Linear variable differential transformer sensor using Fe-rich amorphous wires as an active core

Results concerning linear variable differential transformer (LVDT) displace ment measurements using Fe77.5Si7.5B15 amorphous wires as movable core are presented. Taking advantage of the large Barkhausen (LBE) effect in amorpho us wire, a small exciting field and a small number of windings in the secon dary coils are necessary to get an large output signal of the LVDT. The the rmal noise of the output becomes low, due to the small number of coil turns , increasing thus the sensitivity of the LVDT. The results obtained show a linear dependence of the LVDT response on the displacement of the moving co re for displacements up to about 14 mm, with accuracy of 1 mu m. (C) 2000 A merican Institute of Physics. [S0021-8979(00)32808-0].