Air flow detector circuit

Posted on Feb 5, 2014

The filament of a incandescent bulb is the sensing part of the circuit. When there is no air flow the resistance of the filament will be low. When there is air flow the resistance drops, because the moving air will remove some of the heat generated in the filament. This variations in the resistance will produce variation of voltage across the filame

Air flow detector circuit
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nt. These variations will be picked up by the opamp (LM339) and the brightness of the LED at its output will be varied proportionally to the airflow. The current source should be capable of supplying 50mA to the filament. around 80 to 100 ohms in value. if your filament resistance is more than 100 ohms this circuit will not work. you have to use portion of the bulb filament instead of full length. use around 50 to 60 ohms of it. Dear Seetharaman, i am doing a project very similar to this. It is like im using a wind flow sensor. Is there any way that you could help me with this please Thanks in advance Air flow detector is user to find the adequate air flow in a system. (may be a bower or a cooling fan air flow) Here the positive temperatue coefficient charecterestic of the bulb filament is used for detecting the air flow(the air flow will cool the bulb filament (which is heated by constant current flow through it). Once the air flow decreases the bulb temperature will increase its resistance will increase which will detected and indicated by the LED. I am making this project in my college and i am required to submit the report but due to lack of adequate information i am unable to make the report. so kindly help me by providing some more information on this topic or your report on this project. Thankyou. Hi Sir, i am doing a project on air flow detector and i have to submit a report on that but i dont have enough...

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