The Development of a Dedicated Signal Transfer System

This paper describes the development of the Dedicated Signal Transfer System (DSTS) to fulfill the instrumentation requirements of a tilt-rotor wind tunnel model. The system is used to amplify the low level signals of the blade strain and blade pressure sensors of the model. The DSTS Front End Unit contains modular signal conditioners with built-in excitation regulators, which amplify and digitize the sensor signals in the rotating part of the model. The resulting digital data are sent to the ground part of the system using a fiber-optic cable. The signal conditioners can be remotely configured for gain, input offset compensation, AC/DC input and filter bandwidth. This approach reduces both the size of the cable and the size of the electrical slip ring normally used for analogue transfer of the data. Application of a fiber-optic cable further improves the susceptibility to Electromagnetic Interference caused by the model driving electrical motor.