AUTOMATIC ROOM POWER CONTROLLER2.ppt

7/30/2019 AUTOMATIC ROOM POWER CONTROLLER2.ppt

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BY

B.RAMANAND(08331A0414)

CH.SWAROOP E.SANTOSH

(08331A0431) (08331A0438)

CH. DILLESWARA RAO

(08331A0430)

Under the guidance of

Sri K.SATYANARAYANA RAJU

M.Tech

Assistant professor


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1. INTRODUCTION

2. CIRCUIT DIAGRAM

3. INPUT SECTION

4. POWER SUPPLY SECTION5. COMPARATOR SECTION

6. COUNTING SECTION

7. RELAY SECTION

8. ADVANTAGES9. POSSIBLE MODIFICATIONS

10. CONCLUSIONS

11. REFERENCES


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1. Many a time we forget to switch off appliances likelights, fans and air-conditioners before leaving ourhouse. This leads to considerable wastage of electricityapart from reducing the life of the appliance.

2. A circuit is presented here which senses theabsence of occupants in a room and automaticallyshuts off the power to a particular appliance, say, atube light or fan. It turns on the appliance again when

someone enters the room


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It has 2 major componentswhich describes the inputsection

1) laser diodes

2) LDRs (light dependentresistors)


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A laser diode, also known as an injectionlaseror diode laser.

It is a semiconductor device that producescoherent radiation (in which the waves are all atthe same frequency and phase) in the visible

or infrared (IR) spectrum when current passesthrough it.


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A photoresistor or light dependent resistor (LDR) is aresistor whose resistance decreases with increasingincident light intensity.

It can also be referred to as a photoconductor or CdSdevice, from "cadmium sulfide," which is the materialfrom which the device is made and that actuallyexhibits the variation in resistance with light level.


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It has 3 major

components whichdescribes this section

1) Step down transformer

2) Rectification and

filtering3) regulation


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A transformer is a device that transfers electricalenergy from one circuit to another through inductivelycoupled conductorsthe transformer's coils. A varyingcurrent in the first orprimary winding creates a varyingmagnetic flux in the transformer's core and thus avarying magnetic field through the secondary winding.This varying magnetic field induces a varying EMF , or

"voltage", in the secondary winding. This effect iscalled inductive coupling.


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7809 is a voltage regulator integrated circuit(IC) whichis widely used in electronic circuits.


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BASIC COMPARATOR:

An op-amp can beused as a comparator.

It consists of 2 inputs,Vref and Vin

When

V1 < V2 , Vout = 0

and whenV1> V2 , Vout=1

Here V1=Vin, V2=Vref


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This section isHEART of thecircuit which usesLM324

It delimits the

losses occurred dueto traditionalcircuits

Person enteringshould be counted

by counter1 andpersons leaving theroom should becounted bycounter2 . This iscontrolled by this

section


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This section uses twoCD 4017 counters .

A reset switch to resetthe counters

Counters are followedby and gates forsupplying the pulse torelay for automatic

action


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Operation of relay


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Operation :

1) The high output of theAND gate makes thetransistor T1 conductvia resistor R16, hencethe relay de-energises.

2) Otherwise transistor T2conducts getting base

current via resistor R18and relay energises toswitch on the appliance


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1. Inexpensive

2. Simple

3. Rugged

4. Doesnt require programming knowledge

5. Can count the persons entering and leaving the roomthrough a single door


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1. The circuit can be modified to indicate the number ofpersons entering and exiting the room. For thepurpose, you need to connect LEDs between the

ground and the outputs of decade counters through1k resistors

2. One limitation of the circuit is that it cannot countmore than ten persons in succession. When theeleventh person enters the room the circuit resets.

This problem can be overcome by cascading moredecade counters


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1. For a conventional microcontroller based circuit if themicrocontroller fails the complete software installationis required but in this circuit just replacement of thehardware is required.

2. Considerable wastage of power can be reduced.


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1. ELECTRONICS FOR YOU february 2011 edition

2. PRINCIPLES OF POWER SYSTEM by V.K.Mehta

3. UNDERSTANDING OPERATIONAL AMPLIFIER

SPECIFICATION by JIM KARKI (e book)4. LASER DIODES by Denford road

5. http://www.chipswinner.com/ends/LM324.pdf

6. http://www.pira.cz/pdf/bc548.pdf


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AUTOMATIC ROOM POWER CONTROLLER2.ppt