Before I adventure further in that exchange, what do mean exactly by 'RVDT
angle' ?
Maybe this clears up.
LVDTs
The linear variable differential transformer (LVDT) is a sensor used to measure displacement in the industrial environment. An LVDT consists of three coils of wire wound on a hollow form. A core of permeable material can slide freely through the center of the form. The inner coil is the primary coil, which is excited by an AC source as shown. Flux formed by the primary is linked to the two secondary coils, inducing an AC voltage in each coil. When the core is centrally located in the assembly, the voltage induced in each primary is equal. If the core moves to one side or the other, a larger AC voltage is induced in one coil and a smaller AC voltage in the other because of changes in the flux linkage associated with the core.
RVDTs
The
rotational variable differential transformer (RVDT) is used to measure rotational angles and operates under the same principles as the LVDT sensor. The LVDT uses a cylindrical iron core, while the RVDT uses a rotary ferromagnetic core.
Item 6 in drawing below are the 4 RVDTs.
