1 Answer
The purpose of a Wheatstone bridge is to measure unknown resistance by balancing two legs of a bridge circuit. It was invented by Samuel Hunter Christie in 1833, and later popularized by Charles Wheatstone in 1843.
Here’s how it works in simple terms:
- Rx as the unknown resistor, and
- R3 as a variable resistor or another known resistor.
\[
\frac{R1}{R2} = \frac{Rx}{R3}
\]
From this equation, you can solve for the unknown resistance Rx if you know the values of R1, R2, and R3.
- Strain Gauges and Temperature Sensors: It is also used in sensors like strain gauges, where the resistance of a material changes with deformation or temperature.
In summary, the Wheatstone bridge is mainly used for precise measurements of unknown resistances and is crucial for applications requiring high accuracy.
Here’s how it works in simple terms:
- Basic Setup: A Wheatstone bridge consists of four resistors arranged in a diamond shape. The bridge has:
- Rx as the unknown resistor, and
- R3 as a variable resistor or another known resistor.
- Balanced Condition: The idea is to adjust the value of R3 until the bridge is “balanced.” When the bridge is balanced, the voltage across the middle (between R1-R2 and Rx-R3) is zero. At this point, the ratio of the resistors in one leg of the bridge is equal to the ratio in the other leg.
- Formula: The condition for a balanced Wheatstone bridge is:
\[
\frac{R1}{R2} = \frac{Rx}{R3}
\]
From this equation, you can solve for the unknown resistance Rx if you know the values of R1, R2, and R3.
- Applications:
- Strain Gauges and Temperature Sensors: It is also used in sensors like strain gauges, where the resistance of a material changes with deformation or temperature.
In summary, the Wheatstone bridge is mainly used for precise measurements of unknown resistances and is crucial for applications requiring high accuracy.