Gere

Part one Internship report Executive summery This report is written in almeda textile factory it includes the brief history & back ground of the company this means how the factory is established & with what type of materials were began its work & how the raw materials which are brings either from abroad or domestic raw materials are being changed in to product & what type of steps are used to produce them additionally we explain how the machines are operate mechanically & electrically in order to perform the desired task again we describe the working flow all the productive & non productive/supportive departments include in the factory particularly for a machine it is called scouring bleaching machine which is found in processing department since we have been working in this section therefore we could describe briefly all the working principles ,working flow /procedure & generally how it operate related with mechanical department & its currently efficiency additionally we can realize how good we have been in performing our task from the explanation again we include the measures that we have taken in order to over come these challenges finally we explain how we improving our practical skills, up grade our theoretical knowledge ,improving inter personal communication skills & the knowledge that we gained in terms of entrepreneur ship skill etc .

Vision: 

Almeda is committed in creating a Hub for excellence in the textile field in Africa in general and Ethiopia in particular.

Mission: 

To boost the assets of the company.

Objective: 

To support the society and be involved in the development endeavors of the region in particular and the nation in general.

Quality Policy:

  

Understanding, Researching and Meeting the Customers needs and Expectations. Creating and Maintaining a motivational and conducive environment in which people would become quality conscious. Enhancing quality assisted by appropriate information systems.

Chapter one Back ground of the company Almeda textile factory (ALTEX) is one of the non governmental entities that were situated seven kilo meters from center of Adwa or seventeen kilo meters from center of Axum at main road Adwa to Axum & 1006kilometer from Addis Ababa & 233 kilometer from Mekele capital of Tigray region. Almeda Textile PLC (privet limited company) is located amidst the beautiful mountains. There is an air port capable of handling small plains at Axum near the mills site. A part from other alternatives the factory is directly linked with Djibouti for import/export incidentals. Almeda textile is the biggest textile manufacturing company in the country it has100 million birr sales volume that is 7o% sales in local market &30% volume in global market. Almeda enjoying from complete new production lines imported from; Switzerland, Italy, Germany, & Japan that makes up total investment of 94.22million USD. Employing expatiates to ensure efficient quality & low cost production availability of local cotton of top quality & the prevalence of well trained & highly motivated employees. Favorable site policies & intensified management support. Almeda is one of companies of the EFFERT (endowment fund for rehabilitation of Tigray) with an objective to enhance the investment opportunity; the group is ready to cooperate with other companies & individuals who have interesting in investing in the region. Besides the company aims at getting acceptable rate of return on its investment for the provision of quality products & services & for satisfying its customer, The company has its own management system modern technology to produce high quality product with low cost & to succeed in the local international marketing effectively in its management system the company have different department to facilitate & perform all activities that carried out in the company. The department can be divided in to production department & service giving department.

Production departments: Are department those aimed in producing the product with good quality & product that has the best value on marketing. These production departments are:1) 2) 3) 4) 5) 6)

Spinning department Weaving department Wet processing department Circular knitting department Knitting department Garment department

Service giving departments: Are departments that support & facilitate the production departments & the whole company in succeeding their aim & target plan effectively. These are:1) 2) 3) 4) 5) 6) 7)

Marketing department Supply procurement department Finance department Planning & product development department QMS & System development department Human resource department Engineering department

Main products & Service

Almeda textile componey can manufactured high quality fabrics and fabric products with modern technology, machines and high quality chemicals. But , the major products produced in almeda textile companey‟s are as follows

 rib stop – a cloth for solidures  plain – a cloth which makes up and down  plain pic  twill –which is diagonal(z or s shape) example:- eagle foam  canvas  terry  Shirts  Trousers  Work Wear  Shorts

 Bed-Sheets

Main customers of almeda Guna:  Pillow cover  Bedsheet

Messebo:  Cap  Trouser  Work jacket

 Over all of long sleeve

Altex oromia police & federal police  Workers uniform  shirt  Work trouser  Trouser

Local :  Cap  Bib trouser

QC-supply:  Bib trouse  Short sleeve over all

tigray police:

 trouser and shirt  long sleeve overall

military of national defence :  cap  trouser  shirt

beggali  work jacket & work overcoat  bib and race

OVER ALL WORK FLOW OF ALMEDA TEXTILE FACTORY Raw material store

Spinning department

Waving department

Knitting processing department

Woven processing department

Woven garment

Chapter two Overall internship experience section of the company we have been working: In aletex there are seven departments but since we were instructed to spend our time in this department we are mainly visited this department. So that, we have been working in woven processing and processing sections of the company. But this mean we were not restricted working only at this department. Processing department :- is to produce quality product which satisfy's the requirements of customer with a minimum cost of production. Textile processing :- is the process which gives color to textile material the color given to the textile material by dyeing, bleaching and printing processes is responsible for the attractiveness of the textiles. Processing plays a great role in value adding by products which contributes maximizes profit in Almeda Textile Plc. the department can produce up to 800,000 meters per month. Machine availability:

Singing&Desizing

The operation of singeing & desizing

Scouring/Bleaching

The operation of scouring & bleaching machine Machine status:-is set from the operation panel. Generally there are four different machine status can be selected.  During preparation the corresponding compartment are filled with water & chemical and if necessary heated.  In the status stand by all drives & pumps switched off, all valves shut, all automatically functions are blocked. For service reason , the pumps & valves can be operated manually.  In the status production the range can be operated ,also water & chemical are fed & heating is done according to recipe at emptying all the compartments & filter boxes are operating in automatic . Operaion mode:-the operation mode defines the kind of operation of the machine. The operation mode s will be selected as the operation panel. OM1 roller bed in feed OM2 continuous 1 OM3 roller bed out feed OM4 continuous 2(with out steamer or washing only) Fabric guidance Impregnator bleaching :-the fabric guidance is affected in a tight strand manner through the impregnator & through the dip-sat in to the steamer . Dip-Sat bleaching:-the fabric is guided from the Fx –squeezer position over the impregnator to the dip-sat . Main drives :-each main drive can be switched ON-OFF respectively over the operation panel then individually run forward or backward. Auxiliary drives:-they are running in connection with the corresponding main derives

Non stop batch changing at the entrance:-the cloth scary is used for batch changing while the rang is running. The empty one is replaced by a full one with stopping the range. For the scary control the 3- buttens, filling scary start, filling scary stop, empting scray stop (reset) are used. Non stop batch changing at the exit:-the close scray is used for the batch changing while the range is running. The batch is replaced by empty one with out stopping the range. For the scray control the two buttens, sochor stop, sochor quit are used. Circulation pumps(counter current pump):-all pumps provided with dry, run protection. if there is no liquid level the pumps will be stopped. after there is again enough liquid with in the filter boxes . Dosing pumps :-the dosing is used for the controlled feeding of chemicals into the operating liquor according to the different recipes. Dosing process :-the dosing is made according to different control inputs , according cloth weight , incoming quantity or pre-set PH value. a dosing impulse is always made when the control input has reached the level for a dosing unit there by a minimum difference b/n set &actual chemical quantity is reached. Chemical dosing at the DIP-SAT:-via high precise dosing the d/t recipe components are feeded into the self cleaning filter & mixed there with a circulation pump the chemical fed into the dip-sat & distributed over the whole cloth width by means of feeding channel. The chemicals are dosed in ml/kg fabric weight the H2o quantity of the liquor pick up of the fabric. Chemical dosing at the impregnator:-the impregnation compartment is filed with H2o via solenoid valve up to the level mark .the composition of the liquor, the fabric weight as well as speed of the rang is set at the operation channel. Acid dosing at the washing compartment:-the dosing pump operates at the pre selection of acetic acid dosing .in accordance with set PH value. The required ph value of the washing liquor is set at the operation panel. Filling water valves:- filling is done during machine status preparation until the over flow level of the compartment is reached . Heating (steam valves):- the control of heating valves is made by a set value or actual value comparison of the temperature .the temperature regulators are subordinated to the operation panel. The heating valves can‟t open if the discharge valves are open.

Stenter

Printing

Inspection

Woven processing department can produce:       

Different shirting's (100% cotton and polyester cotton blend) Different canvases Different sheeting(Dyed, printing and bleached Denims Military uniforms (plain and rib stop) Polyester cotton blend twills 100% cotton twills (dyed and bleached Chino trouser

WORK FLOW IN THIS SECTION

Weaving department

Dryer

Gray inspection

processing

Singeing&De sizing

Scouring &bleaching

Stenter 1,2

Printing

Loop steamer

Stenter 1,2

Customer

Inspection

Rolling&Fold ing

Garment

Mercerizing

Washing

Stenter 1,2

Dyeing

Washing

Stenter 1,2

Garment

Rolling&Fold ing

Inspection

Customer

Sanforizing

Process flow chart D/COTTEN

DYED P/ COTTEN

PRINTED

DYED PRINTED

TWILL BLEACH OPT---

Singeing& desizing

Singeing& desizing

Singeing& Desizing

Singeing& Desizing

Singeing & Desizing

Half bleach

Half bleach

Half bleach

Half bleach

Half bleach

Mercerizi ng

Drying

Dry

Drying

Mercerizi ng

M/wash

Heat setting

Tint

Heat set

Opt bleach

D/widden

Dyeing

Print

Dying

Finish

Dyeing

D/wash

Curring

D/wash

Insection

D/wash

D/dry

Finish

D/dry

D/dry

Finish

Inspection

Repellant

Finish

Inspection

Inspection

Dry Widden

Print

Curring

Finish

Inspection

Working Activities As a company almeda textile company participates on many activities, such as, spinning, weaving, processing, knitting, garmenting and so on. But we stay in almeda textile company to gather experience on the processing department and we work in detail on these activities on the process of how to control over flow of water or chemicals feed in the tank. During staying time the site supervisor made us to participate in many woven processing related activities as an example in developing the aware of knowhow about the application of plc in the level control , method study and method study procedures, how to perform the efficiency of the company, e.t.c. When we joined in to the project the site supervisor gives us a lecture about all activities that take place in the project for one week. After a week we try to participate on simple activities with the electricians But after two weeks the site supervisor gives us a theoretical assignment relative to the structure that helps us to do well. Such as overview of the seven departments. In addition to the above activities, I also have been executing on the following work tasks . 

On the operation of level control



Flame control



Mixer control

Procedure and methods used  The main procedures and the work tasks are:

Direct observation and attending in the whole processes and activities of a controlling mechanism.



Finding the problems faced in processing department related to control & instrumentation stream.



Selecting the main problems to be researched



Finding the best solution of these problem .



the main procedures and methods were: select the electrical components such as plc controller, Temperature controller, potentiometer , pressure switch, air valve solenoid, level controller, taco generator ,ac/dc motor , ac/dc converter, timer, contactors, relays, inverters, bridge rectifier e.t.c.  understanding the function & characteristics of each devices.  Advantage & disadvantage of these devices

Challenges facing in work tasks As we expected, we have faced so many problems in our staying in the internship program some of the difficulties are.  Site language- when we joined in to the project the name of woven processing material made confusion.  Work flow- since our site is too vast one worker (employee) can work in many or more than one works. This make us confused to separate the workers to communicate with us or to help us by their profession.  Experience of the employee-while asking a question they lose a confidence, since they are not experienced. They have not able to communicate freely with us.

Measures to solve challenges As we mentioned, we were faced with a lot of challenges, we had look alternatives to solve them. To solve these problems or challenges we have taken the following measures.  To solves the challenges regarding to site language we decide to create a good relationship with the daily workers of the department. All things are simple to know on process after a time.  To know the work task of each employees we decided to arrange a program that meets with the employee for each then the problem is solved and they are volunteer (responsible) to accept our program.

 The challenges regarding to experience as explained above we have good friend ship with all the workers or employees, so it helps to build a confidence and to communicate with us freely, at that time we get a good experience form the employee and from the skilled persons. Generally most of the challenges were solved through our effort after hard working.

Part two Internship project Chapter one Controlling overflow of feed water tank

Introduction Controlling overflow of feed water in tank is a crucial mechanism in our day to day activity. In our surrounding it is common to observe that plentiful of water is wasted from tank. To avoid such a problem we have tried to design a mechanism of controlling this overflow of water using a concept of control & instrumentation. The level of liquid in a tank can be measured directly by monitoring the position of the liquid surface or indirectly by measuring some variable related to the height. One of the direct methods is floating mechanism by using mechanical actuators we could, however, have controlled the liquid level by means of an electronic Control system. We thus might have had a level sensor supplying an electrical signal which is used, after suitable signal conditioning, as an input to a computer where it is compared with a set value signal the difference between the error signal, then used to give an appropriate response from the computer output. This is then, after suitable signal conditioning, used to control the movement of an actuator in a flow control valve and so determine the amount of water feed in to the tank.

Problem statement &justification    

There is plc control problem There was no floating ball Lack of differential amplifier It is not automatic

Objective of the project This project explains how to control the over flow of feed water tank by using electrical controlling system. We design this controlling system by proper selection of mechanisms and components like: Proper selection of sensors and signal conditioning element. Proper selection of micro processor Proper selection of actuator Construction of Boolean circuit and Proper PLC programming.

Methodology An automatic control system for the control of feed water tank could involve a displacement sensor, after suitable signal conditioning, feeding an electrical signal to the input of a computer where it is compared with the set value and value of signal generated. This is then acted on by the computer to give at its output a signal, which, after suitable signal conditioning, might be used to control a water over flow and hence the water tank. Such a system can readily be programmed to give different level at different position of the floating ball. Here is the schematic flow diagram of the over flow controlling system of a feed water tank used to maintain a constant water level in a tank. The reference value is the initial setting of the lever arm arrangement so that it just cuts off the water supply at the required level. When water is drawn from the tank the float moves downwards with the water level. This causes the level arrangement to move linearly and the wiper in the potentiometer moves linearly over the resistance element to produce voltage.

(A) Schematic diagram of water level control

(B)Block diagram of water level control

Controlling Mechanism Over flow of water tank is controlled by using floating system. The working mechanism of the controlling system is as follows. When the water flows up ward the floating ball connected to the lever moves up ward. The lever also connected to the wiper (slider) of potentiometer. When the floating ball moves up ward the lever pushes the wiper so the potentiometer reads the distance covered by the lever and convert it to voltage. The error voltage produced in potentiometer is amplified by differential amplifier and it is converted from analogue input to digital out put (A/D) by successive approximations. The out put from ADC is processed in the micro processer and gives an out put to the digital-to-analogue converter (DAC) called R-2R ladder network converter. The R-2R ladder network converts the digital in put to analogue out put (voltage or current), this current also converted to pressure by a current to pressure converter in order to actuate the actuator valve. The valve is push button valve with inside spring to return up the valve. If the pressure produced from the current to

pressure converter is greater than the pressure of the spring, then it is closed. If not the valve is open.

Figure controlling system

Literature review History of PLC PLC were first introduced in 1960‟s. the primary reason for such adevice was eliminating the large cost involved in replacing the complicated relation based machine control system.Bedford associates proposed something called amodular digital controller(MODICON) to major US car manufacture. Other companies at the time proposed computer based schemes.one of which of based up on PDP-S. the MODICON OS4 brought the word‟s first PLC in to commertial production. When aproduction requirements changed so did the control sytem. This becomes very expenssive when the change is frequent, scincerelays are mechanical device that also have alimited life time which required strict adhesion to maintenance schedule. Troubleshooting was also quite tedious when so many relays are involved. These “new controllers” also had to be easly programmed by maintenance are plant engineers.the life time had to be long and programming changes easly performance. They also had to servive the harsh industrial enviroment.

What is a PLC? A Programmable Logic Controller, PLC is a digital computer used for automation of industrial processes, such as control of machinery on factory assembly lines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result. A PLC (i.e. Programmable Logic Controller) is a device that was invented to replace the necessary sequential relay circuits for machine control. The PLC works by looking at its inputs and depending upon their state, turning on/off its outputs. The user enters a program, usually via software, that gives the desired results. PLC are used in many “real world” applications. If

there is industry present, chances are good that there is a plc present. Almost any application that needs some type of electrical control has a need for a PLC. A programmable logic controller, commonly known as PLC, is a solid state, digital , industrial Computer using integrated circuits instead of electromechanical devices to implement control functions. It was invented in order to replace the sequential circuits which were mainly used for machine control. They are capable of storing instructions, such as sequencing, timing, counting, arithmetic, data manipulation and communication, to control machines and processes. PLC have many definitions for example: According to NEMA(National Electrical Manufacture‟s Association ,USA),the definition of PLC has been given as “Digital electronic devices that uses a programmable memory to store instructions and to implement specific functions such as logic , sequencing, timing, counting, and arithmetic to control machines and processes.” Figure below illustrates conceptual diagram of PLC application

Fig 2.1 PLC conceptual application digram

Basic parts of PLC:All programmable controllers contain a CPU, memory, power supply, I/O modules, and programmable devices. Basic parts of the PLC are as follows: Processor  Memory  Input/output devices  Programming panel or unit  Power supply

Those can be shown in block diagram as shown below:

Fig 2.2 basic parts of PLC

Processors module:Processor module is the brain of the PLC. Intelligence of the PLC is derived from microprocessor being used which has the tremendous computing and controlling capability. Central processing –unit (CPU) performs the following tasks: Scanning  Execution of program  Peripheral and external device communication  Self- diagnostic Power of PLCs depends on the type of microprocessors being used. Small size PLCs use 8-bit microprocessors where as higher order controllers use bit-slice microprocessor in order to achieve faster instruction execute. Modern day PLCs vary widely in their capabilities to control real world devices, like some processors are able to handle the I/O devices as few as six and some are able to handle 40000 or more. The no. of input/output control of PLCs depends on the, hardware, software, overall capacity and memory capability of the PLCs.

The CPU upon receiving instruction from the memory together with feedback on the status of the I/O devices generates commands for the output devices. These commands control the devices on a machine or a process. Devices such as solenoid valves, indicator lamps, relay coils and motor starters and typical loads to be controlled. The machine or process input elements transmit signal to input modules which in turn, generates logic signal to the CPU.CPU monitors the input like selector switches, push buttons etc. Operating system is the main workhouse of the system and hence performs the following tasks: Executions of application program  Management of memory  Communication between programmable controller and other units  i/o handling of interfaces  resource sharing  diagnostics Note:- operating system stored in ROM(non –volatile) memory, whereas application program are stored in RWM(read-write memory). There are many types of input modules to choose from. The type of input module selection depends upon the process, some example of input modules are limit :-switches, proximity switches and push buttons etc. nature of input classification can be done in three ways, namely: low/high frequency  analog/digital (two-bit, multi-bit)  maintained or momentary  5V/24V/110V/220V switched Some most industrial power systems are inherently noisy:- electrical isolation is provided between the input and the processor. Electromagnetic interference (EMI) and radio frequency interference (RFI) can cause severe problems in most solid state control systems. The component used often to provide electrical isolation within I/O cards is called an optical isolator or opto-coupler. Typically, there are 8 to 32 input points on any one input modules. Each input point is assigned a unique address by the processor.

Output modules:Output modules can be used for devices such as solenoids, relays, contractors, pilot lamps and led readouts. Output cards usually have 6 to 32 output points on a single module. Output cards, like input cards, have electrically isolation between the load being connected and the PLC. Analog output cards are a special type of output modules that use digital to analog conversion. The analog output module can take a value stored in a 12 bit file and convert it to an analog signal. Normally, this signal is 0-10 volts dc or 4-20ma. This analog signal is often used in equipment, such as motor-operated valves and pneumatic position control device. Each output point is identified with a unique address.

Addressing scheme:-

Each I/O device has to be identified with a unique address for exchange of data. Different manufacturer apply different method to identify i/o devices. One of the addressing schemes may be “X1 X2 X3 X4 X5” where  X1 = input or output designation fixed by hardware  X2 = i/o rack number in PLC (user designation)  X3 = modules slot number in i/o rack (fixed by hardware)  X4 X5 = terminal number (fixed by hardware) For example,” 1 2 3 13” implies that input is at rack 2 , module slot no.3 and terminal address no.13.

Programming unit:It is an external, electronic handheld device which can be connected to the processors of the PLC when programming changes are required. Once a program has been coded and is considered finished, It can be burned in to ROM. The contents of ROM cannot be altered, as it is not affected by power failure. Now a day‟s EPROM/EEPROM are provided in which program can be debugged at any stage. Once the program is debugged, programming unit is disconnected; and the PLC can operate process according to the ladder diagram or the statement list.

Communications in PLC:There are several methods how a PLC can communicate with the programmer, or even with another PLC. PLCs usually built in communication ports for at least RS232, and optionally for RS 485, and Ethernet. Mod bus is the lowest common denominator communication protocol. Others are various field buses such as profibus, interbus-s, foundation field bus, etc. PLCs are becoming more and more intelligent .in recent years, PLCs have been integrated in to industrial networks, and all the PLCs in an industrial environment have been plugged in to a network. The PLCs are then supervised by a control center. There exist many types of networks, SCADA (supervisory control and data acquisition)

Operation of PLC:During program execution, the processor reads all the inputs, and according to control application program, energizes and de-energizes the outputs. Once all the logic has been solved, The processors will update all the outputs. The process of reading the inputs, executing the control application program, and updating the output is known as scan. During the scan operation, the processor also performs housekeeping tasks. The inputs to the PLCs are sampled by processor and the contents are stored in memory. Control program is executed, the input value stored in memory are used in control logic calculations to determine the value of output. The outputs are then updated. The cycle consisting of reading of inputs, executing the control program, and actuating the output is known as “scan” and the time to finish this task is known as “scan time”. The speed at which PLC scan depends upon the clock speed of CPU. The time to scan depends upon following parameter: Scan rate  Length of the program  Types of functions used in the program Faster scan time implies the inputs and outputs are updated frequently. Due to advance techniques of ASIC (application specific integrated circuit) within the microcomputer for specific functions, scan time of different PLCs have reduced greatly. As PLCs have developed and expanded, programming languages have developed with them. Programming languages allow the user to enter a control program into a PLC using an established syntax. Today‟s advanced languages have new, more versatile instructions, which initiate control program actions.

These new instructions provide more computing power for single operations performed by the instruction itself. In addition to new programming instructions, the development of powerful I/O modules has also changed existing instructions. These changes include the ability to send data to and obtain data from modules by addressing the modules‟ locations. For example, PLCs can now read and write data to and from analog modules. All of these advances, in conjunction with projected industry needs, have created a demand for more powerful instructions that allow easier, more compact, function-oriented PLC programs. The three types of programming languages used in PLCs are: Ladder  Boolean  Grafcet But we are focused on the first type of PLC programming languages

Results & Discussion Mathematical and Electrical modeling Modeling of the tank Consider a simple liquid level system shown below where a tank is supplying liquid through an out let. Under steady conditions, let

be the liquid flow rate in to the tank and

is the steady liquid head in the tank obviously

Let

be the out flow rate, while

=

be a small increase in the liquid in flow rate from its steady state value. This increase in liquid

in flow rate causes increase of head of the liquid in the tank by H, resulting in increase of liquid out flow rate by: =

⁄

The system dynamics is described by the liquid flow rate balance equation. Rate of liquid storage in the tank = rate of liquid in flow – rate of liquid out flow. There fore the equation is given by:

Where: C - The capacitance of the tank and R - The total resistance offered by tank outlet and pipe

Modeling of potentiometer Wipes 2 3 The relationship between

and

If load

, The total resistance of potentiometer will be: = (1-x)

(

)

here we have express xVs in terms of Vo just like the following

xVs=VoRp/RLx (1_x) +Vo Error due to the attachment of =Vo, but

Vo=

(

is:

)

VL=xVs-e , here we have to express Vo in terms of Vs.

xVs= (xVs-e) (Rp/RLx) (1_x) +xVs+e e = (xVs_e) Rp/RL (x_x^2) Here we have simplified & collect like terms we will get the following result. e (1+xRp/RL_x^2Rp/RL)=VsRp/RL(x^2_x^3) In this case the term (1+xRp/RL-x^2Rp/RL) is all most one. So that the error voltage be comes………..

Proper selection of sensors and signal conditioning element Selection of sensor The term sensor is used for an element which produces a signal relating to the quantity being measured. Thus in the case of, say an electrical resistance temperature element, the quantity being measured is temperature and the sensor transforms an input of temperature in to a change in resistance. In this project the type of sensors that we have selected is water level sensor which is float system potentiometer which is a displacement sensor.

Potentiometer: A potentiometer consists of a resistance element with a sliding contact which can be moved over the length of the element. Such element can be used for linear or rotary displacements, the displacement being converted in to a potential difference. An important effect to be considered with potentiometer is the effect of a load RL connected across the output. The potential difference across the load VL is only directly proportional to VO if the load resistance is infinite. For finite loads, however, the effect of the load is to transform what was a linear relationship between output voltage and angle into a non-linear relationship.

Signal conditioning element The output signal from the sensor of a measurement system has generally to be processed in some way to make it suitable for the next stage of the operation. The signal may be, for example , too small and have to be amplified, contain interference which has to be removed, be non-linear and require linearization, be analogue and have to be made digital. Be digital and have to be made analogue, be a resistance change and have to be made into a current change, be a voltage change and have to be made into a suitable size current change, etc. All these changes can be referred to as signal conditioning.

Figure Signal conditioning element The operational amplifier: the basis of many signal conditioning modules is the operational amplifier. The operational amplifier is a high gain d.c amplifier, the gain typically being of the order of 100 000 or more, that is supplied as an integrated circuit on a silicon chip. There are different types of circuits that might be used with operational amplifiers when used as signal conditioners. In this project we select the differential amplifier. Differential Amplifier: differential amplifier is one that amplifies the difference between two input voltages. Since there is virtually no current through the high resistance in the operation amplifier between

the two input terminals, there is no potential drop and thus both the inputs X will be at the same potential. The voltage Vref is across resistors Rf and R2 in series

=220v V=

± error voltage

Error for potentiometer is:

Assumptions taken are:

=0.1 =220V V=

± error voltage

(

(

)

)

For the differential Amplifier The Assumptions are: The gain of the amplifier is:

,

Binary conversion system: 5

From MSB

LSB

1

2

1

1

0

1

1 11V

least significant bit

most significant bit

(1011)

Analogue-to-Digital converters (A/D): The input to an analogue-to-digital converter is an analogue signal and the output is a binary word that represents the level of the input signal. These binary words that represent the level of the input are done on the above calculation which gives the result: 11V

(1011)

There are a number of forms of analogue-to-digital converter, the most common being successive approximations, ramp, dual ramp and flash. Successive approximations are probably the most commonly

used method. The figure below illustrates the subsystems involved.

figure analogue-to-digital converters (successive approximation) operation of the successive approximation is based on binary search. Initially , the register provides an out put corresponding to half the range(1011) If the analog input is greater ,then MSB = 1,else LSB =0 The resister performs the same operation from MSB to LSB. The advantage of successive approximation is: Much faster in counting  The DAC output converges on the analog signal input In much larger steps than with the 0-to-full count sequence of the regular counter.

Digital-to-Analogue converter (D/A): A simple form of digital-to-analogue converter uses a summing amplifier to form the weighted sum of all the non-zero bits in the input word. The input to a digital-to-analogue converter (DAC) is a binary word: the output is an analogue signal that represents the weighted sum of then non-zero bits represented by the word. Thus, for example, an input of 0010 must give an analogue output which is twice that given by an input of 0001.

Figure digital to analog convertor There are different types of conversion mechanism systems of digital to analogue converter. From these types the most commonly used is UsingR-2R ladder network. This R-2R ladder network. Over comes the problem of obtaining accurate resistances over a wide range of values, only two values being required. The figure is shown below:

Figure Digital-to-Analogue converter (D/A) We are considering the four bit DAC as shown in the figure above .the connected to vref will generate a current that flows towards to the inverting input of the op-amp which will be halved by the resistor network at each node. Therefore, the current contribution of each input is weighted by its position in the binary number.

Selection of Actuator Actuation systems are the elements of control systems which are responsible for transforming the output of a microprocessor of control system into a controlling action on a machine or device. Thus for example, we might have an electrical output from the controller which has to be transformed into a linear motion to move a load. Another example which can be use in this project is that where an electrical output from the controller has to be transformed into an action which controls the amount of liquid passing along a pipe. A mechanical actuation system which is a POPPET VALVE was selected in this project.

Figure High-vacuum-valves

POPPET VALVE: Poppet valves incorporate a manual or mechanically operated plunger, which is normally held in the closed position by a spring or by air pressure. Depressing the plunger opens the valve and allows air to flow. A seal is achieved between the plunger and the valve seal by means of flat discs and washers, O-rings or spherical closures.

Figure Poppet valve One of the main advantages of poppet valves is their relative simplicity, with a minimum of moving parts. They are also self-cleaning, using the purging effect of the fluid flow, and require little maintenance. Although poppet valves have a short stroke before maximum flow is achieved, they can only be operated in an open or closed position, making it difficult to regulate the flow path through the valve. Poppet valves are not suitable for complex switching operations, where a combination of inputs and outputs are required. They can also be affected by fluctuations in input pressure, which increases or decreases the actuation force needed to open the valve seal.

Construction of Boolean circuit CONDITIONS Condition 1: water is at a full level Condition 2: water is at a low level Statement State 1: the water flow stops at full level of water tank State2: the water flow starts at low level of water tank

Define the Boolean variable B - State of height detector A - State of water level sensor Y - Stop over flow of water C- Poppet valve C= 0 full level 1 low level Write the quasi logic statement Y is high or 1 when: If A is high and C is 0. AND If B is high and C is 0. OTHERWISE Y is 0 or low Write the Boolean function: Y= f (A, B, C) C is 0 – full level C is 1 – low level Y= (A.C). (B.C) Boolean function

Figure Boolean circuit diagram

PLC programming Programmable logic controllers (PLC) have a high reliability. The PLC is electrically isolate by opt isolator or relays from potentially damaging voltages and currents at input/output ports: battery backed RAM protects the application software from power failures or corruption and the construction is so designed that the PLC can operate reliably in industrial conditions for long periods of time. Using software called cross-assembler the program for controlling overflow water tank is given below: In put port=3 Out put port=1

The PLC Programming is written as follows A program for the security system of a use variable declaration A

var.

PORTB0

„signal A

B

var.

PORTB1

„signal B

C

var.

PORTB2

„signal C

Y

var.

PORTA1

„signal Y

DEFINE CONSTANTS

Height

con

1

„up ward movement potentiometer

Level

con

1

„floating up ward

„Main Program If (C=1) then „Water at low level If (height=0) „At low height Then Water flow End if If(C=0) then „Water at high level If (height=1) „At high height Then Stop water flow End if End if End if End program

CONCLUSION AND RECOMENDETION

Fluid reservoirs are mostly used in our day to day life. Doing this there are some problems occurred due to some limitations of the working principle of the reservoirs and pumps used, but the main is that the over flowing of the fluid (water) in the tank. Such things have a great effect on wastage of many (cost), time etc. to control this problem we have to use automatic electrical controlling systems like overflow feed water tank controller systems, which is the main objective of this project. Controlling overflow of feed water in tank is a crucial mechanism in our day to day activity. In our surrounding it is common to observe that plentiful of water is wasted from tank. To avoid such a problem we have tried to design a mechanism of controlling this overflow of water using a concept of mechatronics. In this design we made a proper selection of sensors, signal conditioning element, analog to digital converter, microprocessor elements, digital to analog converter, and actuators.

REFFERENCE 1. 2.

W. Bolton; 2nd edition I.J Nagrath & M. Gopal; 3rd edition

3.Internet: Google search a) Http //F:/senser.htm b) Http//www. superior boiler worke.ink c) Http// www. Amplifier application

Benefits gained from the internship

We have gained some good experience during the four month internship period. Some of the experiences includes: We have gained knowledge of organizational structure and how to behave in a company.  We have learnt about working processes in industries , especially about leather  We have learnt how important it is to be punctual!  We have improved my technical and personal skills that I have learned theoretically becoming familiar with new techniques and methods.  We have sometimes exercised individual responsibility and develop strong teamwork skills with the workers  It makes build up a network of professional contacts for future opportunities and references. To illustrate I would like to explain one by one

Practical skill I have developed a confidence to do the given work practically with out any problem and I also observe practical work is more simple than theoretical.

Differentiatng theoretical skill Vs practical skill  theoretical knowledge is not always unfulfilled in practical application, though sometimes it might seem that way.  It‟s important to realize that in the workplace, what matters is not the amount of practical exprience or theoretical background that an individual has. What matters is how much an individual is able to effectively deal with the realities around him. Theory and practical exprience are just complimentary means to that end.  Gaining knowledge from practical work is easier than from theoretical learning process.

Interpersonal communication skill

It is how well you communicate with someone & how well you behave or carry yourself or simply which means interpersonal skills are how people relate to one another. As an illustration, it is generally understood that communicating respect for other people or professionals with in will enable one to reduce conflict & increase participation or assistance in obtaining information or completing tasks. Having positive interpersonel skills increase the productivity in the organization since the number of conflicts is reduced. Informal situation, it allows communication to be easy & comfortable. People with good interpersonal skills can generally control the feelings that emerge in difficult situations & respond appropriatly, instead of being overwhelmed by emotion. Confidence of the behavior is also play important role in decision to take risk.

Improving team player skills there are a number of benefits for teamwork among them are: 

Distributing the work load

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Reinforcing individual capabilities

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Creating participation & involvement.

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Making better decision

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Feeling like we play a part in the work being done

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Generating a diversity of ideas

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Teamwork also allows me to make friends & enjoy a better social exprience when studying & working. Because everyone also has an aim to achieve a goal more efficiencly than we called before & finding other enthusiastic individuals to liaise with is the firest step to bettering your self.

 One of the most important qualities to have when collabrating with others is the ability to communicate.

Leadership skills Leadership decision is very important in any work. I have developed an ablity to build consensus in the face of uncertainty.

Work ethics Ethics tells us about moral duties & obligations & so that & our behavior is right, truthfull and just. From terms of under standing about work ethics related issue i have observed about two types of work ethics, these are :1. Personal ethics – some of the personal ethics are personal, i.e. a person adopts them on his/her own will. These may be sincerity, respect for the job, regularity, punctuality , seriosness. 2. Specific to a work situation – work ethics specific to work situation are : 

Keeping certain information, confidential

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Maintaining cordial relation with the ethics & agencies that a company has

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Being prepared to takeup new tasks

Ethical problems related to work  Irregularity and lack of punctuality  Rude and impolite behavior  Inadquate knowledge and skill  Wastage of resources  Disregard of rules and procedures  Disrespect for the job

Entrepreneurship skill As a successful enterprenuer ship i will have to work closely with people – this is were it is critical to be able to build great relationships with my team,customers, suppliers, some holders and more. Frome this field practice i have grasped the following type of interpersonal skills.these are: leadership and motivation  communication  personal relations  ethics Not everybody is born a natural entrepreneur.Enternership is a skill that can alwayes be developed and expanded .Here are some ideas based on my personal experiance that will help kids or adults acqure usefull skills to be come asuccessful entrprenure. Some of the entrpreneur skills need that:

Inititative –have to have the motivation to take the initative and creat on your own.

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Responsiblity –have to responsiblity for your motion and understand the importantes of responsibility.

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Creativity –should have asense of creativity ,innovation and always be one step a head in ideas.

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Communication- have to be abele to communicate your ideas, net work and connect with other.

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Leadership –need to be abele to be the leader and be in charge of a project ,or company.

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Problem solving –have to have the ability to solve simple or more complicated problems.

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Determination –have to be extremely motivated and help going even when things are tough.