Automatic Speed Controller

AUTOMATIC SPEED CONTROLLER Design and fabrication project report submitted in partial fulfillment of the requirements for the award of degree of

BACHELOR OF TECHNOLOGY in

MECHANICAL ENGINEERING By

N. SYAM MANOHAR

T. SHARON ROSE KUMAR

(Regd. No. 15FE1A03C4)

(Regd. No. 15FE1A03C7)

T. NIKHIL SASTRY

S. AKHIL KRISHNA

(Regd. No. 16FE5A0335)

(Regd. No. 15FE1A03C3) under the guidance of

Sri. K. SIVA KRISHNA, M.Tech Assistant Professor

DEPARTMENT OF MECHANICAL ENGINEERING VIGNAN'S LARA INSTITUTE OF TECHNOLOGY & SCIENCE

(Approved by AICTE, New Delhi & Affiliated to JNTUK, Kakinada) Vadlamudi-522 213, Andhra Pradesh September, 2018

(i)

DEPARTMENT OF MECHANICAL ENGINEERING VIGNAN'S LARA INSTITUTE OF TECHNOLOGY & SCIENCE (Approved by AICTE New Delhi & Affiliated to JNTUK, Kakinada) Vadlamudi-522 213, Andhra Pradesh

CERTIFICATE This is to certify that the Design and fabrication project work entitled “AUTOMATIC SPEED CONTROLLER" is submitted by N. SYAM MANOHAR (Regd. No. 15FE1A03C4); T. SHARON ROSE KUMAR (Regd. No. 15FE1A03C7); T. NIKHIL SASTRY (Regd. No. 16FE5A0335); S. AKHIL KRISHNA (Regd. No. 15FE1A03C3) to the Department of Mechanical Engineering, Vignan’s Lara Institute of Technology & Science, Vadlamudi in partial fulfilment of the requirements for the award of Degree of Bachelor of Technology in Mechanical Engineering.

Dr. P. Bhaskara Rao, Ph.D. Head of the Department

K. SIVA KRISHNA, M. Tech Assistant Professor Guide

(ii)

DECLARATION We hereby declare that the work presented in this project report entitled "Automatic Speed Controller" is an authentic record of original workdone by us under the guidance of Sri. K. SIVA KRISHNA, Assistant Professor and submitted for the award of Degree of Bachelor of Technology to the Department of Mechanical Engineering of Vignan's Lara Institute of Technology & Science, Vadlamudi. This work has not been submitted elsewhere for the award of any other diploma/degree.

Place: Vadlamudi

N. Syam Manohar

(Reg. No. 15FE1A03C4)

Date:

T. Sharon Rose Kumar

(Reg. No. 15FE1A03C7)

T. Nikhil Sastry

(Reg. No. 16FE5A0335)

S. Akhil Krishna

(Reg. No. 15FE1A03C3)

(iii)

ACKNOWLEDGEMENT We am highly indebted to my guide, Sri. K. Siva Krishna, Assistant Professor for his sincere involvement and contribution to this project. This project would not have been completed without the help and support received from Head of the Department of Mechanical Engineering, Dr. P. Bhaskara Rao, Professor. Hence, the author is very much grateful to him. We would like to express my glad and proud gratitude to the honorable Principal, Dr. K. Phaneendra Kumar, Ph.D., Professor of Mechanical Engineering for his encouragement and support given to complete this project. We are grateful for the support received from the Apex Innovations Pvt. Ltd, IC Engine Research Laboratory to complete this project. My heartfelt thanks are due to Mr. Radha Krishna Gopidesi, Research Associate, VIT University, Vellore for his encouragement and technical support given to complete this project. We would like to thank all my classmates, teaching and non-teaching staff of this college for all the support and encouragement given during this work. Last, but not least, we would like to thank my parents for all the support.

N. SYAM MANOHAR.

(Reg. No. 15FE1A03C4)

T. SHARON ROSE KUMAR.

(Reg. No. 15FE1A03C7)

T. NIKHIL SASTRY.

(Reg. No. 16FE5A0335)

S. AKHIL KRISHNA.

(Reg. No. 15FE1A03C3) (iv)

ABSTRACT

In present situations, controlling the speed of the vehicles at the sensitive zones is a complicated process as it requires manpower and mobile speed measuring mechanism to control. So, we developed an innovative mechanism to automatically control the vehicles speed irrespective of the driver`s recklessness.

This mechanism is kept in the vehicle and it reads for the RF code to know whether any kind of sensitive zone is started or not. When it receives a code for sensitive zone, it automatically takes over control to reduce speed.

The above project is designed with the popular microcontroller MCS51series 89C52 &RF transponders TK5530, U2270 chips. The RF transmitter in the vehicle continuously transmits the data and searches for the RF code. When it receives a code, it transmits that code to the micro controller and comparison of that code is done in the micro controller. If that code matches with sensitive zone`s starting code, it activates the control relay and car speed is reduced. Again, if the sensitive zones ending code is received, the micro controller automatically de-activates the control relay and the vehicle`s speed is attained to normal state.

(v)

CONTENTS Certificates

(i) - (ii)

Declaration

(iii)

Acknowledgement

(iv)

Abstract

(v)

List of Figures CHAPTER 1

(vi) - (ix) INTRODUCTION

1–2

1.1 Block Diagram 1.2 Circuit Diagram CHAPTER 2

LITERATURE REVIEW

2.1 Microcontroller89C52 2.1.1 Features 2.1.2 Pin Diagram and its Description 2.1.2.1 Pin Diagram 2.1.3 Architecture of 89C52 2.2 The On-Chip Oscillators 2.2.1 Program Memory Lock Bits 2.2.2 Program Counter and Data Pointer 2.2.3 A & B Registers 2.2.4 Flags & The Program Status Word (PSW)

3 - 10

CHAPTER 3

MATERIAL AND METHODS

3.1 Crystal Oscillator 3.2 Power Supply 3.2.1 Description 3.2.2 Circuit Diagram 3.3 Voltage Regulator 3.3.1 Positive Voltage Regulator 3.4 Transformer 3.4.1 Introduction 3.4.2 Principle 3.4.3 Step-Down Transformer 3.5 Voltage Regulator 3.6 Buzzer 3.8.1 Buzzer Driver 3.7 Liquid Crystal Display (L.C.D) 3.7.1 Introduction 3.7.2 Features 3.7.3 L.C.D Screen 3.7.4 L.C.D Basic Commands 3.7.5 L.C.D Initialization 3.7.6 L.C.D Interfacing with the microcontroller

11 - 26

CHAPTER 4

EXPERIMENTATION

27 - 30

4.1 Working 4.1.1 Resistor 4.1.2 Capacitor 4.1.3 Transistor 4.1.4 Infrared Sensors 4.1.4.1 Active Infrared Sensors 4.1.4.2 Passive Infrared Sensors 4.2 Applications CHAPTER 5

PROGRAM CODE

31 - 36

CHAPTER 6

CONCLUSION AND REFERENCES

37 - 38

LIST OF FIGURES FIG NO.

TITLE

PAGE NO.

1

Block Diagram

1

2

Circuit Diagram

2

3

Pin Diagram

4

4

Architecture of 89C52

5

5

Reset Connection

8

6

On-Chip Oscillator

9

7

Crystals for Timing Purpose

11

8

Oscillator Circuit in microcontroller

13

9

Example of a Crystal Oscillator

14

10

Block Diagram of Power Supply

15

11

Step-Down Transformer

19

12

Block Diagram of R.P.S

19

13

Voltage Regulator

20

14

Buzzer Drive

22

15

Alphanumerical L.C.D

23

16

L.C.D Screen

24

17

Model of Automatic Speed Limiter

27

CHAPTER 1 INTRODUCTION 1.1 BLOCK DIAGRAM On the road:

VEHICLE ID IN TK5530

RF ANTENNA

In the vehicle: RF RECEIVER ANTENNA

125 KHz RF RECEIVENG MODULE

RF READER MODULE

MICRO CONTROL LER

LCD MODULE

REL AY DRIV ER

RESET LOGIC

RELAY

OSCILLATOR BUZZER DRIVER

BUZZER

Fig 1: Block Diagram 1

RFID Tag TK5530

RF Antenna 125KHz

10k

VCC

CON9

1 2 3 4 5 6 7 8 9

9v ? BATTERY

VCC 10k

C? 1000/25

+ 10/16

+

1

33p

33p

C? 11.0592

Y?

C?

8.2K

10mf /16v

C? 100/16

2

VCC

VOUT GND

GN D

3

VIN +

19

18

10

9

VCC

AT89C52

40

VCC

23 22 21

28 27 26

39 38 37 36 35 34 33 32

RN1=?

D? 4007

1 2 3 4 5 6 7 8 9

U? L7805

31

1 2

D? 4007

+ Buz -

VCC

Q? BC547

12 V

D? 4148 Q? BC547

+12v

14A 13A 12A 11A 10A 9A 8A 7A 6A 5A 4A 3A 2A 1A

LCD

J?A

1 2

3

RL?

4

5

R? 8.2K

R? 8.2K

Motor

VCC

1.2 CIRCUIT DIAGRAM

Fig 2: Circuit Diagram

2

20

CHAPTER 2 LITERATURE REVIEW 2.1 MICROCONTROLLER89C52 2.1.1 FEATURES:  Compatible with MCS-51 Products.  8K Bytes of In-System Reprogrammable Flash Memory.  Endurance: 1,000 Write/Erase Cycles.  Fully Static Operation: 0 Hz to 24 MHz  Three-level Program Memory Lock.  256 x 8-Bit Internal RAM.  32 Programmable I/O Lines.  Three 16-bit Timer/Counters.  Eight Interrupt Sources.  Programmable Serial Channel.  Low Power Idle and Power Down Modes

2.1.2 PIN DIAGRAM AND ITS DESCRIPTION: The microcontroller generic part number actually includes a whole family of microcontrollers that have numbers ranging from 8031to 8751 and are available in N-Channel Metal Oxide Silicon (NMOS) and Complementary Metal Oxide Silicon (CMOS) construction in a variety of package types.

3

2.1.2.1 PIN DIAGRAM:

Fig 3: Pin Diagram With 4Kbytes of Flash Programmable and Erasable Read Only Memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard MCS-51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C52 is a powerful microcomputer which provides a highly flexible and cost-effective solution to many embedded control applications. 4

The AT89C52 provides the following standard features: 4 Kbytes of Flash, 256 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power Down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.

2.1.3 ARCHITECTURE OF 89C52:

Fig 4: Architecture of 89C52 5

Port 0: Port 0 is an 8-bit open drain bidirectional I/O port. As an output port each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high-impedance inputs. Port 0 may also be configured to be the multiplexed low order address/data bus during accesses to external program and data memory. In this mode P0 has internal pull-ups. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pull-ups are required during program verification Port 1: Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 1 also receives the loworder address bytes during Flash programming and program verification. Alternate functions of port are,

Port 2: Port 2 is an 8-bit bidirectional I/O port with internal pullups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pullups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data .

6

memory that use 16-bit addresses (MOVX A,@DPTR). In this application it uses strong internal pull-ups when emitting 1s. During accesses to external data memory that uses 8-bit addresses (MOVX A,@RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification. Port 3: Port 3 is an 8-bit bidirectional I/O port with internal pullups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups. Port 3 also serves the functions of various special features of the AT89C52 as listed below: Alternate functions of port 3 are,

RST: RST means RESET; 89C52 uses an active high reset pin. It must go high for two machine cycles. The simple RC circuit used here will supply voltage (Vcc) to reset pin until capacitance begins to charge. At a threshold of about 2.5V, reset input reaches a low level and system begin to run.

7

Fig 5: Reset Connection ALE/PROG: Address Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode. PSEN: Program Store Enable is the read strobe to external program memory. When the AT89C52 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory. EA/VPP: External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at OOOOH up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to Vcc for internal program executions. This pin also receives the 12-volt programming .

8

XTAL1: Input to the inverting oscillator amplifier and input to the internal clock operating circuit XTAL2: Output from the inverting oscillator amplifier. T2: External count input to Timer/Counter 2, Clock out. T2EX: Counter 2 capture/reload trigger & direction control.

2.2 THE ON-CHIP OSCILLATORS: Pins XTAL1 and XTAL2 are provided for connecting a resonant network to form an oscillator. The crystal frequency is basic internal clock frequency. The maximum and minimum frequencies are specified from 1to 24MHZ. Program instructions may require one, two or four machine cycles to be executed depending on type of instructions. To calculate the time any particular instructions will take to be executed, the number of cycles ‘C’, T = C*12d / Crystal frequency Here, we chose frequency as 11.0592MHZ. This is because, baud= 2*clock frequency/(32d. 12d[256d-TH1]).The oscillator is chosen to help generate both standard and nonstandard baud rates. If standard baud rates are desired, an 11.0592MHZ crystal should be selected. From our desired standard rate, TH1 can be calculated. The internally implemented value of capacitance is 33 pf.

Fig 6: On-Chip Oscillators

9

2.2.1 Program Memory Lock Bits: On the chip there are three lock bits which can be left unprogrammed (U) or can be programmed (P) to obtain the additional features. When lock bit 1 is programmed, the logic level at the EA pin is sampled and latched during reset. If the device is powered up without a reset, the latch initializes to a random value, and holds that value until reset is activated. It is necessary that the latched value of EA agree with the current logic level at that pin in order for the device to function properly.

2.2.2 Program Counter and Data Pointer: The 89C52 contains two 16-bit registers: the program counter (PC) and the data pointer (DPTR), Each is used to hold the address of a byte in memory. The PC is the only register that does not have an internal address. The DPTR is under the control of program instructions and can be specified by its 16-bit name, DPTR, or by each individual byte name, DPH and DPL. DPTR does not have a single internal address, DPH and DPL are each assigned an address.

2.2.3 A & B Registers: The 89C52 contains 34 general-purpose, working, registers. Two of these, registers A and B, hold results of many instructions, particularly math and logical operations, of the 89C52 CPU. The other 32 are arranged as part of internal RAM in four banks, B0-B3, of eight registers. The A register is also used for all data transfers between the 89C52 and any external memory. The B register is used for with the A register for multiplication and division operations.

2.2.4 Flags and the Program Status Word (PSW): Flags may be conveniently addressed, they are grouped inside the program status word (PSW) and the power control (PCON) registers.

10

CHAPTER 3 MATERIALS AND METHODS 3.1 CRYSTAL OSCILLATOR A crystal oscillator (sometimes abbreviated to XTAL on schematic diagrams) is an electronic circuit that uses the mechanical resonance of a physical crystal of piezoelectric material along with an amplifier and feedback to create an electrical signal with a very precise frequency. It is an especially accurate form of an electronic oscillator. This frequency is used to keep track of time (as in quartz wristwatches), to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters. Crystal oscillators are a common source of time and frequency signals. The crystal used therein is sometimes called a "timing crystal".

Fig 7: Crystals for timing purposes A miniature 4.000 MHz quartz timing crystal enclosed in an hermetically sealed package. A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. 11

Almost any object made of an elastic material could be used like a crystal, with appropriate transducers, since all objects have natural resonant frequencies of vibration. For example, steel is very elastic and has a high speed of sound. It was often used in mechanical filters before quartz. The resonant frequency depends on size, shape, elasticity and the speed of sound in the material. High-frequency crystals are typically cut in the shape of a simple, rectangular plate. Low-frequency crystals, such as those used in digital watches, are typically cut in the shape of a tuning fork. For applications not needing very precise timing, a low-cost ceramic resonator is often used in place of a quartz crystal. When a crystal of quartz is properly cut and mounted, it can be made to bend in an electric field, by applying a voltage to an electrode near or on the crystal. This property is known as piezoelectricity. When the field is removed, the quartz will generate an electric field as it returns to its previous shape, and this can generate a voltage. The result is that a quartz crystal behaves like a circuit composed of an inductor, capacitor and resistor, with a precise resonant frequency. Quartz has the further advantage that its size changes very little with temperature. Therefore, the resonant frequency of the plate, which depends on its size, will not change much, either. This means that a quartz clock, filter or oscillator will remain accurate. For critical applications the quartz oscillator is mounted in a temperaturecontrolled container, called an crystal oven, and can also be mounted on shock absorbers to prevent perturbation by external mechanical vibrations. Quartz timing crystals are manufactured for frequencies from a few tens of kilohertz to tens of megahertz. More than two billion (2 × 109) crystals are manufactured annually. Most are small devices for wristwatches, clocks, and electronic circuits. However, quartz crystals are also found inside test and measurement equipment, such as counters, signal generators, and oscilloscopes.

12

Fig 8: Oscillator circuit in Micro controller The crystal oscillator circuit sustains oscillation by taking a voltage signal from the quartz resonator, amplifying it, and feeding it back to the resonator. The rate of expansion and contraction of the quartz is the resonant frequency, and is determined by the cut and size of the crystal. A regular timing crystal contains two electrically conductive plates, with a slice or tuning fork of quartz crystal sandwiched between them. During startup, the circuit around the crystal applies a random noise AC signal to it, and purely by chance, a tiny fraction of the noise will be at the resonant frequency of the crystal. The crystal will therefore start oscillating in synchrony with that signal. As the oscillator amplifies the signals coming out of the crystal, the crystal's frequency will become stronger, eventually dominating the output of the oscillator. Natural resistance in the circuit and in the quartz crystal filter out all the unwanted frequencies. One of the most important traits of quartz crystal oscillators is that they can exhibit very low phase noise. In other words, the signal they produce is a pure tone. This makes them particularly useful in telecommunications where stable signals are needed, and in scientific equipment where very precise time references are needed. The output frequency of a quartz oscillator is either the fundamental resonance or a multiple of the resonance, called an overtone frequency. A typical Q for a quartz oscillator ranges from 104 to 106. The maximum Q for a high stability quartz oscillator can be estimated as Q = 1.6 × 107/f, where f is the resonance 13

Environmental changes of temperature, humidity, pressure, and vibration can change the resonant frequency of a quartz crystal, but there are several designs that reduce these environmental effects. These include the TCXO, MCXO, and OCXO (defined below). These designs (particularly the OCXO) often produce devices with excellent short-term stability. The limitations in short-term stability are due mainly to noise from electronic components in the oscillator circuits. Long term stability is limited by aging of the crystal. Due to aging and environmental factors such as temperature and vibration, it is hard to keep even the best quartz oscillators within one part in 10-10 of their nominal frequency without constant adjustment. For this reason, atomic oscillators are used for applications that require better long-term stability and accuracy. Although crystals can be fabricated for any desired resonant frequency, within technological limits, in actual practice today engineers design crystal oscillator circuits around relatively few standard frequencies, such as 10 MHz, 20 MHz and 40 MHz. Using frequency dividers, frequency multipliers and phase locked loop circuits, it is possible to synthesize any desired frequency from the reference frequency. Care must be taken to use only one crystal oscillator source when designing circuits to avoid subtle failure modes of metastability in electronics. If this is not possible, the number of distinct crystal oscillators, PLLs, and their associated clock domains should be rigorously minimized, through techniques such as using a subdivision of an existing clock instead of a new crystal source. Each new distinct crystal source needs to be rigorously justified since each one introduces new difficult to debug probabilistic failure modes, due to multiple crystal interactions, into equipment.

Fig 9: Example of A Crystal Oscillator 14

3.2 POWER SUPPLY 3.2.1 Description: The Power Supply is a Primary requirement for the project work. The required DC power supply for the base unit as well as for the recharging unit is derived from the mains line. For this purpose center tapped secondary of 12V-012V transformer is used. From this transformer we getting 5V power supply. In this +5V output is a regulated output and it is designed using 7805 positive voltage regulator. Rectification is a process of rendering an alternating current or voltage into a 1unidirectional

one. The component used for rectification is called ‘Rectifier’. A rectifier permits

current to flow only during positive half cycles of the applied AC voltage. Thus, pulsating DC is obtained to obtain smooth DC power additional filter circuits required.

3.2.2 Circuit diagram: +12v 1N4007 X 2

230v / 12v- 0 -12v 500mA Transformer

2200µF/25 v 100µF/25v

Fig 10: Block diagram of power supply A diode can be used as rectifier. There are various types of diodes. However, semiconductor diodes are very popularly used as rectifiers. A semiconductor diode is a solid-state 15

device consisting of two elements is being an electron emitter or cathode, the other an electron collector or anode. Since electrons in a semiconductor diode can flow in one direction only-form emitter to collector-the diode provides the unilateral conduction necessary for rectification.The rectified Output is filtered for smoothening the DC, for this purpose capacitor is used in the filter circuit. The filter capacitors are usually connected in parallel with the rectifier output and the load. The AC can pass through a capacitor but DC cannot, the ripples are thus limited and the output becomes smoothed. When the voltage across the capacitor plates tends to rise, it stores up energy back into voltage and current. Thus, the fluctuation in the output voltage is reduced considerable.

3.3 VOLTAGE REGULATOR: The LM 78XXX series of the three terminal regulations is available with several fixed output voltages making them useful in a wide range of applications. One of these is local on card regulation. The voltages available allow these regulators to be used in logic systems, instrumentation and other solid state electronic equipment. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents. The LM78XX series is available in aluminum to 3 packages which will allow over 1.5A load current if adequate heat sinking is provided. Current limiting is included to limit the peak output current to a safe value. The LM 78XX is available in the metal 3 leads to 5 and the plastic to 92. For this type, with adequate heat sinking. The regulator can deliver 100mA output current. The advantage of this type of regulator is, it is easy to use and minimize the number of external components. The following are the features voltage regulators: a) Output current in excess of 1.5A for 78 and 78L series b) Internal thermal overload protection c) No external components required d) Output transistor sage area protection 16

3.3.1 POSITIVE VOLTAGE REGULATOR: The positive voltage regulator has different features like, Output current up to 1.5A. No external components. Internal thermal overload protection. High power dissipation capability. Internal short-circuit current limiting. Output transistor safe area compensation. Direct replacements for Fairchild microA7800 series. Nominal

Regulator

Output Voltage 5V 6V 8V 8.5V 10V 12V 15V 18V 24V

uA7805C uA7806C uA7808C uA7885C uA7810C uA7812C uA7815C uA7818C uA7824C

3.4 TRANFORMER 3.4.1 INTRODUCTION: A transformer is an electrical device that transfers energy from one circuit to another by magnetic coupling, without requiring relative motion between its parts. A transformer comprises two or more coupled windings, and, in most cases, a magnetic core to concentrate magnetic flux. A changing voltage applied to one winding creates a time-varying magnetic flux in the core, which induces a voltage in the other windings. The transformer is one of the simplest of electrical devices, yet transformer designs and materials continue to be improved. 17

Transformers come in a range of sizes from a thumbnail-sized coupling transformer hidden inside a stage microphone to huge gigawatt units used to interconnect large portions of national power grids. All operate with the same basic principles and with many similarities in their parts.

3.4.2 PRINCIPLE: A transformer can be likened to a mechanical gearbox, which transfers mechanical energy from a high-speed, low torque shaft to a lower-speed, higher-torque shaft, but which is Not a source of energy itself. A transformer transfers electrical energy from a high-current, lowvoltage circuit to a lower-current, higher-voltage circuit.

3.4.3 STEP DOWN TRANSFORMER: The Power Supply is a Primary requirement for the project work. The required DC power supply for the base unit as well as for the recharging unit is derived from the mains line. For this purpose, center tapped secondary of 12V-012V transformer is used. From this transformer we getting 5V power supply. In this +5V output is a regulated output and it is designed using 7805 positive voltage regulators. This is a 3 Pin voltage regulator, can deliver current up to 800 milliamps. Rectification is a process of rendering an alternating current or voltage into a unidirectional one. The component used for rectification is called ‘Rectifier’. A rectifier permits current to flow only during positive half cycles of the applied AC voltage. Thus, pulsating DC is obtained to obtain smooth DC power additional filter circuits required. A diode can be used as rectifier. There are various types of diodes. However, semiconductor diodes are very popularly used as rectifiers. A semiconductor diode is a solidstate device consisting of two The supply given is the +5V D.C. The incoming power is 230V A.C there is a need to convert it into +5V D.C.

18

+12v 1N4007 X 2

230v / 12v- 0 -12v 500mA Transformer

2200µF/25 v 100µF/25v

Fig 11: Step-Down Transformer The input A.C supply is stepped down from 230V to 9-0-9V. The rectifier consists of diodes D1 and D2 makes the supply D.C. that is, unidirectional waveform. The output from rectifier is a URDC, whose value is 12.726V peak to peak. The voltage regulator makes this URDC to RDC of +5V. The capacitor C1 is used to maintain constant voltage between two consecutive positive cycles where as C2 is used to remove the fluctuations caused by regulator. Here we are selecting 12.726V as a peak value. Because of fluctuations, the peak voltage may decrease, then regulator cannot step up to +5V. If we select peak value, a higher one, then the problem can be overcome.

Fig 12: Block Diagram of R.P.S

19

A regulated power supply which maintains the output voltage constant irrespective of A.C mains fluctuations or load variations is known as regulated power supply. A regulated power supply consists of an ordinary power supply and voltage regulating device. The output of ordinary power supply is fed to the voltage regulator which produces the final output. The output voltage remains constant whether the load current changes or there are fluctuations in the input A.C voltage. The rectifier converts the transformer secondary A.C voltage into pulsating voltage. The pulsating D.C voltage is applied to the capacitor filter. This filter reduces the pulsations in the rectifier D.C output voltage. Finally, it reduces the variations in the filtered output voltage.

3.5 VOLTAGE REGULATOR: As the name itself implies, it regulates the input applied to it. A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. In this project, power supply of 5V and 12V are required. In order to obtain these voltage levels, 7805 and 7812 voltage regulators are to be used. The first number 78 represents positive supply and the numbers 05, 12 represent the required output voltage levels. The L78xx series of three-terminal positive regulators is available in TO-220, TO-220FP, TO-3, D2PAK and DPAK packages and several fixed output voltages, making it useful in a wide range of applications. These regulators can provide local on-card regulation, eliminating the distribution problems associated with single point regulation.

Fig 13: Voltage Regulator 20

Each type employs internal current limiting, thermal shut-down and safe area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1 A output current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltage and currents.

3.6 BUZZER: A buzzer or beeper is a signaling device, usually electronic, typically used in automobiles, household appliances such as a microwave oven, or game shows. It most commonly consists of a number of switches or sensors connected to a control unit that determines if and which button was pushed or a preset time has lapsed, and usually illuminates a light on the appropriate button or control panel, and sounds a warning in the form of a continuous or intermittent buzzing or beeping sound. Initially this device was based on an electromechanical system which was identical to an electric bell without the metal gong (which makes the ringing noise). Often these units were anchored to a wall or ceiling and used the ceiling or wall as a sounding board. Another implementation with some AC- connected devices was to implement a circuit to make the AC current into a noise loud enough to drive a loudspeaker and hook this circuit up to a cheap 8-ohm speaker. Now-a-days, it is more popular to use a ceramic-based piezoelectric sounder like a Son alert which makes a high-pitched tone. Usually these were hooked up to “driver” circuits which varied the pitch of the sound or pulsed the sound on and off

3.6.1 Buzzer Driver: The circuit is designed to control the buzzer. The buzzer ON and OFF is controlled by the pair of switching transistors (BC 547). The buzzer is connected in the Q2 transistor collector terminal. When high pulse signal is given to base of the Q1 transistors, the transistor is conducting and close the collector and emitter terminal so zero signals is given to base of the Q2 transistor. 21

Transistor and buzzer is turned OFF state. When low pulse is given to base of transistor Q1, the transistor is turned OFF. Now 12V is given to base of Q2 transistor so the transistor is conducting and buzzer is energized and produces the sound signal.

VCC

12 V

+ Buz -

D? 4007

Q? BC547

Fig 14: Buzzer Driver

3.7 LIQUID CRYSTAL DISPLAY 3.7.1 INTRODUCTION: LCD stands for Liquid Crystal Display. LCD is finding wide spread use replacing LEDs (seven segment LEDs or other multi segment LEDs) because of the following reasons: 1. The declining prices of LCDs. 2. The ability to display numbers, characters and graphics. This is in contrast to LEDs, which are limited to numbers and a few characters. 3. Incorporation of a refreshing controller into the LCD, thereby relieving the CPU of the task of refreshing the LCD. In contrast, the LED must be refreshed by the CPU to keep displaying the data. 4. Ease of programming for characters and graphics. These components are “specialized” for being used with the microcontrollers, which means that they cannot be activated by standard IC circuits. They are used for writing different messages on a miniature LCD. 22

A model described here is for its low price and great possibilities most frequently used in practice. It is based on the HD44780 microcontroller (Hitachi) and can display messages in two lines with 16 characters each. It displays all the alphabets, Greek letters, punctuation marks, mathematical symbols etc. In addition, it is possible to display symbols that user makes up on its own. Automatic shifting message on display (shift left and right), appearance of the pointer, backlight etc. are considered as useful characteristics.

3.7.2 FEATURES:  Interface with either 4-bit or 8-bit microprocessor.  Display data RAM  80 8 bits (80 characters).  Character generator ROM  160 different 5 7 dot-matrix character patterns.  Character generator RAM  8 different user programmed 5 7 dot-matrix patterns.  Display data RAM and character generator RAM may be  accessed by the microprocessor.  Numerous instructions  Clear Display, Cursor Home, Display ON/OFF, Cursor  ON/OFF, Blink Character, Cursor Shift, Display Shift.  Built-in reset circuit is triggered at power ON.

Fig 15: A general purpose alphanumeric LCD, with two lines of 16 characters. 23

3.7.3 LCD SCREEN: LCD screen consists of two lines with 16 characters each. Each character consists of 5x7 dot matrix. Contrast on display depends on the power supply voltage and whether messages are displayed in one or two lines. For that reason, variable voltage 0-Vdd is applied on pin marked as Vee. Trimmer potentiometer is usually used for that purpose. Some versions of displays have built in backlight (blue or green diodes). When used during operating, a resistor for current limitation should be used (like with any LE diode).

Fig 16: LCD Screen

3.7.4 LCD BASIC COMMANDS: All data transferred to LCD through outputs D0-D7 will be interpreted as commands or as data, which depends on logic state on pin RS: RS = 1 - Bits D0 - D7 are addresses of characters that should be displayed. Built in processor addresses built in “map of characters” and displays corresponding symbols. Displaying position is determined by DDRAM address. This address is either previously defined or the address of previously transferred character is automatically incremented. RS = 0 - Bits D0 - D7 are commands which determine display mode. List of commands which LCD recognizes are given in the table below:

I/D 1 = Increment (by 1) 0 = Decrement (by 1)

R/L 1 = Shift right 0 = Shift left 24

S 1 = Display shift on

DL 1 = 8-bit interface

0 = Display shift off

0 = 4-bit interface

D 1 = Display on

N 1 =Display in two lines

0 = Display off

0 = Display in one line

U 1 = Cursor on

F 1 = Character format 5x10 dots2

0 = Cursor off

0 = Character format 5x7 dots

B 1 = Cursor blink on 0 = Cursor blink off

D/C 1 = Display shift 0 = Cursor shift

3.7.5 LCD INITIALIZATION: Once the power supply is turned on, LCD is automatically cleared. This process lasts for approximately 15mS. After that, display is ready to operate. The mode of operating is set by default. This means that: 1. Display is cleared 2. Mode DL = 1 Communication through 8-bit interface N = 0 Messages are displayed in one line F = 0 Character font 5 x 8 dots 3. Display/Cursor on/off D = 0 Display off U = 0 Cursor off B = 0 Cursor blink off 25

4. Character entry ID = 1 Addresses on display are automatically incremented by 1 S = 0 Display shift off Automatic reset is mainly performed without any problems. Mainly but not always! If for any reason power supply voltage does not reach full value in the course of 10mS, display will start perform completely unpredictably? If voltage supply unit can not meet this condition or if it is needed to provide completely safe operating, the process of initialization by which a new reset enabling display to operate normally must be applied. Algorithm according to the initialization is being performed depends on whether connection to the microcontroller is through 4- or 8-bit interface. All left over to be done after that is to give basic commands and of course- to display messages.

3.7.6 LCD INTERFACING WITH THE MICROCONTROLLER:

Vcc P2.0 P2.1 P2.2

4 (RS) 5 (R/W) 6(EN)

1 2 3

LCD

89C51

P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7

D0 D1 D2 D3 D4 D5 D6 D7

Gnd

PRESET (CONTRA ST CONTROL

15 16

Vcc Gnd

FOR BACK LIGHT

26

CHAPTER 4 EXPERIMENTATION 4.1 WORKING:

Fig 17: Model of Automatic Speed Limiter

4.1.1 RESISITOR: Resistors limit current. In a typical application, a resistor is connected in series with an LED: Enough current flows to make the LED light up, but not so much that the LED is damaged. The 'box' symbol for a fixed resistor is popular in the UK and Europe. A 'zig-zag' symbol is used in America and Japan: Resistors are used with transducers to make sensor subsystems. Transducers are electronic components which convert energy from one form into another, where one of the forms of energy is electrical. A light dependent resistor, or LDR, is an example of an input transducer. Changes in the brightness of the light shining onto the surface of the LDR result in changes in its resistance. An input transducer is most often connected along with a resistor to make a circuit called a potential divider. 27

In this case, the output of the potential divider will be a voltage signal which reflects changes in illumination Microphones and switches are input transducers. Output transducers include loudspeakers, filament lamps and LEDs. In other circuits, resistors are used to direct current flow to particular parts of the circuit, or may be used to determine the voltage gain of an amplifier. Resistors are used with capacitors to introduce time delays. Most electronic circuits require resistors to make them work properly and it is obviously important to find out something about the different types of resistor available, and to be able to choose the correct resistor value, in

,

, or M , for a particular application.

4.1.2 CAPACITORS: A capacitor or condenser is a passive electronic component consisting of a pair of conductors separated by a dielectric. When a voltage potential difference exists between the conductors, an electric field is present in the dielectric. This field stores energy and produces a mechanical force between the plates. The effect is greatest between wide, flat, parallel, narrowly separated conductors. An ideal capacitor is characterized by a single constant value, capacitance, which is measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them. In practice, the dielectric between the plates passes a small amount of leakage current. The conductors and leads introduce an equivalent series resistance and the dielectric has an electric field strength limit resulting in a breakdown voltage. The properties of capacitors in a circuit may determine the resonant frequency and quality factor of a resonant circuit, power dissipation and operating frequency in a digital logic circuit, energy capacity in a high-power system, and many other important system characteristics. Many of these capacitors also have a capital letter to indicate their tolerance rating, according to the following coding system. 28

4.1.3 TRANSISTOR: A transistor is a semiconductor device used to amplify and switch electronic signals. It is made of a solid piece of semiconductor material, with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current flowing through another pair of terminals. Because the controlled (output) power can be much more than the controlling (input) power, the transistor provides amplification of a signal. Some transistors are packaged individually but many more are found embedded in integrated circuits. The transistor is the fundamental building block of modern electronic devices, and its presence is ubiquitous in modern electronic systems

4.1.4 INFRARED SENSORS: Active and passive infrared sensors are manufactured for traffic applications. The sensors are mounted overhead to view approaching or departing traffic or traffic from a sidelooking configuration. Infrared sensors are used for signal control; volume, speed, and class measurement, as well as detecting pedestrians in crosswalks. With infrared sensors, the word detector takes on another meaning, namely the light-sensitive element that converts the reflected or emitted energy into electrical signals. Real-time signal processing is used to analyze the received signals for the presence of a vehicle.

4.1.4.1 ACTIVE INFRARED SENSOR: Active infrared sensors illuminate detection zones with low power infrared energy supplied by laser diodes operating in the near infrared region of the electromagnetic spectrum at 0.85 m. The infrared energy reflected from vehicles traveling through the detection zone is focused by an optical system onto an infrared-sensitive material mounted at the focal plane of the optics. 29

The active infrared laser sensor has two sets of optics. The transmitting optics split the pulsed laser diode output into two beams separated by several degrees as displayed in Figure 24. The receiving optics has a wider field of view so that it can better receive the energy scattered from the vehicles. By transmitting two or more beams, the laser radars measure vehicle speed by recording the times at which the vehicle enters the detection area of each beam.

4.1.4.2 PASSIVE INFRARED SENSORS: Passive sensors detect the energy that is emitted from vehicles, road surfaces, other objects in their field of view, and from the atmosphere, but they transmit no energy of their own. Non-imaging passive infrared sensors used in traffic management applications contain one or several (typically not more than five) energy-sensitive detector elements on the focal plane that gather energy from the entire scene. The detector in a non-imaging sensor generally has a large instantaneous field of view. The instantaneous field of view is equal to the angle, e.g. in the x-y plane, subtended by a pixel. Objects within the scene cannot be further divided into sub-objects or pixels (picture elements) with this device. Imaging sensors, such as modern charge-coupled device (CCD) cameras, contain two-dimensional arrays of detectors, each detector having a small instantaneous field of view. The two-dimensional array gathers energy from the scene over an area corresponding to the field of view of the entire array. Imaging sensors display the pixel-resolution details found in the imaged area.

4.2 APPLICATIONS: 1. Automatic Speed Controller can be installed in an automobile and used for reducing the vehicle speed. 2. It is used to prevent accidents at hospitals, schools and at required zones etc. 3. It is used for saving the fuel in the vehicle by slowing down the speed of vehicle. 4. It can be used any type of vehicle i.e. cars, lorries, buses, etc. 30

CHAPTER 5 PROGRAM CODE

;P1.0 ;P1.1 ;P0 = DISP DATA ;P2.7 = RS ;P2.6 = R/W ;P2.5 = EN ;P2.4=SW1 ;P2.3=SW1 ;P2.2=SW1 ; 50H = DISP LOCATION ADD ; 51H = DISP VALUE ; 60H = voltage set value ; 61H = frq set value ; 70H = voltage READ value ; 71H = frq READ value

TXD

MACRO

JNB TI,$ CLR TI MOV SBUF,R6 MACEND 31

3

ORG 0 LJMP START ORG 0050H START: CLR P2.0 CLR P2.1 LCALL LCDINI LCALL DEL MOV DPTR,#0900H LCALL TLINE MOV DPTR,#0910H LCALL BLINE LCALL SSEC MOV DPTR,#0920H LCALL TLINE MOV DPTR,#0930H LCALL BLINE ;********* READ VAL DISP

***********

MOV R6,#FFH XX1:

LCALL SSEN

32

CLR A MOV A,51H CPL A MOV 51H,A MOV 50H,#8BH MOV A,51H MOV 70H,A LCALL VFDIS ;------------MOV 75H,#00H LCALL SCOMP CLR A MOV A,75H CJNE A,#01H,XX2 SETB P2.0 SETB P2.1 LJMP XX1 XX2:

CLR P2.0

CLR P2.1 LJMP XX1 ;*********** VOL COMP ********* TLINE: CLR p2.7 CLR p2.6 MOV P0,#80H LCALL WRI MOV R7,#00H TKL: CLR A

33

MOVC A,@A+DPTR MOV P0,A LCALL WRD INC DPTR INC R7 CJNE R7,#10H,TKL RET BLINE: CLR p2.7 CLR p2.6 MOV P0,#C0H LCALL WRI MOV R7,#00H BKL: CLR A MOVC A,@A+DPTR MOV P0,A LCALL WRD INC DPTR INC R7 CJNE R7,#10H,BKL RET ********* SPEED SENSE ************ SSEN:

;MOV PSW,#18H

JNB P1.0,EXITX MOV R6,#00H mov r2,#05H

34

SD1:

mov r3,#FFH

SD2:

mov r4,#FFH

WE: JB P1.1,EXITX MOV R0,#FFH DJNZ R0,$ JB P1.1,WE INC R6 ;----------------MOV R5,#01H GBY:

MOV R1,#05H

GBX:

JB P1.1,EXITX

MOV R0,#FFH DJNZ R0,$ DJNZ R1,GBX DJNZ R5,GBY ;---------------VVVV: CJNE R6,#FFH,WEE LJMP WER WEE:

djnz r4,WE

djnz r3,SD2 djnz r2,SD1 WER: EXITX: MOV 51H,R6 MOV PSW,#00H

35

RET ;*********** VOL COMP ********* SCOMP: CLR C CLR A MOV A,#64H

;SET VOL DATA

CJNE A,70H,GTLS1 RET GTLS1: JNC GT1 MOV 75H,#01H GT1: RET ;-----------------------;##############################

36

CHAPTER 6 CONCLUSION The main objective of the project is to control the speed of vehicles at sensitive zones which exceed the specified speed limit. The RF transmitter in the vehicle continuously transmits the data and searches for the RF code. When it receives a code, it transmits that code to the micro controller and comparison of that code is done in the micro controller. If that code matches with sensitive zone`s starting code, it activates the control relay and car speed is reduced. Again, if the sensitive zones ending code is received, the micro controller automatically de-activates the control relay and the vehicle`s speed is attained to normal state.

37

FUTURE SCOPE  We can modify the system with the help of GPS to identify the respective zones.  We can also modify the system with efficient braking system in association with air flow control to the carburetor.  This system can be more effectively used for any kind of automobiles such as lorries, buses, cars, bikes etc.

REFERENCES  Kenneth J. Ayala, The 8051Microcontroller.  Muhammad Ali Mazidi, The 8051 Microcontroller and Embedded Systems.  Vijay Garg, Principles and Applications of GSM.

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