AC-Operated Rotary Variable Differential Transformers
RVDTs incorporate a proprietary noncontact design that dramatically improves long term reliability when compared to other traditional rotary devices such as syncros, resolvers and potentiometers. This unique design eliminates assemblies that degrade over time, such as slip rings, rotor windings, contact brushes and wipers, without sacrificing accuracy.
High reliability and performance are achieved through the use of a specially shaped rotor and wound coil that together simulates the linear displacement of a Linear Variable Differential Transformer (LVDT). Rotational movement of the rotor shaft results in a linear change in the output signal, directly proportional to change in shaft angle, over +/-60 degrees from the null position. The phase of this output signal indicates the direction of displacement from the null point. Noncontact electromagnetic coupling of the rotor provides infinite resolution, thus enabling absolute measurements to a fraction of a degree.
The R30A and R36AS RVDTs are AC operated rotary transducers. AC excitation of 3 V rms results in a ratiometric AC output voltage That varies in direct proportion to the change in angular position of the transducer shaft. AC operation eliminates the need for integrated signal conditioning components thereby offering the user an extremely wide operating temperature range of -55°C to 150°C.
Factory calibrated to operate over a ±30 degree range, both the R30A and R36AS offer a nonlinearity of less than ±0.5% of full scale. Extended range operation up to a maximum of ±60° is possible with compromised linearity. The R36AS is distinguished from the R30A in that it incorporates a more rugged stainless steel size 15 package, and MS style connector. The R30A is packaged in a smaller size 11 aluminum housing with flying lead termination for slightly less aggressive applications. Both transducers offer superb performance and long term reliability for applications such as machine tool equipment, valve positioning, and rotary actuator feedback.