an AC bridge be used to measure capacitance?

No, an AC bridge is not suitable for measuring capacitance. It is designed specifically for measuring inductance and resistance.

5. What are the limitations of using an AC bridge?

One limitation of using an AC bridge is that it is only accurate for measuring inductance and resistance at high frequencies. It may also be affected by external factors such as temperature and noise. Additionally, the accuracy of the measurements may be limited by the precision of the components and the skill of the operator.