Abstract
This designed project is a home automation system which based on DTMF connection to control & moniter the home appliances remotely. It overcomes the limitations of conventional of wall switches that use to be operated by physically going near to then and switch on/off .The system uses DTMF technology by which one can we control home appliances by dialling the designated number for particular load as appliances. One person can operate it from home through phone or by making a call to home number from outside. As The system uses DTMF technology which takes instructions from cell phone and creates digital output which initiates relay driver to turn ON/OFF the load appliances. For this system we use components as De-Multiplexer, flip-flopIC, DTMF Decoder. This DTMF technology lets the operator to send commands to control the appliances via a cell phone and avoids the usage of microcontroller. In order to use this system the user has to place a call to the cell phone linked to this system. Once the call is taken by the cell phone connected to the system, the user can now direct commands to on/off the home appliances. For this the system creates use of lamps to establish AC loads and uses 12V transformer to power the system.
TABLE OF CONTENTS
Title page………………………………………………………..1
Certificate……………………………………………………….2
Acknowledgement………………………………………………3
Abstract………………………………………………………….4
List of Chapters………………………………………………….6
List of Figures……………………………………………………8
TABLE OF CHAPTERS
Chapter 1. Introduction……………………………………………
• Problem Summary and Introduction
• Aim and Objective of the project
• Problem Specification
• Brief literature review and Prior Art Search (PAS) about the project
• Plan of their work
• Materials / Tools required.
Chapter2. Design Analysis and Design Methodology …………..
2.1 Empathy canvas
2.2 Ideation canvas
2.3 Product Devlopement canvas
2.4 AEIOU summary canvas
2.5 Design Analysis
Chapter 3. Implementation………………………………………………..
3.1 Results
3.2 Reports
Chapter 4. Summary of the Results……………………………………..
Chapter 5. Reference…………………………………………………………
LIST OF FIGURES
Figure No. Figure Discription Page No
1 EMPATHY CANVAS 15
2 IDEATION CANVAS 17
3 PRODUCT DEVLOPEMENT CANVAS 20
4 AEIOU SUMMARY CANVAS 23
5 BLOCK DIAGRAM OF SYSTEM 24
6 TRANSFORMER 25
7 DIODE 26
8 IC555 28
9 IC555 28
10 DTMF 30
11 CAPACITOR 31
12 CAPACITOR 31
13 CAPACITOR 32
14 CAPACITOR 32
15 INVERTER 34
16 FLIP-FLOP 34
17 VOLTAGE REGULATER 35
18 RESISTER 37
19 DE-MULTIPLEXER 38
20 OPTO-ISOLATER 39
21 LED 39
CHAPTER 1. INTRODUCTION
• This is a circuit lets you to operate your home appliances like lights and fan from your office or any other remote place. If you forgot to switch off the lights or other appliances while going out so don’t worry, our system helps you to turn on/off the appliance with your cell phone. Your cell phone works as remote control to turn on/off your home appliances. You can control & moniter the desired appliance by presetting the corresponding key. The system also gives status of the appliance by voice acknowledgement.
Chapter 1.1 Problem summary.
• We are going to develop a cellular phone based designed for controlling uniformed devices, and it’s also include of system kit, end user has to connect his/her cellphone via head set. when the cellular phone as the call is answered It reacts as in response the user could use this system to control devices. By this caller can press ON/OFF particular device.
• This project we devloped a unique System for Home Automation (DTMF) that is paired with a wireless over cellular network with many appliances in a house. These block diagram many keys, each corresponding to the device that the user choice and sends via a cellular transmitter. These signal and demodulates it & the user’s choice is upon this as the required appliance is triggered.
• By using this developed system solved problem of physically go to turn on / turn off the home appliances like fan,light,tv,etc.
• This system is planned for controlling and moniter the appliances, it requires a cell phone which is used for connect to the system via head set. To active the cell phone part of this system a call is to be placed and as the call is replied, in response the user should enter a three/fouras he/she want digit password for access and the system to control appliances. As the caller press the designet number,as in return of it results in turning ON/OFF specific appliances.The appliances is switching on/off achieved by Relays.
Chapter 1.2 Aim and objectives of the project.
• It can be controlled&moniterd from anywhere.
• It decreases wastage of electricity when anyone forgets to switch off the fans and lights.
• It’s cost is very low compare to other technologies like GSM.
• It is easy way to turn on and turn off the appliances for those who cant’t go to the switchboard physically. That provide them comfort from walking or go near switchboard.
• This system can be planted in houses ,where people frequently forget to switch off electrical appliances.
• This system can be used to control AC’s and heater to set the room temperature when we are outside.
• Manufacture is easy .
• Power feeding is low.
• We can control&moniter appliances from any part of the world.
Chapter 1.3 Problem specification.
• The requirement for the given project because of project firstly it saves the time & money. If you are stuck by traffic you can switch on your microwave oven on slow cooking mode and prepare food . As you reach at your home your food will be ready. As well as You don’t have go to each room for check whether the lights are on/off.
• You can do with a click of single call. And it saves our money in the long run. There is some appliances like a TV which we switch off but not its power supply. There is a Led still glowing and it is consumption of electrical power. If we have this television connected to our project then we could switch off and stop its power supply whenever we want. This is applied for many other appliances like this. Thirdly, it for self-maintenance and security.
• Security as in if we by chance forgot to switch off any of lights then we can switch off from our phones. Lastly, we all know that all this will make our life easy and trouble free.
• Industrial applications for the project made are that one can control home appliances from anywhere in the world even we are sitting a cup of tea in United States of America. Secondly, it reduces wastage of electricity as discussed earlier that if we forget to switch off the lights. Last but not the least it is very low cost compared to other technologies like GSM.
Chapter 1.4 Brief literature review .
• The project is a home automation system that uses DTMF connection to control the home appliances remotely. It overcomes the limitations of conventional wall switches that have to be operated by physically going near to then and switch on the button.
The system uses DTMF by which one can control home appliances by dialing the designated number for particular load.
• One can operate it from home phone or by making a call to home number from outside. The system uses DTMF technology that receives commands from phone and produces digital output which initiates relay driver to switch ON/OFF the load appliances.
• For this the system we use De-Multiplexer, flip flop IC, DTMF Decoder. This DTMF technology allows the user to send commands to operate the appliances via a mobile phone and avoids the use of microcontroller. In order to use this system the user has to make a call to the mobile phone connected to this system.
• Once the call is received by the mobile phone connected to the system, the user can now send commands to operate the home appliances. For this the system makes use of lamps to demonstrate AC loads and uses 12V transformer to power the system.Here is a circuit that lets you operate your home appliances like lights and water pump from your office or any other remote place.
• So if you forgot to switch off the lights or other appliances while going out, it helps you to turn off the appliance with your cell phone. Your cell phone works as remote control to your home appliances. You can control the desired appliance by presetting the corresponding key. The system also gives you voice acknowledgement of the appliance status.
Chapter 1.4 Materials & Tools required.
FOR THIS SYSTEM WE NEED THESE GIVEN HARDWARES ARE GIVEN BELOW .
• Transformer
• Diodes
• 555 Timer
• DTMF decoder
• Capacitor
• Inverter
• Flip flops
• Voltage regulator
• Resistors
• De-multiplexer
• LED’s
• Opto-isolator
Chapter 2. Design Analysis , Design Methodology & implement strategy.
The design analysis and design methodology & implement strategy is expressed in different canvas sheets in brief explanation in this project report. There are canvas sheet are given below.
Chapter 2.1. EMPATY CANVAS
• USER :
HOME As this project is made for people who can hardly or unable to walk to the switch board and turn on/off the appliances.
OFFICE AND FACTORY .As this project is made to remotely control appliances so it save time for going near switch board and also example as : when you nearby to house and turn on Air Conditioner and when you reach at home the room is cooled up .
• STAKEHOLDER:
HOME As this project is made for people who can hardly or unable to walk to the switch board and turn on/off the appliances
COMPANIES AS his project can be use full to companies like to control the appliances of offices and also to turn on machines automatically and work done.
• ACTIVITY:
PAYING COMFORT OF GO TO TURN ON/OFF SWITCH.As this project work remotely so this provide the comfort by not going to switch board.
TO MONITER AND CONTROL THE APPLIANCE FROM IN/OUT SIDE HOME As this project work remotely so this system can work from in or out side from home because of its DTMF technology which is operated by Mobile Phones and Land Line. And this can also use as monitoring the appliances
SAVE ELECTRICITY. As this project Turn ON/OFF the Appliances so it also give the side facility to save energy as by stop over running of appliance.
HELP THE PHYSICALY UNABLE TO MOVE. As this project work remotely so this provide the comfort by not going to switch board.
• HAPPY STORY
1) I have a friend name raj. Recently I visited his factory and I see some machine which is need to warm up before use and it take 2 or 3 hours to warm up .so they planted automation system and they have to just do call for warm up before 2 hours to leave and in saved time warming period. And in 2 hours the production increase and saves time and money.
2) I have recently visited my friend’s home his grandfather and grandmother lives with then and when his mom and father goes to work and he go to college his grandfather and grandmother stay at home and they have aged and hard to walk so he affix this system to pay comfort to them now his grandfather and grandmother just need to call to light on/off fan etc.
• SAD STORY
1) I have a friend name causal. Who has a grandmother aged 68 he is married and for the look after his grand mother his wife need to be stay at home and can’t go out to work . If like this system was present she didn’t have to stay home . his grand mother will able to turn on/off light fan etc by just calling designet number.like example they need to warm up the food by just putting food in microwave and just call the number and after warmed up call to off and then it is redy to eat. It easy then to work with stove.
2) We recently moved up to Bhavnagar and at new home I found one of the neighbor two older person their son and other family live America they arranged a worker to look after them but when the night duration to worker have to go home and they have to face problems in darkness switch on/off light, on/off fan etc.
PICTURE OF EMPATHY CANVAS
Chapter 2.2. IDEATION CANVAS
• PEOPLE :
AGED PERSON.
PEOPLE UNABLE TO PHYSICALY MOVE.
PEOPLE TO SAVE TIME.
OFFICE AND INDUSTRIES.
• ACTIVITIES:
VISIT AT HOMES.
COLLECTED PROBLEMS.
DTMF TECHNOLOGY.
INFORMATION ABOUT SYSTEM .
• SITUATION/CONTEXT/LOCATION:
HOME.
PHYSICALLY SITUATION TO MOVE.
CONTROL OF APPLIANCES BY IT USE.
COMPANY.
• PROBS/ POSSIBLE SOLUTION
TURN ON/OFF BY PHYSICALY GO TO SWITCH BOARD.
USE ADVANCE SYSTEM LIKE AUTOMATION.
BY DOING WIRNG AND SWITCH BORAD TO NEAREST TO PERSON.
PICTURE OF IDEATION CANVAS SHEET
Chapter 2.3. PRODUCT DEVLOPEMENT CANVAS
• PEOPLE :
AGED PERSON.
PEOPLE UNABLE TO PHYSICALY MOVE..
PEOPLE TO SAVE TIME.
.OFFICE AND INDUSTRIES.
• PURPOSE :
TURN ON/OFF APPLIANCES REMOTELY.
PAYING COMFORT TO AGED PERSON.
• PRODUCT EXPERIANCE :
CONTROL REMOTELY THE APPLIANCE OF HOME & COMPONEY.
TIME AND ELECTRICITY SAVING.
• CUSTOMER REVALIDATION :
SAVING ELECTRICITY .
SAVING TIME.
PROVIDING COMFORT TO PEOPLE.
• REJECT,REDISGN AND RETAIN :
TRANSFOREMER.
DTMF TECH.
MOBILE PHONE.
CONTROL APPLIANCES.
• PRODUCT FEAUTERS :
CONTROL APPLIANCE IN/OUT OF HOME.
SAVING ELECTRICITY.
MONITER APPLIANCES.
• PRODUCT FUNCTIONS :
CONTRON APPLIANCE REMOTELY.
SAVE TIME AND ELECTRICITY.
PROVIDE COMFORT.
• COMPONENT :
DTMF TECHNOLOGY.
TRANSFORMER.
MOBILE PHONE.
DEMULTIPLEXER.
12V POWER SUPPLY.
PICTURE OF PRODUCT DEVLOPMENT CANVAS
Chapter 2.4. AEIOU SUMMARY
• ENVIRONMENT:
ALL WETHER CONDITION.
CONSUME 12V FROM POWER SUPPLY.
• INTERACTION:
AGED PEOPLE.
PHYSICALLY UNABLE TO MOVE.
PEOPLE WHO FORGETS TO SWITCH ON/OFF.
IN COMPONAY MONITER & CONTROL WHOLE ELECTRICLE APPLIANCES.
• OBJECTS:
DTMF TECH..
TRANSFORMER.
12V POWER SUPLLY.
• ACTIVITY:
TURN ON/OFF EASILY FOR AGED PEOPLE.
TURN ON/OFF FOR PHYSICALLY UNABLE TO MOVE.
TURN AC,GYSER LIKE ETC APPLIANCE BEFORE REACH ON.
TURN OFF APPLIANCE AFTER GOING OUT SIDE.
• USERS
AT HOME FOR AGED PERSONS.
AT HOME FOR TIME SAVING FOR NORMAL PEOPLE.
AT OTHER PLACES TO CONTROL AND MONITER.
TO SAVE POWER AND TIME FOR OTHER PLACES.
PICTURE OF AEIOU SUMMARY CANVAS
CHAPTER 2.5 DESIGN ANALYSIS
• As given This is a circuit lets you to operate your home appliances like lights and fan from your office or any other remote place. If you forgot to switch off the lights or other appliances while going out so don’t worry, our system helps you to turn on/off the appliance with your cell phone. Your cell phone works as remote control to turn on/off your home appliances. You can control & moniter the desired appliance by presetting the corresponding key. The system also gives status of the appliance by voice acknowledgement. Which needed some component like pcb, transformer,ic 555 timer,dtmf tech and etc.
• Transformer
A transformer is a static device which convert electrical power in to one circuit to another circuit with out change in frequency. Transformer can be used to increase or decrease the voltage by doing corresponding decrease or increase in current. The principle behind working of a transformer is the mutual induction between two windings linked by common magnetic flux. Basically a transformer constructed of two inductive coils; primary winding and secondary winding. As Given In The Figure The coils are electrically separated but magnetically linked to each other.
Fig- Transformer
When, The primary winding is connected to a source of voltage, The magnetic flux is produced around the winding .These core provides the magnetic path for the flux to get linked in with the secondary winding. Then The flux gets linked with the secondary winding which is called as main ‘flux’ in transformer, And the flux which does not get linked with the secondary winding is called as ‘leakage flux’ In winding.
As the flux produced the direction of it is continuously changing, According to Faraday’s law of electromagnetic induction the EMF gets induced in the secondary winding and This emf is called ‘mutually induced emf . And the frequency of mutually induced emf is equal as that of supplied emf.If the secondary winding is closed circuit so then mutually induced current flows through it, and as well as electrical energy is transferred from one circuit as considerd as primary to another circuit as considerd as secondary. As the working of transformer and it’s principle.There is two type of transformer step up and step down transformer .
• Diode
A diode is the component which is only permits the unidirectional flow of current on condition of if it is operated within a valued specified voltage level. The diode only blocks current if it’s in the reverse direction. when the voltage is within a limited range or else reverse barrier breaks and the voltage over. when this breakdown occurs is called reverse breakdown voltage.
The diode usually behaves as a valve in the electronic and electrical circuit. A P-N junction is the simplw form of the diode which acts as ideally short circuit. when it is in forward biased and it acts as ideally open circuit when it is in the reverse biased. Beside simple PN junction diodes, there are different types of diodes although the fundamental principle is more or less same. So a particular arrangement of diodes can convert AC to pulsating DC, and hence, it is sometimes also called as a rectifier. The name diode is derived from “di-ode” which means a device having two electrodes.
• Symbol of Diode
The symbol of a diode is shown below, the arrowhead points in the direction of conventional current flow.
A simple PN junction diode can be created by doping donor impurity in one portion and acceptor impurity in other portion of a silicon or germanium crystal block. These make a p n junction at the middle portion of the block beside which one portion is p type (which is doped by trivalent or acceptor impurity) and other portion is n type (which is doped by pentavalent or donor impurity).
It can also be formed by joining a p-type (intrinsic semiconductor doped with a trivalent impurity) and n-type semiconductor (intrinsic semiconductor doped with a pentavalent impurity) together with a special fabrication technique such that a p-n junction is formed. Hence, it is a device with two elements, the p-type forms anode and the n-type forms the cathode. These terminals are brought out to make the external connections.
• Working Principle of Diode
The n side will have a large number of electrons and very few holes (due to thermal excitation) whereas the p side will have a high concentration of holes and very few electrons. Due to this, a process called diffusion takes place. In this process free electrons from the n side will diffuse (spread) into the p side and combine with holes present there, leaving a positive immobile (not moveable) ion in the n side. Hence, few atoms on the p side are converted into negative ions. Similarly, few atoms on the n-side will get converted to positive ions. Due to this large number of positive ions and negative ions will accumulate on the n-side and p-side respectively. This region so formed is called as depletion region. Due to the presence of these positive and negative ions a static electric field called as “barrier potential” is created across the p-n junction of the diode. It is called as “barrier potential” because it acts as a barrier and opposes the further migration of holes and electrons across the junction.
• IC 555 TIMER
The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation, and oscillator applications. The 555 can be used to provide time delays, as an oscillator, and as a flip-flop element. Derivatives provide up to four timing circuits in one package
The connection of the pins for a DIP package is as follows:
PIN NAME DISCRIPTION
1 GND Ground reference voltage, low level (0 V)
2 TRIG The OUT pin goes high and a timing interval starts when this input falls below 1/2 of CTRL voltage (which is typically 1/3 VCC, CTRL being 2/3 VCC by default if CTRL is left open). More simply we can say that OUT will be high as long as the trigger is kept at low voltage. Output of the timer totally depends upon the amplitude of the external trigger voltage applied to this pin.
3 OUT This output is driven to approximately 1.7 V below +VCC, or to GND.
4 RESET A timing interval may be reset by driving this input to GND, but the timing does not begin again until RESET rises above approximately 0.7 volts. Overrides TRIG which overrides THR.
5 CTRL Provides “control” access to the internal voltage divider (by default, 2/3 VCC).
6 THR The timing (OUT high) interval ends when the voltage at THR (“threshold”) is greater than that at CTRL (2/3 VCC if CTRL is open).
7 DIS Open collector output which may discharge a capacitor between intervals. In phase with output.
8 VCC Positive supply voltage, which is usually between 3 and 15 V depending on the variation.
• DTMF
Dual-tone multi-frequency
Dual-tone multi-frequency (DTMF) signaling is used for telephone signaling over the line in the voice-frequency band to the call switching center. The version of DTMF used for telephone tone dialing is known by the trademarked term Touch-Tone and is standardized by ITU-T Recommendation Other multi-frequency systems are used for signaling internal to the telephone network.
As a method of in-band signaling, DTMF tones were also used by cable television broadcasters to indicate the start and stop times of local commercial insertion points during station breaks for the benefit of cable companies. Until better out-of-band signaling equipment was developed in the 1990s, fast, unacknowledged, and loud DTMF tone sequences could be heard during the commercial breaks of cable channels in the United States and elsewhere.
Fig
A DTMF telephone keypad
• CAPACITOR
A capacitor is an electrical/electronic device that can store energy in the electric field between a pair of conductors (called “plates”). The process of storing energy in the capacitor is known as “charging”, and involves electric charges of equal magnitude, but opposite polarity, building up on each plate.
Capacitors are often used in electric and electronic circuits as energy-storage devices. They can also be used to differentiate between high-frequency and low-frequency signals. This property makes them useful in electronic filters.
• Capacitor types
Fig 2.3
Capacitors: SMD ceramic at top left; SMD tantalum at bottom left; through-hole tantalum at top right; through-hole electrolytic at bottom right. Major scale divisions are cm.
Fig 2.4
Various types of capacitors. From left: multilayer ceramic, ceramic disc, multilayer polyester film, tubular ceramic, polystyrene, metallized polyester film, aluminum electrolytic. Major scale divisions are cm.
Fig 2.5
2.3 CRYSTAL OSCILLATOR
Fig 2.6
A miniature 4 MHz quartz crystal enclosed in a hermetically sealed HC-49/US package, used as the resonator in a crystal oscillator.
A crystal oscillator is an electronic circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency. This frequency is commonly used to keep track of time (as in quartz wristwatches), to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters/receivers.
• INVERTER
• In one simple inverter circuit, DC power is connected to a transformer through the center tap of the primary winding. A switch is rapidly switched back and forth to allow current to flow back to the DC source following two alternate paths through one end of the primary winding and then the other. The alternation of the direction of current in the primary winding of the transformer produces alternating current (AC) in the secondary circuit.
• The switch in the simple inverter described above, when not coupled to an output transformer, produces a square voltage waveform due to its simple off and on nature as opposed to the sinusoidal waveform that is the usual waveform of an AC power supply. Using Fourier analysis, periodic waveforms are represented as the sum of an infinite series of sine waves. The sine wave that has the same frequency as the original waveform is called the fundamental component. The other sine waves, called harmonics, that are included in the series have frequencies that are integral multiples of the fundamental frequency.
• FLIP-FLOP
• In electronics, a flip-flop or latch is a circuit that has two stable states and can be used to store state information. A flip-flop is a bistable multivibrator. The circuit can be made to change state by signals applied to one or more control inputs and will have one or two outputs. It is the basic storage element in sequential logic. Flip-flops and latches are fundamental building blocks of digital electronics systems used in computers, communications, and many other types of systems.
•
• Flip-flops and latches are used as data storage elements. A flip-flop stores a single bit (binary digit) of data; one of its two states represents a “one” and the other represents a “zero”. Such data storage can be used for storage of state, and such a circuit is described as sequential logic. When used in a finite-state machine, the output and next state depend not only on its current input, but also on its current state (and hence, previous inputs). It can also be used for counting of pulses, and for synchronizing variably-timed input signals to some reference timing signal.
• Flip-flops can be either simple (transparent or opaque) or clocked (synchronous or edge-triggered). Although the term flip-flop has historically referred generically to both simple and clocked circuits, in modern usage it is common to reserve the term flip-flop exclusively for discussing clocked circuits; the simple ones are commonly called latches.[1][2]
• Using this terminology, a latch is level-sensitive, whereas a flip-flop is edge-sensitive. That is, when a latch is enabled it becomes transparent, while a flip flop’s output only changes on a single type (positive going or negative going) of clock edge.
• VOLTAGE REGULATOR
A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level.
It may use an electromechanical mechanism, or passive or active electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.
• Voltage Regulator 7805
The Digilab board can use any power supply that creates a DC voltage between 6 and 12 volts. A 5V voltage regulator (7805) is used to ensure that no more than 5V is delivered to the Digilab board regardless of the voltage present at the J12 connector (provided that voltage is less than 12VDC). The regulator functions by using a diode to clamp the output voltage at 5VDC regardless of the input voltage – excess voltage is converted to heat and dissipated through the body of the regulator. If a DC supply of greater than 12V is used, excessive heat will be generated, and the board may be damaged. If a DC supply of less than 5V is used, insufficient voltage will be present at the regulators output.
Fig 2.8
If a power supply provides a voltage higher than 7 or 8 volts, the regulator must dissipate significant heat. The “fin” on the regulator body (the side that protrudes upward beyond the main body of the part) helps to dissipate excess heat more efficiently. If the board requires higher currents (due to the use of peripheral devices or larger breadboard circuits), then the regulator may need to dissipate more heat. In this case, the regulator can be secured to the circuit board by fastening it with a screw and nut (see below). By securing the regulator tightly to the circuit board, excess heat can be passed to the board and then radiated away.
Fig
• RESISTOR
• A resistor is a two-terminal electrical or electronic component that opposes an electric current by producing a voltage drop between its terminals in accordance with Ohm’s law: The electrical resistance is equal to the voltage drop across the resistor divided by the current through the resistor while the temperature remains the same. Resistors are used as part of electrical networks and electronic circuits.
Fig 2.1
• Axial-lead resistors on tape. The tape is removed during assembly before the leads are formed and the part is inserted into the board.
• Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various compounds and forms. Resistors are also implemented within integrated circuits.
• The electrical function of a resistor is specified by its resistance: common commercial resistors are manufactured over a range of more than nine orders of magnitude. The nominal value of the resistance falls within the manufacturing tolerance, indicated on the component.
• DE-MULTIPLEXER
The data distributor, known more commonly as a Demultiplexer or “Demux” for short, is the exact opposite of the Multiplexer we saw in the previous tutorial.
The demultiplexer takes one single input data line and then switches it to any one of a number of individual output lines one at a time. The demultiplexer converts a serial data signal at the input to a parallel data at its output lines as shown below.
The function of the Demultiplexer is to switch one common data input line to any one of the 4 output data lines A to D in our example above. As with the multiplexer the individual solid state switches are selected by the binary input address code on the output select pins “a” and “b” as shown.
Demultiplexer Output Line Selection
As with the previous multiplexer circuit, adding more address line inputs it is possible to switch more outputs giving a 1-to-2n data line outputs.
The Demultiplexer Symbol
Some standard demultiplexer IC´s also have an additional “enable output” pin which disables or prevents the input from being passed to the selected output. Also some have latches built into their outputs to maintain the output logic level after the address inputs have been changed. However, in standard decoder type circuits the address input will determine which single data output will have the same value as the data input with all other data outputs having the value of logic “0”.
• OPTO-ISOLATER
In electronics, an opto-isolator, also called an opt coupler, photo coupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light.[1] Opt-isolators prevent high voltages from affecting the system receiving the signal.[2] Commercially available opt-isolators withstand input-to-output voltages up to 10 kV[3] and voltage transients with speeds up to 10 kV/us.[4]
• A common type of opt-isolator consists of an LED and a phototransistor in the same opaque package. Other types of source-sensor combinations include LED-photodiode, LED-LASCR, and lamp-photoresist or pairs. Usually opt-isolators transfer digital (on-off) signals, but some techniques allow them to be used with analog signals.
• An opt-isolator contains a source (emitter) of light, almost always a near infrared light-emitting diode (LED), that converts electrical input signal into light, a closed optical channel (also called dielectrically channel[7]), and a photo sensor, which detects incoming light and either generates electric energy directly, or modulates electric current flowing from an external power supply. The sensor can be a photoresist or, a photodiode, a phototransistor, a silicon-controlled rectifier (SCR) or a trial. Because LEDs can sense light in addition to emitting it, construction of symmetrical, bidirectional opt-isolators is possible. An opt coupled solid state relay contains a photodiode opt-isolator which drives a power switch, usually a complementary pair of MOSFETs. A slotted optical switch contains a source of light and a sensor, but its optical channel is open, allowing modulation of light by external objects obstructing the path of light or reflecting light into the sensor.
• LED
• A light-emitting diode (LED) is a two-lead semiconductor light source. It is a p–n junction diode, which emits light when activated.[4] When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.
• An LED is often small in area (less than 1 mm2) and integrated optical components may be used to shape its radiation pattern.[5]
• Appearing as practical electronic components in 1962,[6] the earliest LEDs emitted low-intensity infrared light. Infrared LEDs are still frequently used as transmitting elements in remote-control circuits, such as those in remote controls for a wide variety of consumer electronics. The first visible-light LEDs were also of low intensity, and limited to red. Modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.
• Early LEDs were often used as indicator lamps for electronic devices, replacing small incandescent bulbs. They were soon packaged into numeric readouts in the form of seven-segment displays, and were commonly seen in digital clocks.
• Recent developments in LEDs permit them to be used in environmental and task lighting. LEDs have many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. Light-emitting diodes are now used in applications as diverse as aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, camera flashes and lighted wallpaper. As of 2016, LEDs powerful enough for room lighting remain somewhat more expensive, and require more precise current and heat management, than compact fluorescent lamp sources of comparable output. They are, however, significantly more energy efficient and, arguably, have less environmental concerns linked to their disposal[citation needed] . The governments of some countries are promoting the domestic use of LED-based lighting, and in some cases providing LED-based lighting solutions to the public at subsidized rates
CHAPTER 3. IMPLEMENTION
3.1 System Algorithm:
1. Person who wants to switch on/off a device calls on the phone at the receiver side.
2. The call gets answered automatically if it is not picked up manually till 5seconds.
3. Once the call gets answered we have to enter a password for authentication (in our case it is1 2).
4. Then after entering the password we have to make a choice for switching on/off any device (Press ‘*’ for switch on and ‘#’ for switch off).
5. Then we have to enter the corresponding number for a device that we wish to switch on/off (‘6’ for first device and ‘7’ for the second).
6. After switching on/off device once, if we again want to switch on/off a device than we again have to enter the password and repeat the whole procedure. NoteOn the transmitter side the user controlling the appliance’s has to press each digit for aminimum duration of time, which is40ms
.
3.2 Program algorithm:
1. On start of the system all the devices are off.
2. If a key press is detected, program goes to 3, else it stays here.
3. If the pressed key is 1 then program goes to 4, else it goes to 2.
4. If 2 is pressed (correct password) program goes to 5,else it goes to 2.
5. Now the de-multiplexer checks whether you want to switch on/off the device.
3.3 Performance and evaluation of the system
1. The receiver must reside in a location where a signal with sufficient strength can be received from a cellular phone network.
2. The only person who can communicate with the control module is the person who will be successfully authenticated.
3. Only devices with electrical controlling input ports will be possible targets for control.
4. The receiver must have a power source (230V) attached at all times.
Chapter 4. SUMMARY
Chapter 4.1 ADVANTAGES
• Effective control of home appliances
Effective control of home appliances like Air Conditioners, Water Heaters, Thermal Baths, Furnaces Incubators. Home appliances control, Hotel lights/ fans Control, Shops and Showrooms appliances control, Industrial appliances etc
• Turn Your Webcam into a Security Camera
Instead of installing a surveillance camera you can always use the webcam for keeping track on your children as it can successfully perform the activity of taking note of all activities. Also it is cheap and very minute and the activities can be checked with the help of the internet. Its visible around us that crime is on the increase, families are beginning to aim at purchasing security alarm systems for their homes. Home Automation adds a extra sense of security to your home, using the automation system you can monitor your homes security cameras using a remote device.
• Use Automatic Sprinklers to Water your Garden
You can make your own DIY automatic sprinkler that will reduce your effort of dragging the sprinklers out in the garden. Again you can set a time so that the sprinkler automatically sprinkles water in the yard at the set time.
• Save Money and Time
You can save your money by stopping over run of appliances and also by stopping the unwanted appliance by this system. you can also save time as when you going home by turning on Ac with a call and when you are at home the room is ready for you. As well as we mentioned before at the factory we don’t have to warm up the machine and made the production late so we just ave to call and under the one supervisor the machine will be ready at workers time and production will be higher then before.