REMOTECONTROLLED FAN

REGULATOR

MET’S School ofEngineeringDept. of Electrical & ElectronicsEngineering

Group V

Alvasim P. A.Anumol R.

Geo JoyNimmy Yesudas

Pradeep K. Vijayan

CONTENTSIntroductionBlock DiagramBlock Diagram ExplanationCircuit DiagramAbout the CircuitWorkingApplicationsAdvantagesConclusionReference

INTRODUCTION The aim of this work is to design and constructa remote controlled fan regulator.This circuit allows total control over theequipments without having to move around.The frequency of remote used is typicallyaround

36 KHz.The remote control device sends an infra-redbeam, which is received by the infra-red sensoron the regulator thereby affecting the speed ofthe fan or intensity of light.

BLOCK DIAGRAM

Infrared Receiver Module  The infrared rays transmitted by the remotecontrol are received by IR Receiver.The component used here is capable ofreceiving signals up to 38 KHz.

Monostable MultivibratorMonostable Multivibrator is used for getting anaccurate pulse.The trigger to this is the signals from receivermodule.The output of Monostable Multivibrator (IC1)isused to delay the clock pulse of decadecounter. 

Decade Counter  Decade counter is Mod-10 counter.The count is incremented with each clockpulse.

TransformerThe 230 V AC is step down to 12V by theTransformer .

Regulator Section The rectified output (12V) of the Transformer isregulated to 9V by the Regulator.This 9V is supplied to the whole circuit. 

Opto Coupler  An Opto coupler is used to transmit eitheranalog or digital information from one voltagepotential to another while maintaining isolationof potentials. It is used for low voltages.The output of the Opto coupler is used totrigger the Monostable Multivibrator. 

Opto Isolator An Opto isolator is used to transmit

eitheranalog or digital information from one voltagepotential to another while maintaining isolationof the potentials.

Its operating voltage is higher than that of an Opto coupler.

The output of the Opto isolator is used to drivethe Triac.

Triac A Triac changes its state when its gate

receivesa current pulse. It is a Thyristor with a firing angle of

nearly45 .0

This firing angle determines the speed of thefan. 

CIRCUIT DIAGRAM

The circuit consists of a step down Transformer(12V-0-12V).

The diodes(D1-D6) and the capacitor(C9) constitutes the Rectifier & Filter

section. 7809 is a 9V Regulator. TSOP1738 is the infrared sensor. Zener Diode regulates the voltage across thesensor.

IC1 & IC3 are NE555 IC’s which are wired asMonostable Multivibrators.

IC2 is a Decade Counter. The diodes(D7-D11) & resistors(R5-R9) along withthe Capacitor C5 controls the pulse-width of IC2.

The Transistor(BC548) along with the ResistorsR10 & R11 acts as a switch.

MCT2E is an Opto coupler.

MOC3021 is an Opto isolator.

A Snubber Network consisting of a resistor &capacitor (R13 & C7) regulates the rate of

change of voltage across the Triac. The Triac BT136 regulates the speed of the

fanwith the variations in its firing angle.

WORKING Infrared receiver module TSOP1738 is used

toreceive the infrared signal transmitted byremote control.

The circuit is powered by regulated 9V.

The AC mains is stepped down and rectified.

Pulses from the IR receiver module trigger thetimer NE555 (IC1).

IC1 is wired as a Monostable Multivibrator todelay the clock given to decade counter-cum-

driver IC CD4017 (IC2).

Combination of one of the resistors R5 throughR9 and capacitor C5 controls the pulse width.

NE555 timer (IC3) is wired as a MonostableMultivibrator.

MCT2E (IC5) is wired as a zero-crossingdetector that supplies trigger pulses to

Monostable Multivibrator IC3. MOC3021 (IC4) drives Triac

BT136.The variations in the firing angle affects thevoltage and thus the speed of the fan is varied.

APPLICATIONS Remote controlled Fan Regulator is used

tocontrol the speed of fan from our bed or couch. The same circuit finds its use to control

theIntensity of light at various levels. This circuit also finds it use for switching

ONand OFF any electronic circuit.

ADVANTAGES This circuit is simple to use and

efficient. It can be assembled with

ease. It is cheap and hence very

economic. It is small in

size. 

CONCLUSION The speed of fan & intensity of light can

becontrolled in various levels from off position tomaximum intensity possible.

So it finds its use as night lamp by keeping theintensity of lamp in low level.

The circuit also finds its use for switching ONand OFF any electronic circuitry.

Our normal T.V. remote can be used for thispurpose.

REFERENCE www.electronicsforyou.co

m www.howstuffworks.co

m Linear Integrated circuits –

Gaykwad Electronic Devices and Circuits – J.

B.Gupta