Presented by:
Alvasim P. A.
Anumol R.
Geo Joy
Nimmy Yesudas
Pradeep K. Vijayan

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INTRODUCTION
 The aim of this work is to design and construct a remote controlled fan regulator.
 This circuit allows total control over the equipments without having to move around.
 The frequency of remote used is typically around
36 KHz.
 The remote control device sends an infra-red beam, which is received by the infra-red sensor on the regulator thereby affecting the speed of the fan or intensity of light.
BLOCK DIAGRAM
 Infrared Receiver Module
 The infrared rays transmitted by the remote control are received by IR Receiver.
 The component used here is capable of receiving signals up to 38 KHz.
Monostable Multivibrator
 Monostable Multivibrator is used for getting an accurate pulse.
 The trigger to this is the signals from receiver module.
 The output of Monostable Multivibrator (IC1)is used to delay the clock pulse of decade counter.
Decade Counter
 Decade counter is Mod-10 counter.
 The count is incremented with each clock pulse.
Transformer
 The 230 V AC is step down to 12V by the Transformer .
 Regulator Section
 The rectified output (12V) of the Transformer is regulated to 9V by the Regulator.
 This 9V is supplied to the whole circuit.
Opto Coupler
 An Opto coupler is used to transmit either analog or digital information from one voltage potential to another while maintaining isolation of potentials. It is used for low voltages.
 The output of the Opto coupler is used to trigger the Monostable Multivibrator.
Opto Isolator
 An Opto isolator is used to transmit either analog or digital information from one voltage potential to another while maintaining isolation of the potentials. Its operating voltage is higher than that of an Opto coupler.
 The output of the Opto isolator is used to drive the Triac.
 Triac
 A Triac changes its state when its gate receives a current pulse.
 It is a Thyristor with a firing angle of nearly 450.
 This firing angle determines the speed of the fan.
CIRCUIT DIAGRAM
ABOUT THE CIRCUIT
 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 the sensor.
 IC1 & IC3 are NE555 IC’s which are wired as Monostable Multivibrators.
 IC2 is a Decade Counter.
 The diodes(D7-D11) & resistors(R5-R9) along with the Capacitor C5 controls the pulse-width of IC2.
 The Transistor(BC548) along with the Resistors R10 & 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 fan with the variations in its firing angle.
WORKING
 Infrared receiver module TSOP1738 is used to receive the infrared signal transmitted by remote control.
 The circuit is powered by regulated 9V.
 The AC mains is stepped down and rectified.
 Pulses from the IR receiver module trigger the timer NE555 (IC1).
 IC1 is wired as a Monostable Multivibrator to delay the clock given to decade counter-cum-driver IC CD4017 (IC2).
 Combination of one of the resistors R5 through R9 and capacitor C5 controls the pulse width.
 NE555 timer (IC3) is wired as a Monostable Multivibrator.
 MCT2E (IC5) is wired as a zero-crossing detector that supplies trigger pulses to Monostable Multivibrator IC3.
 MOC3021 (IC4) drives Triac BT136.
 The variations in the firing angle affects the voltage and thus the speed of the fan is varied.
APPLICATIONS
 Remote controlled Fan Regulator is used to control the speed of fan from our bed or couch.
 The same circuit finds its use to control the Intensity of light at various levels.
 This circuit also finds it use for switching ON and 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 be controlled in various levels from off position to maximum intensity possible.
 So it finds its use as night lamp by keeping the intensity of lamp in low level.
 The circuit also finds its use for switching ON and OFF any electronic circuitry.
 Our normal T.V. remote can be used for this purpose.