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Wireless dc motor control through RF

CHAPTER 01

INTRODUCTION

1.1 INTRODUCTION

The aim of our project is High-performance low-cost low-loss wireless DC motor speed

control unit. Nowadays, there are lots of good-quality motor speed controls on the

market. However, their costs are relatively high. A speed control with both low cost and

good performance will be highly marketable, especially for small mobility applications.

On the other hand, the wireless connectivity has a nature of low cost and less

environmental limitations. Combining these ideas together, we came up with this project.

Wireless remote controlled toy cars work on the concept explained in this project. Motor

control through RF communication is a very interesting application and is widely used

in robotics, electronics toys, automation systems etc. This topic covers the way DC

motors can be driven by using the controls from a distant place. The controls are

transferred from one end to another by employing an module. The remote

control application of RF has been extended to operate a motor driver which in turn

controls the direction of motors. Embedded automated machines is a man-made

mechanical device that can move by themselves, whose motion must be modelled,

planned, sensed, actuated, and controlled, and whose motion or behaviour can be

influenced by programming.In the field of industrial electronics, the interaction between

man and machine typically consists of the designing and maintaining the machine by the

human operator. This can be very easily done by using various electronics circuits.

The aim of our project is to construct such a robot which can be controlled wireless

through RF.

1.2 MOTIVATION

Recently, Data acquisition is the process by which events in the real world are sampled

and translated into machine-readable signals. Data acquisition typically involves sensors,

transmitters and other instruments to collect signals, waveforms etc. to be processed and

various functions can be performed and analysed in practical world.

The components of data acquisition systems include appropriate sensors that convert any

measurement parameter to an electrical signal, which is acquired by data acquisition

hardware.

Department Of Electronics & Communication Engineering 1


In our project we are transmitting data using RF technology to our receiver circuitry.

At the receiver part we have a string climbing circuitry which receives wireless signal

through RF technology which is then given to microcontroller as input where it is

decoded and acquired data is provided to motor.

1.3 OBJECTIVE OF THE PROJECT

The wireless remote controller is simple: start, stop, accelerate and decelerate. The

source of the speed control is a 12 V battery and control currents over a range of 0 to

50 A. The controller has a high efficiency for motor loads in the range of 50 to 150

W. It should deliver the nominal power continuously and be able to tolerate slight

overloading for a short period of time. For strong overloading, it should protect the

motor from being damaged for a few seconds, then shut down the motor and request a

reset from the user simultaneously.

1.4 ORGANISATION OF THE PROJECT

Chapter 1 contains the introduction of the topic along with the history of RF based

Wireless dc motor control through RF and the motivation and the objective of making this

project. Chapter 2 contains literature review of various researchers and professors from

their research papers description of which is given in the references. Chapter 3 consists of

full-fledged theory about RF based Wireless dc motor control through RF which is

required for better understanding of the project. It contains existing as well as an ideal

proposed system and the difference between the two can be clearly figured out. Chapter 4

gives the designing methodology and description of various components which are

assembled together to build the circuit. Step by Step circuit description is also given.

Chapter 5 states the working of the project with theoretical concepts. Chapter 6 and

Chapter 7 give the breadboard implementation and its corresponding output respectively.

Chapter 8 contains PCB designs both front end and back end. Chapter 9 contains the

full details of each and every components used in the designing of the circuit. Chapter

10 shows various advantages and some disadvantages of the system which has to be

rectified in near future. Chapter 11 contains current applications of the system and it

clearly embarks a revolution in these fields. Chapter 12 has future improvements

which have to be done to make this more effective. The approximate cost of project is

mentioned in Chapter 13. Finally Chapter 14 gives us the conclusion and

effectiveness of this project. Chapter 15 consists of a list of refrences which is worth

going through.



CHAPTER 2

LITERATURE REVIEW

1. Robert Dale [01]

A DC motor is a type of electric motor powered by DC (direct current)

electricity. DC motors are used to run machinery, often eliminating the need for a

steam engine or internal combustion engine (ICE). DC motors are capable of

operating on rechargeable batteries. Today, DC motors are found in multiple

applications ranging as small as toys or as large as paper machines. Modern DC

motors usually operate in conjunction with power electronic devices.There are two

sects within the realm of DC motors, those requiring commutation (brushed and

brushless) and those not requiring it (homopolar and ball bearing). A brushed DC

electric motor generates torque directly from DC power supplied by internal

commutation, stationary magnets, and rotating electrical magnets. Brushless DC

motors use a rotating permanent magnet or soft magnetic core in the rotor, and

stationary electrical magnets on the motor housing. A motor controller converts DC to

AC (alternating current). Some of the advantages of a brushed DC motor include low

initial cost, high reliability, and simple control of motor speed. Disadvantages include

high maintenance and low life-span for high intensity uses.Maintenance involves

regularly replacing the brushes and springs that carry the electric current, in addition

to cleaning or replacing the commutator. These components are necessary for

transferring electrical power from outside the motor to the spinning wire windings of

the rotor inside the motor. This design is simpler than that of brushed motors because

it eliminates the complication of transferring power from outside the motor to the

spinning rotor. Advantages of brushless motors include long life span, little or no

maintenance, and high efficiency. Disadvantages include high initial cost and more

complicated motor speed controllers.

2. AN Nichat [02]

For speed control of dc motor many methods are available which are either be a

mechanical or electrical for example armature control, field control, flux control

method etc but this methods required large size hardware to implement. So for easy

control of speed and the direction control of dc motor the wireless speed and direction

control of dc motor by using radio frequency technique is very much essential and

economical to used. For variable dc voltage we can used a controlled rectifiers which



are converted a variable dc voltage from fixed dc voltage. Due to their ability to

supply a continuously variable dc voltage. Many analoge and digital chips are used in

firing or controlling circuits but transistor and thyristor control are more accessible

due to their innumerable application in various industry. Recent development in the

area of semiconductor technology have made faster ,very small size microprocessors

and microcontroller are available at in much reduced cost. The microcontroller can

provide a controlling of width of pulse provide to a controlling a voltage of motor

terminal simultaneously the speed of motor can controlled.



CHAPTER 3

THEORY

This project title is ‘Wireless dc motor control through RF’ which is a particular

system for server room. The circuit of this project uses RF module to control DC

motors through a motor driver IC L293D. Transmission is enabled by giving a low bit

to pin14 (TE, active low) of encoder HT12E. The controls for motor are first sent to

HT12E. Pins 10 and 11 (D0-D1) are used to control one motor while pins 12 and 13

(D2-D3) to control another motor. The data signals of encoder HT12E work on

negative logic. Therefore a particular signal is sent by giving a low bit to the

corresponding data pin of encoder.

The parallel signals generated at transmission end are first encoded (into serial format)

by HT12E and then transferred through RF transmitter (434 MHz) at a baud rate of

around 1-10 kbps. The same signals are acquired by RF receiver after which it is

decoded by HT12D. For more details, refer RF remote control.

Since the encoder/decoder pair used here works on negative logic, the decoded

signals are fed to an inverter (NOT gate) IC 74LS04. The proper (inverted) signals are

then supplied to L293D. L293D contains two inbuilt H-bridge driver circuits to drive

two DC motors simultaneously, both in forward and reverse direction.

The motor operations of two motors can be controlled by input logic at pins 2 & 7

and pins 10 & 15. Input logic 00 or 11 will stop the corresponding motor. Logic 01

and 10 will rotate it in clockwise and anticlockwise directions, respectively. Thus,

depending upon the signals generated at the transmission end, the two motors can be

rotated in desired directions



CHAPTER 4

CIRCUIT DETAILS4.1 BLOCK DIAGRAM

This circuit generates a square wave whose frequency and duty ratio are controlled by

two variable resistors.RF transmitter:The transceiver chip will take the output from

the function generator (square wave) and frequency modulates it with the carrier

signal. The modulated signal is then sent through an antenna. The chip we plan to use

is CC1120, a high performance low power RF transceiver made by TI.RF

receiver:The same transceiver chip on the receiving end will pick up the desired

signal, demodulate it and pass it to the signal recovery unit. This block might contain

additional filters depending on the actual quality of the received signal.

Fig 4.1 Block Diagram



4.2 CIRCUIT DIAGRAM

Fig 4.2 Circuit Diagram

In our project we are transmitting data using RF technology to our receiver

circuitry. At the receiver part we have a string climbing circuitry which receives

wireless signal through RF technology which is then given to microcontroller as

input where it is decoded and acquired data is provided to motor.

4.3 LIST OF COMPONENTS

1. Connectors for Supply connection 2. RF Module (Transmitter & Receiver) 3. Capacitor 220uF 4. HT12D5. Resistance 330 ohms 6. LED 7. HT12E 8. Crystal 16 Mhz 9. Amplifier 10. Push button 11. DC Motor12. Battery


http://www.engineersgarage.com/electronic-components/rf-module-transmitter-receiver


CHAPTER 5

WORKING

In many industry such as paper mills, rolling mills, printing machine machine tools,

excavators and cranes etc the dc motor is used for waying a product from one place to

another on the conveyer belt . So due to these the speed and direction control of the dc

motor is very important. purpose. Motor speed controller is to take a signal

representing the required speed and to drive a motor at that speed For that purpose

wireless speed and direction control of dc motor by radio frequency technique is very

crucial with pulse width modulation and H-Bridge converter. The microcontroller

AT89S51 is used to control the dc motor speed and Transistorised h-bridge converter

is used for direction control. By adjusting the duty cycle of pulse from Pulse Width

Modulation technique simultaneously the terminal voltage of motor is change and

hence speed will be vary with terminal voltage. H-Bridge is a DC to DC converter

used for direction and made by 4 transistor switch across it a diode are connected.

Most human feels the inconvenient about changing the fan speed level manually when

the room temperature changes. So, the automatic fan system that automatically

changes the speed level according to the temperature changes is recommended to be

built for solving this problem. There are two threshold in the program, the minimum

temperature and the maximum temperature .If temperature is below the minimum

temperature threshold, the fan will be turned off. If the temperature is above the

maximum temperature threshold, the fan is set to maximum speed.

It is often required to switch electrical appliances from a distance without being a

direct line of sight between the transmitter and receiver. As you may well know, an

RF based wireless remote control system (RF Transmitter & RF Receiver) can be used

to control an output load from a remote place. RF transmitter, as the name suggests,

uses radio frequency to send the signals at a particular frequency and a baud rate.

The RF receiver can receive these signals only if it is configured for the pre-defined

signal/data pattern. An ideal solution for this application is provided by compact

transmitter and receiver modules, which operate at a frequency of 434 MHz and are

available ready-made. Here, the radio frequency (RF) transmission system employs

Amplitude Shift Keying (ASK) with transmitter (and receiver) operating at 434 MHz.



The use of the ready-made RF module simplifies the construction of a wireless remote

control system and also makes it more reliable.

Note that, for the transmission of a unique signal, an encoder is crucial. For this, I

have used the renowned encoder IC HT12E from Holtek. HT12E is capable of

encoding information which consists of N address bits and 12N data bits. Each

address/ data input can be set to one of the two logic states. The programmed

addresses/data are transmitted together with the header bits via an RF transmission

medium upon receipt of a trigger signal. Solder bridges TJ1 and TJ2 are used to set

the address and data bits.The current consumption with a supply voltage of near 5.4V

is about 10 mA. Since the current consumption is very little,the power can also be

provided by standard button cells. Recommended antenna length is 17 cm for 433.92

MHz, and a stiff wire can be used as the antenna. Remember to mount the antenna

(aerial) as close as possible to pin 4 (ANT) of the transmitter module. The “coded”

signal transmitted by the transmitter is processed at the receiver side by the decoder

IC HT12F from Holtek. VR1 and R1 are used to tweak the oscillator frequency of the

decoder to that of the transmitter. Any possible variations due to component

tolerences and/or a different supply voltage can be compensated by this arrangement.

HT12F is capable of decoding informations that consist of N bits of address and 12N

bits of data. HT12F decoder IC receives serial addresses and data from the HT12E

encoder that are transmitted by the RF transmitter module. HT12D compare the serial

input data three times continuously with the local addresses.If no error or unmatched

codes are found, the input data codes are decoded and then transferred to the output

pins. The “Valid Transmission” (VT) pin also goes high to indicate a valid

transmission.For proper operation, a pair of HT12E/HT12F ICs with the same number

of addresses and data format should be chosen. The data bits are set up using solder

bridges RJ1 and RJ2. Output of the decoder is brought out on a pinheader K1 , making

the logical signal available to circuits that need it. This output is also fed to the relay

driver transitor T1. The RF Receiver circuit can be powered from a standard 5VDC

supply. Just as for the RF Transmiitter, the aerial (17 cm for 433.92 MHz) has to be

mounted as close as possible to the RF IN (ANT) pin of the 434MHz RF receiver

module.



CHAPTER 6

SOURCE CODE AND RESULT

int motorPin = 3; void setup() { pinMode(motorPin, OUTPUT); Serial.begin(9600); while (! Serial); Serial.println("Speed 0 to 255");} void loop() { if (Serial.available()) { int speed = Serial.parseInt(); if (speed >= 0 && speed <= 255) { analogWrite(motorPin, speed); } }} Microcontroller Based Temperature Sensing Electronic Fan

Elseif A < 43 Then

Lowerline

Lcd "FAN SPEED 2"

Op = 1 : Waitms 45 : Op = 0 : Waitms 55

Elseif A = 43 Then

Lowerline

Lcd "FAN SPEED 3"


Elseif A < 45 Then

Lowerline

Lcd "FAN SPEED 3"


Elseif A = 45 Then

Lowerline

Lcd "FAN SPEED 4"




Elseif A < 46 Then

Lowerline

Lcd "FAN SPEED 4"


Elseif A = 46 Then

Lowerline

Lcd "FAN SPEED 5"


Elseif A > 46 Then

Lowerline

Lcd "FAN SPEED 5"


End If

Waitms 250

Loop

End



CHAPTER 7

BREADBOARD IMPLEMENTATION4.1 BOARD TYPES

The two most popular PCB types are:

4.1.1 SINGLE SIDED BOARDS

The single sided PCBs are mostly used in entertainment electronics where

manufacturing costs have to be kept at a minimum. However in industrial electronics

cost factors cannot be neglected and single sided boards should be used wherever a

particular circuit can be accommodated on such boards.

4.1.2 DOUBLE SIDED BOARDS

Double-sided PCBs can be made with or without plated through holes. The

production of boards with plated through holes is fairly expensive. Therefore plated

through hole boards are only chosen where the circuit complexities and density of

components does not leave any other choice.

Fig 7.1 Breadboard Implementation



CHAPTER 8

PCB DESIGN

When designing the layout one should observe the minimum size (component body

length and weight). Before starting to design the layout we need all the required

components in hand so that an accurate assessment of space can be made. Other space

considerations might also be included from case to case of mounted components over

the printed circuit board or to access path of present components. It might be

necessary to turn some components around to a different angular position so that

terminals are closer to the connections of the components. The scale can be checked

by positioning the components on the squared paper. If any connection crosses, then

one can reroute to avoid such condition.

All common or earth lines should ideally be connected to a common line routed around

the perimeter of the layout. This will act as the ground plane. If possible try to route the

outer supply line to the ground plane. If possible try to route the other supply lines around

the opposite edge of the layout through the centre. The first set is tearing the circuit to

eliminate the crossover without altering the circuit detail in any way. Plan the layout

looking at the topside to this board. First this should be translated inversely, later for the

etching pattern large areas are recommended to maintain good copper adhesion. It is

important to bear in mind always that copper track width must be according to the

recommended minimum dimensions and allowance must be made for increased width

where termination holes are needed. From this aspect, it can become little tricky to

negotiate the route to connect small transistors. There are basically two ways of copper

interconnection patterns under side the board. The first is the removal of only the amount

of copper necessary to isolate the junctions of the components to one another. The second

is to make the interconnection pattern looking more like conventional point wiring by

routing uniform width of copper from component to component. Etching process requires

the use of chemicals. Acid resistant dishes and running water supply. Ferric chloride is

mostly used solution but other etching materials such as ammonium per sulphate can be

used. Nitric acid can be used but in general it is not used due to poisonous fumes. The

pattern prepared is glued to the copper surface of the board using a latex type of adhesive

that can be cubed after use. The pattern is laid firmly on the copper using a very sharp

knife to cut round the pattern carefully to remove the paper corresponding to the required

copper pattern areas. Then apply the resistant solution,



which can be a kind of ink solution for the purpose of maintaining smooth clean outlines

as far as possible. While the board is drying, test all the components. Check for any free

metal on the copper. The etching bath should be in a glass or enamel disc. If using crystal

of ferric- chloride these should be thoroughly dissolved in water to the proportion

suggested. There should be 0.5 lt. of water for 125 gm of crystal. To prevent particles of

copper hindering further etching, agitate the solutions carefully by gently twisting or

rocking the tray. The board should not be left in the bath a moment longer than is needed

to remove just the right amount of copper. In spite of there being a resistive coating there

is no protection against etching away through exposed copper edges. This leads to over

etching. Have running water ready so that etched board can be removed properly and

rinsed. This will halt etching immediately. Drilling is one of those operations that calls for

great care. For most purposes a 0.5mm drill is used.

8.1 PCB LAYOUT SOLDER SIDE

Fig 8.1 PCB Layout solder side



8.2 PCB LAYOUT COMPONENT SIDE

Fig 8.2 PCB Layout component side

Fig 8.3 PCB Layout component side



CHAPTER 9

COMPONENT DETAILS

9.1 RF Module (Transmitter & Receiver)

Fig 9.1 RF module

The RF module, as the name suggests, operates at Radio Frequency. The

corresponding frequency range varies between 30 kHz & 300 GHz. In this RF system,

the digital data is represented as variations in the amplitude of carrier wave. This kind

of modulation is known as Amplitude Shift Keying (ASK).

Transmission through RF is better than IR (infrared) because of many reasons. Firstly,

signals through RF can travel through larger distances making it suitable for long

range applications. Also, while IR mostly operates in line-of-sight mode, RF signals

can travel even when there is an obstruction between transmitter & receiver. Next, RF

transmission is more strong and reliable than IR transmission. RF communication uses

a specific frequency unlike IR signals which are affected by other IR emitting sources.

This RF module comprises of an RF Transmitter and an RF Receiver. The

transmitter/receiver (Tx/Rx) pair operates at a frequency of 434 MHz. An RF

transmitter receives serial data and transmits it wirelessly through RF through its

antenna connected at pin4. The transmission occurs at the rate of 1Kbps - 10Kbps.The



transmitted data is received by an RF receiver operating at the same frequency as that

of the transmitter.

The RF module is often used alongwith a pair of encoder/decoder. The encoder is used

for encoding parallel data for transmission feed while reception is decoded by a

decoder. HT12E-HT12D, HT640-HT648, etc. are some commonly used

encoder/decoder pair ICs.

9.2 Pin Diagram:

Fig 9.2 pin diagram of RF Transmitter and Receiver



9.3 Pin Description: RF Transmitter

Table no.9.1

Pin No Function Name

1 Ground (0V) Ground2 Serial data input pin Data3 Supply voltage; 5V Vcc4 Antenna output pin ANT

RF Receiver

Table no. 9.2

Pin No Function Name

1 Ground (0V) Ground2 Serial data output pin Data3 Linear output pin; not connected NC4 Supply voltage; 5V Vcc5 Supply voltage; 5V Vcc6 Ground (0V) Ground7 Ground (0V) Ground8 Antenna input pin ANT

9.4 ENCODER

An encoder is a device, circuit, transducer, software program, algorithm or person

that converts information from one format or code to another, for the purposes of

standardization, speed, secrecy, security, or saving space by shrinking size.

It is useful to be able to guarantee certain characteristics about the information that

gets sent across the serial link. These are specific properties that are desirable:

Large transition density

The greater the transition density, the more chances there are for the receiver to

synchronize to the data. With many transitions, a receiver can implement a

voting scheme and synchronize with a greater accuracy.



Minimum transition density

Besides having a high average transition density, it is useful to guarantee that

every word transmitted on the serial link contains a minimum number of

transitions.

Error detection

Although error detection must also be implemented on a higher level, it can be

useful to have a scheme that is able to detect certain types of errors in the

physical layer of the link.

Predefined comma characters

Out-of-band characters are useful for transmitting metadata and for

synchronization purposes. A useful comma sequence must be singular (that is,

it must not appear in any sequence of valid data bits, including overlapped data

characters), and must occur with a uniform alignment relative to byte

boundaries.

Fig 9.3 pin diagram of HT12E



Features

Operating voltage

2.4V~5V for the HT12A

2.4V~12V for the HT12E

Low power and high noise immunity CMOS technology

Low standby current: 0.1_A (typ.) at VDD=5V

HT12A with a 38kHz carrier for infrared transmission medium

Minimum transmission word

Four words for the HT12E

One word for the HT12A

Built-in oscillator needs only 5% resistor

Data code has positive polarity

Minimal external components

HT12A/E: 18-pin DIP/20-pin SOP package

Applications

Burglar alarm system

Smoke and fire alarm system

Garage door controllers

Car door controllers

Car alarm system

Security system

Cordless telephones

Other remote control systems



General Description

The 212 encoders are a series of CMOS LSIs for remote control system applications.

They are capable of encoding information which consists of N address bits and 12_N

data bits. Each address/

data input can be set to one of the two logic states. The programmed addresses/data are

transmitted together with the header bits via an RF or an infrared transmission medium

upon receipt of a trigger signal. The capability to select a TE trigger on the HT12E or

a DATA trigger on the HT12A further enhances the application flexibility of the 212

series of encoders. The HT12A additionally provides a 38kHz carrier for infrared

systems.

9.5 DECODER

A decoder is a device which does the reverse of an encoder, undoing the encoding so

that the original information can be retrieved. The same method used to encode is

usually just reversed in order to decode.

In digital electronics, a decoder can take the form of a multiple-input, multiple-

output logic circuit that converts coded inputs into coded outputs, where the input and

output codes are different. e.g. n-to-2n, binary-coded decimal decoders. Enable inputs

must be on for the decoder to function, otherwise its outputs assume a single

"disabled" output code word. Decoding is necessary in applications such as

data multiplexing, 7 segment display and memory address decoding.

The example decoder circuit would be an AND gate because the output of an AND

gate is "High" (1) only when all its inputs are "High." Such output is called as "active

High output". If instead of AND gate, the NAND gate is connected the output will be

"Low" (0) only when all its inputs are "High". Such output is called as "active low

output".

A slightly more complex decoder would be the n-to-2n type binary decoders. These

type of decoders are combinational circuits that convert binary information from 'n'

coded inputs to a maximum of 2n unique outputs. We say a maximum of 2n outputs

because in case the 'n' bit coded information has unused bit combinations, the decoder

may have less than 2n outputs. We can have 2-to-4 decoder, 3-to-8 decoder or 4-to-16



decoder. We can form a 3-to-8 decoder from two 2-to-4 decoders (with enable

signals).

Similarly, we can also form a 4-to-16 decoder by combining two 3-to-8 decoders. In

this type of circuit design, the enable inputs of both 3-to-8 decoders originate from a

4th input, which acts as a selector between the two 3-to-8 decoders. This allows the

4th input to enable either the top or bottom decoder, which produces outputs of D(0)

through D(7) for the first decoder, and D(8) through D(15) for the second decoder.

A decoder that contains enable inputs is also known as a decoder-demultiplexer. Thus,

we have a 4-to-16 decoder produced by adding a 4th input shared among both

decoders, producing 16 outputs.

Fig 9.4 pin diagram of HT12D

To guarantee these characteristics, an encoder/decoder is used. The encoder takes in

incoming data along with some metadata (such as a signal that indicates whether the

incoming data represents actual data or control characters) and produces an encoded

value which is then transmitted on the link. Similarly, the decoder takes the values

from the link and produces the original value, along with some information such as

whether the incoming character contains any errors, and whether it represents a data or

control character.



Features

Operating voltage: 2.4V~12V

Low power and high noise immunity CMOS technology

Low standby current

Capable of decoding 12 bits of information

Binary address setting

Received codes are checked 3 times

Address/Data number combination

HT12D: 8 address bits and 4 data bits

HT12F: 12 address bits only

Built-in oscillator needs only 5% resistor

Valid transmission indicator

Easy interface with an RF or an infrared transmission medium

Minimal external components

Pair with Holtek_s 212 series of encoders

18-pin DIP, 20-pin SOP package

General Description

The 212 decoders are a series of CMOS LSIs for remote control system applications.

They are paired with Holtek_s 212 series of encoders (refer to the encoder/decoder

cross reference table). For proper operation, a pair of encoder/decoder with the same

number of addresses and data format should be chosen. The decoders receive serial

addresses and data from a programmed 212 series of encoders that are transmitted by a

carrier using an RF or an IR transmission medium. They compare the serial input data

three times continuously with their local addresses. If no error or unmatched codes are

found, the input data codes are decoded and then transferred to the output pins. The

VT pin also goes high to indicate a valid transmission. The 212 series of decoders are

capable of decoding informations that consist of N bits of address and 12_N bits of

data. Of this series, the HT12D is arranged to provide 8 address bits and 4 data bits,

and HT12F is used to decode 12 bits of address information.

Applications

Burglar alarm system Department Of Electronics & Communication Engineering 23


Smoke and fire alarm system

Garage door controllers

Car door controllers

Car alarm system

Security system

9.6 RESISTOR

Resistance is a property of material due to which it opposes the flow of current through it.

When electrons flow through any material, they collide with each other which gives rise to opposition to the flow of current.The unit of resistor is ohm(Ω).

The resistance of a conductor will be 1Ω when it allows 1 A current to flow through it on application of 1 V across its material.

The resistance of conducting material is found to …

1. be directly proportional to the length l of the material,

2. be inversely proportional to the cross-sectional area of the material.

3. depend on the nature of material.

4. depend upon the temperature.

Fig 9.5 Register

9.7 DC POWER SUPPLY



A power supply is an electronic device that supplies electric energy to an electrical load.

The primary function of a power supply is to convert one form of electrical energy to

another and, as a result, power supplies are sometimes referred to as electric power

converters. Some power supplies are discrete, stand-alone devices, whereas others are

built into larger devices along with their loads. Examples of the latter include power

supplies found in desktop computers and consumer electronics devices.

U1

D17805

1 VI VO 3

1N4007

TR1 D2

1N4007 C11000u

D3 +88.8Volts

1N4007TRAN-2P2S

D4

1N4007

Fig 9.6 DC Power Supply

9.8 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. 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. Appearing as practical

electronic components in 1962, 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 even LED

wallpaper. As of 2015, LEDs powerful enough for room lighting remain somewhat more

expensive, and require more precise current and heatmanagement, than compact

fluorescent lamp sources of comparable output.LEDs have allowed new text, video

displays, and sensors to be developed, while their high switching rates are also useful

in advanced communications technology.

Fig 9.7 LED

9.9 TRANSISTOR

A transistor is a semiconductor device to amplify and switch electronic signals and Department Of Electronics & Communication Engineering 26


electrical power. It is composed of semiconductor material with at least three

terminals for connection to an external circuit. A voltage or current applied to one pair

of the transistor's terminals changes the current through another pair of terminals.

Because the controlled (output) power can be higher than the controlling (input)

power, a transistor can amplify a signal. Today, some transistors are packaged

individually, but many more are found embedded in integrated circuits.

The transistor is the fundamental building block of modern electronic devices, and is

ubiquitous in modern electronic systems. Following its development in 1947 by

American physicists John Bardeen, Walter Brattain, and William Shockley, the

transistor revolutionized the field of electronics, and paved the way for smaller and

cheaper radios, calculators, and computers, among other things.

Fig 9.8 Transistor



9.10 CRYSTAL OSCILLATOR

A crystal oscillator is an electronic oscillator circuit that uses the mechanical

resonance of a vibrating crystal of piezoelectric material to create an electrical signal

with a 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 and receivers. The most common

type of piezoelectric resonator used is the quartz crystal, so oscillator circuits

incorporating them became known as crystal oscillators but other piezoelectric

materials including polycrystalline ceramics are used in similar circuits.

Quartz crystals are manufactured for frequencies from a few tens of kilohertz to

hundreds of megahertz. More than two billion crystals are manufactured annually.

Most are used for consumer devices such as wristwatches, clocks, radios, computers,

and cellphones. Quartz crystals are also found inside test and measurement

equipment, such as counters, signal generators, and oscilloscopes.

Fig 9.9 Crystal Oscillator



9.11 VOLTAGE REGULATOR

A voltage regulator is designed to automatically maintain a constant voltage level. A

voltage regulator may be a simple "feed-forward" design or may include negative

feedback control loops. It may use an electromechanical mechanism, or electronic

components. Depending on the design, it may be used to regulate one or more AC or

DC voltages.

Electronic voltage regulators are found in devices such as computer power supplies

where they stabilize the DC voltages used by the processor and other elements. In

automobile alternators and central power station generator plants, voltage regulators

control the output of the plant. In an electric power distribution system, voltage

regulators may be installed at a substation or along distribution lines so that all

customers receive steady voltage independent of how much power is drawn from the line.

Fig 9.10 Voltage Regulator



CHAPTER 10

ADVANTAGES AND LIMITATION10.1 ADVANTAGE

1.This project can be used in Home.

2.This project can be used in Industry.

3.This will help in saving the energy / electricity.

4.To monitor the environments that is not comfortable, or possible, for humans to monitor, especially for extended periods of time.

5.Prevents waste of energy when it’s not hot enough for a fan to be needed.

6.To assist people who are disabled to adjust the fan speed automatically.

10.2 LIMITATION

It can only be maintained by technical person. Thus, it becomes difficult to bemaintained.



CHAPTER 11

APPLICATION

1.Burglar alarm system

2.Control inside elevator control panels.

3.Control inside the pay machines / ticketing machines at parking lots (coin parking).

4.Control inside the cabinets of expressway sign boards.

5.Control of obstacle detection sensors at railroad crossings.

6.Control for the infrared sensors used for intrusion detection for security purposes.

7.This can be used in home application.

8.This circuit can be used in CPU to reduced heat.

9.This can be also be used in the vehicle for the controlling purpose.



CHAPTER 12

FUTURE SCOPE

This future step of an intelligent electric fans that uses intelligent technology such as

increased interchange-ability between motor technologies. and the element used in the

machines. The technology used in this get advanced by using special type of

microcontroller aurdino microcontroller. The electric fan automatically switches the

speed of the fan according to the environment changes. This electric fan system

contain combination of sensor, controller, driver and motor with integration of

embedded controlled programming which means in this case using aurdino as the

main controller.in this project uses which shows the increase and decrease of need to

be reduced to manageable proportions and also show the performance efficiency of

fan speed. This project also prevents the expected performance of the automatic fan

system, construction of hardware and software development to gather the

performance data .This project will also be a part of energy saving device. Finally this

system performance will be evaluated by comparing performance data to the

theoretical.

Definitions need to be agreed for:

– Electronic controller hardware

– Electronic controller software settings

– Load types for controller only comparisons



CHAPTER 13

IDEAS WHICH COULD NOT BE IMPLEMENTED

In future the circuit can be enhanced by connecting a robotics to the circuit so that in

industrial area when a machine crosses the motors, we can inform the control robot by

sending a signal to control robot manager so that damages to the machine can be

avoided by disconnecting the equipment with wireless technology. In the same

manner we can also implement the solar power supply technology for supplying the

voltage to the motor, microcontroller and to the motor but we cannot implement this

technology. We can also implement the wireless connection and remove the wired

from the circuit .



CHAPTER 14

COST OF PROJECT

COMPONENTS COST(IN RS.)

COMPONENTS 820

CABLE AND SOLDERING 45

GLOSSY PAPER 50

SAND PAPER 10

BOX 50

TOTAL= RS.975



CHAPTER 15

CONCLUSION

Once again, everything worked as it was suppose to. You can control a dc motor

using the wireless So this just about brings the tutorial to a close. I would like to take

a moment to say that there are a few tiny things that I may have missed or skipped

while talking about this topic. Feel free to contact me if you feel something is missing

that abosultely should be here.. Be aware there are many, many different types of

motor controller ic's out there. It would be wise to look at some of them and even try

using them to see the different functionality that they offer. Along side looking at

different motor controllers, it would also be a good idea to look at different types of

motors. Some would be: Stepper Motors & Servo Motors. We will have tutorials from

controlling these motors coming in the future.

So this just about brings the tutorial to a close. I would like to take a moment to say

that there are a few tiny things that I may have missed or skipped while talking about

this topic. Feel free to contact me if you feel something is missing that abosultely

should be here.



CHAPTER 16

REFRENCES

1. Robert Dale (vol.09.issue 6). Pages 975-997.

2. AN Nichat (vol.06.issue3).Pages 125-175

3. Electronics Projects with RF – www.jap.hu/electronics.html

4. http://www.pyroelectro.com/tutorials/dc_motor/conclusion.html

5.http://www.electroschematics.com

6.Meshram. P. M. and Kanojiya. R. G. Tunning of controller using Ziegler-Nichols

method for speed control of DC motor.Advances in Engineering Sciences and

Management, 2012 international conference on.pp,117-122.

7.www.engineergarage.com


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