TRAINING REPORT(BHARAT ELECTRONICS LIMITED, KOTDWARA) GOVIND BALLABH PANT ENGINEERING COLLEGE PAURI. SUBMITTED TO: MR. S.K. Soni (O/C Industrial Training) SUBMITTED BY: Ajay Kumar (Electronics&comm.Engg.) CONTENTS Certificate Acknowledgement Preface Introduction to Bharat electronics Introduction to B.E.L kotdwara PPE & Stores Switching Department Defense department MRI Department ACKNOWLEDGEMENT On completion of my Training report I would like to pay regards to all the members of ‘BHARAT ELECTRONICS KOTDWARA’ who accepted me as a trainee and helped me a lot. I am deeply grateful to Dr. H.S Rawat (Assistant Personal Manager H.R.D) who gave me the chance to insight of vocational training of duration of four week. I am also thankful to Mr. S.K Soni, H.O.D Electronics department, G.B Pant engineering college Pauri Garhwal who provided me every help that I needed. DATED: 08/12/2006 AJAY KUMAR B.E. (E.C.E) G.B.P.E.C PAURI (GARHWAL) PREFACE Keeping in view. . The main objective of the vocational training program is to provide Practical knowledge of the product being manufactured and working process in the factory. More over this training gives an engineer a chance to interact with working techniques .and to get familiar with facilities and formalities that one should follow in the Factory. Beside the theoretical and practical knowledge from their institution. the practical problem faced by the students of technical stream a four week training program for engineering students have been designed. A Public sector undertaking ‘BHARAT ELECTRONICS LIMITED’ is significantly working in this field.) MACHLIPATNAM(A.L. all over India.P) PANCHKULA(HARYANA) TALOJA(MAHARASHTRA) CHENNAI(TAMIL NANDU) HYDERABAD(A. Presently there are nine branches of B.L. Defense bought its needed products from Israel.E. Bharat Electronics was incorporated in 1954. but it takes lot of transportation charges.) Here I mainly describe about B.L.INTRODUCTION TO B. and Air force.) KOTDWARA(U. Navy. Bharat Electronics Limited is a big supplier of defense and transmission products. kotdwara whose main products are defense equipments and telephone exchange but at the time of its establishment it was mainly established to meet the defense requirement. They are in BANGALORE(KARNATAKA) GHAZIABAD(U.P. It was first established at Bangalore (Karnataka) to help the military of Defense. famous for the Development and manufacturing of professional grade equipments.P.E. Before its establishment. So Bharat electronics Limited came into picture and thus it was established to support Army.E.A. India is one of the three countries in the world. . Hyderabad.A little knowledge about other branches of ’Bharat Electronics Limited’ is shown below in table: BRANCHES OF B. They are Delhi.L’ all over India.L STATE ESTABLISHM AR NUMBER O EMPLOYE GHAZIABAD PANCHKULA TALOJA PUNE HYDERABAD BANGALORE MACHLIPATNAM CHENNAI KOTDWARA UTTAR PRADESH HARYANA MAHARASHTRA MAHARASHTRA ANDHRA PRADE KARNATAKA ANDHRA PRADE TMIL NANDU UTTRANCHAL 1974 1985 1986 1979 1986 1954 1983 1985 1986 2779 638 569 287 410 9005 534 262 598 Regional offices of Bharat electronics Limited: There are mainly six regional offices of ‘B. Chennai.L’ are central research laboratories Bangalore. Agra.E. and Vishakhapatnam. Mumbai. New Delhi. Calcutta. Marketing offices and service centre: The marketing offices and service centre of ‘B.E.E. Mumbai. • Over seas offices of ‘Bharat Electronics Limited’: New York(United states of America) . and Bangalore. Antenna etc. Filters etc. • Shelters for electronics equipments. Periscopes etc Night vision weapon sights etc Panchkula: • Men portable VHF Tran receivers with encryption unit.g. active and passive components up to 189 Hz. • Some microwave components e.g. Y. electron tubes. .. Goggles. silicon Devices. passive components. Gopal Rao Products of Bharat Electronics Limited: (Branch wise) Bangalore: • Communication products e. LCD. Oscillators. Receivers etc • Satcom(Satellite communication equipment) • Sound and vision Broadcasting Transmitters e.• Singapore Director: Mr. • VHF/UHF Receivers and VHF modulators. Ghaziabad: • Radars • Satellite communication systems.g. mobile broadcasting Transmitter and other TV studio equipments etc. Pune: • • • • X ray tubes and X ray cables Ophthalmic lasers etc Machlipatnam: Passive night vision devices e. Binoculars.g. Transmitters. Photovoltaic cells. Chennai: • Gun control and Drive systems for fighting vehicles. • Radars • Components as semiconductor components. • VHF/UHF Hand field/Mobile Tran receivers. FM Transmitter. Taloja: • Hydraulics for T-72 Tank stabilizers. • Electro optical fire control. sea. • N. ship borne. ECMTA. & air borne applications.B. • Servo Pedestal Platforms for land.000 lines. TAX) • Defense products(BEST. ULSB. HDSL< SPARES etc) .• Fire control systems for armored fighting vehicles. RAX. systems. 512 Port Single Base module. SACU.000 lines. SMART. Hyderabad: Kotdwara: • Electronic welfare equipments(Air borne. land borne ) • Telephone exchanges(Max –L-10. MAX-XL_40.C Protection systems for T-72. E. CONSUIMER OF PRODUCTS The main consumers of products of defense department are defense.L Kotdwara are Exchange and Defense products.E.INTRODUCTION TO B. Main products of B. It has mainly two departments• Switching department • Defense and transmission department Complementary to these department there are some other departments too. .L Kotdwara was established in 1986 by Mr.E. such as development and engineering. K. Material recipt and fabrication. marketing.C Pant. While it’s switching products are exchanges that are consumed by BSNL. KOTDWARA B.L. human resources and development etc. It also makes products for others on demand as it supplies its products to other countries and also to others on demand. PPC AND STORES FLOW CHART OF PPC(Production Planning And Control) Receipt of ESO and WO Document collection Preparation of Bills of materials Issue of MM/SC/C PS Launchin g details Briefing papers Follow up Operators for kit formation . drawing. issue to assembly Analyzing problem of assembly.P. special tools Follow up of short age materials.C.CReceive: Equipment stock order (ESO) from marketing and work order (WO) number from management services. stock.P.C UNIT HEAD • P&A(Personal and administration) • F&A(Finance and accounts) • P&S(Plant and services ) • D&E(Development and engineering) • MS(Management services) • EDP(electronics date process) Above are the departments which come under P. documents and issuing change proposal to D&E Follow up to EDP for requirement calculation (PL. and updating its modification.P. QA to final dispatch to FGS(finished good store) OTHER ACTIVITIES: Maintaining. Wip. check ) Briefing paper for production review.P. plated painted parts. MAIN WORK OF P. . checking in computer. Drawing and Prototype equipment from D&E Material requirement of order from EDP (Electronic data process) PURCHASE: Fabricated parts Raw materials. Kit to assembly/sub contract Issue shortage to assy/sc Final equipment follow up from assembly inspection testing. .PRODUCT GROUP: 1. and then store no. quantity. part no. quantity inspection no. ASSEMBLY PPCStore planning INSPECTION TESTING QUALITY ASSURENCE FLOW CHART OF STORE: CPS QA Prod QA C&T QA STU Material receipt ISSUE MRI CHECK CHECK Stores SO/STU/SR/RR Main work of stores: Receipt of materialFrom material receipt and inspection (MRI) document consist supplier name purchase/sub contract order no. part no. Receipt on stock transfer voucher ( STV) from other inter unit stores and other BEL units (consist of unit/store name ) code. 2. Receipt assembly from inspection/C&T/Testing Issue of materialIn kit (list from computer with taps) On rejection replacement (RR) to assembly testing On store requisition (SR) to QA D&A assembly On STV to other store/other unit Finishing shop Other activity: Making store locations etc Feeding data in computer (issued receipt) Checking receipt material and putting store receipt control (SPC) no on tag Checking physical and computer stock Maintaining traceability and store records.Store return note (SRN) from assembly testing for extra material from fabrication/finishing shop. . MAX-L Main automatic exchange-extra large.000 lines)exchanges these days. According to the capacity of exchanges they can be divided in the following typesRural exchange(40 lines) 128 port rural automatic exchange(80 lines) 128 port RAX has 128 ports but we can only provide 80 lines through it because the rest ports are used for other purpose cards.SWITCHING DEPARTMENT The main products of switching department are exchanges. As we know the working of switch.Large(10. Capacity means the number of lines that can be provided through it. This is supplied to ARMY. 256 port rural automatic exchange(160 lines) 512 port single bus module RAX(400 lines) used in small village or colonies etc. As the subscriber raises the receiver from the cradle switch. STEPS INVOLVED IN MAKING AN EXCHANGE Here we shall discuss the different steps involved in making any product (exchange) and the department involved in it. Switching come from the word “switch”.000 lines). the telephone exchanges of different capacities are made. current flows only when switch is on and does not flow when it is off. Kotdwara branch is making 512 ports SBM RAX(400 lines) and MAX-XL(40. . PPC is called the heart of many departments. MAX-L(40. the transmission is possible or the lines comes in ON condition and when subscriber puts it down the lines becomes OFF or the current through the line becomes zero(subscriber is unable to talk to another person).(centre for the development of telemetries technology). The planning of whole project is done by PPC(Production planning and control unit). All these exchanges and other products of switching department follows C. In switching department.000 lines) This is used in big cities and metro cities. Port means number of terminals. In similar manner the telephone exchanges works.DOT technology. other exchanges are made by this factory on order. The working of PPC is divided into three partsProduction Planning Control PPC controls all the planning of the production and other works or we can say that it keeps the eye on whole of the work of the department. Main automatic exchange. the cards are tested by naked eyes to check whether the connections are OK or not.this card connects or switch off the dialed number with the subscriber(who has dialed the number). RAX switch controller card (RSC). It is also checked that no treks are short circuited. After the successful completion of burn in process the product is now ready for sale. are prepared individually and manually as well as by wave soldering technique. Laequqring is the process in which the card is insulated by spraying a liquid on it so that it becomes insulated to any moisture or dust. After that the material management (MM) department manage the whole of the material that is required. GENERAL ASSEMBLY OF AN EXCHANGEMainly four types of cards (designed PCBs) are used in making an exchange.Now first of all any work that has to be done is planned by PPC. It is now finally inspected.The final assembly of the exchange is done where it is passed through following processesSystem wiring Accessories wiring Cage fabrication Cable assembly Mother board mounting After these processes the exchange manufacturing gets completed. The material is then given to MRI(Material receipt and inspection) where it is being inspected by different tests as in electronics laboratory. These results are compared with the ideal one.this card is used to find out the feeded number of subscribers. This process of testing of exchange for seven days is called BURN IN process. It is then dispatch to the customer.This card sense the dialed number and then feed the dialed number to RAP. Finally the material is stored in switching stores. For making an exchange several cards (PCBs) of different circuits that are required.administrative processor card (RAP). Signaling processor card (SPC).these cards are used to provide terminal from the exchange . Control cardsRAX. These cards are tested by the computer along with the tester and then by giving commands the various tests are completed and give out the results. Terminal cards. in mechanical lab and in MTL(Material test lab) to test the metal chemicals etc. When the testing is complete the card is given for laequering process.This is processor. These are – Control cards Terminal cards(interface cards) Service cards Power supply cards 1. After inspection the exchange is now tested in which it is used in critical condition for seven days so that any fault that can occur during its working can be detected.One terminal card (Line circuit card) can give 8 lines so that there are a number .e. Then bill of materials Department(BOM) makes a list of all the materials that are to be used in making it and then finally make the bill of whole of the material used in it. Thus the manufacturing of the cards is completed. After mounting thus the assembly is complete. When the inspection is complete then the cards are sent for testing. 2. Now these cards are inspected physically i. LCC-line circuit card. of terminal cards in exchange to get the desired number of lines from it. It is a four wire which is used for for trunk calls. which is used for tone generations 1 slots. EMF (ear and mouth four wire trunk) This card is used to combine one exchange with an other exchange(at a longer distance) through 8 lines.this card produces different frequencies for different lines so that the messages of different lines do not get intermixed. DISTRIBUTION OF CARDS IN AN EXCHANGE C128 PORTSRAX128 ports has a total of 26 slots in which the slots covered by different cards are explained as be low4 slots.this unit acts just like memory.covered by 2 TGA (tone generator) cards. And a total of (26-10) slots are therefore cards other then 4 power supply cards and 6 control cards so total number of ports=(26-10)*8=16*8=128 ports Assuming that 8 lines can be given from a card.this card is used to test any terminal card. Conference card(CNF)-this card is used for conferencing so that up to three subscribers can talk to each other. RAX announcement cum tones card (RAT). 5. The information on these wires are . service cardsRAX multi frequency card (RMF). Thus this exchange is called 128 port RAX and we can change the number of lines by exchanging one or more number of LCC cards in place of the terminal cards. 6. Suppose one subscriber dails a number then TSU connects this subscriber with the dialed number. 4. 6 slots. Base processor unit is used for metering. power supply cards. each exchange contains BPU and TSU.it contains two lines with each other. Base processor unit. Terminal card is also called by name “Line distribution card”.covered by six control cards (Tone generator with diagonistics) 2 slots. 10 slots.this card is used to supply the power to the other cards. used to give lines to subscriber and we know that 8 lines can be given from a LCC card so total number of lines given from 128 port rax=10*8=80 lines.covered by EEF (ear and mouth four wire).3.covered by 10 LCC cards.covered by TWT (Two wire trunk).four slots are covered by 2 power supply cards. RAX terminal test card. This is a four wire system which has two wires for ear and two wires for mouth.this card is used for different announces if there is any problem and is also used for producing tones. Besides all these cards. It has two types of memories (floppy type and hard disk type). Used for trunk calls. 1 slots. time switching unit. for memory etc. then the other ckt comes in active position.e. A pre maded programme is filled in computer which give instruction to the tester and test the cards. Any line circuit card which which gives out 8 lines have two similar ckts.amplified by repeaters at receiving station thus it is a four wire system.(256 PRAX): Analog information is first coverted to digital pcm at a bit rate of 64Kb/sec. 30 lines i. Working of Exchange:. at a shorter distance).Thirty two such PCM channels from 4 teminal interface card are time division multiplexed to generate one 32 channel 2. trip trunk. It is just like STD call lines from one exchange to another exchange at a longer distance. sizure etc are separated at the terminal interface cards and carried to the signaling processor on the time multiplexed link. Now day’s digital trunks are used.048 Mb/sec PCM link. ring.The card is tested on both the zero level and one level. These TWT and EMF are analog trunks from which 8 lines can be given. CARD TESTING: Testing of cards is generally done by computerized tester. Two wire trunk (TWT) . This announcement here is done by using RAX announcement cum tones card automatically. Signaling information related to terminations such as dialed digits. Transit automatic exchange (TAX). This is a two wire system in which there are two wires one is called tip and other is called ring. But the condition is that if all the 8 lines of card gets damaged. Let we use one EMF card in an exchange so there are 8 lines (terminals of EMF) from which we can make STD call to the attached exchange or let we are using one TWT so only 8 lines(subscriber) can make STD call when any one of these 8 lines become empty (i.Various test r there .e. 30 subscriber can make STD calls from one exchange to the connected exchange simultaneously from one digital trunk. If any particular line (out of 8 lines)get damage then the other ckt doesn’t activates.e.if one circuit damages.e. Thus from 32 terminal interface card 8 such PCM links are obtained. becomes unbusy).4 of these links r terminated on RSC (Rax Switch Controller Card) of master frame and the other 4 are terminated on RSC of slave frame.it is a two wire trunk which is used to combine two exchanges located near each other (i. detecting reversals etc.These exchanges are used to combine more than one exchanges with each other in which all the terminal cards are replaced by two way trunk or ear and mouth four wire trunks. Thus the subscriber other than these 8 if try to make the call hears the announcement “All routes are busy please dial after some time”.then the other ckt comes in on condition automatically. which contains a capacity of 30 lines i. In this type of exchange 12 slots are covered by Emf & TWT cards and one slot is covered by line circuit cad to give 8 lines(4 exchange or operator). POWER AND RINGING : A dc to dc coverter generates the varios voltages required for the system operation and also provides ringing for subscriber loops as 48 V is required for 512 ports RAX. The SPC is used for outpulsing digits. After heating for the certain time.but if it is not ok. All these test r done with the help of computer and a tester and if the card is ok then it is given for system level assembly.debugging aids test etc.The PCB to be soldered is first of all placed at any temperature so as to prevent it from moisture. The solder in the machine is at near about 250degree centigrade. battery reverse test. ring test. For eg. which comes out in the form of the waves from machine. . Inside the machine it is first passed over hot vapors so that the temperature of PCB is increased. The carrier moves it inside the machine. The solder comes out in the form of waves hence this is called wave soldering. voice test. Before this chamber the card is also dipped in the tin oil which prevents the oxidation of solder. It than moves over the solder. the card goes over hot fumes of flux. Wave soldering is done by wave soldering machine in which the mounted PCB is first put down on a carrier. TIE communication test. then it is maintained and given for soldering.then it is given for finding out errors and tested until it gets ok. copy zero select. In an LCC cards the tests are current test . copy one select. Wave soldering. It is then passed over a hot metal piece to raise the temperature. on-hook .loop coack test.for every card. off-hook test. 00000 BHCA with termination capacity of 40.000 lines as local exchange or 15000 trunks as trunk automatic exchange. There are 32 such terminals interface cards. The C-DOT DSS family is ideally placed to meet the different requirements of any integrated digital network. MOS and low power shottkey TTL and bipolar technologies.each terminal interface card caters to 8 terminations. C-DOT 512 RAX. 16 in each frame (it has two frames-slave frame and master frame). C-DOT 256 RAX. C-DOT DSS-MAX –(MAX-XL): universal digital switch which can be configured for different applications as local.SPECIFICATIONS FOR THE CONSTRUCTION OF DIFFERENT PRODUCTSI. transit or integrated local and transit switch. II. high traffic/load handling capacity up to 8. In this low power dissipation and high operational reliability components used are based on CMOS. All the circuitry has been packaged into 18 types of cards. .512 RAX has four frames each having 16 terminal card with six service card and two power supply cards. III. Similarly the main products of transmission are VLSI. make the job of army head quarters easier.1. Selectivity or to a group of stations or as a broad cast to all the station. Lonely out ports from the first line of defense and every conversation made by jawans on the move. BEL provides the backup for India’s fighting forces. The system has the sophisticated networking feature with which message can be routed to a destination. From VHF/UHF to microwave frequencies. Bharat electronics hosts a wide range of communication equipments. SACV etc. Time division modular exchanges Message transmission and encryption equipment Details of products of defense department: I. VHF/UHF ground to air Tran receivers Static/mobile digital trans cater terminals Satellite communication systems Switching equipment as. BEST. encrypted or otherwise. SPARES etc. HDSL. the details of each product are given below. The system utilizes the BCH error detection and correction algorithm to ensure very reliable message communication. Communication is loud and clear. automatic electronic switches 2.DEFENSE DEPARTMENT The next department where I go was the defense and Transmission department. Messages are prepared by the help of key board and can be edited and connected prior to the transmission. SMART is capable of operating over any voice link and is particularly suited for HF radio link. The main products of defense are SMART. BEL moving on a course of self reliance and global competition. PCM. HART. 25W. receivers UHF Tran receivers with built in encryption (5W. Spurt message alphanumeric radio terminal(SMART) SMART is a microprocessor based store and forward burst transmission equipment which provides easy preparation and transmission of alphanumeric messages. ECMTA. 100W). 30W). This product is engineered for easy maintenance and has a built in test facility with additional features like real time clock facility. DEFENSE COMMUNICATION PRODUCT RANGEHigh frequencies transmitters (500W. matching industry standard world wide. automatic message . Tran receivers (25W. Its burst transmission capability together with powerful forward error control coding reduces the probability of interception and jamming. The system with 24 character alphanumeric LED display provide a simple interactive user interface. It is named defense and transmission because the products made in this department are given to defense and transmission is called because the products made in this section are used in transmission of messages. 1KW). Parking facility is provided which enables an external auto LED line to be held while the operator is busy in attending to other calls. To provide operatibility under low visibility conditions. automatic print facility are also provided by the equipment. Eight links have been provided to cater eight simultaneous calls and selection of free link is automatic. Each line can be individually programmed to work in magneto mode. Calling clearing busy and parking indications are provided by means of LED indicator associated with eac subscriber key. Visual LED indicator. The switch board is designed to work with the current types of magneto telephone and has capacity of 15 lines in its basic configuration and can be expanded to 30 lines by coupling two units.numbering date time. ring indicator is provided to indicate ringing current sent by the operator. by which operator can find out with whom the subscriber is busy at that instant. It is also intended for ground or vehicular installation. An individual clear facility is provided to the operator to clear that particular subscriber call. broadcast cell etc. automatic repeat transmission facility. as all the controls are provided on the front panel of the switch board. Conference among four subscribers can be set up by the operator on request. The operation of the switch board is very simple. It’s ruggedised for use at battalion level and is suitable for field use. Illuminations are provided for the keyboard. Automatic acknowledgement of messages for selective cell transmission and manual acknowledgement facility Built in MODEM Built in test facility that can identify fault card Printer interface for hard copy Design for field application and meets JSSSSSS specifications Capable of operating over broad voice link including telephone lines Engineered for easy maintenance and repair output is given in the form of Led display UNIT LEVEL SWITCH BOARD (ULSB): switch board telephone manual 15 lines. When seventh link is allotted. Some of the important features of the equipment are• • • • • • • • • • • • • • Simple man machine interface. A single LED indicator is used to indicate several conditions as follows- . selective cell . To facilitate access to auto exchange. a visual indication is given by blinking of ‘op’ LED indicating that only one more free link is left out for use. a push button electronic dialer is incorporated.4n (ULSB) is a man portable switch board and requires an operator for its operations. identification facility is provided for operator. Speaking and ringing facilities for the operator are provided by an in built operator circuit and a transistorized ringer respectively. Quick preparation and transmission of MOF messages Powerful editing facility Built in high-grade encryption Powerful forward error control coding Synchronous interleaved burst data transmission Powerful networking support. EB mode or auto junction mode. • Night illumination facility for night firing practices. Black terminal is negative one of the battery. It has been designed to use exclusively at short range and has the facility of night illumination. A pluggable head set with single boom-microphone and earphone is provided for operator’s use. A pair of terminal is provided on front panel for external telephone. The polarity of terminal marked in it should be taken with great care. Control panel which facilitates the operations from a desired location has LEDs for indications. These are three separate terminals for connecting secondary battery. The front panel has diagnostic connector which is used for connecting the diagnostic unit by authorized persons. This equipment can be used for improving the firing standards of recruits and to produce marksman. • motor based up and down movement of targets • Having two way linear movements at variable speeds. • Control panel for operation • Control panel at the voltage point. longer time OFF Night alarm facility is provided by means of a buzzer. • Auto stop at extreme ends. There is a battery compartment to accommodate any one of the following types of the battery packs. • In built safety provision. ECMTA is a target simulator for short range firing practice and is excellent training aid for the soldiers. • LED display for indication of operations. TERMINAL TELEPRINTER BURST ERROR CONTROL SYSTEM FOR TELEPRINTER (BEST): The equipment terminal teleprinter BEST is • • • • . • Battery operated.continuous flash ‘busy’-continuous ON ‘clearing’-ON and OFF ‘parking’-short ON. that can be used for sending ring/speech alternate to the internal ringer and head gear assembly. It is dynamic in nature and has two sub systems mounted with four targets.‘Incoming call’. an earthing terminal is provided for grounding the equipment. The two terminals are for +24V and -24V respectively. • MgMNO2 for using in planes and in deserts • LiSO2 for using at high altitudes and low temperatures. ELECTRONICALLY CONTROLED MINIATURE TARGET APPARATUS (ECMTA): Miniature electronically controlled mounted with dynamic targets. • Semi-reggedised mechanical structure. 15 pairs of terminals for termination for subscribers lines are provided on the back panel while connecting a line to auto exchange as a tie line. • A dry cell adapter for using along with suitable instructions for connecting the battery pack is given in the battery compartment itself. It has also the built in test (bite) facility for indicating faulty module during lower on condition. subset call and net call. The equipment has built in Rs 232 port for interface to any serial mini printer or dot matrix printer for taking hard copy. Messages reception is automatic. HART is designed with SMD and ASIC technology to achieve small size and light weight. Its small size. It is also compatible over the link with the BEST and SMART. of the message. The equipment is capable of operation over poor channel conditions. The equipment is capable of operation over any voice link. DATA SECURITY: The equipment can be operated in clear as well as secure mode. The transmitted data is error protected prior to transmission using BCH block code and bit interleaving. light weight. HART is the new number of the data communication product family of burst error control system for teleprinter (BEST) and SMART and it provides all the features of the family. The probability of error free reception of the 1000 character message under 1 in 100 bit error rate is greater than 99%. auto print mode.microprocessor based forward error control equipment for alphanumeric messages. The error control together with synchronous transmission and correlation detection techniques permit reliable data communication. can be used in vehicular role. Equipment BEST MK II A is a semi ruggedised version suitable for use in military role. It is particularly suited for HF radio links printer interface. It has powerful networking feature and supports selective call. The equipment with this port can also be interfaced with the computer for post processing of the data. The powerful line editor enables editing of the messages entered in the memory. The terminal will provide reliable burst transmission capability to reduce radio channel occupancy time with reduction in probability of interfaces and jamming messages are prepared “off air” with the alphanumeric key board and can be edited if necessary. The group call. The equipment has a built in high grade eipher for encryption of the data and powerful prompt messages for status information. HART:HART A57322is a digital message terminal for preparation and transmission of alphanumeric message. The equipment is capable of operation with conventional teleprinters (baudot terminals) and VDUs (ASCII terminals) and supports interworking. The equipment is provided for the selective call. multiple copy print out. date and time. . the equipment has a built in modemfor interface to voice links. Message reception is automatic. It has additional features like automatic message numbering. auto repeat facility etc. It can be operated from battery. Automatic acknowledgement is provided for the selective call. It gives the message on LED display. The equipment in its shock proof frame. It is a store and forward equipment for field use. and low power consumption features make it ideal for field use. A powerful nonlinear encryption always the encodes the data before the transmission. Messages are prepared ‘off air’ from the terminal and transmitted synchronously in the burst mode over the channel. Signaling information from each channel is suitably arranged at 500bit/sec. The products of exchange after are tested in the environmental lab because the product of defense has to face different environmental conditions in the field. This equipment basically multiplexes the voices of the signal output of 30 telephone channels into 2034KbPS. COT (centre office terminal) 2. 2048 Kb/sec PCM data received from the distance is first converted back to unipolar and then HDB3 decoded into NR2 data. the PCM data from all the 30 channel and multi trans alignment codes to form a 2048 Kb/sec unipolar data.KEYBOARD-Alphanumeric MEMORY CAPACITY-3000 characters OPERATING TEMPERATURE RANGE—20degree C-+55degreeC WEIGHT-1. This is generally used so that the net of wires should not be formed between exchange and subscriber. The equipment works from 48 exchange battery with positive pole earthed. This system is based upon time division multiplexing basis. digital data characteristics of this PCM MUX equipment is in accordance with EEITT recommendation 9722. Similarly signaling information of the individual channels are demultiplexed and extended over the individual circuits. Decoder converts the 64Kb/sec PCM data into an analog signal after passing through an in built filter. In this way 30 lines can be connected to exchange through two wires. The total consumption is about 40 Watts for the MUX and signaling units combined together. RT (radio terminal) One COT controls two or three RT boxes and one RT box can control 10 lines on it. in this transmitting direction speech signal from the telephone is passed to the encoder.S. The coder initially band limits the 3-4 KHz and then converts the analog signal into 64 KbPS PCM data.L): This is a small rural exchange (device) which has mainly two parts1.D.2 kg DIMENSION-52*225*112 mm HIGH BIT RATE DIGITAL SUBSCRIBER LINE (H. 2048 Kb/sec clock is extracted from this stream and various control and timing pulses required for demultiplexing are generated. +5Vsupply -5V supply required by the integrated circuits are derived in thepower supply units. in the receive direction. This is again passed through HDBB coder and U?B converter so as to convert into a suitable form for transmitting over the line. PRIMARY PCM MUX VLSI: This MUX equipment is not latest generation making use of the mono channel code and custom built VLSI chips. The various machines used in environmental lab for the environmental testing are given below along with their applications and specifications: . 50-30 lines can be given through a COT We can call it as an accessory for the exchange because we connect it after the exchange. test space. test space-143*78*200 cmcube 3.0 to 25mm.5 Kg 9. -70 degree C to +120 degree C. bump test machine. peak deceleration 40+/-49.2*1.VBT-250 10.test space. displacement-0 to13 mm. TA 2500-@)^/csta 6. Heracus votsch vcm 04/2240/w 3. vertical vibrations test machine VVT-00 9. Behind it we place the PCB on which we have to apply solder.4*2*3.2metre cube 2.10%to 95% relative humidity. test space 2.test space-60*60cm sqr 6. Damp heat chamber. hot chamber ambient to +22degree C. 40 degree c to +70 degree C. max load.test space-47*65*80 centimetre sqr 4. thermal shock chamber heracus votsch Vm52/08/22 4. The whole of the process involved in surface mounting is given below. mini test chamber heracus votsch VMTO4/30 Specifications: 1. test space 1*1*1mtrs cube 7.Description: 1. vibration testing system.5 crores. -40 degree C to 130 degree C. cold heat chamber Heracus votsch VMT07/64 11. This machine is divided into three parts- stencil printer pick and place hot air conventionreflow over stencil printer is the machine by which we fix dry solder on the tracks where SMT have to be used. -40degree C to+180 degree C 10% to 95% relative humidity test space. the solder is put on . -70degree C to 180 degree c. The whole of the cost of the surface mounting machines is near about 2.40*40*50 cm cube 10.displacement. test space-1. capacitors etc are in the form of small chip and these are soldered on the copper side of the PCB by surface mounting machines. 5 to 50 Hz. height of drop -25+/-4mm. For starting the process. Kas co industries 8. Dry heat chamber.5*63124 cm cube 5. angelantoni elinate system 7.UN hot T2 DICIE. max load-50 Kg. Heracus votsch vlk 04/1000 5.35*25*375mmcube SURFACE MOUNTING TECHNOLOGY (SMT):This is a new technology in which some components as resistors.113. 40 degree C to 100degreeC. Cold heat camber. cold chamber_80 degree C.2mtrs cube. work space60*60cm sqr 8.129. 5 Hz to5KHz.2*1. Walk in chamber VCK204/10015-dv 2. A pre made stencil is fixed in it which have holes in it according to the places on the PCB on which we have to apply the solder. T (material clearance and transit department) and make a consignment.e. few samples are taken and tested. electronics lab 2.R. material test lab (MTL) to test the metals. It does not lie in any other state.I DEPARTMENT Material receipt and inspection department receives all the necessary components and materials used in a product and inspected it thoroughly and then forwarded it to the store.e. to complete the soldering process. the solder used in the stencil printer is an alloy which is made from Sn. Ag. The solder may contain Sn=63% and Pb=37% This solder is used because it remains only in two conditions i. M. After applying solder this PCB is given to the pick and place machine which picks the right component and mount it on the PCB with the help of the data that was feeded in it before. These strips are grounded to earth through a wire so that the component may not get damage. Here I also want to give or explain about the solder used in manual or wave soldering. WORKING: M.R. molten state or solid state. Now the component or the material goes through their respective tests. ELECTROSTATIC PRECAUTIONS: A blue colour conductor strip is tied by the workers to prevent the components from electrostatic shoks. BEL Kotdwara brought the solder from a Delhi Dealer and the pre made stensils are bought from Mumbai. It is divided into three sub departments. and Pb. All the tests of any quantity of the material is done in the sampling process i.I receive the material from M.the stencil and a wiper pushes and pulls it and spread it in the stencil so that the solder drops down from holes on the PCB.C. After completion of these tests and reports MRI makes final ICRR and then issue the material to their respective stores which pays the money to MRI and then MRI paid it to the dealer. In this process the temperature is increased slowly in steps and also decrease in steps after reaching to the temperature near about 250 degree C. chemicals etc. It is much costlier (cost near about 4000Rs/Kg) and is an international product. The depth of the solder can be controlled by the distance between stencil and PCB. handling over performance (CHOP) of the received material. • Approval of manufacturer • Dimensional checking • Functional checking After these tests the MRI department makes a report MIR(material inspection report) in which it remarks whether the material be accepted or rejected.e. mechanical lab 3. The mounted PCB is then placed in the hot air convention reflow over to heat the solder and tighten the components i. 1. The PCB is heated to the temperature whatever needed in the oven. We know that as we move or work then an instantaneous electrostatic . After receiving the step involved is its counting and reporting back to MCT where ICRR (inspection cum receive report) is made in which there is detail of quantity of the material. COMPUTERISED IC TESTERS This test is done by computer and a premade program is feeded in computer decoding to which the tester gets different instructins from computer and test the IC .It also checks whether the component is ok or not. It is somewhat similar to computerized IC tester because we give input commands to the tester just as we give commands in computerised testing. shall consist of 12 digits to designate assemblies. subassemblies. MAGNIFIER Magnifier is used to look at the tracks of PCB so that they did not interconnected or short or open in between. manufactured parts. IC TESTERS Two types of IC testers in the factory are 1) Nickie-Dickie IC tester 2) Computerised IC tester Nickie-Dickie it is an electronic device which test different ICs having upto 40 pins . The rest of the work is done by tester itself. Check digit is used to identify the correctness of the number Let the no is 5000 003 457 Then it is multiplied by 100 and divided by 97 as 5000003457*100/97 Now reminder is subtracted from 97 as 97-17=80 Then check digit for this number is 80 so number is 5000 003 465 80 .it is a computerized system in which we have to give commands and connect the componenets on two pins . HOLE GAUGE Hole gauge is a device which I used to see the width of the holes in PCB.energy is induced in our body which may be of hundreds or thousands of volts. LCR SOR TESTER This tester is used to test the values of inductance . DIGIT NUMBERING SYSTEM Each item shall be uniquely identified by only one number irrespective of whether it is imported or manufactured. machinery and not the production items. tools . Two digits are as the check digits. Every part no. It measures in mm. components. This electrostatic energy gets discharged instantenously but if this high voltage goes to component then the component may damage so to prevent the components we need electrostatic precautions. capital items. capacitance and reristance . In this testing we can check ICs upto 40 pins. material. 9th. as 4 is used for electronics components 2nd digit denotes the unit of the bharat electronics as 1 is used for the Bangalore unit. . Thus it is all about I have learned in my vocational training.97 is taken because it is based on mod 97 system.10th digit indicates the serial number and 11th& 12th digit as we know indicates the check number. The various digits are used to indicate the data’s the first digit denotes the type of material as electronic component. Third digit denotes the various originating drawing offices of BEL Bangalore as follows0-cdo-1 1-reserved th 4 digit denotes a composite assembly drawing as 3 for PCB assembly. capital item etc. 5th digit shall indicate source of the PCB design as 0-in house design 1-indian defense cabs th 6 digit indicates the function of PCBas 0-power supply card 1-indicates control card seventh digit shall indicate environmental severity of use of PCB as 1-army static 2-for army mobile 8th. TRAINING REPORT (BHARAT ELECTRONICS LIMITED. KOTDWARA) Submitted by-AJAY KUMAR (Electronics and communication engg) .