ACKNOWLEDGE MENT

First of all I wish to express my sincere thanks to the UNIVERSITY

INSTITUTE OF ENGINEERING AND TECHNOLOGY, PANJAB UNIVERSITY,

which introduce the scheme of providing practical training for technical student

during the 4-year course of B.E.

With the drastic development of technology & speedy industrializations

of the country I consider myself to fortunate to have undergone practical training

in “INSTRUMENTATION LTD.”

I am very thankful to Mr. S.KHATRI (Head of Training Department, I.L) &

other concerned person of IL, Kota for their guidance; constant encouragement,

strong support & kind help of understand many technical aspects in my training

period.

.

PREFACE

I took my practical training of 30days from 03-06-2010 to 03-07-2010 at

“INSTRUMENTATION LIMITED “which is a govt. of India enterprises. According to the

rule of UNIVERSITY INSTITUTE OF ENGINEERING AND TECHNOLOGY, PANJAB

UNIVERSITY towards the fulfillment of 4 years degree course of B.E. We are supposed

to go training of 30 days after 2nd year.

The object of practical training in engineering filed is to co-relate the theory

with practical knowledge & to make student familiar with industrial environment.

I have been fortunate to get practical training in such a industry which has

been continuous by climbing the Dadder of development utilizing the latest

technology .here I could knowledge of various equipment which are tested & calibrated

in the enterprise.

My report that follow is the summary of all the knowledge that I gained

additional.

INTRODUCTION

“INSTRUMENTATION LTD, KOTA” is a govt. of India enterprises established in Kota

(Raj.) in 1966-67 with the prime objective of attaining self-reliance in the field of contract

& automation for the process industry.

The major products that IL presently manufacturing is: -

1) Process control Instruments

2) Control Values

3) Railway signaling system

4) Sets of Telecommunication

5) Microprocessor Based Recorders

6) Digital switching system

7) Rural Automatic Exchange

8) Main Automatic Exchange

9) Panels

10)Defense Products

Today, IL is supplying these control Equipments to various sectors of the industries viz.

power, steel fertilizer, chemical, petrochemical, refineries, cement, paper textiles, space,

oil, gas, the turn over target is more than 150 cores.

It has its plant at Kota, Palakkad with over 25 years of experience and a dedicated work

force. IL has measured all complicities of control system requirements can lead you

right through your project from system design detailed engineering, manufacturing,

installation final commissioning to after sales services & customer training.

IL after establishing itself as an undisputed leader has crossed the Indian border to

supply equipment on turnkey basis in International market. It has supplied

instrumentation on turnkey basis for 2 thermal power stations in Malaysia & established

a service center at kufa complex in Iraq, supplied instrumentation for Ethiopian Petrol

Company of Ethiopia, supplied instrumentation for Esphahan steel plant Iran & also a

major breakthrough has been made in capturing the market for Hi-tech digital control

system for refineries in the USSR.

All work-center of IL, are well equipped & appropriately upgraded with manufacturing

capability & capacity. The men power are well experienced & also given exposure to

various new technologies. To meet the equipment in working environment, all work

places are adequately dust controlling.

For assembly &testing of hi-tech electronic instrument, totally dust free air conditional

hall are used with static protection.

With the development of technology & speedy industrialization of the country, I

consider myself fortunate one to have undergone practical training in

“INSTRUMENTATION LTD, KOTA”

There are 7 departments or sections in Kota unit:-

(1) UPS centre

(2) PCB Centre

(3) Telecom Division

(4) Railway Relay

(5) Digital Electronics Unit

(6) Maintenance Shop (Electrical)

(7) Gas Analyzer (Production)

(8) Defense Project Department

(9) Assembly Shop

Card assembly (PCB Centre)

Types of card assembly

1. Through-hole (TH)

2. Surface Mount Technology (SMT)

Surface mount technology (SMT) IS AN ELECTRONICS ASSEMBLY TECHNIQUE

where electronic components are mounted to the surface of printed circuit board without

holes drilled through the board for insertion of component leads. The SMT devices must

be precisely placed on the circuit board and held in the position by solder paste or glue

until the soldering process, which is usually automated, can make connection.

BENEFITS OF SMT

Reduction in package size results in greater functionality in the same board area.

Reduction in weight, mobile and handhold electronic items such as video

cameras and cellophanes are example, which have low weight and high

performance.

Reduction in noise. This is primarily due to small electrical paths compared to

leaded components.

Higher operating speeds due to shorter interconnect.

Types of assembling

1. Full SMT board with parts on one or both sides of the board.

2. A combination of through-hole and SMT components.

3. Only through-hole components.

Assembly Procedure for SMT

Surface mount assembly is basically a four-step process:-

1. Print the solder paste/ glue.

2. Place the components.

3. Reflow the paste to form the solder interconnection between the component and

the land area of the board.

4. Clean up.

Equipments used

1. Screen Printer- To print the solder paste / glue on the board.

2. Pick & Place Machine – To place the component on the printed board.

3. Re-Flow Oven – To place the component on the printed board.

4. Wave-Soldering Machine – For soldering of Through – Hole components.

From an equipment standpoint, the pick & place machine is the most complicated. It

alone performs functions handled by three to four machines in standard through – Hole

assemblies. The manufacturing line is much simpler, uses less space, requires few

manpower, have a shorter cycle time.

Advantage of SMT

SMT allows production of more reliable assemblies, increased board density, and

reduced weight, volume and cost. Considerable cost saving can also be realized

through a reduction in material as well as the labor costs associated with automated

assembly.

Pick and mount machine:- This machine is very important it is only one machine at

IL , Kota in Rajasthan. This machine is very costly (6 crores Rs. /-) It picks up small

component. With the help of programming we put in the computer and mount on the

PCB. This machine mount small Component on the PCB at first after this we solder the

PCB. After this we solder the PCB component after this we take out card and test it.

When any component short then we check it manually and remove difficulties and after

we give to testing after testing we clean the card and liquor.

Soldering machine: - It is a big machining in which we insert the card and there is a

sensor. We pass the card on the heating plate. This plate is divided in to three parts first

part is low heated, second one is higher heated and third one is very higher heated.

After this card and heating plat distance is large due to the pullges after this we pass the

card on the melt liquid of Ag+Sn+Pb. Then card is solder by the liquid .Temp. 2400c

and we soldered 10 cards at a time and card soldering time is one second.

Activity Flow Chart

Various assembly Processes:-

1. Issue of Kits

2. Numbering

3. Baking

4. Mechanical Assembling

5. Mounting

6. Pre-Solder Inspection

7. Soldering

COMPONENT FORMING

ASSEMBLY OF PCB’S

RECTIFICATION

PRE-SOLDER INSPECTION

KITS FROM STORE

SOLDERING OF PCB’S

CLEANING

REWORK

POST SOLDER INSPECTION

TO TESTING & REPAIR CENTER

8. Post-Solder Inspection

1. Issue of Kits:

During the assembly of PCB’s several operations are required initially various

components which are required for the purpose of assembly are received from the

store, in the form of kit then following process are made on the PCB’s before final

clearance and dispatch to the testing and repairing center.

2. Numbering:-

The purpose of numbering the PCB’s is to lay down the procedure for

identification & traceability of the products. The PCB’s are identified at the initial stages

and higher stages by providing the serial no. on them which is of 10 digit code.

X X X X X X X X X X

Manufacturer Code Serial Number of the Card

Manufacturing Unit

Year of Production

Month of production (1-9; A,B,C)

3. Baking :-

Before proceeding to the various operations, the baking operation is done due to

following:-

During soldering the card passes through different temperature range in pre-

heating and soldering chamber. If baking is not done prior to soldering the card may be

distorted at high temperature. During baking the card becomes dry & it can bear thermal

shocks during soldering.

The baking is done in a furnace at 1200c. The baking erent cards.

It is 1 hour in use of simple layer.

4 Hour in case of 2-4 layers.

6 Hour for above 4 layers.

4. Mechanical Assembly: -

Although we are using the electronic components in assembly. But some

components are assembled fastened by mechanical tools fasters. Components which

are mechanically assembled are connectors, injectors, switches etc. components, which

are assembled on later stages are:-

1. Those components which may be spoiled during soldering.

2. Those components which may be provide obstacle during soldering.

5. Mounting: -

After exception of kits mounting is done with the help of following steps:-

A. Forming: -

After receipt of kit of required PCB, which is to be assembled, the

Forming operation is done with the help of component list (C.L.) in the

Following steps:-

Cutting: -

Several components bear long leads & these leads may

Create problem in soldering. Hence leads of such components cut

In the required length with the help of required tool.

.Bending:-

These are some components, which can’t be used directly in

Their original shape. A particular pitch (specified length) is there

The leads of their length components are given the required

Shape with the help of required tool. The pitch distance is also

Maintain during the pending now it become the easiest & perfect

To maintain the pitch distance through tools.

B. Binning: -

With the help of component list, all the components are kept in

different boxes called BINS. It makes simple & easier to mounting of

components on the card. It is done in order

Save product cost

Saving labor cost

C. Mounting: -

During forming operation, the components are kept in different bins

(boxes). The cutting and bending operation is performed. For the required

components, now the components are ready for mounting purpose. The

assembler purpose. The assembler start mounting of there formed

components. These are mounted on PCB’s with the help of proper tools

does the mounting properly (manually)

6.Pre _solder inspection: -

As soon as the mounting .is over these assembled cards are offered for

inspection, which are known as “re solder inspection of any mistake as there in

mounting there it is reworked by the assembles and if mounting is ok then these are

send for soldering.

7. Soldering: -

These two type of technique is used for the soldering of PCB’s.

1. Through Hole Technology

2. Surface Mount

Technology [SMT]

1. Through Hole Technology: -

In this wave soldering machine are used for soldering through hole

components of the printed circuits.

Wave soldering: -

It is done by using the wave soldering mic.The wave soldering is

the process consisting of 5 sub process:-

1. Fluxing

2. Pre heating

3. Wave soldering

4. Rework &touch up

1. Fluxing: -

Fluxing is done to remove the oxidation and other containments; no

clean flux is used as solvents. Fluxer is of form Fluxer type. Excess flux is

removed by using the air knife arrangement.

2. PRE-HEATING:-

After fluxing & removal of excess flux, the PCB moves to the pre

heating section ,where the solder side of the PCB receives hot radiations from

heaters & this the oxidation & other continuation. The PCB is completely dry &

it can bear thermal shocks. Here 6 heaters are there. Their temp, Rises

gradually giving rises of 20 to 250C by each. Heater temperature rises from

220 to 3600c.

3. Wave soldering: -

After pre-heating. We move to wave soldering. The solder bath

contains the molten solder. This solder is pumped with the help of the pump.

Here PCB comes in contact with molten solder. Solder get soldered. After

soldering the PCB’s are kept in a card rack to avoid distortion.

4. Cleaning: -

After soldering PCB’s are cleaning by isopropyl alcohol.

8. Rework & Touch-up: -

After soldering & cleaning rework is done. Its advantages are:-

i. Solder defects are rectified

ii. Proper touch up is given.

KOTA

Instrumentation Limited’s state-of- art Electronic assembly’s plant at Kota is equipped to

assemble & test the PCB’s for through – hole, SMT & combination of both. The unit set

up is clean, Dust free & AC environment, ESD protected. The centrally air condition

PCB assembly & testing area is spread over 20,000 square feet.

Process Capabilities

Fully automatic SMD Double sided SMD & PTH

Fine pitch placement 12 mil BGA Placement 0.04 mm.

Passive Placement 0204 BGA & fine pitch rework

No clean / water soluble solder

Paste & flux Conformal coating

Electro-mechanical system assembly

Complete turnkey final assembly

Of your product Functional card / system testing

Inward Good inspection

PICK & PLACE, EUROPLACER VITESSE

WE HAVE FULLY AUTOMATIC PROGRAMMABLE PICK & PLACE M/C MODEL

VITESSE OF M/S. EUROPLACER. THE MACHINE IS MOST VERSATILE. IT CAN

PLACE NOTONLY CHIP COMPONENTS BUT ALSO COMPONENTS IN TRAYS,

TUBES & TAPES. IT CAN PLACE COMPONENTS CHIPS, SOT, SOD, MELFS, MINI-

MELFS, SOIC, PLCC, QFP, PQF, BGA…….

Important Features of an Automatic SMD Pick & Place System

Component Size: 0402

Component Placement Speed: 20,000Component/hour

Feeder Capacity: 198 feeders.

Ability to handle all type of components, in tape, sticks and trays.

Quick Change-Over.

Vision correction to align leaded components.

Head: Two head with 8 nozzles.

Software: The software is window NT based operating program can be used

ON-Line as well as OFF-Line. System.

RAILWAY SIGNALING RELAYS (RSR)

REPORT

1. Introduction

2. What is a relay and where it is used

3. Related terms and their meanings

4. Components

5. Working

6. Calibration

7. Specification of various relays manufactured at instrumentation Ltd. Kota

Introduction

Railway Signaling Systems are basically intended for dispatch and control of

trains in the fail-safe manner. These are most vital systems involving human safety

I.L has executed large turnkey Railway signaling jobs for Western Railway, Southern-

Central Railway, RITES, IRCON, and NTPC etc.

What is a relay?

A relay is a multi switch device with multiple mating contact pairs. The contact

configuration consists of two types of contact pairs-front and back. The back contact

pairs are normally closed and the front contact pairs are normally open. When a relay

is energized the status of front and back contact pairs reverses. Relay manufactured at

instrumentation limited (Kota) are electromechanical type neutral line and track relays.

They work on the following two main operating principles:-

a) ELECTROMAGNETIC ATTARACTION

b) ELECTROMAGNETIC INDUCTION

The load current flowing through the magnetic coil generates magnetic flux in the core

and this flux is responsible for functioning of relays.

TYPES OF RELAYS:-

a) Overload Relay

b) INDUCTION TYPE Over current Relay

c) PLUNGER TYPE Over current Relay

HOWEVER, I.L manufactures three types of signaling relays. They are: -

a) LINE RELAY: - This type of relay is used for classification of

line. It gives signal to lines for up and down. There are two

signals Red and Green. Here, red signal indicates that the line

is busy whereas the green signal indicates that line is clear.

b) TRACK RELAY: - This type of relay is used for changing track

at railway station. As we know only two lines up and down are

present & number of lines are present at railway station.

c) KEYLOCK RELAY: - These are automatic relay & are used for

the protection of accidents when train arrives &gate is

automatically closed. These all types of relays are controlled at

control room

Related terms and their meanings:-

Pick up voltage/current:

Minimum voltage/current at which relay operates i.e. normally closed

contact pairs change to normally open.

Drop away volt /current:

Maximum voltage/current at which relay releases fully. i.e. The contacts

acquire their normal positions.

Contact gap:

The voltage/current variation between the first back break and the last

front make, when the voltage/current applied gradually increasing step by step.

Ultimate pick up: -

Minimum voltage/current at which the armature touches the core of the

coil. Ultimate pick up is achieved after all the front contact achieves ‘close’ status.

Operating time: -

The time that is taken by the relay from application of voltage to change of

state of contacts. This is taken on each contact.

Release time:-

The time taken by the relay from removal of rated voltage to change of

state of contacts.

COMPONENTS:-

Relay broadly consists of:

1. Contact block assembly

2. Magnetic assembly

3. Armature assembly

4. Relay base

Contact block assembly:

Contact block assembly mounted on the relay base consists of ten

contact blocks. The first two from the coil end are for coil termination and the

rest are used in pairs as mating contacts. The two contacts in each pair

consist of one silver and one sig (silver impregnated graphite) contact. Each

contact block consists of maximum four contacts that can be either silver or

sig contact depending on the configuration. Each contact has a

corresponding mating contact of other type in the adjacent contact block

hence the two forming a switch. The operating card supported by adjust

spring at one and inserted in the slots provided in the operating arm at the

other, is interwoven in slots provided in the contact springs so as to move

only the silver contacts. The sig contacts are kept in position by the slots

provided in adjustment card, which in turn are supported at one end by

suppurated at one end by support spring and by adjustment card bracket at

the other.

Magnetic assembly:

Also mounted on relay base, the magnetic assembly consists of coil,

yoke, pivot plate; adjustment card bracket and armature return spring.

Armature assembly:

The armature riveted with the operating arm is pivoted on the pivot

plate such that it can rotate a small angle in the plane perpendicular to the

line of the armature and the pivot plate.

WORKING:-

As the relay is plugged in the plug board it becomes operational. The contact

pairs are connected with the circuit receiving 3v. The coil on the other hand receives

supply in two modes-no supply (off) and full supply (on). Full supply given to the relay is

enough for the relay to pick up (energize) and their values (either in current or in voltage

as in case of track relay and line relay respectively) depend on the specification of the

relay. When the coil supply is in ‘off’ condition the back contact – pairs are in ‘open’

status.

As the supply is given to the coil, it develops a magnetic field that attracts the armature

towards itself, since the armature is a magnetic material. The magnetic field provides

the torque for the armature to rotate about the pivot. The magnetic field developed by

the coil depends on the current within. This current will however increase to its peak

value from zero (initially) following exponential curve because of the reverse magnetic

field developed due to induction effect. When the torque on the armature due to

magnetic field increase enough to overcome the opposing the torque of armature return

spring and operating cards, the relay energize and the armature rotates about the pivot.

The operating arm rotates with it. However the rotation if operating arm can be

visualized as linear movement in the direction parallel to the relay since the angle of

rotation is small. This linear movement is transferred to operating card and in turn to the

silver

CALIBRATION

Calibration involves adjustment of various electrical and mechanical parameters for

proper functioning of Relay. Calibration is done on a special stand and with tools made

for this purpose. The parameters that are adjusted are:

Pickup / Drop away voltage:

The relay should energize and energize at specific voltage / current. These

parameters are function of various torqueses’s acting on armature assembly viz

magnetic force, armature return spring force and the operating card force. For

adjustment the last two forces are varied to obtain the desired effects.

Contact Pressure:

The SIG contact springs should press against the adjustment card slots with a

pressure not less than 40 grams, this pressure is introduced in the springs by bending

machines at the manufacturing stage. However little adjustment if required, is done at

calibration stage. Tension gauges of suitable range measure the pressure. The

pressure is required to ensure proper contact between silver and SIG contacts.

Contact gap:

Ideally all back contacts should break simultaneously and all the front contacts

should make simultaneously as the relay energizes. But this is not achieved in practice.

So, out of all the back contacts, usually there is one contact to break first and one to

break last Likewise there is one front contact to make first and one to make last. The

voltage / current variation between first back break and last front make should be less

than 0.6V.

None overlapping:

The distance traversed by the contact assembly between the last back contact

break and the front contact make should be not less than 0.3 mm. This is ensuring that

any font and back contacts do not achieve ‘close’ status simultaneously. Test conducted

to achieve this at inspection stage is non-bridging test.

Thrust:

Whenever the silver and SIG contacts mate, the silver contact pushes the SIG

contacts to ensure firm contact. The SIG contacts that are supported by the edge of

adjustment card at its free end moves away from the edge by a distance that should be

not less than 0.4mm. The calibrator with the help of feeler gauge ensures this distance.

Specification of relays manufactured at Instrumentation Ltd. Kota

Type of Relay Rated Pick Up (PU) Drop Off Contact from Contact

Resist

Coil

Resist

Relevant

Standards

at 20 C

Q Series neutral line

Q Series neutral line

Q Series neutral line

Q Series neutral line

Track plug in type

Track plug in type

Volt Current

(mA)

Volt Current(

mA)

Volt Curr(mA

)

Front Back Mohm Ohm

BRS 930 A/

IRS 23 , 34

-Do-

-Do-

BRS 939A/IRS

23, 34

BRS 939A/IRS

23, 34

24

24

24

24

1.4

1.4

80

80

109

109

156

156

< 19.6

< 19.6

< 19.6

< 19.6

-

-

-

-

-

-

120-140

103-117

>3.6

>3.6

>3.6

>3.6

-

-

-

-

-

-

>68%PU

>68%PU

12

8

12

8

2

2

4

8

4

8

1

2

<200

<200

<200

<200

<200

<200

300

300

220

220

9

9

CAULKING OF AG CONTACT

OPERATION MACHINE IN USE

1. Ultrasonic Cleaning of Contact Block 1. Set of Vibronics ultra Sonic Cleaner

500W

2. Caulking 2. Hydraulic press 2.5T [Hydraulics Press

Machine]

3. Checking of contacts by S. blade OK

NOT OK

4. Spot Welding 4.Spot Welder 120 Watt

5. Soldering 5.Soldering Machine

6. Ultra sonic Cleaning of fixed 6.Set of Vibronics Ultra Sonic cleaner 500W

Contact Assembly (SIG)

7. Polishing

8. Bending

9. Vapour Degreasing 9.Vapour Degreasing Plant

10.Baking of fixed contact assembly 10.Furnance

OA ASSEMBLY:

For the production railway signaling Relay. We required following test stand.

1. IR / IS TEST

IR Test at 500v.dc

IS Test at 1 kV, AC (1 to 2 sees)

Both the test conducted in b / w

(a) Body to terminal (BT)

(b) Terminal to Terminal (TT)

2. NON – BRIDGING TEST

1. Test of physical gap b/w Back and Front Contact at 500v DC

3. ACIMMUNITY TESTING

(1) 300 V, ac (Gradually) Back contact should not break.

(2) 300V, ac (Abruptly) Back contact should not break.

(3) 1000V, ac (Abruptly) Front contact should not make.

GAS ANALYZERS

Gas Analyzers are the instruments used for continuous measurement of percentage of

a particular gas in a gas mixture. It plays an important role in process engineering

where it provides information on composition of a gas mixture in the process leading to

straight forward quality control and cost saving. On the basis of values obtained from

the gas Analysis, there is a possibility of correcting the process and altering it in such a

manner that it is optimized.

Based on the principle of measurement there are broadly following types of Gas

Analyzers that have been manufactured / supplied by IL Kota:-

S.NO. TYPE OF ANALYSER GAS MEASURED

1. Paramagnetic O2

2. Thermal Conductivity H2, SO2, CO2, Ar.

3. Infrared CO, CO2, SO2, NH3

4. Zirconium’s Probe type Analyzer O2

All the above Analyzers are continuous measuring type Analyzers i.e. the gas available

in the process which is to be analyzed is continuously fed to the Analyzers, it gets

measured and then goes to exhaust. However the process gas is normally not suitable

for directly feeding to Analyzers. A gas sampling system is used to make the process

gas suitable for feeding to the Analyzer. The sampling system consists of following

accessories:-

1. Gas sampling probe

2. Heating device

3. Condensate removal and filtration device

4. Sample gas cooler

5. Diaphragm pump

6. Pressure Reducer

7. Flow meter

Working Principle:-

1. Paramagnetic Analyzer: - it works on the principle that out of all the gases

oxygen is a gas which is highly paramagnetic in nature i.e. the molecules of

oxygen gas have got the property to get attracted by magnetic field. Based on

this analyzer is used for measurement of oxygen.

2. Thermal Conductivity Analyzer: - this Analyzer works on the principal of different

thermal conductivities of different gases. Hydrogen is a gas, which has very

conductivity as compared to other gases like nitrogen, argon etc. this analyzer is

used in thermal power plants for monitoring of H2 in Terbogenerator cooling.

3. Infra Red Analyzer: -This analyzer works on the principle that all Polly atomic,

non-elemental gases absorb the infrared radiation selectively in a particular

bandwidth or frequency spectrum. Based on this specific absorpt ion of infrared

radiation, the IR analyzer is used for measurement of co, co2, ch4, nh3, and

hydrocarbon etc.

4. Zirconia’s Probe Oxygen Analyzer:-This analyzer work on the principle that a disc

of zirconium oxide material acts as a solid electrolyte, when it is subjected to

different partial pressure of oxygen on its two sides. The mV generated across

the 2 sides of the Zr O2 disc is governed by Nernst equation:-

Emf= KT log 10 (P1/P2)

P2= partial pr. Of O2in measured gas on one side.

P1=partial pr. Of o2 in reference gas on other side.

T= Absolute temperature.

K= an arithmetic constant

C= cell constant

In the above equation since all other are constant, the Emf generated is a

function of P2 I e % of O2 in measured gas.

UPS (Uninterrupted Power Supply)

What is UPS: -

The basic UPS consist of rectifier/charger, inverter, external source of stored

power (usually a battery), associated circuitry, protective devices and accessories for

proper operation. The basic function of UPS is to continue power supply to critical load

within its specified tolerances during a failure or deterioration of the normal power

supply. Continuity of electric power to critical load shall be maintained for emergency

period with the UPS supplied externally stored power up to the specified time or until the

restoration of normal power source.

Necessity of UPS: -

Main AC is not clean power. It has inherent defects & poses no danger to

sophisticate & sensitive electronic instruments. The sensitive load is frequently

subjected to voltage variation, transients, interruption and frequency variation.

According to IBM the UPS Systems are capable to overcome 99.9% of power line

disturbances.

The most common kind of main disturbances are as follows: -

Disturbances Equipments used

Voltage Variation Voltage Stabilizers

Electrical Noise Insulated Transformer

Frequency Variation UPS

Large Harmonics UPS

Power Failure UPS

The disastrous consequences of such disturbances are now well known to users of

computers. They cause:

Lost data

Scrambled data

Component failures

Down time of complete equipment

Basic Types of UPS: -

OFF LINE UPS

ON LINE UPS

OFF LINE UPS: -

BATTERY

In OFF LINE UPS input is directly connected to output.

Inverter is not used in this type of UPS.

Output will be in square form.

Because input is directly connect to output so to reduced disturbances a Buck-

Boost converter is use.

Frequency may vary according to input applied.

ON LINE UPS: -

BY PASS

Static Switch

BATTERY

In ON LINE UPS Input is connected to load through inverter.

Output is in sine form.

Frequency of output is constant.

BATTERY

CHARGER

INVERTER

INPUT

BATTERY

CHARGER

INVERTER

INPUT

In case of inverter failure there is an emergency system called BY PASS to

directly connect input to output load.

WORKING of UPS: -

The UPS System basically consists of Rectifier, Inverter, Transfer Switch and

Battery.

Under normal condition, the battery charger supplies the entire power necessary

to the inverter for supplying the load, and simultaneously charges the battery in float

charging condition. The battery charger affects charging the battery automatically.

If power failure occurs, the inverter is supplied the DC power from battery and

supplies continuously the stable AC power to the load. After restoration of power the

UPS come back to normal operation.

The transfer switch or static switch is used to transfer load from inverter mode to

bypass mode. In case inverter becomes faulty the load is transferred from inverter to

Bypass automatically.

The battery used in home segment is generally Lb-Acid tubular (wet type)

batteries and require maintenance periodically. The most critical part of maintenance of

battery is to keep level of acid to required level by adding distilled water. Also the life of

battery is of 2-3 years.

In UPS it is general to use Scaled Maintenance FREE Batteries that do not

require any topping of distilled water. These batteries also have limited life of 2-3 years.

However SMF batteries are very sensitive to temperature and their life reduces

drastically if temperature goes above 25 deg C. So it is batter to keep UPS in cooler

places.

Parallel Configuration of UPS: -

To increase the reliability, UPS should be used in parallel redundant

configuration. In this load is equally shared by both UPS, in case of failure at any one ,

full load is taken by other UPS . If both UPS fail, then the load is transferred to by pass.

Battery: -

Battery plays an important role in UPS. The higher the back up time , more

batteries are required . This adds cost to the battery and stronger chargers required to

charge the battery. Further batteries have definite 3 to 5 years of life. Also, the life of

batteries gets further detiorated due to high environmental temperature. Therefore,

batteries suitable only for optimum battery backup time must be taken and UPS must be

backed up with a generator to take care of large duration of power outage.

Application: -

In critical and higher end application such as power plants, refinery or industries

using computer-controlled equipments, all the instrumentation & critical loads are on

UPS supply. Failure of controls and tripping of plants causing tremendous loss. As such

reliability of UPS power supply are very important parameter. This is achieved by using

higher configuration of UPS. In one such configuration called parallel redundant

configuration, two UPS are used with their output paralleled. During normal operation

both the UPS supplies 50% load. In case of failure of one UPS or taken out for

maintenance, the other UPS automatically start supplying 100% load. In the worst case

when both UPS fail load is transferred to Automatic Voltage Stabilizer without break in

load through static transfer switch.

QUALITY ASSURANCE

The Eight Quality Management Principles

Each major clause of ISO 9001-2000 has been based upon the following eight Quality

Management principles:-

Customer Focus: Organizations depend on their customer and therefore should

understand current and future customer needs, should meet customer requirements

and strive to exceed customer expectations.

Leadership: Leaders establish unity of purpose, direction and the internal environment

of the organization. They create the environment in which people can become fully

involved in achieving the organizations objectives.

Involvement of people: People at all levels are the essence of an organization and

their full involvement enables their abilities to be used for the organizations benefits.

Process Approach: A desired result is achieved more efficiently when related

resources and activities are managed as a process.

System approach to management: Identifying, understanding and managing a system

of inter related processes for a given objectives contributes to the effectiveness and

efficiency of the organizations.

Continual improvement: A permanent objective of the organization is continual

improvement.

Factual approach to decision making: Effective decisions are based on the logical or

intuitive analysis of data and information.

Mutually beneficial supplier relationships: the ability of the organization and its

suppliers to create value enhanced by mutually beneficial relationships.

QA-UPS

For the purpose of quality of UPS following test are taken:-

1. Temperature testing (At 19deg C and at 40 deg C).

2. After exhausting the battery of UPS again temperature testing.

3. Output should be fixed given by manufacturer.

4. Testing of rectifier output, inverter output and battery output.

5. Ripple testing between battery and rectifier.

QA-PCB

Two types of inspection are there for the purpose of quality assurance

1. Pre solder inspection

2. Post solder inspection

1. Pre solder inspection: -Following inspection are there in pre solder inspection: -

Card should not have any component having wrong value at any particular

position.

Card should not have defective component.

Card should not have any missing component.

Card should not have any lifted component.

2. Post solder inspection: - Following inspection are there in pre solder

inspection: -

Card should not have any component having wrong value at any particular

position.

Card should not have defective component.

Card should not have any missing component.

Card should not have any lifted component.

Card should not have any solder defects.

Card should not have any unsoldered component.

No shorting should be there.

No disconnection should be there.

TELECOM TECHNOLOGY

This field of telecommunication has evolved from a stage when signs, drum beats and

semaphores were used for long distance communication to a stage when electrical;

radio & electro-optical signals are used. Telecommunication networks carry information

signals among entities, which are geographically apart. Long distance voice

communication is “Telephony”. Early switching systems were manual and operator

oriented. Limitations of operator switching systems were quickly recognized and

automatic exchanges came into existence. Automatic switching can be classified as

electromechanical and electronic. Electromechanical switching systems and are batter

known as stronger switching systems.

With the introduction of automatic switching system various disadvantages of the

manual exchanges were overcome; some of them are:

In a manual exchange the subscriber needs to communicate with the operator

and a common language becomes an important factor. In multilingual areas

this aspect may pose problem. On the other hand, the operation of an

automatic exchange is language independent.

A greater degree of privacy is obtained in automatic exchanges, as no operator

is normally involved in setting up and monitoring a call.

Establishment and release of calls are faster in automatic exchanges. It is not

unusual in manual exchange, for an operator to take quite a few minutes to

notice the end of a conversation and release the circuits. This could be very

annoying particularly to the business subscribers who may like to make a

number of calls in quick succession.

In an automatic exchange, the time required to establish and release a call

remains more or less of the same order irrespective of the load on the system

or the time of the day. In a manual switching system, this may not be true.

However the major disadvantages of this stronger system is its dependence as

moving parts and contacts that are subjected to wear and tear. Also the control

functions in the strowger systems are performed by circuits associated with the

switching element in the system. However in the cross bar system the call

switching equipment and the call control equipment are separate. So these

strowger systems were replaced by the Cross Bar Switching Systems, which

were designed using the common control concept.

INTRODUCTION TO TELECOM DIVISION: -

Telecom division comprises of: -

a) Manufacturing / production

b) Quality Control

c) Production Planning & System

d) Evaluation & Revalidation

e) PCB Assembly Shop

I.L has been pioneer in manufacturing, supplying & servicing of Electronic

Telephones Exchanges based on C-DOT (Centre for Development of Telematics). C-

DOT provides economical means for serving metropolitan, web on & rural environment.

C-DOT has high traffic / load handling capacity up to 8,000,000 BHCA with termination

capacity of 40,000 lines as local exchanges. Thus C-DOT is easy to maintain & highly

reliable.

C-DOT DSS BUILDING MODULES

C-DOT DSS consists of following basic modules:-

a) BASE MODULE

b) CENTRAL MODULE

c) ADMINISTRATIVE MODULE

d) INPUT OUTPUT MODULE

A) BASE MODULE (BM): -

BASE MODULE (BM) is the basic growth unit of the system. It interfaces the

external world to the switch. The interface may be subscriber lines, analog & digital

trunks. Each base module has Interface up to 2024 (2K) terminals. The number of base

modules directly corresponds to exchange size. It carries out majority of calls

processing functions & operation maintenance function with the help of Input Output

Module

FUNCTIONS: -

a) Analog to Digital conversion of all signals on analog lines & trunks.

b) Interface to digital trunks & digital subscriber.

c) Switching the calls between terminal connected to same base module

d) Communication with the administrative module via the control module for

administrative functions

BASE MODULE hardware is spread over four units: -

a) Analog Terminal Unit (ATU): -

For interfacing analog lines & trunks & provides special circuits.

b) Digital Terminal Unit (DTU): -

For interfacing trunks i.e.; MBPS PCM lines. Each digital trunk

synchronization (DTS) card along with the digital trunk channel associated signaling

(DTC) card interfacing 30 digital trunks.

c) Time Switching Unit (TSU): -

It has a time switch for time switching within the BM, a control switch for

control message communication within the BM & between BM and a service unit for

providing call processing support services

B) CENTRAL MODULE (CM) : -

CENTRAL MODULE (CM) is responsible for interbase module calls,

communication between BM & AM and providing local clock and network

synchronization. For this function, CM has a space switch controller and a control

message switch.

CM provides connectivity up to 16 BM. Each BM interfaces with CM via two

512 channel parallel buses each operating at 4 Mbps. These buses are called bus 0 &

bus 1 and each bus carries information of 512 subscribers transmitted by the BM in the

reverse direction after space switch controller (SSC) two parallel buses carry the

switched voice information of 512 subscribers each at 4 Mbps towards the BM.

C) ADMINISTRATIVE MODULE (AM): - ADMINISTRATIVE MODULE (AM) performs

system level resource allocation & processing on a centralized basis. It performs all the

memory and the time processing support functions and also administrative functions.

D) INPUT OUTPUT MODULE (I/O M): -

INPUT OUTPUT MODULE (I/O M) is a duplex computer that interfaces various

secondary devices like disk drives and up to 8 serial ports for video display units, which

are used for man-machine interface communication

ISDN (Integrated Services Digital Network) :-

ISDN is an integrated network for various types of communication services

handling digitalized voice (telephone) and non voice (data) information. ISDN

support a variety of services including the existing voice and data services and a

host of new services. A short list of some of the new services is:

Videotex, Electronic mail, Digital facsimile, Teletex access, Electronic fund

transfer, Image and graphics exchange, document storage and transfer, automatic

alarm services, audio and video conferencing.

CONCLUSION

Hence, in last I can say that taking training in such an organization provided to

very beneficial for me. I learn write a lot about electronic exchange, PCB unit. I also got

firsthand knowledge of how an industry practically works.

These all are necessary to know for an Engineering Graduate. Now we can think

a better in the field of an engineering industry by learning such things in the systematic

way.

At the end I would like to thank my co- workers and teachers who helped me in

preparing this meaningful report. I hope this report will be successful to make others

understand about the various technology and process used to prepare various

equipments.

PRACTICAL TRAINING

AT

SUBMITTED BY:

ADITYA

ECE-1 GROUP-1

UE85006