Principle and characteristics of linear variable differential transformer

Principle of linear variable differential transformer:

The oscillator generates a high-frequency reference electromagnetic field, and has a built-in movable ferromagnetic spindle and two sets of induction coils. When the spindle moves, the intensity changes and two voltage values ​​are induced by the induction coils. The movement amount can be calculated by comparison. If the direction of movement needs to be sensed, only one set of primary coils needs to be added to the power supply side, and the direction of movement can be determined by the phase of the induced voltage. The general measurement range is 0.1mm to 1m, the resolution is 0.1μm, and the accuracy is 0.01-0.05% of the full scale.

Linear variable differential transformer characteristics:

(1) The output voltage indicates the displacement amount, and the voltage polarity indicates the displacement direction

(2) Non-linearity: ±0.1%~±1%FS

(3) Sensitivity: 10~45mV/Mil (1mil= In)

(4) Wide load impedance range

(5) Frequency range: 50Hz~10kHz

(6) Resolution: 2μm

(7) (Linear) Range: 0~±3in

(8) No fatigue loss