Bridge circuits are widely used in electrical engineering for measuring physical parameters like strain, temperature, pressure, and displacement through transducers. Transducers convert physical quantities into electrical signals, typically in the form of resistance changes. However, the relationship between the physical parameter and the output voltage of a bridge circuit is often non-linear, especially when only one arm of the bridge contains the transducer. This non-linearity can lead to inaccurate measurements and complicate data analysis.
Bridge Linearization aims to address this issue by modifying the bridge circuit to obtain a more linear relationship between the physical parameter and the output voltage. This allows for more accurate measurements and simpler data processing.
Why is Linearization Necessary?
Methods for Achieving Bridge Linearization:
Reduction of Bridge Sensitivity: This method focuses on reducing the sensitivity of the bridge circuit to changes in transducer resistance. This can be achieved by:
Using Two Transducers: This approach involves using two transducers that generate signals with opposite signs. These transducers are connected to opposite arms of the bridge. The resulting output voltage reflects the difference between the two transducer signals, leading to a more linear output. This method is particularly effective in applications where the measured parameter has a symmetrical effect on the transducers, like a strain gauge pair measuring the bending of a beam.
Current Source Excitation: Traditional bridge circuits are powered by voltage sources. However, using a current source instead provides a constant current through the bridge, independent of the transducer resistance. This eliminates the influence of resistance changes on the output voltage, resulting in a more linear response.
Design Considerations for Bridge Linearization:
Benefits of Bridge Linearization:
By incorporating bridge linearization techniques, engineers can achieve more precise and reliable measurements using transducer-based bridge circuits. This leads to more accurate data, better control of physical processes, and improved overall system performance.
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