Mini project presentation

AUTOMATIC TEMPERATURECONTROLLED FAN

Abhilash.K.M(02)Abin Baby(03)Ajith Kumar R(04)Bineesh Babu P(10)

College of Engineering Munnar

College of Engineering Munnar

Mini project byStudents of College of Engineering, Munnar

College of Engineering Munnar

INTRODUCTION

Ordinary fan regulatorsElectronic fan regulators

College of Engineering Munnar

Why automatic temperature controlled fan?

*Automatic speed control*Low power loss*Reduce Current Consumption*Allows fan to ramp up or down smoothly to new speed*Increase Fan Life*A single temperature or all temperatures can control the fan speed.*Small size and economic

College of Engineering Munnar

Thermistor

High Gain

Amplifier

Comparator

Bridge Rectifier

Triac Optocoupler

Increase intemperature

BLOCK DIAGRAM

AC supply230 V, 50Hz

230 VAC

College of Engineering Munnar

Components Used

*Thermistor*IC LM324*IC µA741*Resistors*Zener diodes*Optocoupler (MOC3011)*Triac(BT 136)

College of Engineering Munnar

CIRCUIT DIAGRAM

College of Engineering Munnar

LM324

* 4 OpAmps in a single IC

College of Engineering Munnar

NEED OF OPTOCOUPLER

* Basically an opto-isolator, designed to transfer electrical signals by utilizing light waves to provide coupling with electrical isolation between its input and output. *The main purpose of an opto-isolator is to prevent high voltages or rapidly changing voltages on one side of the circuit from damaging components or distorting transmissions on the other side.

Schematic diagram of an opto-isolator showing source of light (LED) on the left, dielectric barrier in the center, and sensor (phototransistor) on the right.

College of Engineering Munnar

THERMISTOR

• A thermistor is a type of resistor • resistance varies significantly with 

temperature• used as current limiters,

temperature sensors, self-resetting overcurrent protectors, and self-regulating heating elements

College of Engineering Munnar

TRIAC

• speed controls for electric fans

• TRIACs are bidirectional and so current can flow through them in either direction.

•  TRIACs can be triggered by either a positive or a negative current applied to its gate electrode.

• Once triggered, the device continues to conduct until the current drops below a certain threshold, called the holding current.

College of Engineering Munnar

OUR PROGRESS

We have designed and wired the circuit on the bread board level, and the output is obtained upto 2 stages.

REFERENCE

Wikipedia, electronicsforyou.com

COST250 rs

College of Engineering Munnar

THANK YOU