Industrial Training Report

Sponsored by

A.T.S INFOTECH Pvt. Ltd. Fergusson College Road, Pune, Maharashtra 411036

Submitted to

Department of Electronics & Communication Engg.Sushila Devi Bansal College of Engineering

Umaria, AB Road, near Rau, Indore- 453331

Partial fulfillment of Bachelor of Engineering degree in Electronics & Communication Engg.

Submitted by

SAGAR VAIDYA0834EC001096

Department of Electronics & Communication Engineering

SD Bansal College of Engineering, Indore

CERTIFICATE

This is to certify that Mr. SAGAR VAIDYA, a student of Electronics

& Communication Engineering Roll No 0834EC081096 has

completed his Industrial Training during the academic year 2012-

2013 as partial fulfillment of B.E. course.

Internal Examiner External Examiner

Date… Date…

Rajiv Gandhi Proudyogiki Vishwavidyaalaya

2

CERTIFICATE

This is to certify that Mr. SAGAR VAIDYA, a student of Electronics

& Communication Engineering Roll No 0834EC081096 has

completed his Industrial Training during the academic year 2012-

2013 as partial fulfillment of B.E. course.

Internal Examiner External Examiner

Date… Date…

3

Industrial training report formatPage 3: Scan copy of Certificate from Industry (Should be on Industry’s letterhead

Acknowledgement

4

The successful completion of this report is the result of many dedicated effort and this

report would be incomplete without giving due credit to them .This acknowledgement is

but a small token of this help in our endeavor.

First and foremost, we wish to express our deepest gratitude to Scientect Director our we

are also heartily thankful to college, our other faculty member of our department for their

kind cooperation in order to completion of this synopsis. Who led us inspires and

motivated us with his guidance at all times providing us with best facilities and

environment for completion of this work. Their keen interest and decision has benefited

us to extent that cannot be spanned in words.

Many other persons helped us in the course of the report but there do not figure

here.Our most sincere thanks to them unknown’s they remain.

Once again we thank one and all…..!

SAGAR VAIDYA

0834EC081096

EMBEDDED SYSTEM

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An electronic device with a programmable component which is not easily accessible to user

is called Embedded System. Today, Embedded Systems are a part of human lives. We are

surrounded and being helped by this embedded systems in our day to day activities. Fields

where embedded systems are being used are Mobile communication, mobile computing

devices, home appliances, music Systems, automobiles etc.

Often the terms microcontroller and microprocessor are confusing. A microcontroller is

actually has more features than microprocessors. Besides the processor it also has I/O ports,

internal timers/counters, internal RAM and ROM. Microcontrollers are programmed using

assembly and high level languages. Assembly languages are controller specific and

machine friendly but the program written in assembly languages are quite lengthy. At the

same time, high level languages such as C and Java are also being used to program

microcontrollers. High level languages are user friendly and eliminate redundancy from the

programs written in assembly languages.

Despite its relatively old age, the 8051 is one of the most popular microcontrollers in use

today. Many derivative microcontrollers have since been developed that are based on--and

compatible with--the 8051. Thus, the ability to program an 8051 is an important skill for

anyone who plans to develop products that will take advantage of microcontrollers.

The 8051 has three very general types of memory. To effectively program the 8051 it is

necessary to have a basic understanding of these memory types.

Properties Of The Embedded System:

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Event driven system.

Microcontroller/ microprocessor based.

Application specific.

Closed system.

Battery operated.

Portable

Types of Embedded System :

SMALL SCALE : 8 to 16 bit micro processor or micro controllers are used in

this category. Programming languages used are Assembly and C.

LARGE SCALE : 32 to 64 bit micro processor or micro controllers are used in

this category. Programming languages used are Assembly, C, J2ME and VC++.

SOPHISTICATED: 32 to 64 bit micro processor or micro controllers are used

in this category. It is supported by RTOS (Real Time Operating System).

MICROCONTROLLERS

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INTRODUCTION

Circumstances that we find ourselves in today in the field of microcontrollers had their be

ginnings in the development of technology of integrated circuits. This development has

possible to store hundreds of thousands of transistors into one chip. That was

a prerequisitefor production of microprocessors, and the first computers were made by

adding external peripherals such as memory, input-output lines, timers and other. Further

increasing of the volume of the package resulted in creation of integrated circuits it is

same .These integrated circuits contained both

processor and peripherals. That is how the first chip containing amicrocomputer, or what

would later be known as a microcontroller came about.

DEFINITION OF A MICROCONTROLLER

Microcontroller, as the name suggests, are small controllers. They are like single chipcom

puters that are often embedded into other systems to function as processing/controlling

unit. For example, the remote control you are using probably has microcontrollers inside

that do decoding and other controlling functions. They are also used in automobiles,

washing machines, microwave ovens, toys etc, where automation is needed. The key

features of microcontrollers include:

High Integration of FunctionalityMicrocontrollers sometimes are called single-chip computers because they have on-chip

memory and I/O circuitry and other circuitries that enable them to function as small

standalone computers without other supporting circuitry.

Field Programmability, FlexibilityMicrocontrollers often use EEPROM or EPROM as their storage device to allow

field programmability so they are flexible to use. Once the program is tested to be correct

then large quantities of microcontrollers can be programmed to be used in embedded

system. Easy to Use Assembly language is often used in microcontrollers and since they

usually follow RISC architecture, the instruction set is small. The development package

of microcontrollersoften includes an assembler, a simulator, a programmer to "burn" the

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chip and a demonstration board. Some packages include a high level language compiler

such as a C compiler and more sophisticated libraries.

Most microcontrollers will also combine other devices such as:

A Timer module to allow the microcontroller to perform tasks for certain time periods.

A serial I/O port to allow data to flow between the microcontroller and other devices such

as a PC or another microcontroller.

An ADC to allow the microcontroller to accept analogue input data for processing

PIN CONFIGURATION

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INPUT/OUTPUT PORTS : There are four I/O ports in 8051 micro controller

named as P0, P1, P2, and P3.

P0: Also used as address data multiplexed lines.

P1 : It is used as I/O ports and termed as single purpose port.

P2: Also used as higher order byte address lines.

P3: The pins of this port are used as Timer pins, interrupt pins, read write pins etc.

Program Counter (PC): It points the location of the program for the CPU. It instructs

CPU from where to fetch instruction and decode it, CPU will generate necessary

signal due to which it connected at ROM’s 1H address.

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Stack Pointer: It holds the address of the memory location where stack is located.

Stack is automatically used in microcontroller whenever a subroutine is called. The

location at which controller has to return after execution of subroutine is stored in

stack.

The total range of the RAM is from 00H to 7FH. Within this bit addressable RAM is

there which ranges from 20H to 2FH.

The pins of the micro controller are explained below.

Reset: It resets total 8051 micro controller.

RXD: It receives data in serial communication.

TXD: It transmits data in serial communication.

INT0: External interrupt for timer 0

.INT1: External interrupt for timer1

T0:Timer0.T1Timer1.

RD: To read into external memory.

WR: To write into external memory.

XTAL1 & XTAL2: To connect the crystal oscillator.

ALE: Address latch enable which is used to access the address location from

external  memory.

PSEN: Program store enable which is used for storing programming

codeintothe external memory.

EA: External Access: 64 KB of ROM is the limit for external memory

Capacitor is storing charge permanently until we use it. Crystal Oscillator is used to

generate a carrier signal with stable frequency. With the help of this oscillator we will

deduce the execution speed in terms of bytes/ sec. It generates 12 clock pulses /machine

cycle. Capacitors provide charge for crystal oscillator. If we are not connecting any

external memory to micro controller, EA is connected to Vcc in case of 8051.

RAM ARCHITECTURE

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The 8051 has a bank of 128 bytes of  Internal Ram . This Internal RAM is found on-chip on the 8051 so it is the fastest RAM available, and

it is also the most flexible in terms of reading, writing, and modifying its contents.

Internal RAM is volatile, so when the 8051 is reset this memory is cleared. The 128 bytes

of internal ram is subdivided as shown on the memory map. The first 8 bytes (00h - 07h)

are "register bank 0". These alternative register banks are located in internal RAM in

addresses 08h through 1Fh.Bit memory actually resides in internal RAM, from addresses

20h through 2Fh. The 80 bytes remaining of Internal RAM, from addresses 30h through

7Fh, may be used by user variables that need to be accessed frequently or at high-speed.

This area is also utilized by the microcontroller as a storage area for the operating stack

Register Banks

The 8051 uses 8 "R" registers which are used in many of its instructions. These

"R"registers are numbered from 0 through 7 (R0, R1, R2, R3, R4, R5, R6, and R7).These

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registersare generally used to assist in manipulating values and moving data from one

memory locationto another. The concept of register banks adds a great level of flexibility

to the 8051

.

Bit Memory

The 8051, being a communication oriented microcontroller, gives the user the ability to

access a number of bit variables These variables may be either 1 or 0. There are 128 bit

variables available to the user, numbered 00h through 7Fh. The user may make use of

these variables with commands such as SETB and CLR. It is important to note that Bit

Memory is really a part of Internal RAM. In fact, the 128 bit variables occupy the 16

bytes of Internal RAM from 20h through 2Fh.

Special Function Register (SFR) Memory

Special Function Registers (SFRs) are areas of memory that control specificfunctionality

of the 8051 processor. For example, four SFRs permit access to the 8051’s

32input/output lines. Another SFR allows a program to read or write to the 8051’s serial

port .SFR is a part of Internal Memory. This is not the case. When using this method of

memory access(it’s called direct address), any instruction that has an address of 00h

through 7Fh refers to an Internal RAM memory address; any instruction with an address

of 80h through FFh refers to an SFR control register.

REGISTERS

The Accumulator

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The Accumulator, as its name suggests, is used as a general register to accumulate the

results of a large number of instructions. It can hold an 8-bit (1-byte) value and is the

most versatile register .

The "R" registers

The "R" registers are a set of eight registers that are named R0, R1, etc. up to and

including R7. These registers are used as auxiliary registers in many operations.

The "B" Register

The "B" register is very similar to the Accumulator in the sense that it may hold an 8-

bit(1-byte) value. The "B" register is only used by two 8051 instructions: MUL AB and

DIV AB.

The Data Pointer (DPTR)

The Data Pointer (DPTR) is the 8051’s only user-accessible 16-bit (2-byte) register. The

Accumulator, "R" registers, and "B" register are all 1-byte values. DPTR, as the name

suggests, is used to point to data. It is used by a number of commands which allow the

8051 to access external memory.

The Program Counter (PC)

The Program Counter (PC) is a 2-byte address which tells the 8051 where the next

instruction to execute is found in memory. When the 8051 is initialized PC always starts

at0000h and is incremented each time an instruction is executed..

The Stack Pointer (SP)

The Stack Pointer, like all registers except DPTR and PC, may hold an 8-bit (1-

byte)value. The Stack Pointer is used to indicate where the next value to be removed

from the stack should be.

ADDRESSING MODES

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"Addressing mode" refers to how you are addressing a given memory location. The

addressing modes are as follows, With an example of each: Immediate Addressing MOV

A, #20hDirect Addressing MOV A, #30hIndirect Addressing MOV A, @R0External

Direct MOVX A, @DPTR Code Indirect MOVC A, @A+DPTR Each of

these addressing modes provides important flexibility.

INTERRUPTS

An interrupt is a special feature which allows the 8051 to provide the illusion

of "multitasking," although in reality the 8051 is only doing one thing at a time..

Timers

Timers are one of the categories of hardware time delays. Time delays are used to keep a

system into halting System or sleepy mode. We have two timers-timer0, timer1.

Hardware time delays are used to generate exact time delays.

LCD INTERFACING

LCD BACKGROUND

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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 data from an external

source (in this case, the 8051) and communicates directly with the 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, 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

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high (1), the data being sent is text data which sould 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.

ADC INTERFACING

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ADC0804 Pinout and Typical Connections

As shown in the typica circuit, ADC0804 can be interfaced with any microcontroller.

You need a minimum of 11 pins to interface ADC0804, eight for data pins and 3 for

control pins. As shown in the typical circuit the chip select pin can be made low if you

are not using the microcontroller port for any other peripheral (multiplexing).

There is a universal rule to find out how to use an IC. All you need is the datasheet of the

IC you are working with and take a look at the timing diagram of the IC which shows

how to send the data, which signal to assert and at what time the signal should be made

high or low etc.

Note: Keep this in mind that whenever you are working with an IC and you want to

know how to communicate with that IC, then simply look into the timing diagram of that

IC from its datasheet. It gives you complete information that you need regarding the

communication of IC.

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The above timing diagrams are from ADC0804 datasheet. The first diagram (FIGURE

10A) shows how to start a conversion. Also you can see which signals are to be asserted

and at what time to start a conversion. So looking into the timing diagram FIGURE 10A.

We note down the steps or say the order in which signals are to be asserted to start a

conversion of ADC. As we have decided to make Chip select pin as low so we need not

to bother about the CS signal in the timing diagram. Below steps are for starting an ADC

conversion. I am also including CS signal to give you a clear picture. While programming

we will not use this signal.

1. Make chip select (CS) signal low.

2. Make write (WR) signal low.

3. Make chip select (CS) high.

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4. Wait for INTR pin to go low (means conversion ends).

Once the conversion in ADC is done, the data is available in the output latch of the ADC.

Looking at the FIGURE 10B which shows the timing diagram of how to read the

converted value from the output latch of the ADC. Data of the new conversion is only

available for reading after ADC0804 made INTR pin low or say when the conversion is

over. Below are the steps to read output from the ADC0804.

1. Make chip select (CS) pin low.

2. Make read (RD) signal low.

3. Read the data from port where ADC is connected.

4. Make read (RD) signal high.

5. Make chip select (CS) high.

D.C. MOTOR

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An electric motor is a machine which converts electrical energy into mechanical energy.

Principle:

    It is based on the principle that when a current-carrying conductor is placed in a magnetic field, it experiences a mechanical force whose direction is given by Fleming's Left-hand rule and whose magnitude is given by

                     Force, F = B I l newton     

                       Where B is the magnetic field in weber/m2.

                                 I is the current in amperes and 

                                 l is the length of the coil in meter.             

The force, current and the magnetic field are all in different directions. 

    If an Electric current flows through two copper wires that are between the poles of a magnet, an upward force will move one wire up and a downward force will move the other wire down.     

The Stepper Motor

 The stepper motor operation is directly related to the following points:

 The motor’s rotation has several direct relationships to the applied pulses.

 The sequence of applied pulses is directly related to the direction of motor shaft rotation.

 The speed of the motor shaft rotation is directly related to the frequency of the input

pulses.

 The length of rotation is directly related to the number of input pulses applied.

 The motor operates whenever command is given from the computer. It is a four-phase

DC motor. When the command for rotating right or left is given, the micro controller

supplies power to each of the four winding sequentially in steps. Thus, the motor rotates

accordingly. However, the output of the micro controller is only +5 Volts. Which is not

sufficient to drive the motor. This needs to be amplified to make it useful for the motor.

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That is why, the signal is first passed through a driver circuit (NPN General Purpose

Amplifier 845c). The voltage gain of this driver circuit is unity, but the current gain is

times for each transistor. Now, this current amplified signal is made to pass through a

power circuit (407), where it is voltage amplified and made influential enough to operate

the stepper motor. since, the stepper motor has four windings, and each winding needs to

be controlled individually, the controller sends signal for each winding through a separate

pin and therefore, each signal is provided with a separate pair of driver and power circuit.

 A major question arising is why the use of stepper motor and not the servo motor, since,

the servomotor has the distinct advantage of operating both in AC and DC. Well,

following are the advantages of the stepper motor:

 The rotation angle of the motor is proportional to the input pulse.          

 The motor has full torque at standstill (if the windings are energized).

 Precise positioning and repeatability of movement since good stepper motors have an

accuracy of 3 - 5% of a step and this error is non cumulative from one step to the next.

 Excellent response to starting/stopping/reversing.

 Very reliable since there are no contact brushes in the motor. Therefore the life of the

motor is simply dependant on the life of the bearing.

 The motors response to digital input pulses provides open-loop control, making the

motor simpler and less costly to control.

 It is possible to achieve very low speed synchronous rotation with a load that is directly

coupled to the shaft.

A wide range of rotational speeds can be realized, as the speed is proportional to the

frequency of the input pulses.

Less cost.

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Degree of rotation is a function of their construction and therefore consistent.

No feedback is necessary for positional or speed control.

Any errors present are non-cumulative.

 Still however, the choice between the two depends on the application for which they are

being used. But the economical operation of the stepper motor makes it a synthesisers

first choice.

  RELAY

A relay is really a remotely controlled switch.  In the diagram above, a power circuit contains a switch which is opened and closed by operation of a relay.   The relay is activated by a magnetic core which is energized when a controlling switch is closed.  As the core is energized, it lifts and closes a pair of contacts in a second circuit - usually a power circuit.  The current required for the relay is usually much lower than that used for the power circuit so it can be provided by a battery. 

Rectifiers

It is used to convert alternating current into direct current. Alternating current being bi-

directional flows in one direction during positive half cycle and in other direction during

negative half cycle. There can be half wave rectifier circuit or a full wave bridge rectifier

circuit. There are several ways of connecting diodes to make a rectifier to convert AC to

DC. The bridge rectifier is the most important and it produces full-wave varying DC. A

full-wave rectifier can also be made from just two diodes if a centre-tap transformer is

used, but this method is rarely used now that diodes are cheaper. A single diode can be

used as a rectifier but it only uses the positive (+) parts of the AC wave to produce half-

wave varying DC

In mains-supplied electronic systems the AC input voltage must be converted into a DC

voltage with the right value and degree of stabilization. Figures 1 and 2 show the simplest

rectifier circuits. In these basic configurations the peak voltage across the load is equal to

the peak value of the AC voltage supplied by the transformer’s secondary winding. For

most applications the output ripple produced by these circuits is too high. However, for

some applications - driving small motors or lamps, for example - they are satisfactory. If

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a filter capacitor is added after the rectifier diodes the output voltage waveform is

improved considerably. Figures 3 and 4 show two classic circuits commonly used to

obtain continuous voltages starting from an alternating voltage. The Figure 3 circuit uses

a center-tapped transformer with two rectifier diodes while the Figure 4 circuit uses a

simple transformer and four rectifier diodes.

DESIGN SPECIFICATION

PCB DESIGNINGThe main purpose of printed circuit is in the routing of electric currents and signal

through a thin copper layer that is bounded firmly to an insulating base material

sometimes called the substrate. This base is manufactured with an integrally bounded

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layer of thin copper foil, which has to be partly etched or removed to arrive at a pre-

designed pattern to suit the circuit connections, or other applications as required.

The term printed circuit board is derived from the original method where a printed pattern

is used as the mask over wanted areas of copper. The PCB provides an ideal baseboard

upon which to assemble and hold firmly most of the small components.

From the constructor’s point of view, the main attraction of using PCB is its role as the

mechanical support for small components. There is less need for complicated and time

consuming metal work of chassis contraception except perhaps in providing the final

enclosure. Most straight forward circuit designs can be easily converted in to printed

wiring layer the thought required to carry out the inversion cab footed high light an

possible error that would otherwise be missed in conventional point to point wiring .The

finished project is usually neater and truly a work of art.

Actual size PCB layout for the circuit shown is drawn on the copper board. The board is

then immersed in FeCl3 solution for 12 hours. In this process only the exposed copper

portion is etched out by the solution.

Now the petrol washes out the paint and the copper layout on PCB is rubbed with a

smooth sand paper slowly and lightly such that only the oxide layers over the Cu are

removed. Now the holes are drilled at the respective places according to component

layout as shown in figure.

LAYOUT DESIGN

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

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

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

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

printed circuit board or to access path of present components.

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It might be necessary to turn some components around to a different angular position so

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

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

can reroute to avoid such condition.

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

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

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

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

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

Plan the layout looking at the topside to this board. First this should be translated

inversely, later for the etching pattern large areas are recommended to maintain good

copper adhesion. It is important to bear in mind always that copper track width must be

according to the recommended minimum dimensions and allowance must be made for

increased width where termination holes are needed. From this aspect, it can become

little tricky to negotiate the route to connect small transistors.

There are basically two ways of copper interconnection patterns under side the board.

The first is the removal of only the amount of copper necessary to isolate the junctions of

the components to one another. The second is to make the interconnection pattern looking

more like conventional point wiring by routing uniform width of copper from component

to component.

ETCHING PROCESS

Etching process requires the use of chemicals. Acid resistant dishes and running water

supply. Ferric chloride is mostly used solution but other etching materials such as

ammonium per sulphate can be used. Nitric acid can be used but in general it is not used

due to poisonous fumes.

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

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

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

required copper pattern areas. Then apply the resistant solution, which can be a kind of

ink solution for the purpose of maintaining smooth clean outlines as far as possible.

While the board is drying, test all the components.

Before going to next stage, check the whole pattern and cross check with the circuit

diagram. Check for any free metal on the copper. The etching bath should be in a glass or

enamel disc. If using crystal of ferric- chloride these should be thoroughly dissolved in

water to the proportion suggested. There should be 0.5 lt. of water for 125 gm of crystal.

To prevent particles of copper hindering further etching, agitate the solutions carefully by

gently twisting or rocking the tray.

The board should not be left in the bath a moment longer than is needed to remove just

the right amount of copper. In spite of there being a resistive coating there is no

protection against etching away through exposed copper edges. This leads to over

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

rinsed. This will halt etching immediately.

Drilling is one of those operations that call for great care. For most purposes a 0.5mm

drill is used. Drill all holes with this size first those that need to be larger can be easily

drilled again with the appropriate larger size.

COMPONENT ASSEMBLY

From the greatest variety of electronic components available, which runs into thousands

of different types it is often a perplexing task to know which is right for a given job.

There could be damage such as hairline crack on PCB. If there are, then they can be

repaired by soldering a short link of bare copper wire over the affected part.

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The most popular method of holding all the items is to bring the wires far apart after they

have been inserted in the appropriate holes. This will hold the component in position

ready for soldering.

Some components will be considerably larger .So it is best to start mounting the smallest

first and progressing through to the largest. Before starting, be certain that no further

drilling is likely to be necessary because access may be impossible later.

Next will probably be the resistor, small signal diodes or other similar size components.

Some capacitors are also very small but it would be best to fit these afterwards. When

fitting each group of components mark off each one on the circuit as it is fitted so that if

we have to leave the job we know where to recommence.

Although transistors and integrated circuits are small items there are good reasons for

leaving the soldering of these until the last step. The main point is that these components

are very sensitive to heat and if subjected to prolonged application of the soldering iron,

they could be internally damaged.

All the components before mounting are rubbed with sand paper so that oxide layer is

removed from the tips. Now they are mounted according to the component layout.

SOLDERING

This is the operation of joining the components with PCB after this operation the circuit

will be ready to use to avoid any damage or fault during this operation following care

must be taken.

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1. A longer duration contact between soldering iron bit & components lead can

exceed the temperature rating of device & cause partial or total damage of the

device. Hence before soldering we must carefully read the maximum soldering

temperature & soldering time for device.

2. The wattage of soldering iron should be selected as minimum as permissible for

that soldering place.

3. To protect the devices by leakage current of iron its bit should be earthed

properly.

4. We should select the soldering wire with proper ratio of Pb & Tn to provide the

suitable melting temperature.

5. Proper amount of good quality flux must be applied on the soldering point to

avoid dry soldering.

THE ULTIMATE GAINS OF THE TRAINING:THE ULTIMATE GAINS OF THE TRAINING:

This training had been some what unforgettable for all of us. ‘Beyond expectation’ were

the words on the mind of each of the trainees, as far as the benefits of this training are

concerned. If every one of us starts writing about the gains of the training the list would

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be somewhat too long for the comfort of anyone who wants to go through them.

However, the main gains are as listed below:

1) COMPONENT IDENTIFICATION :

The first step of the training started with our introduction to the family of electronic

components. This introduction had the motto of making us understand the

components in a better way. The difference in the working, build and connections of

different diodes, resistors, capacitors, bridges, regulators, etc as well as finding of

their respective values from the codes written over them, is one of the most basic step

of entering the world of electronics. That’s why it was great to start from the baseline

aiming at the top.

2) PCB DESIGNING AND FABRICATION :

Next in the training scheme came the very new experience of PCB designing and

fabrication on our own. Firstly, we started with the simple task of making a power

supply on a PCB, drawing the tracks of circuit by hand in order to better understand

the proper positioning of components on the PCB, track width, and distance between

the pins of a single component. Then, we moved to the more advanced portion of

PCB designing using the software. Software like Express PCB and Eagle were quite

handy in designing the PCB. The software Multisim was also introduced to us, which

was quite interesting as it helped to check and realize an electronic circuit without

actually making it. The trainees were taught the very basic steps of using these

software to design one’s PCB and it really became a fun experience to use them.

3) MINOR PROJECT SELECTION AND GUIDANCE

The selection of a unique, realizable and comprehensive project was one of the

most tedious job for us. Techoz helped us through this problem. We were furnished

with concepts of hundreds of such projects giving us enough alternatives to choose

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from. As the choosing of project was over, its implementation was made more

comfortable with the incredible guidance from our Guides. From PCB Designing and

its fabrication to the shielding and packing of our projects Techoz was enough helpful

to be grateful.

4) INTRODUCTION TO MICROCONTROLLER AND PROGRAMMING :

Today the simplest of the equipments have microcontroller inside them. From

mobiles to computers, the microcontrollers have reached everywhere. That’s why the

Microcontroller class was one of the most precious of the gains we had. Here we

studied the microcontrollers, particularly AT89C51 from the Atmel family. In

addition to this, we were taught the assembly language programming of this

microcontroller, which we practically tested on the computer using the software

‘Keil’. Also we learnt to program the microcontroller by interfacing it to the

computer. Thus, looking at the shortness of the training period we had a

comprehensive know-how of the AT89C51.

ABOUT THE ORGANIZATION : “SCIENTECT”, that’s what it represents. Geared with industrial professionals who

provide integrated, innovative and practical training solutions, this institute provides the

practical platform to trainees which they always miss.The methodology is highly

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practical and performance oriented with the well-equipped laboratory, technical library

and internet facilities. Techoz gives a chance to develop the raw imaginations into reality

from project selection to its implementation, industrial trainings and on-job training for

all branches of engineering “Techoz” really sets an example of the word “solutions”.The

best thing about Techoz is that it doesn’t makes you feel the burden of your assignment

or projects, rather makes you enjoy even the most tedious of works. The Team here lets

you experiment, play with the problems and the circuits, lets you make mistakes and

learn on your own with just the right quantity of guidance, enough to bring out one’s raw

talent and understanding.

FACILITIES:FACILITIES:

1) HARDWARE LAB :

Equipped with components ranging from the simplest registers to the valuable

microcontrollers, this lab has it all. Registers, capacitors, regulators, diodes, timers, ICs,

switches, relays, any shape, name or value, you name it and you have the maximum

probability of finding one. Bread boards, digital multimeters, soldering irons, latest

oscilloscope etc ranging from the simplest instruments to the most complex one, all of

them available here are of great help in component testing, soldering and on-board

diagnosis.

The equipment for interfacing of microcontroller (8051) with LCD, keyboards etc are

greatly helpful in making the students better understand the working and concepts of

microcontroller programming.

2) INTERNET FACILITY :

One of the most advantageous features of the institute. None of us, among the trainee

knew the better use of internet before. From datasheets of components to simple

questions of microcontroller one could find them all at just one click of the mouse. This

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facility available to us for the slightest of query made us also aware with the more

beneficial aspect of internet rather than the regular mail services or browsing.However,

the internet was one the most memorable features also. In our off-time, it had been great

fun locating our native places, our college on Google Earth.

3) COMPUTER LAB:

The computer lab has computers to the reach of each student with the best software for

understanding the concepts of C/C++, Microcontroller programming and the software for

circuit designing and simulation. It is of great help to test the theoretical concepts,

practically and understand the minute steps of computer programming.

4) PCB LAB:

This lab provides the students a great opportunity to bring their circuits and imaginations

on real Printed Circuit Boards (PCB). This lab contains all the arrangements to bring

down the circuits made by software on computer as it is, on the PCB and thus gives a

great support in the completion of electronic projects.

5) TECHNICAL LIBRARY:

Hundreds and thousands of electronic projects, schematic diagrams, and datasheets of

components, guide books and reference books makes the Technical library at Techoz

wonderful. There are so many articles related to engineering of electronic equipmentsthat

we (undergoing a short term training program) felt short of time to go through even 10%

of them.

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