Wind direction indicator

Numpon Mahayotsanun and James Washington built a device that measuresand indicates wind direction

Horizontal airflow passes between two lucite plates. Electrically heated resistors in the center warn the air. A ring of diodes detects the temperature of the air as it emerges in 8 compass directions.

A computer reads the difference signal from every pair of adjacent diodes, and determines where the warm ones are.

A small motor turns the arrow in the background to indicate wind axis and direction.

Closeup of one of the diodes. (The forward voltage of a diode depends on temperature)

Wind's eye view. A small fan was used for testing.