Question

Can DC signal be used to excite an LVDT "Linear variable differential transformer"? Why?

Answer 1

Answer:No

The LVDT consists of a primary winding,a ferromagnetic movable core and two identical secondary windings connected in series opposition.

For primary winding an AC excitation voltage is applied.The movable core is placed between primary and secondary winding.Depemding on core moves in forward or backward directions ,the generated output voltage changes.

Hence if the primary core is excited with DC ,there is no flux linkage with the secondary because of saturated core.Hence the LVDT should be always excited with ac source.