AIR FLOW DETECTOR SYSTEM

MINI PROJECT-2ON

AIR FLOW DETECTOR

NAME REG NO.:-

ANOOP KAMAL MINZ U10EE003ANUPAM KUMAR U10EE004BISHWARUP MUKHERJEE U10EE006

Abstract:-

This circuit can give a visual indication of the rate of air flow. It can be also used to check whether there is air flow in a given space.

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 high.

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 filament.

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.

CIRCUIT DIAGRAM:-

Live circuit

Component required:-S NO. TOTAL QTY DISCRIPTIONR1 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

IC1 1 7805 IC

IC2 1 LM339 IC

L1 1 filament

D1 1 LEDMISC1Board, Wire, Sockets for ICs, etc.

IC 7805

7805 is a voltage regulator integrated circuit. It is a member of 78xx series of fixed linear voltage regulator ICs. The voltage source in a circuit may have fluctuations and would not give the fixed voltage output. The voltage regulator IC maintains the output voltage at a constant value. The xx in 78xx indicates the fixed output voltage it is designed to provide. 7805 provides +5V regulated power supply. Capacitors of suitable values can be connected at input and output pins depending upon the respective voltage levels.

IC LM339

LM339 is a comparator IC with four inbuilt comparators. A comparator is a simple circuit that moves signals between the analog and digital worlds. It compares two input voltage levels and gives digital output to indicate the larger one. The two input pins are termed as inverting (V-) and non-inverting (V+). The output pin goes high when voltage at V+ is greater than that at V-, and vice versa. In common applications, one of the pins is provided with a reference voltage and the other one receives analog input from a sensor or any external device. If inverting pin (V-) is set as reference, then V+ must exceed this reference to result in high output. For inverted logic, the reference is set at V+ pin.

WORKING OF IC LM399

Pin Description:  

100k chip resistorSpecifications of MDST-1-100K-W-ESA-N-1-N-Y

Track Resistance

100kohmTrack Taper Linear

No. Of Turns 1 Power

Rating 200mW

No. Of Gangs 1 Svhc No SVHC (18-Jun-2010)

Resistor Element Material Variable Rotary

Approval Category

VDE

Potentiometer Mounting

Panel

Rohs Compliant Yes

Lead Free Status / RoHS Status

Lead free / RoHS Compliant

APPLICATION:-

• Industrial gas flow measurement

• Leak detection in pressurized air systems

• Spirometers

• Air intake of combustion engines

CONCLUSION

Thus, the circuit can give a visual indication of the rate of air flow.

It can be also used to check whether there is air flow in a given space.

The filament of an incandescent bulb is the sensing part of the circuit.

When there is no air flow the resistance of the filament will be low.

Thus the air flow is been detected and as an output the LED indicates.

BIBLIOGRAPHY

http://www.wikipedia.org/ WIKIPEDIA.

http://electronicsforu.com.asp ELECTRONIC FOR YOU.

http://www.circuit-projects.com/ CIRCUIT PROJECT.

http://www.aaroncake.net AARON CAKE.

http://electroschematics.com/ ELECCTRON SCHEMATICS.