A wind-sensor interface using thermal sigma delta modulation techniques

An electronic interface for an integrated wind-sensor is described. The sen sor is based on a heated silicon chip that is cooled asymmetrically by the wind. The interface maintains the entire chip at a constant temperature abo ve that of the airflow by dynamically regulating the power dissipated in fo ur on-chip resistors used as heaters. The voltages required to drive these resistors are bit-streams generated using thermal Sigma Delta (YA) modulati on techniques. These bit-streams can be directly connected to an external m icroprocessor, where they are decimated to obtain digital words representin g the power dissipated in each heater. An explicit analog-to-digital (A/D) converter in the interface electronics is, thus, not required. It is shown that wind speed and direction may be accurately determined from the measure d power dissipated in the heaters. (C) 2001 Elsevier Science B.V. All right s reserved.