i.l. report

A

Practical Training Report

On

“Instrumentation Ltd, Kota”

Submitted in partial fulfillment for the award of the degree of

BACHELOR OF TECHNOLOGY

In

Electronics &Comm. Engineering

2010-2011

(14 May2010- 12June2010)

Submitted to: - Submitted by:

Mr. Yogesh Bhomia Ms. Purva Agarwal

Associate Prof. & Head 07EAIEC077

Department of Electronics Engg. B.Tech. IV Yr. VII Sem

DEPARTMENT OF ELECTRONICS ENGINEERING

ARYA INSTITUTE OF ENGINEERING & TECHNOLOGY

SP-40, RIICO INDUSTRIAL AREA, KUKAS, JAIPUR, RAJASTHAN

RAJASTHAN TECHNICAL UNIVERSITY, KOTA

SP-40, RIICO INDUSTRIAL AREA, JAIPUR (RAJASTHAN) – 302 022

CERTIFICATE

This is to certify that the Practical Training Seminar report on “Instrumentation

Ltd.” at Instrumentation Ltd., Kota (Rajasthan) from 14th May 2010 to 12th

June 2010 is submitted by Ms. Purva Agarwal (07EAIEC077) in partial

fulfillment for the award of degree of Bachelor of Technology in Electronics &

Communication Engineering has been found satisfactory and is approved for

submission.

Mr. P.K. Sharma Mr. Yogesh Bhomia

(Seminar Coordinator) (Head)Assistant Professor Associate ProfessorDep’t. Of Electronics Engineering Dep’t. Of Electronics Engineering

DEPARTMENT OF ELECTRONICS ENGINEERING ARYA INSTITUTE OF ENGINEERING & TECHNOLOGY

SP-40, RIICO INDUSTRIAL AREA, JAIPUR (RAJASTHAN) – 302 022

ACKNOWLEDGEMENT

First of all I wish to express my sincere thanks to the Rajasthan Technical University, Kota.

Which introduce the scheme of providing practical training for technical student during for?

Technical student during the 4-year course of B.TECH.

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.

II

ABSTRACT

I took my practical training of 30 days from 14 th May 2010 to 12th June 2010 at

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

Rajasthan Technical University towards the fulfillment of four years degree course of B. Tech. we are

suppose to go training of 30 days after 3rd year.

The object of practical training in engineering field is to co-relate the theory with practical knowledge

and to make student familiar with industrial environment.

I have been fortunate to get practical training in such an industry which has been continuous by

climbing the ladder of development utilizing the latest technology. Here I could get knowledge of

various equipment which are tested & calibrated in their enterprise. My report that follows is the

summary of all the knowledge that I gained.

III

FIGURE LIST

Fig.1 Introduction…………………….AIET/DOECE/2010-11/PTS/01

Fig. 2 PCB………………………. ……AIET/DOECE/2010-11/PTS/03

Fig. 3 PCB………………………. ……AIET/DOECE/2010-11/PTS/04

Fig. 4 UPS………………………. ……AIET/DOECE/2010-11/PTS/10

Fig. 5 Off line UPS…………………….AIET/DOECE/2010-11/PTS/12

Fig. 6 On line UPS……………… …….AIET/DOECE/2010-11/PTS/13

Fig. 7 Working of UPS…………...........AIET/DOECE/2010-11/PTS/14

Fig. 8 SDDS…………………….. …….AIET/DOECE/2010-11/PTS/17

Fig. 9 SEM……………………… …….AIET/DOECE/2010-11/PTS/23

Fig. 10 Railway signaling relay…. …….AIET/DOECE/2010-11/PTS/27

Fig. 11 Relay……………………... ……AIET/DOECE/2010-11/PTS/28

Fig. 12 Circuit diagram of relay….. ……AIET/DOECE/2010-11/PTS/30

Fig. 13 Telecom………………….. …….AIET/DOECE/2010-11/PTS/33

Fig. 13 Telecom………………….. …….AIET/DOECE/2010-11/PTS/35

Fig. 14 Model of the process approach…. AIET/DOECE/2010-11/PTS/41

IV

TABLE LIST

Table 1 Salient features of screen printer…………………………AIET/DOECE/2010-11/PTS/06

Table 2 Necessity of UPS…………………………………………AIET/DOECE/2010-11/PTS/11

Table 3 Main disturbances in UPS………………………………..AIET/DOECE/2010-11/PTS/11

Table 4 Battery AH calculation for UPS………………………….AIET/DOECE/2010-11/PTS/14

Table 5 Gas analyser……………………………………………... AIET/DOECE/2010-11/PTS/25

Table 6 Capacity comparisons of switching systems……………..AIET/DOECE/2010-11/PTS/37

V

SYMBOLS

VI

CONTENTS

1. Introduction AIET/DOECE/2010-11/PTS/01

2. Card Assembly AIET/DOECE/2010-11/PTS/03

3. Digital Control System AIET/DOECE/2010-11/PTS/08

4. UPS AIET/DOECE/2010-11/PTS/10

5. SPV Dusk Dawn System AIET/DOECE/2010-11/PTS/17

6. Static Energy Meter AIET/DOECE/2010-11/PTS/20

7. Gas Analyser AIET/DOECE/2010-11/PTS/25

8. Railway Signalling system AIET/DOECE/2010-11/PTS/27

9. Overview Of Telecom Technology AIET/DOECE/2010-11/PTS/33

10. Digital Switching AIET/DOECE/2010-11/PTS/36

11. Quality Management AIET/DOECE/2010-11/PTS/40

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 Instruments2. Control Values3. Railway signaling system4. Sets of Telecommunication5. Microprocessor Based Recorders6. Digital switching system7. Rural Automatic exchange8. Main Automatic exchange9. Panels10. Defense Products

AIET/DOECE/2010-11/PTS/01There are Nine departments or sections in Kota unit:-

1. Assembly Shop2. Telecom Division3. Digital Electronics Unit4. Maintenance Shop(Electrical)5. Railway Relay6. Gas Analyzer(Production)7. Defense Project Department8. PCB centre9. UPS centre

I visit only these section in my training period:-

1. Card Assembly (PCB centre)2. Railways Signaling Relay3. Gas Analyzer4. UPS (Engineering, Production, Servicing)

AIET/DOECE/2010-11/PTS/02

CARD ASSEMBLY

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 interconnects.


Types of SMT Assemblies

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. Reflow Oven – To reflow the paste to form the solder interconnection.

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 most saving can also be realized through a reduction in material as

well as the labor costs associated with automated assembly.

Instrumentation Limited’s state-of-art Electronic assemblies plant at Kota is equipped to assemble &

test the PCBs for through-hole, SMT & combination of both. The unit set up by us 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 min.

* Passive Placement 0204 * BGA & fine pitch rework

* No Clean/water soluble Solder

Paste & Flux * Conformal coating

* Electro-mechanical system assemble

* Complete turnkey final assembly

Of your product * Functional card/system testing

* Inward Good inspection


EQUIPMENTS

SCREEN PRINTER, SPEEDLINE MPM 100

SCREEN PRINTER IS USED FOR PLACING GLUE OR SOLDER PASTE, WE HAE SPEED LINE

SEMI AUTOMATIC PRINTER (MODEL NO. MPM ULTRAPRINT 100)

SALIENT FEATUES OF SCREEN PRINTER:

1. PRINT AREA : 450 mm x 400 mm

2. BOARD SIZE : 70 mm x 19 mm to 500 mm x 450 mm

3. X-Y ADJUSTMENT : + 10 mm

4. ROTARY ADJUSTMENT : + 40

5. PRINT SPEED : 10 mm to 70 mm/s

PICK & PLACE EUROPLACER VITNESS

WE HAVE FULLY AUTOMATIC PROGRAMMABLE PICK & PLACE M/S MODEL VITNESS

OF M/S. EUROPLACER. THE MACHINE IS MOST VERSATILE. ITS CAN PLACE NOTONLY

CHIP COMPONENTS BUT ALSO COMPONENTS IN TRAYS, TUBES & TAPES. IT CAN

PLACE COMPONENTS CHIPS, SOT, SOD, MELES, MINI-MELFS, SOIC, PLCC, OFP, PQF,

BGA….

Important Features of an Automatic SMD Pick & Place System

* Component Size: 0402

* Component Placement Speed: 20,000 Component/hour

* Feeder Capacity: 198 feeders

* Ability to handle all types of components in tape, sticks, and trays. Quick change-over.

* Vision correction to align leaded components.


* Head. Two head with 8 nozzles.

* Should be able to handle all sizes of tapes.

* Software: The software is Windows NT based operating system. This program can be used ON-Line as well as OFF-Line.

Programmable Tape Trolley

The programmable tape trolley is an ‘Intelligent’ version of the normal passive trolley. Each trolley is

of the same intelligence as the other programmable feeder’s available offering:

Component recognition

Data entry by micro-terminal

Programming by computer and auto adjustment of picking position

It has capacity of 33 separate channels and accepts 8, 12, 16 and 24 mm tape elements.

Each tape element for 8, 12, 16, 24 mm tape comprises:

Receptacle to receive and feed the tape

A cover to hold the tape in place


Digital Control System

Instrumentation Limited, Kota supplies the control & Instrumentation System; contradict, to the

process industries like thermal, steel, refinery, & chemical plants etc. The systems offered in technical

collaboration with Hartmann & Braun Germany are.

- Contronic – 3

- Contronic – 3 I

- Contronic– E

- Contronic – Symphony

It is a microprocessor based digital control system for controlling the Boiler & Turbine parameters,

Temperature, Pressure, and Flow & Level.

- Signal Conditioning

- Modulating Control

- Sequence Control

- Power Amplification

(Diagram I)

Signal Conditioning

It forms the link between the measured value and the automation units as well as the process

monitoring. The process variables are acquired by 2 and 4 wire transmitters and converted into

electrical into electrical signals it performs-

- Fusing & Supply

- Line Monitoring

- Limit Value

- Signal Conditioning & Distribution

- Disturbance Monitoring

- Correction Computer

- Redundance Circuit


Modulating & Sequence Control

Depending upon the requirement, the system function as closed loop or open loop control. The

control functions, Proportional, (P), Integral (I) and derivative (D) action are performed as PI or PID

both as continuous or step controller. Each controller unit has three section, Control, Logic and

Disturbance section. Apart from control functions it performs.

- Monitoring of positioning loop including final control element

- Analog signal monitoring

- Output limitation in manual and automatic

- Signal storing after supply failure

Power Amplification

This subsystem amplify the output of the individual drive control unit to drive the actuators,

motorized drive or solenoid valves.

Information & Monitoring

The information output via individual indicators and annunciations is available on the control desk.

However comparing, sorting and prospective display are on VDU and takes place via the system bus.

Information displays are available at any time to assist the operator such as

- Plant overview

- Curve and bar display

- Identification field displays

- Measuring point display

- Event sequence display


Uninterrupted Power Supply (UPS)

What is UPS or Basic Definition of UPS?

The basic UPS shall consist of rectifier/charger, inverter, external source of stored power (usually a

battery), associated circuitry, protective devices and accessories as required for proper operation.

The basic UPS shall continue to supply power to the critical load within its specified tolerances

during a failure or deterioration of the normal power supply. Continuity of electric power to the

critical load shall be maintained for emergency period with the UPS supplied externally stored power

up to the specified time or until restoration of normal power source.


Necessity of UPS

Main AC is not a clean power. It has inherent defects & poses danger to sophisticate & sensitive

electronic instruments. The sensitive load is frequently subjected to voltage variation, transients,

interruption and frequency variation. The major computer’s manufacturer has done studies on

quantities of main disturbances in AC supply. IBM had done a study on mains disturbances at 29

different locations for 16 months & observed that a total of 6244 disturbances were registered. The

breakup of disturbances registered were as follows:

%

Transients 4507 times 72

Under Voltages 1569 times 25

Over Voltages 103 times 1.8

Interruptions 65 times 1.2

According to IBM the static UPS Systems are capable to overcome 99.9% of these 6244 power line

disturbances.

Similarly Bell lab also published a report on the quality of power of American Power Network,

monitoring at 24 different sites. It indicated that 87.2% of the main disturbances were cases of under

voltages, while 7.4% were impulses of transients and 4.7% true power failures.

The most common kind of main disturbances are as below:

Remedial Measures

(Equipment Used)

Voltage Variation Voltage Stabilizers

Electrical Noise Insulated Transformer

Frequency Variation UPS

Large Harmonics UPS

Power Failure UPS


The above type of disturbances is common to Western Europe and other developed countries like

USA and there is no reason to imagine that these will be attenuated in the future.

They will even increase due to bare fact that our public electrical networks will be more and more

severely overloaded and submitted to numerous accidents, failures and strikes.

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

In most micro computers, switched mode power supplies cannot tolerate main interruptions longer

than 10 milliseconds, so that losses of data will be more frequent than in other computers.

Types Of UPS

1. Off Line UPS

2. On Line UPS

Off Line UPS

In offline 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 connected to output. To reduce

disturbances, a buck boost convertor is used. Frequency may vary according to input applied.


On Line UPS

Input is connected to load through inverter.

Output is in sine form.

Frequency of output is constant.

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. Charging the

battery is effected automatically by the battery charger.

If the 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.

Battery AH Calculation for UPS/Inverter (used in Homes)

The some of the house hold appliance have typical ratings as below. (The rating may vary from

manufacturer to manufacturer & model to model.)

Tube with Electronic Choke 35 W Tube with Cu Choke 55 W TV 60 W Computer 100 W Air Cooler 170 W AC 1 ton 1400 W


Refrigerator (small) 225 W Washing M/C Automatic 325 W 36/48 inch Ceiling Fan 50 W

In order to calculate the battery requirement for a particular load calculate the wattage of appliances

required to be used during power cut. For example we want use two tube lights CU Choke & two fans

during power cut.

The total wattage of appliances become 55x2+50x2=210 W

The VA rating of inverter/UPS is given by Wattage/Rated Power Factor of load (say 0.7)

210/0.7=300 VA

So we require an inverter with rating 300 VA. It would be prudent to go for higher rating inverter say

500VA.

The inverter/UPS available in local market has poor efficiency of order of 60%. Therefore the input

watt of inverter (Output Load in Watt/Efficiency).

210/0.6 = 350 W

In case inverter use one battery the battery voltage is taken as 12 V

The current drawn by the inverter from battery during power cut is equal to input watt of

inverter/battery voltage 350/12 = 29.1 A say 30 A

Now suppose we want back-up of 2 hrs. Than inverter will be drawing energy from battery.

30 A x 2 hrs = 60 AH

The rating of battery is generally given as C20 capacity which means if 1/20 th current is drawn from

battery (5A from 100AH battery) then it will give backup of 20 hrs. However if current is drawn at

higher rate say 1C (100 A) it will give a back-up of ½ approximately.


As in case of inverter/UPS the current drawn is higher (of the order of 1C) the battery AH required

corresponding to 60AH (energy drawn from battery) is approximately

3.125 x 60 AH = 187.5 AH. So we will be taking a battery 200 AH.

The battery used in home segment are generally LB-Acid tubular (wt type) batteries and require

maintenance periodically. The most critical part of maintenance of battery is to keep level of acid to

required level (generally marked on battery container) by adding distilled water (available at petrol

Pumps in sealed bottles). Also the life of locally assembled batteries is of order 2-3 years and require

replacement than after.

In UPS it is general to use Sealed Maintenance Free Batteries which do not require any topping by

distilled water. These batteries also have limited life of 2-3 years & require replacement then after.

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

temperature goes above 25 deg C. so it is better to keep UPS with batteries in cooler places of house.

Critical Applications

In critical higher end applications such as Power Plant, Refinery or industries using computer

controlled equipments, all the instrumentation & critical loads are on UPS supply. Failure of UPS

cause failures 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

outputs 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 fail load is transferred to Automatic Voltage

Stabilizer without break in load through static transfer switch.


SPV Dusk Dawn System (SDDS)


Working Principle and Application

SPV Dusk Dawn System (SDDS) is a system which controls the switching of lights mainly Street

light) on a routine basis depending upon the intensity of surrounding (ambient) light. If the

surrounding light intensity decreases below a certain level, the lights are switched ON after certain

delay which is pre programmed as per requirement.

If the surrounding light intensity is regained above the acceptance level, the lights are switched OFF

after a delay of one minute (to assure the confirmed availability of surrounding light.)

The delay of one minute in switching OFF the lights is introduced to avoid the false sensing of lights

in form of surges, lightening etc.

Few lights can be switched OFF after a period of say 3-4 Hours from the ON time for saving the

energy since these lights are not to be kept ON further more. These lights are positioned on alternate

poles. The time 3-4 hours is also settable through DIP switches placed on controller PCB.

For further saving energy, another few lights can be switched OFF after a period of say

6-7 hours form the ON time since light requirement on the roads in the late night is very less. These

lights are positioned on alternate poles. The time 6-7 hours is also settable through DIP switches

placed on controller PCB.

The total lights are switched OFF on Down.

The cycle repeats on next day evening on Dusk.


For the conformity of lights must OFF on Dawn condition, lights are switched OFF after a fixed

period of 11-12 hours settable through DIP switches on controller PCB irrespective of sensor signal

(i.e. ambient light intensity condition).

In case of some problem or otherwise, the lights can also be switched ON or OFF manually if

required.

In case of high current or fault conditions on load side, the MCCB’s protect the whole system by

tripping the individual circuit.

Static Energy Meter (SEM)

Working Principle & Application

Static Energy meter Single Phase 5-30 A: - It is a watt hour meter for measuring energy consumed in

a load of single phase up to 30 Amps. It is Static Type i.e. no moving parts inside it like Disc as in

case of conventional type.

It measures as low as 10mA AC current as drawn by Neon Lamp/LED’s etc. It is anti Tampering i.e.

it measures Energy through current of both the lines phase and Neutral and take the reading of

Maximum of the two, thus no Tampering can be done.

It is made strictly as per New IS 13799:1999 and tested for rigorous Evaluation Test well approved

by BIS (Beauro of Indian Standards).

Its working principle is as follows:-

Input current is being measured by two CTs and is fed to IC 9607M (Same) and voltage is fed via a pt

to the IC. IC output is the form of pulses is fed to pulse counter (Electro Mechanical) and counter

increments with each pulse. Also different outputs are indicated with the help of LED’s such as

shown above for different condition. One LED indicates for power is ‘ON’ another for Pulse

indication (i.e. Calibration), Third is for Anti Tampering (Earthed Load) and 4th for Reverse Current.

Thus all different conditions are indicated on the front of Meter.

Meter is Tested for Calibration on Min. Load (10mA) to 30A 600% of Rated Current (i.e. 5A) on

power factor from unity to 0.5 (Lag) and 0.8(Lead). It should be within the limits of Class 1 (1%).

The calibration LED indicates on each pulse and can be calibrated for a meter constant of 6400 IMP

per KWH while counter has ONE increment on 640 IMPs for me /10th KWH (Unit).

It is Tested for No Load i.e. it should not indicate increment of Reading while on NO Load (called

CREAP Test).


It is tested for actual Reading on Counter (Dial Test).

It is tested for repeatability of Error with respect to Time. It should be within Limit of 0.5% (for class

1)


Static Energy Meter (SEM)

Working Principle & Application

TYPICAL APPLICATION

In figure 1, the components required for a stand-alone power metering application, is shown.

Current transformers are used for mains current sensing. The channel showing the highest power

consumption will be selected by the SA9607M for energy metering.

The most important external components for the SA9607M integrated circuit are the current sense

resistors, the voltage sense resistors as well as the bias setting resistor.

Current Sense Resistors

The resistors R1, R2, R3 and R4 define the current level into the current sense inputs of the device.

The component should be selected for input currents of 16U ARMS into the current channels of the

SA9607M at IMAX (rated current of the meter). The voltage drop of the resistors R10 and R17

should be at least 20mV.

Where:

IL = Line current/CT-ratio

R10 = Termination resistor

R11 = Termination resistor

Voltage Sense Resistors

R9, R8, R6 and R5 set the current for the voltage sense input. The values should be selected so that

the input current into the voltage sense input (virtual ground) is set to 14 ARMS.

Bias resistor

R7 defines all on-chip bias and reference currents. With R7 = 24k., optimum conditions are set. R7

may be varied within 10% for calibration purposes. Any change to R7 will affect the output

quadratically (i.e.: R7 = +5%, fp = +10%).


FEATURES

Provides direct interface to mechanical counters

Monitors Live and Neutr for tamper detection

Performs bi-directional energy measurement

Various setup modes selectable

Meets the IEC 521/1036 Specification for Class AC watt hour meters

Total power consumption rating below 25mW

Adaptable to different types of sensors

Operates over a wide temperature range

Precision voltage reference on chip.

DESCRIPTION

The SAMES SA9607M is a single –phase be-directional energy metering integrated circuit. It

provides a mono-chip solution for energy meters with Electro-mechanical displays, such as stepper

motors and impulse counters.

Two current sensor inputs allow the measurement of energy consumption on both the live and

neutral.


Direction detection of energy flow as well as other common tamper conditions are flagged.

The power consumption on both the neutral are continuously measured and the larter of the two is

selected for energy metering.

The SA9607M drives the calibration LED and the electromechanical counter directly.

The SA9607M integrated circuit is available in 20 pin dual-inline plastic (DIP-20) and small outline

(SOIC-20) package types.


Gas Analyser

Working Principles & Application

Gas Analysers are the instruments used for continues 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 form the gas Analysis, there is a possibility of correction 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 Analyses 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. Zirconia probe type Analyser O2

All the above Analysers are continuos measuring type Analysers i.e. the gas available in the process

which is to be analyazed is continuously fed to the Analyser, it gets measured and then goes to

exhaust. However the process gas in normally not suitable for directly feeding to Analyser. A gas

sampling system is used to make the process gas suitable for feeding to the Analyser.


The sampling system consists of following accessories.

1. Gas sampling probe

2. Heating device

3. Condenste removal and filtration device

4. Sample gas cooler

5. Diaphragm pump

6. Pressure Reducer

7. Flow meter

Working Principle

1. Paramagnetic Analyser:- 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 the principle, paramagnetic Analyser

is used for measurement of oxygen.

2. Thermal Conductivity Analyser:- This Analyser works on the principle of different

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

conductivity as compared to other gases like Nitrogen, Argone etc. This Analyser is used

in Thermal Power plants for monitoring of H2 in Terbogenerator Cooling.

3. Infra Red Analyser:- This Analyser works on the principle that all polly Atomic, Non

Elemental gases absorb the infrared radiation selectively in a particular band width or

frequency spectrum. Based on this specific absorption of infrared radiation, the IR

analyzer is used for measurement of CO, CO2, CH4, NH3, and Hydrocarbon etc.

4. Zirconia Probe Oxygen Analyser:- This Analyser works 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)+C

P2 = Partial Pr. Of O2 in 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

AIET/DOECE/2010-11/PTS/ 26

Railway Signaling Relay

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

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-font 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.

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 rated voltage to change of

state of contacts. This parameter is taken on each contact.

Release time: The time taken by the relay form removal of rated voltage change of state of contacts.


Components

Relay broadly consist 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 tem contact blocks. The first two from

the coil end are for coil termination and te rest are used in pairs as mating contacts. The two contacts

in each pair consist of one silver and one SIG (Siver Impregnated Graphite) contact. Each contact

block consists of maximum four contacts that can be either silver of 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 end and

inserted in the slots provide in the operation arm at the other, is interwoven in slots provided in the

contact sprigs 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 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 contact 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 (energise) and its

valus (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 torque of armature return

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

operating arm rotates with it. However the rotation of operating arm can be visualized as linear

movement in the direction parallel to the length of 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 relays. 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 energise and denergise at specific

voltage/currents these parameters are function of various torques action 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 that 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 energies. 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.

Ono overlapping: The distance traversed by the contact assembly between the last back

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

any front 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 cad 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.


Overview of 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 system were manual and operator oriented. Limitations of operator manned switching

system were quickly recognized and automatic exchanges came into existence. Automatic switching

systems can be classified as electromechanical and electronic. Electromechanical switching systems

include step-by-step system and are better known as strowger switching systems.

1. With the introduction of automatic switching system various disadvantages of the manual

exchanges were over come; 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 problems. On the other hand, the operation of an automatic exchange is language

independent.

A greater degree of privacy is obtained in automatic exchanges. It is not unusual in a

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.

2. However the major disadvantage of this strowger 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 System, which were designed using the common control concept.

Both strowger and cross bar switching systems were slow in call processing as they used

electromechanically components, effects were made to increase the speed of control and

signaling b/w in the exchanges. Further with the development in the field of electronics it

was realized that in principle, the registers and transistors of common control systems

could be replaced by a single digital computer. These modern digital computers

There are basically two approaches to organizing stored program control: Centralized and

Distributed. Early Electronic Switching Systems (ESS) developed during the period 1970-

75 almost invariably used centralized control. Although many present day exchange

designs continue to use centralized SPC, with the advent of low cost powerful

microprocessors and very Large Scale Integration (VLSI) chips such as programmable

Logic Controllers (PLC), distributed SPC is gaining popularity.


Centralized SPC

In centralized control, all the control equipment is replaced by a single processor, which

must be quite powerful. It must be capable of processing 10 to 100 calls per second,

depending on the load on the system, and simultaneously performing many other ancillary

tasks. A typical control configuration of an ESS using centralized SPC.

With the wide use of electronics in the field of Telecommunication. Various Digital

Switching Systems (DSS) came into existence.


B.DIGITAL SWITCHING

SIGNALLING IN TELECOMMUNICATION

INTRODUCTION

A Telecommunication network establishes and realizes temporary connections, in accordance with

the instructions and information received from subscriber lines and interchange trunks, in form of

various signals. Therefore, it is necessary to interchange information between an exchange and it

external environment i.e. between subscriber line and exchange, and between different exchanges.

Though these signals may differ widely in their implementation they are collectively known as

telephone signals.

A signal system uses a language, which enable so switching equipments ot converse for the purpose

of setting up calls like any other language it possesses a vocabulary of varying size and varying

precision.i.e. a list of signals, which may also vary in size and syntax in the form of a complex set of

rules. Governing the assembly of these signals.

This hand out discusses the growth of various signaling system i.e. Digital Switching System (DSS)

used in Indian Telecommunication.

EWSD

It has been designed by M/S Siemens of Germany. It consist the following working units.

Digital Line Unit (DLU), line Trunk Group (LTG), Switching Network (SN), Co-ordination

Processor (CP), Common channel Signalling Network Control (CCNC)


FCTEX-150 SWITCHING SYSTEM

The FETEX-150 Digital switching system has been designed M/s Fujitsu of japan. It mainly consists

of following units.

Line Connecter A (LC-A) & B(LC-B) with Digital Terminals for PCM Junctions (DT), Analog Trunk

(AT), Receiver unit for MFC Code Generator/Receiver (REC), Digital Switch Module (DSM), Call

Processors (CPR), Main Processor, I/O Units, Common Channel Signalling Equipment (CSE)

AXE-10 SWITCHING SYSTEM

The AXE-10 Digital switching system has been designed by M/s Ericsson of Sweden. It mainly

consists of following subsystems.

Subscriber Switching Subsystem (SSS), Trunk & Signalling Subsystem (TSS), Group Switching

Subsystem (GSS), Regional Processor Subsystem (RPS), Central Processor Subsystem (CPS), input/

output System (IOS), Common Channel Signalling Subsystem (CCS)

E-10B & NEW SWITCHING SYSTEMS

CAPACITY COMPARISONS

CHARACTERISTC E-10B AXE-10 FETEX-150 OCB283 EWSD

PCMs 384 2048 2048 2048 2048

Trunks 10,000 60,000 60,000 60,000 60,000

Subscribers 49,000 65,000 2,40,000 2,00,000 2,50,000

BHCA 1,90,000 8,00,000 10,00,000 8,00,000 15,00,000

Traffic (Erl.) 4,000 26,000 24,000 25,000 25,200

CCS# 7 No. Yes Yes Yes Yes

ISDN No. Yes Yes Yes Yes


OCB 283 DIGITAL SWITCHING SYSTEM

This system has been developed by CIT ALCATEL of France and therefore has many similarities to

its predecessor E-10B (also known as OCB 181 in France.)

The first OCB 283 exchanges of RI I versions were commissioned in Brest (France) and (Beijing)

(China) in 1991. The first OCB-283 exchange came to India in 1993.

OCB 283 has a double removing facility.

The traffic handling capacity of the system is huge. It can handle 8,00,000 BHCA and 25,000 Erlangs

of traffic. Depending on the traffic, a maximum of 2,00,000 subscribers or 60,000. The OCB 283

system is made up of only 35 types of cards.

FEW THINGS TO REMEMBER

1.ISDN

The ISDN is an abbreviation of Integrated Services Digital Network. The current communication

networks vary with the type of service, such as telephone network, telex network, and digital data

transmission network, on the other hand, the ISDN is an integrated network for various types of

communication services handling digitized 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 important new services is:

Videotext, Electronic mail, Digital facsimile, Teletex access, Electronic fund transfer, Image and

graphics exchange, Document storage and transfer, Automatic alarm services, e.g. smoke, fire, police

and medical, Audio and Video conferencing.


ISDN SERVICES

A wide range of services

(a) The ISDN provides the following functions.

Packet Switching Services

Circuit Switching Services

Leased Circuit Service

Circuit switching services includes both telephone and data circuit switching.

(b) ISDN can interface with various terminals, such as telephone set, FAX, Video terminal or

personal computer to provide range of services.

(c) The ISDN can be summarized by two statements:

ISDN offers a variety of services, such as telephone, data and image transmission through one

network.

ISDN handles all information digitally.

2. CCS # 7

Signaling System # 7 was derived form the earlier SS6, which explains the similarities, SS7 provides

much more capability than SS6. where used fixed-length signal units, SS7 uses variable-length signal

units, providing more versatility and flexibility. SS7 also uses high-speed data links (56 kbps). This

makes the signaling network much faster than SS6. in International networks, the data links operate at

64 kbps. Study is under way to increase this in the United States to 1.544 Mbps, and internationally to

2.048 Mbps.

Before deploying SS7, cellular providers were dependent on X.25 networks to carry

IS-41 signaling information through their network. This did not allow them to inter-correct through

the Public Switched Telephone Network (PSTN) because the X.25 network was not compatible with

the PSTN signaling network (SS7). The cellular providers are aggressively changing this situation

today, deploying their own SS7 networks. By the end of 1995, almost all cellular providers will have

completed their SS7 networks.


(ISO : 9001-2000, Qualify Management System)

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

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

achieving the organization 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 objective contributes to the effectiveness and efficiency of

the organization.

- 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.


MODEL OF THE PROCESS APPROACH

ISO : 9000-2000

QUALITY MANAGEMENT SYSTEM

GENERAL REQUIREMENT

The organization shall establish, document, implement, maintain and continually improve the

effectiveness of a quality management system in accordance with the requirements o this

International Standard.

The organizational shall :

a) Identify the process needed for the quality management system its application

throughout the organization.

b) Determine the sequence and interaction of these process.

c) Determine criteria and methods needed to ensure both the operation and control of

these process on effective.

d) Ensure the availability of resources and information necessary to support the operation

and monitoring of these processors.

e) Monitors, measure, and analyze these process, and implement action necessary to

achieve planned results and continual improvements of these process.

These processes shall be managed in organization in accordance with the requirements of this

International Standard.

Note : Processes needed for the quality management system referred to above, should include

processes for management activities, provision of resources, product realization and measurement.

Where an organization chooses to outsource an process that affects product conformity with

requirements the organization shall ensure control over such processes control of such outsourced

processes shall be identified within the quality management system.


CONCLUSION

Hence, in last I can say that taking training in such an organisation 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 Enginnering Graduation. Now we can think a better in the

field of an enginnering industries 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 successfully to make understand about the various

technologies and processes used to prepare various equipments.

REFERENCES

WEBSITES REFERRED

www.il.in\ups\online

www.il.in\ups\offline

www.wikipedia.com\relays

BOOKS REFERRED

Lecture notes from IL

Power electronics by “Dr. P.S. Bhimra”

Practical handbook on UPS

i.l. report

Documents

aietdoece201011pts25

aietdoece201011pts11

aietdoece201011pts14

kota rajasthan

practical training report

object of practical

engineering field

training period