Capacitive displacement sensor - QuickField simulation example
Capacitive displacement sensor working principle is based on the capacitance change with variation of the mutual position of the two coaxial cylindrical electrodes.
How can the capacitance of a coaxial displacement sensor be calculated as the inner electrode moves?
Answer Typical applications Geometry
Given
Task
Solution
Results
Engineering question
Calculate the stored electric-field energy for successive electrode positions and use it to determine the capacitance.
capacitive touch electrodes, touch sensor buttons, human interface sensors
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Simulation problem
Problem Type
Axisymmetric problem electrostatics.
Relative permittivity of air ε = 1.
Calculate the capacitance as a function of the inner cylinder's displacement.
We apply the potential difference of ΔU = 1 V to the cylinders and measure the electric field energy W stored in the air.
The capacitance is 2*W / ΔU ².
A set of QuickField problems with different cylinders position is automatically generated by the Label Mover tool.
At zero displacement the capacitance is 2*7.57e-12 / 1² = 15.14 pF.
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