Circuit Project Electronic

This simple circuit uses an incandescent lamp to detect airflow. With the filament exposed to air, a constant current source is used to slightly heat the filament. As it is heated, the resistance increases. As air flows over the filament it cools down, thus lowering it’s resistance. A comparator is used to detect this difference and light an LED. With a few changes, the circuit can be connected to a meter or ADC to provide an estimation on the amount of air flow.

Read more original source:
http://www.aaroncake.net/circuits/airflow.htm

This entry was posted on Friday, August 15th, 2008 at 8:20 am and is filed under detector. You can follow any responses to this entry through the RSS 2.0 feed.