Air-powered sensor

This paper describes an application for powering wireless sensors. We use air motion to drive a miniature wind turbine. The intent is to use the device indoors, in air ducts used for heating, ventilating, and air-conditioning. We used commercially available off the shelf components for the airflow turbine. A low-speed, three-phase, brushless DC servomotor was used for the generator. A three-phase bridge constructed from six diodes was used to convert the AC current from the motor to DC current required by low-power sensors. We used a four-inch fan blade for the turbine blade. We conducted a set of tests on the airflow turbine using resistive loads to demonstrate its energy conversion potential. We also showed that it could power a wireless sensor continually.