Air Flow Detector

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 100 Ohm 1/4W Resistor R2 1 470 Ohm 1/4W Resistor R3 1 10k 1/4W Resistor R4 1 100K 1/4W Resistor R5 1 1K 1/4W Resistor C1 1 47uF Electrolytic Capacitor U1 1 78L05 Voltage Regulator U2 1 LM339 Op Amp L1 1 #47 Incandescent lamp with glass removed (See "Notes") D1 1 LED MISC 1 Board, Wire, Sockets for ICs, etc.

Notes

1. The glass will have to be removed from L1 without breaking the filament. Wrap the glass in masking tape and it in a vise. Slowly crank down until the glass breaks, then remove the bulb and carefully peel back the tape. If the filament has broken, you will need another lamp.