Motors, Sensors & Components : Position Transducers

Position transducers, designed and manufactured by Woodward MPC, employ the technical principles associated with AC transformers. A fixed excitation voltage applied to the transducer produces a corresponding output voltage. The output voltage amplitude is directly variable according to the angular position of a rotatable core member. The device is known industrially as a rotary variable transformer (RVT). In addition to the basic RVT, Woodward MPC also manufactures several variations based on the generic scheme. RVDTs are a popular option where system requirements demand not only single-channel, non-redundant position sensing, but require built-in test features. Woodward MPC's practice is to design all coil windings to provide slightly higher output than specified. The RVT is then connected to a representative test load and individually trimmed by selecting and internally terminating a calibrating resistor across the output leads; this process results in a unit-to-unit perfect scale factor, and maximizes interchangeability in the field.