LVDT Output Calculator
Convert between core displacement and output voltage for an LVDT (linear variable differential transformer) using its sensitivity and the excitation voltage.
- Vout = S × Vexc × d = 50 × 3 × 4 = 600 mV
LVDT Output Formula
d = Vout ÷ (S × Vexc)
S is the sensitivity in mV per volt of excitation per mm of displacement, Vexc the excitation voltage and d the core displacement from the null position. The output amplitude is proportional to displacement; its phase relative to the excitation shows the direction. Sensitivity is quoted at a specific excitation frequency.
Worked example
An LVDT with 50 mV/V/mm at 3 V excitation gives 150 mV per mm, so a 4 mm displacement gives 600 mV; full scale at ±10 mm is 1500 mV.
Frequently Asked Questions
What is an LVDT?
A transformer with one primary and two secondary coils and a movable core. Moving the core changes the coupling, giving an output proportional to displacement.
What is the null position?
The core position where both secondaries are equal and the differential output is near zero.
Does excitation voltage matter?
Yes. Output is proportional to excitation, so use a stable source or a ratiometric signal conditioner.
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