Visves varaya Technological University Belgaum -590018

Visvesvaraya Technological University

Belgaum-590018

Project Report – 8th Semester (2014-15)

“SPEED SYNCHRONIZATION OF MULTIPLE MOTORS IN TEXTILE & STEEL MILLS”

Submitted in partial fulfillment of the requirement for the award of the degree

Bachelor of Engineering

In

Electrical and Electronics Engineering

Submitted by

1. Name: ANIL KUMAR RAJAK USN No-1NH11EE703 2. Name: ANKIT KUMAR USN No-1NH11EE705 3. Name: ANKUR SHUKLA USN No-1NH11EE707 4. Name: VIVEK KUMAR SINGH USN No-1NH11EE759

June 2015

Under the guidance of SANTHOSH S

[ Asst. Professor ]

NEW HORIZON COLLEGE OF ENGINEERING Department of Electrical and Electronics Engineering

Permanent affiliated to VTU, Approved by AICTE and ISO9001:2008 certified

A Recipient of Prestigious State Award 2012 conferred by the Government of Karnataka

Marathahalli Ring Road, Bellandur Post,

Bangalore – 560 103

New Horizon College of Engineering (A Recipient of Prestigious State Award 2012 by the Government of Karnataka)

(Accredited by NBA, Permanent affiliation by VTU)

Ring Road, Kadubisanahalli, Bellandur Post, Near Marathahalli.

Bangalore – 560 103

Department of Electrical and Electronics

CERTIFICATE

Certified that the project work entitled “SPEED SYNCHRONIZATION OF MULTIPLE

is a bonafide work carried out by ANIL MOTORS IN TEXTILE & STEEL MILLS”

KUMAR RAJAK (1NH11EE703), ANKIT KUMAR (1NH11EE705), ANKUR SHUKLA

(1NH11EE707),VIVEK KUMAR SINGH (1NH11EE759) in partial fulfillment for the

award of the degree of Bachelor of Engineering in Electrical and Electronics of

the Visvesvaraya Technological University, Belgaum during the year 2014-2015. It

is certified that all corrections / suggestions indicated for internal assessment have

been incorporated in the report deposited in the departmental Library. The

project report has been approved as it satisfies the academic requirements in the

respect of project work prescribed for the Bachelor of Engineering Degree.

SANTHOSH S Prof. Mahesh.K Dr. Manjunatha

Asst. Professor HOD - EEE PRINCIPAL

Submitted by

NAMES

1. ANIL KUMAR RAJAK USN No - 1NH11EE703

2. ANKIT KUMAR USN No – 1NH11EE705

3. ANKUR SHUKLA USN No – 1NH11EE707

4. VIVEK KUMAR SINGH USN No - 1NH11EE759

Name of the Examiners Signature with date

Declaration

We the student of eighth semester, B.E-Electrical And Electronics Engineering, New

Horizon College of Engineering, Bangalore, hereby declare that the project entitled “SPEED

SYNCHRONIZATION OF MULTIPLE BLDC MOTORS IN TEXTILE & PAPER

MILLS USING MICRO CONTROLLER”, embodies the report of our project work,

independently carried out by us under the guidance of SANTHOSH S, Assistant Professor,

Department of Electrical and Electronics Engineering, as partial fulfilment of the award of

the degree of Bachelor of Engineering in Electrical and Electronics Engineering of the

Visvesvaraya Technological University.

We also declare that, to the best of our knowledge and belief, the work reported

herein does not form part of any other project on the basis of which a degree or award was

conferred on an earlier occasion on this by any student.

Place: Bangalore

Date:

ANIL KUMAR RAJAK (1NH11EE703)

ANKIT KUMAR (1NH11EE705)

ANKUR SHUKLA (1NH11EE707)

VIVEK KUMAR SINGH (1NH11EE759)

ACKNOWLEDGEMENT

I wish to place my sincere thanks to our Chairman Dr. Mohan Manghnani,

Dr. Manjunatha, Principal, New Horizon College of Engineering for permitting us to

undertake this topic as the part of my curriculum.

I whole-heartedly thank our HOD Mr. MAHESH . K for his guidance. I am also indebted to

all other teaching and non-teaching faculty members who gave me their valuable time and

guidance.

I take this opportunity to express my deep sense of gratitude and respect towards my guide

and seminar coordinator SANTHOSH S (Asst. Prof. Department of electrical & electronics

engineering) NEW HORIZON COLLEGE OF ENGINEERING, BANGALORE. I am

very much indebted to him for the generosity, expertise and guidance I have received from

him while collecting data on this seminar and throughout my studies. Without him support

and timely guidance, the completion of my seminar would have seemed a farfetched dream.

In this respect I find ourselves lucky to have him as our guide. It is a great pleasure for me to

express my gratitude towards those who are involved in the completion of my Project report.

SPEED SYNCHRONIZATION OF MULTIPLE BLDC MOTORS IN TEXTILE & PAPER MILLS

USING MICRO CONTROLLER

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Dept. of EEE-NHCE Page 1

ABSTRACT

The aim of this project is synchronization of multiple motors using wireless technology. This

project uses radio frequency to synchronize motor speeds. This is applicable to many

industries like textile mills, steel plants, paper plants wherein all the motors used on conveyor

are desired to be synchronized. For example, in textile mills where multiple motors work

simultaneously on a conveyor belt to draw clothes, it is essential that all the motors there

should run at same speed, so that balanced tension is achieved to avoid clothes getting

damaged. In this project motors are wirelessly synchronized to make the differential speed

error among multiple motors to zero. One motor acts as transmitter and all the rest as

receivers. Thus, if a particular speed is set in the transmitter then all other motors speed

would be matched to the same speed of the main motor. The mode of communication is radio

frequency. BLDC motors used operate on the basis of PWM control. Each motor has a closed

loop feedback mechanism providing RPM reference by a shaft mounted IR sensor

arrangement whose output is fed to the controller in the circuit. A display unit displays the

full speed and one can enter the desired percentage with help of a keypad to obtain the

required speed for all the motors. The pulse width output from the microcontroller would be

automatically adjusted to maintain the DC power to the motor such that the entered speed

percentage matches the running RPM. The above operation is carried out by using one opto

isolator and a MOSFET for driving the BLDC motor duly interfaced from the

microcontroller. In various stages of operations motors have to rotate at different speeds, so if

we change the speed in transmitting motor then rest of the motors are adjusted accordingly.

The whole operation is made simple by using this technology. Manpower and time is also

saved in this system. The future works include giving intelligence to the whole system like if

any of the motor senses any fault, the whole system will shutdown



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Table of contents: Page No

1. INTRODUCTION…………………………………………………………………….1

2. OBJECTIVES………………………………………………………………………....5

3. DRAWBACKS OF USING CONVEYOR BELT FOR SPEES SYNCHRONIZATION

4. SOLUTION FOR OLD CONCEPT OF CONVEYOR BELTS………………………6

5. HARDWARE REQUIREMENTS

5.1. TRANSFORMERS………………………………………………………………7

5.2. VOLTAGE REGULATOR (LM7805)…………………………………………..8

5.3. RECTIFIER…………………………………………………………………….. 9

5.4. FILTER…………………………………………………………………………..10

5.5. MICROCONTROLLER…………………………………………………………11-16

5.6. LIQUID CRYSTAL DISPLAY…………………………………………………17-19

5.7. KEY PAD………………………………………………………………………..20-21

5.8. Opto ISOLATOR………………………………………………………………..22-23

5.9. MOSFET………………………………………………………………………...24-25

5.10. DC MOTOR……………………………………………………………………26-28

5.11. IR LED…………………………………………………………………………29-30

5.12. PHOTODIODE…………………………………………………………………31

5.13. LED……………………………………………………………………………..32

5.14. RESISTOR……………………………………………………………………...33-34

5.15. CAPACITOR…………………………………………………………………...35-37

5.16. RF MODULE…………………………………………………………………...38-40

6. PWM………………………………………………………………………………...41-42

7. SOFTWARE REQUIREMENTS…………………………………………………...43-44

8. SCHEMATIC DIAGRAM………………………………………………………….45-46

9. CIRCIT DIAGRAM………………………………………………………………...47



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10. POWER SUPPLY…………………………………………………………………48-50

11. OPERATION……………………………………………………………………...51-53

12. FLOW CHART……………………………………………………………………54

13. HARDWARE COMPONENT…………………………………………………….55

14.HARDWARE TESTING…………………………………………………………..56

14.1. CONTINUITY TEST

14.2. POWER ON TEST

15. CONCLUSION…………………………………………………………………….57

16. REFERANCE………………………………………………………………………58



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CHAPTER 1

INTRODUCTION:

Multi-motor systems has vast application industrial environment. Applications can be found

in offset printing, paper machines, textiles industries and robotics also. Therefore speed

synchronization of all these motors is very essential in order to avoid damage to the product.

In this project motors are wirelessly synchronized to make the differential speed error among

multiple motors to zero. One motor acts as transmitter and all the rest as receivers. Thus, if a

particular speed is set in the transmitter then all other motors speed would be matched to the

same speed of the main motor. A display unit displays the full speed and one can enter the

desired percentage with help of a keypad to obtain the required speed for all the motors. The

pulse width output from the microcontroller would be automatically adjusted to maintain the

DC power to the motor such that the entered speed percentage matches the running RPM.

The above operation is carried out by using one opto isolator and a MOSFET connected to

motor In textile industry many processes require speed synchronization of more than one

motors involved in the process. Rolling of cloth should be synchronized with the speed of

weaving spindle to avoid damage and motor speed synchronization is vital in conveyor belt

driven by multiple motors. Abrupt load variations may cause hunting or oscillatory behaviour

in d. c. machines. This behaviour can be detrimental to the process. The digitally controlled d.

c. machines can have much aggravated phenomenon owing to poor sampling period

selection. Traditionally processes are synchronized through mechanical transmission system

consisting of a line shaft gears, pullers etc. Among the available software mechanisms

master-slave synchronization is a widely used technique. Multi-motor applications have

become very attractive field in industrial applications replacing in traditional mechanical

coupling. Many textile applications involved synchronized speed motors. For example

wrapping of clothes should be synchronized with the speed of weaving spindle to avoid

damage and Similarly in some cases the speed of long conveyor belt driven by multiple\

motors is need to be constant. In such types of applications master slave technique is used as

a software mechanism to synchronize the speed of different motors to avoid damage.



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CHAPTER 2

OBJECTIVE

The purpose of this project is synchronization of multiple motors using wireless technology.

This project uses radio frequency to synchronize motor speeds. This is applicable to many

industries like textile mills, steel plants, and paper plants wherein all the motors used on

conveyor are desired to be synchronized. In textile mills where multiple motors work

simultaneously on a conveyor belt to draw clothes, it is essential that all the motors should

run at same speed, so that balanced tension is achieved to avoid clothes getting damaged

.Manpower and time is also saved in this system. User can set the desired rpm for the motors.

As This system is wireless, it is easy to operate and control the system Multiple motors used

in textile industry, or any other for cloth drawing needs to be synchronized for same speed.

Traditionally we use conveyor belts in order to synchronize multiple motor. But this has

many draw backs.



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CHAPTER 3

Drawbacks of using conveyor belt for speed synchronization.[Earlier

Method]

• The master will be the hardest to start, stop and maintain smooth motion on.

• All motors should be connected parallel.

• As there are moving belts between the motors, we need to service and change them

regularly.

• The design of master/follower motors in the system may be series, branch, or mixed.

• Again the system and its product will determine what piece of equipment is directly

synched or digitally rationed to each other piece of equipment.

• Maintenance is bit difficult as there are more mechanical parts.

Solution for old Concept of Conveyor Belt :

There are so many solutions for this problem. But those are not that reliable. In order to

reduce human intervention and save the labor cost and time we can use microcontroller to

control, operate and synchronize this task. As compared to conveyor method is compatible as

it involves hardware as well as software. We can program microcontroller to control its speed

and also can set the required speed through keypad. Synchronization can done either wired or

wirelessly. In this project we are using RF communication technology for wireless

communication. In this project motors are wirelessly synchronized to make the differential

speed error among multiple motors to zero. One motor acts as transmitter and all the rest as

receivers. Thus, if a particular speed is set in the transmitter then all other motors speed

would be matched to the same speed of the main motor. The mode of communication is radio

frequency. Motors used operate on the basis of PWM control. Each motor has a closed loop

feedback mechanism providing RPM reference by a shaft mounted IR sensor arrangement

whose output is fed to the controller in the circuit. A display unit displays the full speed and

one can enter the desired percentage with help of a keypad to obtain the required speed for all

the motors. The pulse width output from the microcontroller would be automatically adjusted

.



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CHAPTER 4

HARDWARE COMPONENTS:

TRANSFORMER

Transformers convert AC electricity from one voltage to another with a little loss of power.

Step-up transformers increase voltage, step-down transformers reduce voltage. Most power

supplies use a step-down transformer to reduce the dangerously high voltage to a safer low

voltage.

FIG: A TYPICAL TRANSFORMER

The input coil is called the primary and the output coil is called the secondary. There is no

electrical connection between the two coils; instead they are linked by an alternating

magnetic field created in the soft-iron core of the transformer. The two lines in the middle of

the circuit symbol represent the core. Transformers waste very little power so the power out

is (almost) equal to the power in. Note that as voltage is stepped down and current is stepped

up. The ratio of the number of turns on each coil, called the turn„s ratio, determines the ratio

of the voltages. A step-down transformer has a large number of turns on its primary (input)

coil which is connected to the high voltage mains supply, and a small number of turns on its

secondary (output) coil to give a low output voltage.



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CHAPTER 5:

VOLTAGE REGULATOR 7805

Features

• Output Current up to 1A.

• Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V.

• Thermal Overload Protection.

• Short Circuit Protection.

• Output Transistor Safe Operating Area Protection.

Description

The LM78XX/LM78XXA series of three-terminal positive regulators are available in the

TO-220/D-PAK package and with several fixed output voltages, making them useful in a

Wide range of applications. Each type employs internal current limiting, thermal shutdown

and safe operating area protection, making it essentially indestructible. If adequate heat

sinking is provided, they can deliver over 1A output Current. Although designed primarily as

fixed voltage. regulators, these devices can be used with external components to obtain

adjustable voltages and currents.



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CHAPTER 6:

RECTIFIER

A rectifier is an electrical device that converts alternating current (AC), which periodically

reverses direction, to direct current (DC), current that flows in only one direction, a process

known as rectification. Rectifiers have many uses including as components of power supplies

and as detectors of radio signals. Rectifiers may be made of solid state diodes, vacuum tube

diodes, mercury arc valves, and other components. The output from the transformer is fed to

the rectifier. It converts A.C. into pulsating D.C. The rectifier may be a half wave or a full

wave rectifier. In this project, a bridge rectifier is used because of its merits like good

stability and full wave rectification. In positive half cycle only two diodes ( 1 set of parallel

diodes) will conduct, in negative half cycle remaining two diodes will conduct and they will

conduct only in forward bias only



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CHAPTER 7:

FILTER

Capacitive filter is used in this project. It removes the ripples from the output of rectifier and

smoothens the D.C. Output received from this filter is constant until the mains voltage and

load is maintained constant. However, if either of the two is varied, D.C. voltage received at

this point changes. Therefore a regulator is applied at the output stage. The simple capacitor

filter is the most basic type of power supply filter. The use of this filter is very limited. It is

sometimes used on extremely high-voltage, low-current power supplies for cathode-ray and

similar electron tubes that require very little load current from the supply. This filter is also

used in circuits where the power-supply ripple frequency is not critical and can be relatively

high. Below figure can show how the capacitor changes and discharges.

RESULTANT OUTPUT WAVE FORM



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CHAPTER 8:

MICROCONTROLLER AT89S52

The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes

of in-system programmable Flash memory. The device is manufactured using Atmel„s high-

density non volatile memory technology and is compatible with the industry standard 80C51

instruction set and pin out. The on-chip Flash allows the program memory to be

reprogrammed in-system or by a conventional non volatile memory programmer. By

combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip,

the Atmel AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-

effective solution to many embedded control applications. The AT89S52 provides the

following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog

timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt

architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the

AT89S52 is designed with static logic for operation down to zero frequency and supports two

software selectable power saving modes. The Idle Mode stops the CPU while allowing the

RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-

down mode saves the RAM contents but freezes the oscillator, disabling all other chip

functions until the next interrupt or hardware reset

Features:

• Compatible with MCS®-51 Products

• 8K Bytes of In-System Programmable (ISP) Flash Memory – Endurance: 10,000

Write/Erase Cycles

• 4.0V to 5.5V Operating Range

• Fully Static Operation: 0 Hz to 33 MHz

• Three-level Program Memory Lock

• 256 x 8-bit Internal RAM

• Programmable I/O Lines

• Three 16-bit Timer/Counters

• Eight Interrupt Sources

• Full Duplex UART Serial Channel



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• Low-power Idle and Power-down Modes

• Interrupt Recovery from Power-down Mode

• Watchdog Timer

• Dual Data Pointer

• Power-off Flag

• Fast Programming Time

• Flexible ISP Programming (Byte and Page Mode)

• Green (Pb/Halide-free) Packaging Option

Pin Configurations of AT89S52

PIN DIAGRAM OF AT89S52



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Pin Description:

VCC: Supply voltage.

GND: Ground.

Port 0: Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin can

sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high-

impedance inputs. Port 0 can also be configured to be the multiplexed low-order address/data

bus during accesses to external program and data memory. In this mode, P0 has internal pull-

ups. Port 0 also receives the code bytes during Flash programming and outputs the code bytes

during program verification. External pull-ups are required during program verification

Port 1:

Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 1 output buffers can

sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the

internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being

pulled low will source current (IIL) because of the internal pull-ups. In addition, P1.0 and

P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the

timer/counter 2 trigger input (P1.1/T2EX).

Port 2:




pulled low will source current (IIL) because of the internal pull-ups. Port 2 emits the high-

order address byte during fetches from external program memory and during accesses to

external data memory that uses 16-bit addresses (MOVX @ DPTR). In this application, Port

2 uses strong internal pull-ups when emitting 1s. During accesses to external data memory

that uses 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function

Register.

Port 3:



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pulled low will source current (IIL) because of the pull-ups.

RST:

Reset input. A high on this pin for two machine cycles while the oscillator is running resets

the device. This pin drives high for 98 oscillator periods after the Watchdog times out. The

DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the default

state of bit DISRTO, the RESET HIGH out feature is enabled.

ALE/PROG:

Address Latch Enable (ALE) is an output pulse for latching the low byte of the address

during accesses to external memory. This pin is also the program pulse input (PROG) during

Flash programming. In normal operation, ALE is emitted at a constant rate of 1/6 the

oscillator frequency and may be used for external timing or clocking purposes. Note,

however, that one ALE pulse is skipped during each access to external data memory.

PSEN:

Program Store Enable (PSEN) is the read strobe to external program memory. When the

AT89S52 is executing code from external program memory, PSEN is activated twice each

machine cycle, except that two PSEN activations are skipped during each access to external

data memory.

EA/VPP:

External Access Enable. EA must be strapped to GND in order to enable the device to fetch

code from external program memory locations starting at 0000H up to FFFFH. Note,

however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should

be strapped to VCC for internal program executions. This pin also receives the 12-volt

programming enable voltage (VPP) during Flash programming.



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XTAL1:

Input to the inverting oscillator amplifier and input to the internal clock operating circuit

XTAL2:

Output from the inverting oscillator amplifier.

Oscillator Characteristics:

XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which

can be configured for use as an on-chip oscillator, as shown in Figure 1. Either a quartz

crystal or ceramic resonator may be used. To drive the device from an external clock source,

XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 6.2. There are

no requirements on the duty cycle of the external clock signal, since the input to the internal

clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage

high and low time specifications must be observed.

Oscillator Connections

External Clock Drive Configuration



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Idle Mode

In idle mode, the CPU puts itself to sleep while all the on chip peripherals remain active. The

mode is invoked by software. The content of the on-chip RAM and all the special functions

registers remain unchanged during this mode. The idle mode can be terminated by any enabled

interrupt or by a hardware reset.

Power down Mode

In the power down mode the oscillator is stopped, and the instruction that invokes power down is

the last instruction executed. The on-chip RAM and Special Function Registers retain their values

until the power down mode is terminated. The only exit from power down is a hardware reset.

Reset redefines the SFRs but does not change the on-chip RAM. The reset should not be activated

before VCC is restored to its normal operating level and must be held active long enough to allow

the oscillator to restart and stabilize



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CHAPTER 9:

LIQUID CRYSTAL DISPLAY

Description:

This is the example for the Parallel Port. This example doesn't use the Bi-directional feature

found on newer ports, thus it should work with most, if not all Parallel Ports. It however doesn't

show the use of the Status Port as an input for a 16 Character x 2 Line LCD Module to the

Parallel Port. These LCD Modules are very common these days, and are quite simple to work

with, as all the logic required running them is on board.

Pros:

• Very compact and light

• Low power consumption

• No geometric distortion

• Little or no flicker depending on backlight technology

• Not affected by screen burn-in

• No high voltage or other hazards present during repair/service

• Can be made in almost any size or shape

• No theoretical resolution limit

LCD Background

Frequently, an 8051 program must interact with the outside world using input and output

devices that communicate directly with a human being. One of the most common devices

attached to an 8051 is an LCD display. Some of the most common LCDs connected to the

8051 are 16x2 and 20x2 displays. This means 16 characters per line by 2 lines and 20

characters per line by 2 lines, respectively. Fortunately, a very popular standard exists which

allows us to communicate with the vast majority of LCDs regardless of their manufacturer.

The standard is referred to as HD44780U, which refers to the controller chip which receives



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data from an external source (in this case, the 8051) and communicates directly with the

LCD.

LCD

44780 LCD BACKGROUND

The 44780 standard requires 3 control lines as well as either 4 or 8 I/O lines for the data bus.

The user may select whether the LCD is to operate with a 4-bit data bus or an 8-bit data bus.

If a 4-bit data bus is used the LCD will require a total of 7 data lines (3 control lines plus the

4 lines for the data bus). If an 8-bit data bus is used the LCD will require a total of 11 data

lines (3 control lines plus the 8 lines for the data bus).

The three control lines are referred to as EN, RS, and RW. The EN line is called "Enable."

This control line is used to tell the LCD that you are sending it data. To send data to the LCD,



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your program should make sure this line is low (0) and then set the other two control lines

and/or put data on the data bus. When the other lines are completely ready, bring EN high (1)

and wait for the minimum amount of time required by the LCD datasheet (this varies from

LCD to LCD), and end by bringing it low (0) again. The RS line is the "Register Select" line.

When RS is low (0), the data is to be treated as a command or special instruction (such as

clear screen, position cursor, etc.). When RS is high (1), the data being sent is text data which

should be displayed on the screen. For example, to display the letter "T" on the screen you

would set RS high. The RW line is the "Read/Write" control line. When RW is low (0), the

information on the data bus is being written to the LCD. When RW is high (1), the program is

effectively querying (or reading) the LCD. Only one instruction ("Get LCD status") is a read

command. All others are write commands--so RW will almost always be low .Finally, the

data bus consists of 4 or 8 lines (depending on the mode of operation selected by the user). In

the case of an 8-bit data bus, the lines are referred to as DB0, DB1, DB2, DB3, DB4, DB5,

DB6, and DB7.



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CHAPTER 10:

KEYPAD

A keypad is a set of buttons arranged in a block or "pad" which usually bear digits, symbols

and usually a complete set of alphabetical letters. If it mostly contains numbers then it can

also be called a numeric keypad. Keypads are found on many alphanumeric keyboards and

on other devices such as calculators, push-button telephones, combination locks, and digital

door locks, which require mainly numeric input. Keypads are a part of HMI or Human

Machine Interface and play really important role in a small embedded system where human

interaction or human input is needed. Matrix keypads are well known for their simple

architecture and ease of interfacing with any microcontroller



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MATRIX KEYPAD

SCANNING OF MATRIX KEYPAD:

There are many methods depending on the connection keypad with micro controller, but the

basic logic is same the columns are made as input and drive the rows making them as output;

this whole procedure of reading the keyboard is called scanning. In order to detect which key

is pressed from the matrix, the row lines are to be made low one by one and read the

columns. Assume that if Row1 is made low, then read the columns. If any of the key in row1

is pressed then correspondingly the column 1will give low that is if second key is pressed in

Row1, then column2 will give low. This is how Scanning is done. So to scan the keypad

completely, we need to make rows low one by one and read the columns. If any of the

buttons are pressed in a row, it will take the corresponding column to a low state which

shows that a key is pressed in that row. If button 1 of a row is pressed then Column 1 will

become low, if button 2 then column2 and so on...this is the way of working by a keypad.



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CHAPTER 11:

OPTO ISOLATOR (MCT2E)

Opto-isolators, or Opto-couplers, are made up of a light emitting device, and a light sensitive

device, all wrapped up in one package, but with no electrical connection between the two,

just a beam of light. The light emitter is nearly always an LED. The light sensitive device

may be a photodiode, phototransistor, or more esoteric devices such as thyristors, triacs e.t.c.

A lot of electronic equipment nowadays is using optocoupler in the circuit. An optocoupler or

sometimes refer to as opt isolator allows two circuits to exchange signals yet remain

electrically isolated. This is usually accomplished by using light to relay the signal. The

standard opt coupler circuits design uses a LED shining on a phototransistor-usually it is a

npn transistor and not PNP. The signal is applied to the LED, which then shines on the

transistor in the IC. The light is proportional to the signal, so the signal is thus transferred to

the phototransistor. Opt couplers may also comes in few module such as the SCR,

photodiodes, TRIAC of other semiconductor switch as an output, and incandescent lamps,

neon bulbs or other light source. The optocoupler usually found in switch mode power supply

circuit in many electronic equipment. It is connected in between the primary and secondary

section of power supplies. The opt coupler application or function in the circuit is to:

1. Monitor high voltage

2. Output voltage sampling for regulation

3. System control micro for power ON/OFF

4. Ground isolation

If the optocoupler IC breakdown, it will cause the equipment to have low power, blink, no

power, erratic power and even power shut down once switch on the equipment. Many

technicians and engineers do not know that they can actually test the optocoupler with their

analog multimeter. Most of them thought that there is no way of testing an IC with an analog

meter. This is the principle used in Opto−Triacs and opto−SCRs, which are readily available

in Integrated circuit (I.C.) form, and do not need very complex circuitry to make them work.

Simply provide a small pulse at the right time to the Light Emitting Diode in the package.

The light produced by the LED activates the light sensitive properties of the Triac or

Thyristor gateand the power is switched on. The isolation between the low power and high

power circuits in these optically connected devices is typically several thousand volts.



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Collector dark current

This is the current that can flow through the output phototransistor when it is turned off.

Collector-emitter saturation voltage

When the output transistor is fully turned on (saturated), this is the voltage there will be

between the collector and emitter.

Isolation resistance

This is the resistance from a pin in the input side to a pin on the output side. It should be very

high.

Response time

The rise and fall times are the times that the output voltage takes to get from zero to

maximum. The rise time is very much dependant on the load resistor, since it is this that is

pulling the output up. Therefore this value is always quoted with a fixed load resistance. Note

however that the value, 100 Ohms, is much less than you are likely to use in practice. This is

another of the manufacturer„s attempts to make the product look better than it is!

Cutoff frequency

This is effectively the highest frequency of square wave that can be sent through the

Optoisolator. It is actually the frequency at which the output voltage is only swinging half the

amplitude than at DC levels (-3Db = half). It is therefore linked with the rise and fall times.

Current Transfer Ratio (CTR)

This is the ratio of how much collector current in the output transistor that you get given a

certain amount of forward current in the input side LED. It is affected by how close the LED

and phototransistor are inside the device, how efficient they both are, and many other factors.

In fact it is not a constant but varies wildly with LED forward current.



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CHAPTER 12:

MOSFET

The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET)

is a device used for amplifying or switching electronic signals. The basic principle of the

device was first proposed by Julius Edgar Lilienfeld in 1925. In MOSFET„s, a voltage on the

oxide-insulated gate electrode can induce a conducting channel between the two other

contacts called source and drain. The channel can be of n-type or p-type and is accordingly

called an nMOSFET or a pMOSFET. It is by far the most common transistor in both digital

and analog circuits, though the bipolar junction transistor was at one time much more

common. A variety of symbols are used for the MOSFET. The basic design is generally a line

for the channel with the source and drain leaving it at right angles and then bending back at

right angles into the same direction as the channel. Sometimes three line segments are used

for enhancement mode and a solid line for depletion mode. Comparison of enhancement-

mode and depletion-mode MOSFET symbols, along with JFET symbols (drawn with source

and drain ordered such that higher voltages appear higher on the page than lower voltages).

An example of using the MOSFET as a switch



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In this circuit arrangement an Enhancement-mode N-channel MOSFET is being used to switch a

simple lamp "ON" and "OFF" (could also be an LED). The gate input voltage VGS is taken to an

appropriate positive voltage level to turn the device and the lamp either fully "ON", (VGS = +ve)

or a zero voltage level to turn the device fully "OFF", (VGS = 0). If the resistive load of the lamp

was to be replaced by an inductive load such as a coil or solenoid, a "Flywheel" diode would be

required in parallel with the load to protect the MOSFET from any back-emf. Above shows a

very simple circuit for switching a resistive load such as a lamp or LED. But when using power

MOSFET's to switch either inductive or capacitive loads some form of protection is required to

prevent the MOSFET device from becoming damaged. Driving an inductive load has the opposite

effect from driving a capacitive load. For example, a capacitor without an electrical charge is a

short circuit, resulting in a high "inrush" of current and when we remove the voltage from an

inductive load we have a large reverse voltage build up as the magnetic field collapses, resulting

in an induced back-emf in the windings of the inductor. For the power MOSFET to operate as an

analogue switching device, it needs to be switched between its "Cut-off Region" where VGS = 0

and its "Saturation Region" where VGS (on) = +ve. The power dissipated in the MOSFET (PD)

depends upon the current flowing through the channel ID at saturation and also the "ON-

resistance" of the channel given as RDS (on).



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CHAPTER 13:

BRUSHLESS DC MOTOR

Brushless DC motors (BLDC motors, BL motors) also known as electronically

commutatedmotors (ECMs, EC motors) are synchronous electric motors powered by direct-

current (DC) electricity and having electronic commutation systems, rather than mechanical

commutators and brushes. The current-to-torque and frequency-to-speed relationships of

BLDC motors are linear

BLDC MOTOR

BLDC motors may be described as stepper motors, with fixed permanent magnets and

possibly more poles on the rotor than the stator, or reluctance motors. The latter may be

without permanent magnets, just poles that are induced on the rotor then pulled into

alignment by timed stator windings. However, the term stepper motor tends to be used for

motors that are designed specifically to be operated in a mode where they are frequently

stopped with the rotor in a defined angular position; this page describes more general BLDC

motor principles, though there is overlap.



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Brushless Versus Brushed Motor

Limitations of brushed DC motors overcome by BLDC motors include lower efficiency and

susceptibility of the commutator assembly to mechanical wear and consequent need for

servicing, at the cost of potentially less rugged and more complex and expensive

controlelectronics. BLDC motors develop maximum torque when stationary and have

linearly decreasing torque with increasing speed as shown in the adjacent figure

Brushless DC Electric Motor Torque-Speed Characteristics

A BLDC motor has permanent magnets which rotate and a fixed armature, eliminating the

problems of connecting current to the moving armature. An electronic controller replaces the

brush/commutator assembly of the brushed DC motor, which continually switches the phase

to the windings to keep the motor turning. The controller performs similar timed power

distribution by using a solid-state circuit rather than the brush/commutator system. BLDC

motors offer several advantages over brushed DC motors, including more torque per weight

and efficiency, reliability, reduced noise, longer lifetime (no brush and commutator erosion),

elimination of ionizing sparks from the commutator, more power, and overall reduction of

electromagnetic interference (EMI). With no windings on the rotor, they are not subjected to

centrifugal forces, and because the windings are supported by the housing, they can be cooled

by conduction, requiring no airflow inside the motor for cooling. This in turn means that the

motor's internals can be entirely enclosed and protected from dirt or other foreign matter. The

maximum power that can be applied to a BLDC motor is exceptionally high, limited almost



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exclusively by heat, which can weaken the magnets. (Magnets demagnetize at high

temperatures, the Curie point, and for neodymium-iron-boron magnets this temperature is

lower than for other types.) A BLDC motor's main disadvantage is higher cost, which arises

from two issues. First, BLDC motors require complex electronic speed controllers to run.

Brushed DC motors can be regulated by a comparatively simple controller, such as a rheostat

(variable resistor). However, this reduces efficiency because power is wasted in the rheostat.

Second, some practical uses have not been well developed in the commercial sector. For

example, in the Radio Control (RC) hobby, even commercial brushless motors are often

hand-wound while brushed motors use armature coils which can be inexpensively machine-

wound. (Nevertheless, see "Applications", below.) BLDC motors are often more efficient at

converting electricity into mechanical power than brushed DC motors. This improvement is

largely due to the absence of electrical and friction losses due to brushes. The enhanced

efficiency is greatest in the no-load and low-load region of the motor's performance curve.

Under high mechanical loads, BLDC motors and high-quality brushed motors are comparable

in efficiency. AC induction motors require induction of magnetic field in the rotor by the

rotating field of the stator; this results in the magnetic and electric fields being out of phase.

The phase difference requires greater current and current losses to achieve power. BLDC

motors are microprocessorcontrolled to keep the stator current in phase with the permanent

magnets of the rotor, requiring less current for the same effect and therefore resulting in

greater efficiency. In general, manufacturers use brush-type DC motors when low system cost

is a priority but brushless motors to fulfill requirements such as maintenance-free operation,

high speeds, and operation in explosive environments where sparking could be hazardous.

Applications:

Consumer electronics

Transport

Heating and ventilation

Industrial engineering

Model engineering



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CHAPTER 14:

IR LED

An IR LED, also known as IR transmitter, is a special purpose LED that transmits infrared

rays in the range of 760 nm wavelength. Such LEDs are usually made of gallium arsenide or

aluminum gallium arsenide. They, along with IR receivers, are commonly used as sensors.

The appearance is same as a common LED. Since the human eye cannot see the infrared

radiations, it is not possible for a person to identify whether the IR LED is working or not,

unlike a common LED. To overcome this problem, the camera on a cell phone can be used.

The camera can show us the IR rays being emanated from the IR LED in a circuit

Features

• Extra high radiant power

• low forward voltage

• suitable for high pulse current operation intensity

• high reliability

Chip Materials

• Dice Material : GaA1As/GaAs

• Lens Color : Water Clear



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Difference between white LED and IR LED

There are a couple key differences in the electrical characteristics of infrared LEDs versus

visible light LEDs. Infrared LEDs have a lower forward voltage, and a higher rated current

compared to visible LEDs. This is due to differences in the material properties of the

junction. A typical drive current for an infrared LED can be as high as 50 milliamps, so

dropping in a visible LED as a replacement for an infrared LED could be a problem with

some circuit designs. IR LEDs aren„t rated in millicandelas, since their output isn„t visible

(and candelas measure light in a way weighted to the peak of the visible spectrum). They are

usually rated in milliwatts, and conversions to candelas aren„t especially meaningful



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CHAPTER 15

PHOTODIODE

A photodiode is a type of photo detector capable of converting light into either current or

voltage, depending upon the mode of operation. Photodiodes are similar to regular

semiconductor diodes except that they may be either exposed (to detect vacuum UV or X-

rays) or packaged with a window or optical fibre connection to allow light to reach the

sensitive part of the device. Many diodes designed for use specifically as a photodiode will

also use a PIN junction rather than the typical PN junction

Principle of operation

A photodiode is a PN junction or PIN structure. When a photon of sufficient energy strikes

the diode, it excites an electron, thereby creating a mobile electron and a positively charged

electron hole. If the absorption occurs in the junction's depletion region, or one diffusion

length away from it, these carriers are swept from the junction by the built-in field of the

depletion region. Thus holes move toward the anode, and electrons toward the cathode, and a

photocurrent is produced.



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CHAPTER 16

LED

LEDs are semiconductor devices. Like transistors, and other diodes, LEDs are made out of

silicon. What makes an LED give off light are the small amounts of chemical impurities that

are added to the silicon, such as gallium, arsenide, indium, and nitride. When current passes

through the LED, it emits photons as a byproduct. Normal light bulbs produce light by

heating a metal filament until its white hot. Because LEDs produce photons directly and not

via heat, they are far more efficient than incandescent bulbs. Not long ago LEDs were only

bright enough to be used as indicators on dashboards or electronic equipment. But recent

advances have made LEDs bright enough to rival traditional lighting technologies. Modern

LEDs can replace incandescent bulbs in almost any application. LEDs are based on the

semiconductor diode. When the diode is forward biased (switched on), electrons are able to

recombine with holes and energy is released in the form of light. This effect is called

electroluminescence and the color of the light is determined by the energy gap of the

semiconductor. The LED is usually small in area (less than 1 mm2) with integrated optical

components to shape its radiation pattern and assist in reflection.

LEDs present many advantages over traditional light sources including lower energy

consumption, longer lifetime, improved robustness, smaller size and faster switching.

However, they are relatively expensive and require more precise current and heat

management than traditional light sources. Applications of LEDs are diverse. They are used

as low-energy and also for replacements for traditional light sources in well-established

applications such as indicators and automotive lighting. The compact size of LEDs has

allowed new text and video displays and sensors to be developed, while their high switching

rates are useful in communications technology. So here the role of LED is to indicate the

status of the components like relays and power circuit etc…



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CHAPTER 17

RESISTORS

A resistor is a two-terminal electronic component designed to oppose an electric current by

producing a voltage drop between its terminals in proportion to the current, that is, in

accordance with Ohm's law: V = IR Resistors are used as part of electrical networks and

electronic circuits. They are extremely commonplace in most electronic equipment. Practical

resistors can be made of various compounds and films, as well as resistance wire (wire made

of a high-resistivity alloy, such as nickel/chrome). The primary characteristics of resistors are

their resistance and the power they can dissipate. Other characteristics include temperature

coefficient, noise, and inductance. Less wellknown is critical resistance, the value below

which power dissipation limits the maximum permitted current flow, and above which the

limit is applied voltage. Critical resistance depends upon the materials constituting the

resistor as well as its physical dimensions; it's determined by design. Resistors can be

integrated into hybrid and printed circuits, as well as integrated circuits. Size, and position of

leads (or terminals) are relevant to equipment designers; resistors must be physically large

enough not to overheat when dissipating their power.

A resistor is a two-terminal passive electronic component which implements electrical

resistance as a circuit element. When a voltage V is applied across the terminals of a resistor,



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a current I will flow through the resistor in direct proportion to that voltage. The reciprocal of

the constant of proportionality is known as the resistance R, since, with a given voltage V, a

larger value of R further "resists" the flow of current I as given by Ohm's law: Resistors are

common elements of electrical networks and electronic circuits and are ubiquitous in most

electronic equipment. Practical resistors can be made of various compounds and films, as

well as resistance wire (wire made of a high-resistivity alloy, such as nickel-chrome).

Resistors are also implemented within integrated circuits, particularly analog devices, and can

also be integrated into hybrid and printed circuits. The electrical functionality of a resistor is

specified by its resistance: common commercial resistors are manufactured over a range of

more than 9 orders of magnitude. When specifying that resistance in an electronic design, the

required precision of the resistance may require attention to the manufacturing tolerance of

the chosen resistor, according to its specific application. The temperature coefficient of the

resistance may also be of concern in some precision applications. Practical resistors are also

specified as having a maximum power rating which must exceed the anticipated power

dissipation of that resistor in a particular circuit: this is mainly of concern in power

electronics applications. Resistors with higher power ratings are physically larger and may

require heat sinking. In a high voltage circuit, attention must sometimes be paid to the rated

maximum working voltage of the resistor. The series inductance of a practical resistor causes

its behavior to depart from ohms law; this specification can be important in some high-

frequency applications for smaller values of resistance. In a low-noise amplifier or pre-amp

the noise characteristics of a resistor may be an issue. The unwanted inductance, excess

noise, and temperature coefficient are mainly dependent on the technology used in

manufacturing the resistor. They are not normally specified individually for a particular

family of resistors manufactured using a particular technology. A family of discrete resistors

is also characterized according to its form factor, that is, the size of the device and position of

its leads (or terminals) which is relevant in the practical manufacturing of circuits using them.



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CHAPTER 18

CAPACITORS

A capacitor or condenser is a passive electronic component consisting of a pair of conductors

separated by a dielectric. When a voltage potential difference exists between the conductors,

an electric field is present in the dielectric. This field stores energy and produces a

mechanical force between the plates. The effect is greatest between wide, flat, parallel,

narrowly separated conductors. An ideal capacitor is characterized by a single constant value,

capacitance, which is measured in farads. This is the ratio of the electric charge on each

conductor to the potential difference between them. In practice, the dielectric between the

plates passes a small amount of leakage current. The conductors and leads introduce an

equivalent series resistance and the dielectric has an electric field strength limit resulting in a

breakdown voltage. The properties of capacitors in a circuit may determine the resonant

frequency and quality factor of a resonant circuit, power dissipation and operating frequency

in a digital logic circuit, energy capacity in a high-power system, and many other important

A capacitor (formerly known as condenser) is a device for storing electric charge. The forms

of practical capacitors vary widely, but all contain at least two conductors separated by a

nonconductor. Capacitors used as parts of electrical systems, for example, consist of metal

foils separated by a layer of insulating film. Capacitors are widely used in electronic circuits

for blocking direct current while allowing alternating current to pass, in filter networks, for

smoothing the output of power supplies, in the resonant circuits that tune radios to particular

frequencies and for many other purposes. A capacitor is a passive electronic component

consisting of a pair of conductors separated by a dielectric (insulator). When there is a



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potential difference (voltage) across the conductors, a static electric field develops in the

dielectric that stores energy and produces a mechanical force between the conductors. An

ideal capacitor is characterized by a single constant value, capacitance, measured in farads.

This is the ratio of the electric charge on each conductor to the potential difference between

them. The capacitance is greatest when there is a narrow separation between large areas of

conductor, hence capacitor conductors are often called "plates", referring to an early means of

construction. In practice the dielectric between the plates passes a small amount of leakage

current and also has an electric field strength limit, resulting in a breakdown voltage, while

the conductors and leads introduce an undesired inductance and resistance.

Theory of operation

Capacitance

Charge separation in a parallel-plate capacitor causes an internal electric field. A dielectric

(orange) reduces the field and increases the capacitance

A simple demonstration of a parallel-plate capacitor



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A capacitor consists of two conductors separated by a non-conductive region. The

nonconductive region is called the dielectric or sometimes the dielectric medium. In simpler

terms, the dielectric is just an electrical insulator. Examples of dielectric mediums are glass,

air, paper, vacuum, and even a semiconductor depletion region chemically identical to the

conductors. A capacitor is assumed to be self-contained and isolated, with no net electric

charge and no influence from any external electric field. The conductors thus hold equal and

opposite charges on their facing surfaces, and the dielectric develops an electric field. In SI

units, a capacitance of one farad means that one coulomb of charge on each conductor causes

a voltage of one volt across the device. The capacitor is a reasonably general model for

electric fields within electric circuits. An ideal capacitor is wholly characterized by a constant

capacitance C, defined as the ratio of charge ±Q on each conductor to the voltage V between

them: Sometimes charge build-up affects the capacitor mechanically, causing its capacitance

to vary. In this case, capacitance is defined in terms of incremental changes: Energy storage

Work must be done by an external influence to "move" charge between the conductors in a

capacitor. When the external influence is removed the charge separation persists in the

electric field and energy is stored to be released when the charge is allowed to return to its

equilibrium position. The work done in establishing the electric field, and hence the amount

of energy stored, is given by: Current-voltage relation The current i(t) through any

component in an electric circuit is defined as the rate of flow of a charge q(t) passing through

it, but actual charges, electrons, cannot pass through the dielectric layer of a capacitor, rather

an electron accumulates on the negative plate for each one that leaves the positive plate,

resulting in an electron depletion and consequent positive charge on one electrode that is

equal and opposite to the accumulated negative charge on the other. Thus the charge on the

electrodes is equal to the integral of the current as well as proportional to the voltage as

discussed above. As with any antiderivative, a constant of integration is added to represent

the initial voltage v (t0). This is the integral form of the capacitor equation, . Taking the

derivative of this, and multiplying by C, yields the derivative form, The dual of the capacitor

is the inductor, which stores energy in the magnetic field rather than the

electric field. Its current-voltage relation is obtained by exchanging current and voltage in the

capacitor equations and replacing C with the inductance L



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CHAPTER 19

RF MODULE

What is RF?

RF itself has become synonymous with wireless and high-frequency signals, describing

anything from AM radio between 535 kHz and 1605 kHz to computer local area networks

(LANs) at 2.4 GHz. However, RF has traditionally defined frequencies from a few kHz to

roughly 1 GHz. If one considers microwave frequencies as RF, this range extends to 300

GHz. The following two tables outline the various nomenclatures for the frequency bands.

The third table outlines some of the applications at each of the various frequency bands

Features

• Range in open space(Standard Conditions) : 100 Meters

• RX Receiver Frequency : 433 MHz

• RX Typical Sensitivity : 105 Dbm

• RX Supply Current : 3.5 Ma

• RX IF Frequency : 1MHz

• Low Power Consumption

• Easy For Application

• RX Operating Voltage : 5V

• TX Frequency Range : 433.92 MHz

• TX Supply Voltage : 3V ~ 6V

• TX Out Put Power : 4 ~ 12 Dbm



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RF TRANSMITTER

315/433 MHz TRANSMITTER

General Description: The ST-TX01-ASK is an ASK Hybrid transmitter module. ST-

TX01-ASK is designed by the Saw Resonator, with an effective low cost, small size,

and simple-to-use for designing. Frequency Range: 315 / 433.92 MHZ. Supply

Voltage: 3~12V. Output Power: 4~16dBm Circuit Shape: Saw



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RF RECEIVER

315/434 MHz ASK RECEIVER

General Description:

The ST-RX02-ASK is an ASK Hybrid receiver module. A effective low cost solution for using at

315/433.92 MHZ. The circuit shape of ST-RX02-ASK is L/C. Receiver Frequency: 315 / 433.92

MHZ Typical sensitivity: -105dBm

Supply Current: 3.5mA IF Frequency: 1MHz

Features:

﹣20℃～＋70℃

age: 5 Volts.



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CHAPTER 20

PWM

Pulse-width modulation (PWM) is a commonly used technique for controlling power to an

electrical device, made practical by modern electronic power switches. The average value of

voltage (and current) fed to the load is controlled by turning the switch between supply and

load on and off at a fast pace. The longer the switch is on compared to the off periods, the

higher the power supplied to the load is. The PWM switching frequency has to be much

faster than what would affect the load, which is to say the device that uses the power.

Typically switching„s have to be done several times a minute in an electric stove, 120 Hz in a

lamp dimmer, from few kilohertz (kHz) to tens of kHz for a motor drive and well into the

tens or hundreds of kHz in audio amplifiers and computer power supplies. The term duty

cycle describes the proportion of on time to the regular interval or period of time; a low duty

cycle corresponds to low power, because the power is off for most of the time. Duty cycle is

expressed in percent, 100% being fully on. The main advantage of PWM is that power loss in

the switching devices is very low. When a switch is off there is practically no current, and

when it is on, there is almost no voltage drop across the switch. Power loss, being the product

of voltage and current, is thus in both cases close to zero. PWM works also well with digital

controls, which, because of their on/off nature, can easily set the needed duty cycle. PWM

has also been used in certain communication systems where its duty cycle has been used to

convey information over a communications channel.



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Power delivery

Variable-speed fan controllers for computers usually use PWM, as it is far more efficient

when compared to a potentiometer or rheostat. (Neither of the latter is practical to operate

electronically; they would require a small drive motor). Light dimmers for home use employ

a specific type of PWM control. Home use light dimmers typically include electronic

circuitry which suppresses current flow during defined portions of each cycle of the AC line

voltage. Adjusting the brightness of light emitted by a light source is then merely a matter of

setting at what voltage (or phase) in the AC half cycle the dimmer begins to provide electrical

current to the light source (e.g. by using an electronic switch such as a triac). In this case the

PWM duty cycle is the ratio of the conduction time to the duration of the half AC cycle

defined by the frequency of the AC line voltage (50 Hz or 60 Hz depending on the country).

These rather simple types of dimmers can be effectively used with inert (or relatively slow

reacting) light sources such as incandescent lamps, for example, for which the additional

modulation in supplied electrical energy which is caused by the dimmer causes only

negligible additional fluctuations in the emitted light. Some other types of light sources such

as lightemitting diodes (LEDs), however, turn on and off extremely rapidly and would

perceivably flicker if supplied with low frequency drive voltages. Perceivable flicker effects

from such rapid response light sources can be reduced by increasing the PWM frequency. If

the light fluctuations are sufficiently rapid, the human visual system can no longer resolve

them and the eye perceives the time average intensity without flicker (see flicker fusion

threshold). In electric cookers, continuously-variable power is applied to the heating elements

such as the hob or the grill using a device known as a Simmertat. This consists of a thermal

oscillator running at approximately two cycles per minute and the mechanism varies the duty

cycle according to the knob setting. The thermal time constant of the heating elements is

several minutes, so that the temperature fluctuations are too small to matter in practice.

Applications

1) Telecommunications

2) Power delivery

3) Voltage regulation

4) Audio effects and amplification



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CHAPTER 21

SOFTWARE REQUIREMENTS

INTRODUCTION TO KEIL MICRO VISION (IDE):

Keil an ARM Company makes C compilers, macro assemblers, real-time kernels, debuggers,

simulators, integrated environments, evaluation boards, and emulators for

ARM7/ARM9/Cortex- M3, XC16x/C16x/ST10, 251, and 8051 MCU families. Keil

development tools for the 8051 Microcontroller Architecture support every level of software

developer from the professional applications engineer to the student just learning about

embedded software development. When starting a new project, simply select the

microcontroller you use from the Device Database and the μVision IDE sets all compiler,

assembler, linker, and memory options for you. Keil is a cross compiler. So first we have to

understand the concept of compilers and cross compilers. After then we shall learn how to

work with keil

CONCEPT OF COMPILER

Compilers are programs used to convert a High Level Language to object code. Desktop

compilers produce an output object code for the underlying microprocessor, but not for other

microprocessors. I.E the programs written in one of the HLL like ‗C„ will compile the code

to run on the system for a particular processor like x86 (underlying microprocessor in the

computer). For example compilers for Dos platform is different from the Compilers for Unix

platform So if one wants to define a compiler then compiler is a program that translates

source code into object code. The compiler derives its name from the way it works, looking at

the entire piece of source code and collecting and reorganizing the instruction. See there is a

bit little difference between compiler and an interpreter. Interpreter just interprets whole

program at a time while compiler analyses and execute each line of source code in

succession, without looking at the entire program. The advantage of interpreters is that they

can execute a program immediately. Secondly programs produced by compilers run much

faster than the same programs executed by an interpreter. However compilers require some

time before an executable program emerges. Now as compilers translate source code into



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object code, which is unique for each type of computer, many compilers are available for the

same language

CONCEPT OF CROSS COMPILER

A cross compiler is similar to the compilers but we write a program for the target processor

(like 8051 and its derivatives) on the host processors (like computer of x86). It means being

in one environment you are writing a code for another environment is called cross

development. And the compiler used for cross development is called cross compiler. So the

definition of cross compiler is a compiler that runs on one computer but produces object code

for a different type of computer

KEIL C CROSS COMPILER

Keil is a German based Software development company. It provides several development

tools like

• IDE (Integrated Development environment)

• Project Manager

• Simulator

• Debugger

• C Cross Compiler, Cross Assembler, Locator/Linker

The Keil ARM tool kit includes three main tools, assembler, compiler and linker. An

assembler is used to assemble the ARM assembly program. A compiler is used to compile the

C source code into an object file. A linker is used to create an absolute object module suitable

for our incircuit emulator



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CHAPTER 22

SCHEMATIC DIAGRAM



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CHAPTER 23:

CIRCUIT DIAGRAM:

TRANSMITTING UNIT

RECEIVING UNIT:



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CHAPTER 24:

POWER SUPPLY:

Step down transformer Bridge rectifier Filter Regulator

The 230V AC supply is first stepped down to 12V AC using a step down transformer.

This is then converted to DC using bridge rectifier.

The AC ripples is filtered out by using a capacitor and given to the input pin of

voltage regulator 7805.

At output pin of this regulator we get a constant 5V DC which is used for MC and

other ICs in this project

The circuit uses standard power supply comprising of a step-down transformer from 230Vto

12V and 4 diodes forming a bridge rectifier that delivers pulsating dc which is then filtered

by an electrolytic capacitor of about 470μF to 1000μF. The filtered dc being unregulated, IC

LM7805 is used to get 5V DC constant at its pin no 3 irrespective of input DC varying from

7V to 15V. The input dc shall be varying in the event of input ac at 230volts section varies

from 160V to 270V in the ratio of the transformer primary voltage V1 to secondary voltage

V2 governed by the formula V1/V2=N1/N2. As N1/N2 i.e. no. of turns in the primary to the

no. of turns in the secondary remains unchanged V2 is directly proportional to V1.Thus if the

transformer delivers 12V at 220V input it will give 8.72V at 160V.Similarly at 270V it will

give 14.72V.Thus the dc voltage at the input of the regulator changes from about 8V to 15V

because of A.C voltage variation from 160V to 270V the regulator output will remain

constant at 5V. The regulated 5V DC is further filtered by a small electrolytic capacitor of



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10μF for any noise so generated by the circuit. One LED is connected of this 5V point in

series with a current limiting resistor of 330Ω to the ground i.e., negative voltage to indicate

5V power supply availability. The unregulated 12V point is used for other applications as and

when required.

STANDARD CONNECTIONS TO 8051 SERIES MICRO CONTROLLER:

ATMEL series of 8051 family of micro controllers need certain standard connections. The

actual number of the Microcontroller could be ―89C51‖ , ―89C52‖, ―89S51‖, ―89S52‖,

and as regards to 20 pin configuration a number of ―89C2051‖. The 4 set of I/O ports are

used based on the project requirement. Every microcontroller requires a timing reference for

its internal program execution therefore an oscillator needs to be functional with a desired

frequency to obtain the timing reference as t =1/f. A crystal ranging from 2 to 20 MHz is

required to be used at its pin number 18 and 19 for the internal oscillator. It may be noted

here the crystal is not to be understood as crystal oscillator It is just a crystal, while connected

to the appropriate pin of the microcontroller it results in oscillator function inside the

microcontroller. Typically 11.0592 MHz crystal is used in general for most of the circuits

using 8051 series microcontroller. Two small value ceramic capacitors of 33pF each is used

as a standard connection for the crystal as shown in the circuit diagram

RESET:

Pin no 9 is provided with an re-set arrangement by a combination of an electrolytic capacitor

and a register forming RC time constant. At the time of switch on, the capacitor gets charged,

and it behaves as a full short circuit from the positive to the pin number 9. After the capacitor

gets fully charged the current stops flowing and pin number 9 goes low which is pulled down

by a 10k resistor to the ground. This arrangement of reset at pin 9 going high initially and

then to logic 0 i.e., low helps the program execution to start from the beginning. In absence of

this the program execution could have taken place arbitrarily anywhere from the program

cycle. A pushbutton switch is connected across the capacitor so that at any given time as

desired it can be pressed such that it discharges the capacitor and while released the capacitor

starts charging again and then pin number 9 goes to high and then back to low, to enable the

program execution from the beginning. This operation of high to low of the reset pin takes



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place in fraction of a second as decided by the time constant R and C. For example: A 10μF

capacitor and a 10kΩ resistor would render a 100ms time to pin number 9 from logic high to

low, there after the pin number 9 remains low.

External Access(EA):

Pin no 31 of 40 pin 8051 microcontroller termed as EA¯ is required to be connected to 5V

for accessing the program form the on-chip program memory. If it is connected to ground

then thecontroller accesses the program from external memory. However as we are using the

internal memory it is always connected to +5V.

OPTOCOUPLER:

Opto coupler is a 6 pin IC. It is a combination of 1 LED and a transistor. Pin 6 of transistor is not

generally used and when light falls on the Base-Emitter junction then it switches and pin5 goes to

zero. If input of the diode is zero and other end of diode is GND then the output is one.

which gives logic zero as output.

n as input then light falls on transistor so that it conducts, that makes

transistor switched ON and it forms short circuit this makes the output is logic zero as collector of

transistor is connected to ground



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CHAPTER 25:

OPERATION

CONNECTIONS:

A 230v-12v step down transformer is connected to the bridge rectifier, a blocking diode is

connected at the output of bridge rectifier, a 100 mf capacitor is connected after blocking

diode, a 7805 voltage regulator is connected after 1000mf capacitor, a 10mf capacitor is

connected at the output of voltage regulator, a red LED is connected with a series resistor

330ohms. Now +5v dc is generated at the output of voltage regulator The 40th pin of micro

controller is connected to the +5v dc and 20th pin of controller is connected to the ground. A

crystal oscillator is connected at 18th and 19th pins of controller, a push button is connected

at 19th pin of controller, a 10micro farad„s capacitor is connected across the push button, a

10k resistor is connected to the 19th pin and grounded two 33pf capacitor are connected at

the crystal pins. Keypads are connected to port 1 of each microcontroller, 3 control pins of

LCD are connected to port 3.5 to 3.7 of all MCs and 8 data pins of the LCD are connected to

port 2. LCD 16th pin is GND and 2nd and 15th pins are connected to Vcc. The anode of IR

LED is connected to Vcc via 220ohms resistors, cathode is GND. The cathode of photo diode

is connected to Vcc through 1k resistor, anode is connected to a variable resistor 1k & third

pin of variable resistor is connected to base of a n-p-n transistor, emitter is grounded and

collector is connected to 12th pin of micro controller, being pulled up with 2.2k resistor. The

output pin of micro controller i.e. P0.7 is connected to the 2nd pin of opto isolator & 1 pin of

the opto is connected to 5volt +ve via a resistor of 330 ohms. Pin 4 & 5 that works like a

switch of the opto feeds a MOSFET that is wired to operate the BLDC motor as per the

circuit. Pin 11 of master MC is connected to pin 10 of slave-1 MC. The 11th pin of slave-1

MC is connected to pin 10 of slave-2 MC.

While logic high during the on time duty cycle is delivered by the microcontroller to the input

of the OPTO U3 , The opto led glows to bring the opto transistor pin no 5 and 6 to conduct .

Now 12V supply is given at the junction point of R7 and R8 and reaches the gate of the

mosfet Q1 via D4 for Q1 to conduct thus enabling the motor to get supply to run. A

freewheel diode isused across the motor to conduct the charge stored in the motor during off

period. During off time of the duty cycle the opto transistor does not conduct and the charge



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which is stored in the gate of Q1 forces Q3 to conduct while the motor stops. This ON and

OFF the motor reduces the speed . The DC power is available to the motor via the MOSFET

as per the PWM generated by micro controller depending upon the input given to micro

controller from a keypad. As well as the speed is displayed on a liquid crystal display. To

sense the speed of BLDC motor an IR LED in photo diode arrangement is used. The value of

speed is changed in percentage by using fuzzy logic. Fuzzy logic is something i.e.

approximate but not accurate. So a program is written in to micro controller that uses fuzzy

logic due to which we get the values almost equal to accurate values. A 230v -12v step down

transformer is used to decrease AC supply voltage to 12v, now this ac voltage is rectified by

using a full wave bridge rectifier, a blocking diode is used before the filter capacitor to get the

pulsating D.C. to get the fixed output D.C a 7805 voltage regulator is employed because

micro controller fixed +5v pure DC. To filter pulsating D.C an electrolytic capacitor of value

470 micro farad„s or 1000micro farads is connected at the input of 7850. One more

electrolytic capacitor is connected at the output of 7850 to remove complete ripple„s if there

any +5v D.C. A LED with series resistors is connected to indicate the power. Micro

controller has to generate PWM pulses as per error signal received from the speed sensing

input to match the keyboard input in order to run the motor at the input RPM. A push button

is connected at the 9th pin of micro controller which is known as reset a 10 micro farad„s

electrolytic capacitor is connected across the button and a 10k resistor is used to pull down

9th pin of micro controller. When this reset pin is pressed during the operation , the program

written in micro controller starts from beginning A crystal across oscillator of value 11.0592

MHz is connected across 18th & 19th pins of micro controller with the 33pico farad„s

ceramic capacitors are connected for stabilising it

To sense the speed of BLDC motor an infrared(IR) diode and photo diode are used. When

light falls on photo diode the resistance across it decreases and vice versa. Hence photo diode

is employed in a potential divider with a variable resistor. This potential divider supplies

voltage to an N-P-N transistor whose collector is connected to micro controller input. So, the

IR LED and photo diode are placed near the shaft of BLDC motor and a white spot is made

on the shaft infrared light gets reflected by white colour and the reflected light keeps falling

on photo diode, due to which the voltage across it keeps changing thereafter the voltage at

base of transistor also changes therefore at the collector of transistor a pulse is generated

which is given to micro controller for counting the number of rotations per minute of D.C



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motor. This sensed speed is displayed on LCD in rpm. To change the speed a keypad is used

as an input to the micro controller. By using this we can enter how much percentage of speed

would be required for the motor to run. Pressing ‗#„ twice the maximum running speed is

stored. After which pressing ‗*„ the desired percentage of speed is entered. There after

pressing # the desired speed is saved which are displayed on the LCD. There after the on time

of the pulse width progressively goes on reducing to result the speed reduction. Speed sensors

continuously send the error signal to pin 12 of the MC to lock the running speed of the motor

at the desired speed. This desired speed is sent to the receiver1and receiver2 through RF

communication. Receivers get the desired speed from the transmitter and run the motor at

that speed by controlling the pulse width modulation



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CHAPTER 26:

FLOW CHART:

OPERATION PROCEDURE

1. Press „#‟ once display shows the store Max RPM.

2. Press „#‟ again to store Max.RPM.

3. Press „*‟ to get the required RPM. Display shows % of Req_RPM:

4. Enter the required percentage using Keypad. 5. Press „#‟ to save the required RPM



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HARDWARE COMPONENT:

HARDWARE TESTING

CONTINUITY TEST:

In electronics, a continuity test is the checking of an electric circuit to see if current flows

(that it is in fact a complete circuit). A continuity test is performed by placing a small voltage

(wired in series with an LED or noise-producing component such as a piezoelectric speaker)

across the chosen path. If electron flow is inhibited by broken conductors, damaged



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components, or excessive resistance, the circuit is "open". Devices that can be used to

perform continuity tests include multi meters which measure current and specialized

continuity testers which are cheaper, more basic devices, generally with a simple light bulb

that lights up when current flows. An important application is the continuity test of a bundle

of wires so as to find the two ends belonging to a particular one of these wires; there will be a

negligible resistance between the "right" ends, and only between the "right" ends. This test is

the performed just after the hardware soldering and configuration has been completed. This

test aims at finding any electrical open paths in the circuit after the soldering. Many a times,

the electrical continuity in the circuit is lost due to improper soldering, wrong and rough

handling of the PCB, improper usage of the soldering iron, component failures and presence

of bugs in the circuit diagram. We use a multi meter to perform this test. We keep the multi

meter in buzzer mode and connect the ground terminal of the multi meter to the ground. We

connect both the terminals across the path that needs to be checked. If there is continuation

then you will hear the beep sound

POWER ON TEST:

This test is performed to check whether the voltage at different terminals is according to the

requirement or not. We take a multi meter and put it in voltage mode. Remember that this test

is performed without microcontroller. Firstly, we check the output of the transformer,

whether we get the required 12 v AC voltage. Then we apply this voltage to the power supply

circuit. Note that we do this test without microcontroller because if there is any excessive

voltage, this may lead to damaging the controller. We check for the input to the voltage

regulator i.e., are we getting an input of 12v and an output of 5v. This 5v output is given to

the microcontrollers„ 40th pin. we check for the other terminals for the required voltage. In

this way we can assure that the voltage at all the terminals is as per the requirement.



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Observations and Conclusion:

We can Tabulate different speeds of motor as we keep on giving input from the Keypad and

same speed change can be observed and displayed at the receiving motors. From this project

we can successfully control the speed of multiple motors wirelessly through RF

communication. Whatever the percentage of speed that we enter at transmitter unit of system

same can be observed at the receiving motors.The whole operation is made simple by using

this technology. The future works include giving intelligence to the whole system like if any

of the motor senses any fault, the whole system will shutdown By using this technique speed

of two D.C. motors can be synchronized easily by adjusting set point. Master controller sets

the required speed and communicates with two slaves. Speed sensing is done by proximity

sensor.When data from master controller is given to slave controller then that is taken as set

point of the speed hence when system is started the slave micro controller is trying to achieve

the required speed. The purpose to measure speed is to give the system feedback about speed

so that required speed can be achieved by controlling firing angle that is PWM technique

with the help of solid state relay(SSR). The keypad entry flexibility provides us easy

calibration of the system to compare the different operation. Hence this technique of

synchronization can be used in textile industries



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REFERENCE:

TEXT BOOKS REFERED:

1. ―The 8051 Microcontroller and Embedded systems‖ by Muhammad Ali Mazidi and

Janice Gillispie Mazidi , Pearson Education.

2. ATMEL 89S52 Data Sheets.

WEBSITES

www.atmel.com

www.beyondlogic.org

www.wikipedia.org

www.howstuffworks.com

www.alldatasheets.com

[1] PEREZ-PINAL, NUNEZ, C., ALVAREZ, R., CERVANTES, I., “COMPARISON OF

MULTI- MOTOR SYNCHRONIZATION

TECHNIQUES INDUSTRIAL ELECTRONICS SOCIETY”, 30TH ANNUAL

ONFERENCE OF IEEE VOLUME: 2, PP 1670 – 1675, VOL.

2 23, MAY 2005‟

[2] ASHAB MIRZA, DR. SARFRAZ HUSSIAN, “D.C. MOTOR SPEED

SYNCHRONIZATION IN NON LINEAR PROCESS BY

SELECTIVE STATE FEEDBACK & INTEGRAL CONTROL”, PAKISTAN NAVY

ENGG. COLLEGE, NATIONAL UNIVERSITY OF

SCIENCES & TECHNOLOGY (NUST), JAUHAR, 13TH APRIL 2001.

[3] K. BOUDJIT, “REAL-TIME DIGITAL CONTROL USING DSP OF A MULTIPLE

MOTORS SYSTEM”, JOURNAL OF

ELECTRICAL SYSTEMS SPECIAL ISSUE NO. 01, 2009.

[4] FANG HE, WEIMING TONG, QIANG WANG, “SYNCHRONIZATION CONTROL

STRATEGY OF MULTI-MOTOR SYSTEM

BASED ON PROFIBUS NETWORK”. VOL; 1, PP 3029 – 3034, 08 OCTOBER 2007

Ankur Shukla et al. Int. Journal of Engineering Research and Applications www.ijera.com

ISSN : 2248-9622, Vol. 5, Issue 5, ( Part -3) May 2015, pp.

www.ijera.com 1 | P a g e

Speed Synchronization of Multiple Bldc motors In Textile &

Paper Mills Using Micro Controller

Ankur Shukla1, Ankit Kumar

2, Anil Kumar Rajak

3,Vivek Kumar Singh

4,

Santhosh S5

1234 Research Scholar Department of Electrical & Electronics, NHCE, Bangalore, India

5 Asst. Professor Department of Electrical & Electronics, NHCE, Bangalore, India,

Abstract Multiple motor setup has vast application in industries. The application can be in textile mills, paper mills and

robotics. In these all application the synchronization is must between the motors to perform certain task. Speed

synchronization is very essential in these all operation to avoid damage to the product. The synchronization is

done by using microcontroller chip which controls the master slave whose speed is followed by the other motors

which all have to be synchronized.

Index Terms—Speed synchronization, textile mills, paper mills, microcontroller chip, master slave.

I. INTRODUCTION In this project motors are wirelessly

synchronized to make the differential speed error

among multiple motors to zero. One motor acts here

as transmitter and rest of all as receivers. so, if a

particular speed is set in the transmitter then

automatically rest of the motors speed would be

matched to the same speed of the master slave.A

display unit connected with the module will display

the full speed in rpm and the observer can enter the

required percentage with help of a keypad to obtain

the required speed for rest of the motors. The pulse

width output from the microcontroller would be

automatically adjusted by the microcontroller to

maintain the DC power to the motor such that the

entered speed percentage matches the running RPM.

The above operation is taken care by using OPTO

isolator and a MOSFET connected to motor.The aim

of this project is synchronization of multiple motor

System by making use of wireless technology. This

project uses radio frequency to synchronize different

motors speeds. This system is used in many

industries like textile mills, steel plants, and paper

plants where large numbers of the motors used on

conveyor are desired to be synchronized for

performing certain task. In paper mills & textile mills

where multiple motors work together on a conveyor

belt to draw clothes, it is desirable that all the motors

should run at same speed, so that balanced tension

can be achieved to avoid

damage to the clothes. Manpower and time is also

saved in this arrangement. User can set the desired

rpm for the motors. As this system is Wireless, it is

easy to operate and control the system which eases

the whole process. The speed synchronization of

multiple motor arrangements is very important task

which is here carried out wirelessly by using

microcontroller chip. Due to wireless connection

between the motors the motors can be kept in any

position it is not necessary as earlier old concept of

conveyor belt that the motors should be kept only on

parallel series or mixed. with each other.Multiple

motors used in textile industries & paper mills or any

other for cloth drawing or to pull the paper as in

paper mill need to be synchronized for same speed.

Traditionally we use conveyor belts in order to

synchronize multiple motor for such works. But that

has many draw backs. This can be come over by

using the wireless synchronization of multiple

motors.

Drawbacks of using conveyor belt for speed

synchronization. [Earlier Method]

• The master slave [main motor] will be the

hardest to start, stop and maintain smooth motion

on the whole process.

• All the motors should be connected in Parallel.

• As there are moving elements like belts between

the motors, we need to change then if it is not

serviceable and regular service in also required

when they will get damage.

• The design of master slave or follower motors in

the system may be series, branch, or mixed.

• Again the system and its product will determine

what piece of equipment is directly synched or

digitally rationed to each other piece of

equipment.

Maintenance is bit difficult as there are more

mechanical parts in the system.

Solution for old Concept of Conveyor Belt: There are so many other different techniques for

the solution this problem. But those are not that

reliable. In order to reduce man intervention and save

RESEARCH ARTICLE OPEN ACCESS




the labor cost and time both we can use

microcontroller to control, operate and synchronize

this task. As compared to conveyor belt method is

compatible as it involves hardware as well as

software in this module. We can program

microcontroller to control its speed and also can set

the required speed through keypad to get our work

done. Synchronization can done either wired or

wirelessly. In this project we are using RF

communication technology for wireless

communication.

II. HARDWARE REQUIREMENTS: 8051 series Microcontroller, Crystal, RF

MODULE, LEDs, Resistors, Capacitors, Diodes,

Transformer, Voltage Regulator, IR sensor,

MOSFET, Keypad, Transistor, OPTO-isolator,

BLDC fan.

III. SOFTWARE REQUIREMENTS: MPLAB & CCS C compiler. Language:

Embedded C or Assembly.

IV. BLOCK DIAGRAM FOR

TRANSMITTING UNIT:

V. BLOCK DIAGRAM FOR RECEVER

UNIT:

VI. BLOCK DIAGRAM FOR

RECIEVER UNIT:




VII. HARDWARE COMPONET:

VIII. WORKING OF PROJECT: The speed of the motor is sensed by an IR pair

and is displayed on LCD and is also fed to the

MC.

The required speed is entered using a keypad

which is interfaced with MC.

The motor is interfaced to the MC through a

opto-coupler & a MOSFET which drives the

motor.

PWM pulses are generated from MC according

to the entered speed and the motor is adjusted to

that speed and maintained at that speed.

IX. FLOW CHART:




X. SOFTWARE REQUIRED: Keil an ARM Company makes C compilers,

macro assemblers, real-time kernels, debuggers,

simulators, integrated environments, evaluation

boards, and emulators for ARM7/ARM9/Cortex-

M3, XC16x/C16x/ST10, 251, and 8051 MCU

families.

Compilers are programs used to convert a High

Level Language to object code. Desktop

compilers produce an output object code for the

underlying microprocessor, but not for other

microprocessors.

i.e., the programs written in one of the HLL like

‘C’ will compile the code to run on the system

for a particular processor like x86 (underlying

microprocessor in the computer).

For example compilers for Dos platform is

different from the Compilers for Unix

platform So if one wants to define a compiler

then compiler is a program that translates source

code into object code.

XI. ADVANTAGE OF USING BLDC

MOTOR OVER BRUSHED DC

MOTOR: The BLDC motor has to many advantages over the

brushed DC motor which is shown below:

Higher efficiency and reliability

Lower acoustic noise due to absence of brushes

Smaller and lighter

Greater dynamic response

Better speed versus torque characteristics

Higher speed range

Longer life span

XII. OBSERVATIONS AND

CONCLUSION: We can tabulate different-different speeds of

motor as we keep on giving input from the Keypad

and same speed change can be observed and

displayed at the receiving motors. From this project

we can successfully control the speed of multiple

motors wirelessly through RF communication.

Whatever the percentage of speed that we enter at

transmitter unit of system same can be observed at

the receiving motors. The whole operation is made

simple by using this technology. The future works

include giving intelligence to the whole system like if

any of the motor senses any fault, the whole system

will shut down.

REFERENCES: [1]. MOTOR SELECTION for BELT-

CONVEYOR DRIVES by Garry E.

Paulson, P. Eng.

[2]. http://www.bonfiglioli.com/en/industrial/app

lications/conveyors/

[3]. Unique Conveyor Problems and Solutions :-

Fenner Dunlop

[4]. The Use of PIC Microcontrollers in Multiple

DC Motors Control Applications By Dr.

Steve C. Hsiung

[5]. Wireless Digital Control and

Synchronization of Master-Slave Multiple

Motors Using Microcontroller Pratiksha

Shingade, AratiDalavi, Priyanka Shipate,

Megha Barge

[6]. http://www.controldesign.com

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