Wireless Sensor System Supplied By Pressurised Air

Abstract:
This work presents a fluid flow based energy harvesting demonstration system with a wireless sensor interface. The setup consisted of a turbine stage that was supplied by pressurised air, a power conversion circuit and a basic wireless sensor node. The system measured characteristics such as: pressure, temperature, generated voltage and rotational speed of the turbine and transmitted them to a host. Within the development of the system, two different turbine stages have been constructed and tested. The first one was based on a classic turbine design. The second stage was based on a Tesla turbine which has a different working principle than a classic rotor construction. Instead of impulse transmission from the fluid to the rotor-blades, a stack of discs was dragged due to adhesion and viscosity. After development and characterisation of a working turbine stage, the subsequent step was to build a wireless sensor interface between sensor and PC which has been supplied by the turbine. With the Tesla turbine, energy levels of about 250 mW could be provided at rotational speeds of around 6400 rpm at 600 mbar input pressure. These power ratings were sufcient to supply a wireless sensor node that has been realised with a Texas Instruments microcontroller evaluation kit MSP430 eZ430-RF2500.