(##)TYRE PRESSURE MONITORING SYSTEM-

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TYRE PRESSURE MONITORING SYSTEM
Submitted in partial fulfillment of the requirement for the award of DIPLOMA IN MECHANICAL ENGINEERING BY

Under the guidance of

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2004-2005
DEPARTMENT OF MECHANICAL ENGINEERING

CERTIFICATE

Register number: _________________________

This is to certify that the project report titled “TYRE PRESSURE MONITORING SYSTEM” submitted by the following students for the award of the Diploma engineering is record of bonafide work carried out by them.
Done by
Mr. /Ms._______________________________

In partial fulfillment of the requirement for the award of Diploma in Mechanical Engineering During the Year – (2004-2005) _________________ Head of Department Coimbatore –641651. Date:
Submitted for the university examination held on ___________

_______________

Guide

_________________ Internal Examiner Examiner

________________ External

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ACKNOWLEDGEMENT
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ACKNOWLEDGEMENT
At this pleasing moment of having successfully completed our project, we wish to convey our sincere thanks and gratitude to the management of our college to us. ………………………………………, for and our beloved chairman …………………………………………………, who provided all the facilities our We would like to express our sincere thanks to principal forwarding us to do our project and offering adequate duration in completing our project. We are also grateful to the Head of Department Prof. during our project. With deep sense of gratitude, we extend our earnest of & sincere for thanks her to our guide & …………………………………………………….., Mechanical kind encouragement during this project. We also express our indebt thanks to our TEACHING and NON TEACHING staffs of Department guidance …………………………………….., for

her constructive suggestions & encouragement

MECHANICAL

ENGINEERING

DEPARTMENT,

……………………….(COLLEGE NAME).

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TYRE PRESSURE MONITORING SYSTEM

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CONTENTS
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CONTENTS
CHAPTER ACKNOWLEDGEMENT SYNOPSIS 1. INTRODUCTION 2. LITERATURE SURVEY 3. PCB DESIGNING 4. BLOCK DIAGRAM 5. COMPONENTS AND DESCRIPTION 6. WORKING PRINCIPLE
7. ADVANTAGES AND DISADVANTAGES

PARTICULAR

PAGE No.

8. APPLICATIONS 9. LIST OF MATERIAL 10. COST ESTIMATION
11. CONCLUSION AND SCOPE FOR FUTURE WORK

BIBLIOGRAPHY PHOTOGRAPHY

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Chapter-1
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SYNOPSIS
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CHAPTER-1 SYNOPSIS
A Tire Pressure Monitoring System (TPMS) is generally an electronic system designed to monitor the air pressure inside all the pneumatic tires on automobiles, aero plane undercarriages, straddle-lift carriers, forklifts and other vehicles. The system is also sometimes referred to as a Tire Pressure Indication System (TPIS). These systems report real time tire pressure information to the driver of the vehicle - either via a gauge, a display, or a simple low pressure warning light. Furthermore, the plan will urge the implementation of safety.

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Chapter-2
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INTRODUCTION
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CHAPTER - 2 INTRODUCTION
This is an era of automation where it is broadly defined as replacement of manual effort by electronics power in all degrees of automation. The operation remains an essential part of the system although with changing demands on physical input as the degree of mechanization is increased.

Degrees of automation are of two types, viz. • Full automation. • Semi automation.

In semi automation a combination of manual effort and mechanical power is required whereas in full automation human participation is very negligible.

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Chapter-3
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PCB DESIGNING
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CHAPTER - 3 PCB DESIGNING
PRINTED CIRCUIT BOARD (PCB)

Nowadays the printed circuit board hereafter mentioned as PCB’s makes the electronic circuit manufacturing as easy one. In olden days vast area was required to implement a small circuit. To connect two leads of the components, separate connectors are needed. But PCB’s connect the two leads by copper coated lines on the PCB board.

PCB’s are available in various types namely single sided and double sided boards. In single sided PCB’s the copper layer is one side.

MANUFACTURING: First, the wanted circuit is drawn on a paper and it is modified or designed to reduce the space this designed PCB layout is to be drawn on the plain copper coated board. There boards are available in 2 types. 1. Phenolic 2. Glass epoxy

Most computer PCB’s are glass epoxy. To draw the circuit diagrams we can use the black colour paint. Before that the required size of the plane PCB board is

determined from the roughly drawn PCB layout. Using black paint the desired circuit is drawn on the board.

CAD IN PCB: First the PCB layout is designed by CAD. The print out is taken from the computer (of large size) for out clearance. This layer is given to the photography section to get the layout in it’s actual size. From this we can have the positive and negative images of the layout. This photographic image is exposed in the following three methods.

1) Polybluem 2) Chrombin 3) Five star

The exposed mesh is placed on plain copper coated board in correct alignment by using wooden clamps. Special paints are used to spread over the mesh. Paint flow through the board and the layout lines are made on the copper board. Finally, there are fine layouts on the copper board.

ETCHING: This can be done both by manual and mechanical ways by immersing the board in to a solution of formic chloride and hydrochloric acid and finally cleaning the board with soap. CHARACTERISTICS OF EPOXY RESIN

Term Dielectric constant Dissipation factor Dielectric strength Arc Resistance

Definition Relative capacitance to that of air vacuum or dielectric Electrical efficiency of loss Voltage that material can withstand prior to failure Resistance to electrical breakdown initiated by formation of conductive

Range of Options 3-6 0.33 to 0.03 (60 – 1000) Hz 300 – 450 V/min for 0.125 inch thickness 80 –100 sec.

Surface resistivity

path or tracking Resistance to electric current along surface of 1 cm2 measurement

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Chapter-4

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BLOCK DIAGRAM
--------------------------------------------------------------------------------CHAPTER - 4

BLOCK DIAGRAM

PRESSURE SENSOR BATTERY

RELAY MICROCONTROLLER UNIT

ALARM

The block diagram consists of following main parts,



Sensor unit

• Microcontroller unit • Battery

These components are explained the next chapter.

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Chapter-5
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COMPONENTS AND DESCRIPTION
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CHAPTER - 5 COMPONENTS AND DESCRIPTION

The physical setup of this project are given below and it is been explained as follows

1.
2.

Sensor unit Microcontroller unit Battery Bearing with bearing cap Wheel Arrangement Frame Stand

3. 4. 5. 6.

1. SENSOR UNIT:

TYPES OF SENSOR: Passive sensors detect the reflected or emitted electro-magnetic radiation from natural sources, while active sensors detect reflected responses from objects which are irradiated from artificially generated energy sources, such as radar. Each is divided further in to non-scanning and scanning systems.

A sensor classified as a combination of passive, non-scanning and non-imaging method is a type of profile recorder, for example a microwave radiometer. A sensor classified as passive, non-scanning and imaging method, is a camera, such as an aerial survey camera or a space camera, for example on board the Russian COSMOS satellite. Sensors classified as a combination of passive, scanning and imaging are classified further into image plane scanning sensors, such as TV cameras and solid state scanners, and object plane scanning sensors, such as multi-spectral scanners (optical-mechanical scanner) and scanning microwave radiometers. An example of an active, non-scanning and non-imaging sensor is a profile recorder such as a laser spectrometer and laser altimeter. An active, scanning and imaging sensor is radar, for example synthetic aperture radar (SAR), which can produce high resolution, imagery, day or night, even under cloud cover. The most popular sensors used in remote sensing are the camera, solid state scanner, such as the CCD (charge coupled device) images, the multi-spectral scanner and in the future the passive synthetic aperture radar.

SENSOR UNIT:-

The pressure sensor resistor is varying depends upon the alcohol contents of the air. This will be mostly linear to the alcohol. During the normal condition the resistance of sensor shoots up to Meg ohm ranges. CIRCUIT DIAGRAM:-

1K 9V (ZENER) 10K 1000µF 10K 2 3 10K 2.2K 4 1 10K

+

358

LM

POWER SUPPLY UNIT

Alcohol

SENSOR

1N4007

BC547

1K

MICROCONTRO LLER UNIT

LED

1K

AT NORMEL CONDITION:-

In normal condition the Resistance of the Sensor is high. The voltages applied to the non-inverting terminal (+ ive) is low when compared to the inverting terminal voltages (- ive). In that time, the OP-AMP output is –Vsat. (I.e -12 Volt). There is no signal given to the microcontroller unit.

AT LOW PRESSURE CONDITION:-

In low pressure condition the Resistance of the sensor is low due to intensity of the light or fire. The voltages applied to the non-inverting terminal (+ ive) is high when compared to the inverting terminal voltages (- ive). In that time, the OP-AMP output is +Vsat. (I.e +12 Volt). The transistor and in “ON” condition and this signal is given to the microcontroller unit.

2. MICROCONTROLLER UNIT:-

The pressure sensor senses the alcohol contents of the particular room/vehicle. This sensing signal is given to the microcontroller unit. When the current voltage is bellow the setted voltage, the output from the microcontroller activates the relay to function the alarm unit.

MICROCONTROLLER UNIT

Microcontroller Core Features:

• High performance RISC CPU • Only 35 single word instructions to learn • All single cycle instructions except for program branches which are two cycle • Operating speed: DC - 20 MHz clock input, DC - 200 ns instruction cycle • Up to 8K x 14 words of FLASH Program Memory, Up to 368 x 8 bytes of Data Memory (RAM), Up to 256 x 8 bytes of EEPROM Data Memory • Interrupt capability (up to 14 sources) • Eight level deep hardware stack • Direct, indirect and relative addressing modes • Power-on Reset (POR) • Power-up Timer (PWRT) and Oscillator Start-up Timer (OST) • Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation • Programmable code protection • Power saving SLEEP mode • Selectable oscillator options • Low power, high speed CMOS FLASH/EEPROM technology

• Fully static design • In-Circuit Serial Programming (ICSP) via two pins • Single 5V In-Circuit Serial Programming capability • In-Circuit Debugging via two pins • Processor read/write access to program memory • Wide operating voltage range: 2.0V to 5.5V • High Sink/Source Current: 25 mA • Commercial, Industrial and Extended temperature ranges • Low-power consumption: - < 0.6 mA typical @ 3V, 4 MHz - 20 μA typical @ 3V, 32 kHz - < 1 μA typical standby current Pin Diagram Peripheral Features: • Timer0: 8-bit timer/counter with 8-bit prescaler • Timer1: 16-bit timer/counter with prescaler, can be incremented during SLEEP via external crystal/clock

• Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler • Two Capture, Compare, PWM modules - Capture is 16-bit, max. resolution is 12.5 ns - Compare is 16-bit, max. resolution is 200 ns - PWM max. resolution is 10-bit • 10-bit multi-channel Analog-to-Digital converter • Synchronous Serial Port (SSP) with SPI (Master mode) • Universal Synchronous Asynchronous Transmitter (USART/SCI) with 9-bit address detection • Parallel Slave Port (PSP) 8-bits wide, with external RD, WR and CS controls (40/44-pin only) • circuitry for Brown-out Reset (BOR) Brown-out detection Receiver

DEVICE OVERVIEW MEMORY ORGANIZATION There are three memory blocks in each of the PIC16F87X MCUs. The Program Memory and Data Memory have separate buses so that concurrent access can occur and is detailed in this section. The EEPROM data memory block is detailed in Section 4.0. Additional information on device memory may be found in the microcontroller MidRange Reference Manual, (DS33023). Program Memory Organization The PIC16F87X devices have a 13-bit program counter capable of addressing an 8K x 14 program memory space. The PIC16F877/876 devices have 8K x 14 words of FLASH program memory, and the PIC16F873/874 devices have 4K x 14.

Accessing a location above the physically implemented address will cause a wrap around. The RESET vector is at 0000h and the interrupt vector is at 0004h.

Data Memory Organization

The data memory is partitioned into multiple banks which contain the General Purpose Registers and the Special Function Registers. Bits RP1 (STATUS<6>) and RP0 (STATUS<5>) are the bank select bits.

Each bank extends up to 7Fh (128 bytes). The lower locations of each bank are reserved for the Special Function Registers. Above the Special Function Registers are General Purpose Registers, implemented as static RAM. All implemented banks contain Special Function Registers. Some frequently used Special Function Registers from one bank may be mirrored in another bank for code reduction and quicker access.

GENERAL PURPOSE REGISTER

FILE The register file can be accessed either directly or indirectly through the File Select Register (FSR).

SPECIAL FUNCTION REGISTERS The Special Function Registers are registers used by the CPU and peripheral modules for controlling the desired operation of the device. These registers are implemented as static RAM. A list of these registers is given in Table 2-1.

The Special Function Registers can be classified into two sets: core (CPU) and peripheral. Those registers associated with the core functions are described in detail in this section. Those related to the operation of the peripheral features are described in detail in the peripheral features section.

I/O PORTS Some pins for these I/O ports are multiplexed with an alternate function for the peripheral features on the device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. Additional information on I/O ports may be found in the PICmicro™ Mid-Range Reference Manual, (DS33023).

PORTA and the TRISA Register

PORTA is a 6-bit wide, bi-directional port. The corresponding data direction register is TRISA. Setting a TRISA bit (= 1) will make the corresponding PORTA pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output (i.e., put the contents of the output latch on the selected pin). Reading the PORTA register reads the status of the pins, whereas writing to it will write to the port latch. All write operations are read-modify-write operations. Therefore, a write to a port implies that the port pins are read, the value is modified and then written to the port data latch. Pin RA4 is multiplexed with the Timer0 module clock input to become the RA4/T0CKI pin. The RA4/T0CKI pin is a Schmitt Trigger input and an open drain output.

All other PORTA pins have TTL input levels and full CMOS output drivers. Other PORTA pins are multiplexed with analog inputs and analog VREF input. The operation of each pin is selected by clearing/setting the

control bits in the ADCON1 register (A/D Control Register1). The TRISA

register controls the direction of the RA pins, even when they are being used as analog inputs. The user must ensure the bits in the TRISA register are maintained set when using them as analog inputs.

PORTB and the TRISB Register

PORTB is an 8-bit wide, bi-directional port. The corresponding data direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISB bit (= 0) will make the corresponding PORTB pin an output (i.e., put the contents of the output latch on the selected pin). Three pins of PORTB are multiplexed with the Low Voltage Programming function: RB3/PGM, RB6/PGC and RB7/PGD. The alternate functions of these pins are described in the Special Features Section.

Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is performed by clearing bit RBPU (OPTION_REG<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset.

BATTERY:INTRODUCTION:

In isolated systems away from the grid, batteries are used for storage of excess solar energy converted into electrical energy. The only exceptions are isolated sunshine load such as irrigation pumps or drinking water supplies for storage. In fact for small units with output less than one kilowatt. Batteries seem to be the only technically and economically available storage means. Since both the photo-voltaic system and batteries are high in capital costs. It is necessary that the overall system be optimized with respect to available energy and local demand pattern. To be economically attractive the storage of solar electricity requires a battery with a particular combination of properties:

(1) (2) (3) (4) (5) (6)

Low cost Long life High reliability High overall efficiency Low discharge Minimum maintenance (A) (B) Ampere hour efficiency Watt hour efficiency

We use lead acid battery for storing the electrical energy from the solar panel for lighting the street and so about the lead acid cells are explained below.

2.1

LEAD-ACID WET CELL:

Where high values of load current are necessary, the lead-acid cell is the type most commonly used. The electrolyte is a dilute solution of sulfuric acid (H₂SO₄). In the application of battery power to start the engine in an auto mobile, for example, the load current to the starter motor is typically 200 to 400A. One cell has a nominal output of 2.1V, but lead-acid cells are often used in a series combination of three for a 6-V battery and six for a 12-V battery.

The lead acid cell type is a secondary cell or storage cell, which can be recharged. The charge and discharge cycle can be repeated many times to restore the output voltage, as long as the cell is in good physical condition. However, heat with excessive charge and discharge currents shortends the useful life to about 3 to 5 years for an automobile battery. Of the different types of secondary cells, the lead-acid type has the highest output voltage, which allows fewer cells for a specified battery voltage.

2.2

CONSTRUCTION:

Inside a lead-acid battery, the positive and negative electrodes consist of a group of plates welded to a connecting strap. The plates are immersed in the electrolyte, consisting of 8 parts of water to 3 parts of concentrated sulfuric acid. Each plate is a grid or framework, made of a lead-antimony alloy. This construction enables the active material, which is lead oxide, to be pasted into the grid. In manufacture of the cell, a forming charge produces the positive and negative electrodes. In the forming process, the active material in the positive plate is changed to lead peroxide (pbo₂). negative electrode is spongy lead (pb). The

Automobile batteries are usually shipped dry from the manufacturer.

The

electrolyte is put in at the time of installation, and then the battery is charged to from the plates. With maintenance-free batteries, little or no water need be added in normal service. Some types are sealed, except for a pressure vent, without provision for adding water. The construction parts of battery are shown in figure.

2.3 CHEMICAL ACTION:

Sulfuric acid is a combination of hydrogen and sulfate ions.

When the cell

discharges, lead peroxide from the positive electrode combines with hydrogen ions to form water and with sulfate ions to form lead sulfate. Combining lead on the negative plate with sulfate ions also produces he sulfate. There fore, the net result of discharge is to produce more water, which dilutes the electrolyte, and to form lead sulfate on the plates.

As the discharge continues, the sulfate fills the pores of the grids, retarding circulation of acid in the active material. Lead sulfate is the powder often seen on the outside terminals of old batteries. When the combination of weak electrolyte and

sulfating on the plate lowers the output of the battery, charging is necessary.

On charge, the external D.C. source reverses the current in the battery. The reversed direction of ions flows in the electrolyte result in a reversal of the chemical reactions. Now the lead sulfates on the positive plate reactive with the water and sulfate ions to produce lead peroxide and sulfuric acid. This action re-forms the positive plates and makes the electrolyte stronger by adding sulfuric acid.

At the same time, charging enables the lead sulfate on the negative plate to react with hydrogen ions; this also forms sulfuric acid while reforming lead on the negative plate to react with hydrogen ions; this also forms currents can restore the cell to full output, with lead peroxide on the positive plates, spongy lead on the negative plate, and the required concentration of sulfuric acid in the electrolyte.

The chemical equation for the lead-acid cell is

Charge

Pb + pbO₂ + 2H₂SO₄ 2pbSO₄ + 2H₂O

Discharge

On discharge, the pb and pbo₂ combine with the SO₄ ions at the left side of the equation to form lead sulfate (pbSO₄) and water (H₂O) at the right side of the equation. One battery consists of 6 cell, each have an output voltage of 2.1V, which are connected in series to get an voltage of 12V and the same 12V battery is connected in series, to get an 24 V battery. They are placed in the water proof iron casing box.

2.4 CARING FOR LEAD-ACID BATTERIES:

Always use extreme caution when handling batteries and electrolyte.

Wear

gloves, goggles and old clothes. “Battery acid” will burn skin and eyes and destroy cotton and wool clothing.

The quickest way of ruin lead-acid batteries is to discharge them deeply and leave them stand “dead” for an extended period of time. When they discharge, there is a chemical change in the positive plates of the battery. They change from lead oxide when charge out lead sulfate when discharged. If they remain in the lead Sulfate State for a few days, some part of the plate dose not returns to lead oxide when the battery is recharged. If the battery remains discharge longer, a greater amount of the positive plate will remain lead sulfate. The parts of the plates that become “sulfate” no longer store energy. Batteries that are deeply discharged, and then charged partially on a regular basis can fail in less then one year.

Check your batteries on a regular basis to be sure they are getting charged. Use a hydrometer to check the specific gravity of your lead acid batteries. If batteries are cycled very deeply and then recharged quickly, the specific gravity reading will be lower

than it should because the electrolyte at the top of the battery may not have mixed with the “charged” electrolyte.

Check the electrolyte level in the wet-cell batteries at the least four times a year and top each cell of with distilled water. Do not add water to discharged batteries. Electrolyte is absorbed when batteries are very discharged. If you add water at this time, and then recharge the battery, electrolyte will overflow and make a mess.

Keep the top of your batteries clean and check that cables are tight. Do not tighten or remove cables while charging or discharging. Any spark around batteries can cause a hydrogen explosion inside, and ruin one of the cells, and you.

On charge, with reverse current through the electrolyte, the chemical action is reversed. Then the pb ions from the lead sulfate on the right side of the equation re-form the lead and lead peroxide electrodes. Also the SO₄ ions combine with H₂ ions from the water to produce more sulfuric acid at the left side of the equation.

2.5 CURRENT RATINGS: Lead-acid batteries are generally rated in terms of how much discharge currents they can supply for a specified period of time; the output voltage must be maintained above a minimum level, which is 1.5 to 1.8V per cell. A common rating is ampere-hours

(A.h.) based on a specific discharge time, which is often 8h. automobile batteries are 100 to 300 A.h.

Typical values for

As an example, a 200 A.h battery can supply a load current of 200/8 or 25A, used on 8h discharge. The battery can supply less current for a longer time or more current for a shorter time. Automobile batteries may be rated for “cold cranking power”, which is related to the job of starting the engine. A typical rating is 450A for 30s at a temperature of 0 degree F.

Note that the ampere-hour unit specifies coulombs of charge. For instance, 200 A.h. corresponds to 200A*3600s (1h=3600s). the equals 720,000 A.S, or coulombs. One ampere-second is equal to one coulomb. Then the charge equals 720,000 or

7.2*10^5ºC. To put this much charge back into the battery would require 20 hours with a charging current of 10A.

The ratings for lead-acid batteries are given for a temperature range of 77 to 80ºF. Higher temperature increase the chemical reaction, but operation above 110ºF shortens the battery life.

Low temperatures reduce the current capacity and voltage output. The amperehour capacity is reduced approximately 0.75% for each decreases of 1º F below normal

temperature rating. At 0ºF the available output is only 60 % of the ampere-hour battery rating.

In cold weather, therefore, it is very important to have an automobile battery unto full charge. In addition, the electrolyte freezes more easily when diluted by water in the discharged condition.

2.6 SPECIFIC GRAVITY:

Measuring the specific gravity of the electrolyte generally checks the state of discharge for a lead-acid cell. Specific gravity is a ratio comparing the weight of a substance with the weight of a substance with the weight of water. For instance,

concentrated sulfuric acid is 1.835 times as heavy as water for the same volume. Therefore, its specific gravity equals 1.835. The specific gravity of water is 1, since it is the reference. In a fully charged automotive cell, mixture of sulfuric acid and water results in a specific gravity of 1.280 at room temperatures of 70 to 80ºF. as the cell discharges, more water is formed, lowering the specific gravity. When it is down to about 1.150, the cell is completely discharged.

Specific-gravity readings are taken with a battery hydrometer, such as one in figure (7). Note that the calibrated float with the specific gravity marks will rest higher in an electrolyte of higher specific gravity.

The decimal point is often omitted for convenience. For example, the value of 1.220 in figure (7) is simply read “twelve twenty”. A hydrometer reading of 1260 to 1280 indicates full charge, approximately 12.50 are half charge, and 1150 to 1200 indicates complete discharge.

The importance of the specific gravity can be seen from the fact that the opencircuit voltage of the lead-acid cell is approximately equal to

V

=

Specific gravity + 0.84

For the specific gravity of 1.280, the voltage is 1.280 = 0.84 = 2.12V, as an example. These values are for a fully charged battery.

2.7 CHARGING THE LEAD-ACID BATERY:

The requirements are illustrated in figure. An external D.C. voltage source is necessary to produce current in one direction. Also, the charging voltage must be more

than the battery e.m.f. Approximately 2.5 per cell are enough to over the cell e.m.f. so that the charging voltage can produce current opposite to the direction of discharge current.

Note that the reversal of current is obtained just by connecting the battery VB and charging source VG with + to + and –to-, as shown in figure. The charging current is reversed because the battery effectively becomes a load resistance for VG when it higher than VB. In this example, the net voltage available to produce charging currents is 1512=3V.

A commercial charger for automobile batteries is essentially a D.C. power supply, rectifying input from the AC power line to provide D.C. output for charging batteries.

Float charging refers to a method in which the charger and the battery are always connected to each other for supplying current to the load. In figure the charger provides current for the load and the current necessary to keep the battery fully charged. The battery here is an auxiliary source for D.C. power.

It may be of interest to note that an automobile battery is in a floating-charge circuit. The battery charger is an AC generator or alternator with rectifier diodes, driver by a belt from the engine. When you start the car, the battery supplies the cranking

power. Once the engine is running, the alternator charges he battery. It is not necessary for the car to be moving. A voltage regulator is used in this system to maintain the output at approximately 13 to 15 V.

The constant voltage of 24V comes from the solar panel controlled by the charge controller so for storing this energy we need a 24V battery so two 12V battery are connected in series.

It is a good idea to do an equalizing charge when some cells show a variation of 0.05 specific gravity from each other. This is a long steady overcharge, bringing the battery to a gassing or bubbling state. Do not equalize sealed or gel type batteries.

With proper care, lead-acid batteries will have a long service life and work very well in almost any power system. Unfortunately, with poor treatment lead-acid battery life will be very short.

3. BEARING WITH BEARING CAP:-

The bearings are pressed smoothly to fit into the shafts because if hammered the bearing may develop cracks. Bearing is made upon steel material and bearing cap is mild steel. INTRODUCTION Ball and roller bearings are used widely in instruments and machines in order to minimize friction and power loss.

While the concept of the ball bearing dates back at least to Leonardo da Vinci, their design and manufacture has become remarkably sophisticated. This technology was brought to its p resent state o f perfection only after a long period of research and development. The benefits of such specialized research can be obtained when it is possible to use a standardized bearing of the proper size and type. However, such bearings cannot be used indiscriminately without a careful study of the loads and operating conditions. In addition, the bearing must be provided with adequate mounting, lubrication and sealing. Design engineers have usually two possible sources for obtaining information which they can use to select a bearing for their particular application:

a) Textbooks b) Manufacturers’ Catalogs Textbooks are excellent sources; however, they tend to be overly detailed and aimed at the student of the subject matter rather than the practicing designer. They, in most cases, contain information on how to design rather than how to select a bearing

for a particular application. Manufacturers’ catalogs, in turn, are also excellent and contain a wealth of information which relates to the products of the particular manufacturer. These catalogs, however, fail to provide alternatives – which may divert the designer’s interest to products not manufactured by them. Our Company, however, provides the broadest selection of many types of bearings made by different manufacturers.

For this reason, we are interested in providing a condensed overview of the subject matter in an objective manner, using data obtained from different texts, handbooks and manufacturers’ literature. This information will enable the reader to select the proper bearing in an expeditious manner. If the designer’s interest exceeds the scope of the presented material, a list of references is provided at the end of the Technical Section. At the same time, we are expressing our thanks and are providing credit to the sources which supplied the material presented here.

Construction and Types of Ball Bearings

A ball bearing usually consists of four parts: an inner ring, an outer ring, the balls and the cage or separator. To increase the contact area and permit larger loads to be carried, the balls run in curvilinear grooves in the rings. The radius of the groove is slightly larger than the radius of the ball, and a very slight amount of radial play must be provided. The bearing is thus permitted to adjust itself to small amounts of angular

misalignment between the assembled shaft and mounting. The separator keeps the balls evenly spaced and prevents them from touching each other on the sides where their relative velocities are the greatest. Ball bearings are made in a wide variety of types and sizes. Single-row radial bearings are made in four series, extra light, light, medium, and heavy, for each bore, as illustrated in Fig. 1-3(a), (b), and (c).

100 Series

200 Series

300 Series

Axial Thrust

Angular Contact Self-aligning

Bearing

Fig. 1-3 Types of Ball Bearings

The heavy series of bearings is designated by 400.

Most, but not all,

manufacturers use a numbering system so devised that if the last two digits are multiplied by 5, the result will be the bore in millimeters.

The digit in the third place from the right indicates the series number. Thus, bearing 307 signifies a medium-series bearing of 35-mm bore. For additional digits, which may be present in the catalog number of a bearing, refer to manufacturer’s details. Some makers list deep groove bearings and bearings with two rows of balls. For bearing designations of Quality Bearings &

Components (QBC), see special pages devoted to this purpose. The radial bearing is able to carry a

considerable amount of axial thrust. However, when the load is directed entirely along the axis, the thrust type of bearing should be used. The angular contact bear- ing will take care of both radial and axial loads. The self-aligning ball bearing will take care of large amounts of angular misalignment.

An increase in radial capacity may be secured by using rings with deep grooves, or by employing a double-row radial bearing. Radial bearings are divided into two general classes, depending on the method of assembly. These are the Conrad, or nonfilling-notch type, and the maximum, or filling-notch type. In the Conrad bearing, the balls are placed between the rings as shown in Fig. 1-4(a). Then they are evenly spaced and the separator is riveted in place. In the maximum-type bearing, the balls are a

(a) (b) (c) (d) (e) (f) 100 Series Extra Light 200 Series Light 300 Series Medium Axial Thrust Bearing Angular Contact Bearing Self-aligning Bearing Fig. 1-3 Types of Ball Bearings Fig. 1-4 Methods of Assembly notch type (b) Maximum or filling notch type for Ball Bearings (a) Conrad or non-filling

4. WHEEL ARRANGEMENT:-

The simple wheel and braking arrangement is fixed to the frame stand. Near the brake drum, the pneumatic cylinder piston is fixed.

5. FRAME STAND:

This is a supporting frame and made up of mild steel.

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Chapter-6
---------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------

WORKING PRINCIPLE
-------------------------------------------------------------------------------------

CHAPTER - 6 WORKING PRINCIPLE

The pressure sensor senses the pressure contents of the tubes of the air. This sensing signal is given to the microcontroller unit. When there are in required pressure level, there is no signal given to the microcontroller unit.

In our 12 volt battery power supply is used. The power supply output is given to the control unit. Control unit having three relays, they are connected to the alarm unit.

Initially the reference voltage is set with the help of the variable resistance. The air pressure contents is sensed by the sensor and this control signal is given to the microcontroller unit

11 Vcc
10µ/63V 10K PULSE FROM SENSOR 100K 454 Vcc 10K 1.5K

32 RC5 Vcc
0.1µ Vcc 10K 12V

RC0

1K 1N4007 RELAY BC547

ALARM UNIT

5.6V

0.1μ

150K

MICROCONT ROLLER RC1 16F877

13
33pF CRYSTAL 12MHZ 33pF

14 12,31

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Chapter-7
---------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------

ADVANTAGES & DISADVANTAGES
-------------------------------------------------------------------------------------

CHAPTER - 7 ADVANTAGES, APPLICATIONS AND DISADVANTAGES

ADVANTAGES


This circuit detects the air pressure directly This circuit is simple in construction.



• Readily available ICs are used. • Responsibility of the circuit is high. • High Accuracy.

APPLICATIONS


All car owners

• Drivers

DISADVANTAGES


This circuit is not for wireless one.

---------------------------------------------------------------------------------------

Chapter-8
---------------------------------------------------------------------------------------

---------------------------------------------------------------------------------

LIST OF MATERIAL
---------------------------------------------------------------------------------

CHAPTER - 8 LIST OF MATERIAL

Sl. No. i. ii. iii. iv. v. vi. vii. viii. ix.

PARTS

Microcontroller unit Sensors and Relays Power supply (12V D.C) Switch Crystal Oscillator Pressure Sensor Bolts & Nuts Resistors and capacitors Connecting Wire

Qty. 1 1 1 2 1 -

SPECIFICATION Electronic Two way switch 8 Nos -

---------------------------------------------------------------------------------------

Chapter-9
---------------------------------------------------------------------------------------

---------------------------------------------------------------------------------

COST ESTIMATION
---------------------------------------------------------------------------------

CHAPTER - 9 COST ESTIMATION

1. MATERIAL COST:

Amount Sl. No. i. ii. iii. iv. v. vi. vii. viii. ix.
PARTS

Microcontroller unit Sensors and Relays Power supply (12V D.C) Switch Crystal Oscillator Pressure Sensor Bolts & Nuts Resistors and capacitors Connecting Wire

Qty. 1 1 1 2 1 -

(Rs.) Electronic Two way switch 8 Nos -

2. LABOUR COST Programming Cost =

3. OVERHEAD CHARGES

The overhead charges are arrived by “Manufacturing cost”

Manufacturing Cost = = =

Material Cost + Labour cost

Overhead Charges = =

20% of the manufacturing cost

TOTAL COST Total cost = = = Total cost for this project = Material Cost + Labour cost + Overhead Charges

---------------------------------------------------------------------------------------

Chapter-10
---------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------

CONCLUSION AND FUTURE WORK
------------------------------------------------------------------------------------CHAPTER - 10 CONCLUSION AND SCOPE FOR FUTURE WORK

Thus we have made a TYRE PRESSURE MONITORING SYSTEM, Using this arrangement we can control the drunken drive. There by a large amount of energy is saved and it gives a smooth operation.

We are proud that we have completed the work with the limited time successfully. The TYRE PRESSURE MONITORING SYSTEM is working with satisfactory conditions. We are able to understand the difficulties in maintaining the tolerances and also quality. We have done to our ability and skill making maximum use of available facilities.

In conclusion remarks of our project work, let us add a few more lines about our impression project work. Thus we have developed an “TYRE PRESSURE MONITORING SYSTEM” which helps to know how to achieve low cost automation. The application of pneumatics produces smooth operation. By using more techniques, they can be modified and developed according to the applications.

---------------------------------------------------------------------------------

BIBLIOGRAPHY
---------------------------------------------------------------------------------

BIBLIOGRAPHY

# REFRIGERATION AND AIR CONDITIONING

A.S.Sarao, P.S.Gaabi

# TURBO MACHINES K.Pandian

# A.K.SAWHNEY. “A TEXT BOOK OF ELECTRICAL, ELECTRONICS,
INSTRUMENTATION AND MEASUREMENTS”

---------------------------------------------------------------------------------

PROGRAME
---------------------------------------------------------------------------------

PROGRAME

#include<pic.h> #define relay RC5

unsigned int adc1,adc2,result,i;

int sample1(void) { unsigned int dat; ADCON0=0X81; ADGO=1; while(ADGO); dat=ADRESH*256+ADRESL; return dat; }

int sample2(void) { unsigned int dat; ADCON0=0X89; ADGO=1; while(ADGO); dat=ADRESH*256+ADRESL;

return dat; }

void main() { TRISA=0x03;PORTA=0x00; TRISC=0X00;PORTC=0X00; ADCON1=0x84;

while(1) { adc1=sample1(); // adc2=sample2(); // result=adc2-adc1; if(adc1<950)relay=1; else relay=0; } }

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