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FIRE FIGHTING ROBOT

D.MEENAKSHI

G.SILPAV.RAJITHA

Department of Electronics and Communication Engineering

MAHATMA GANDHI INSTITUTE OF TECHNOLOGY(Affiliated to Jawaharlal Nehru Technological University, Hyderabad, A.P.)

Chaitanya Bharathi P.O., Gandipet, Hyderabad – 500 075

2009

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FIRE FIGHTING ROBOT

PROJECT REPORT

SUBMITTED IN PARTIAL FULFILLMENT

OF THE REQUIREMENTS FOR THE DEGREE OF

BACHELOR OF TECHNOLOGY

IN

ELECTRONICS AND COMMUNICATION ENGINEERING

BY

 

D.MEENAKSHI (06261A0412)

G.SILPA (06261A0420)

V.RAJITHA (06261A0456)

Department of Electronics and Communication Engineering (Font: 14, TNR)

MAHATMA GANDHI INSTITUTE OF TECHNOLOGY(Affiliated to Jawaharlal Nehru Technological University, Hyderabad, A.P.)

Chaitanya Bharathi P.O., Gandipet, Hyderabad – 500 075

2009

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MAHATMA GANDHI INSTITUTE OF TECHNOLOGY (Affiliated to Jawaharlal Nehru Technological University, Hyderabad, A.P.)

Chaitanya Bharathi P.O., Gandipet, Hyderabad-500 075

Department of Electronics and Communication Engineering

CERTIFICATE

Date: 24April2009

This is to certify that the project work entitled “Fire Fighting Robot” is a

 bonafied work carried out by

D.Meenakshi (06261A0412)

G.Silpa (06261A0420)

V.Rajitha (06261A0456)

in partial fulfillment of the requirements for the degree of  BACHELOR OF

TECHNOLOGY in ELECTRONICS & COMMUNICATION ENGINEERING by the

Jawaharlal Nehru Technological University, Hyderabad during the academic year 2006-07.

The results embodied in this report have not been submitted to any other University or 

Institution for the award of any degree or diploma.

(Signature)

(Signature)

--------------------------------------T.D.

Bhatt, Associate Professor Mr. Nagbhooshanam

Faculty Advisor/Liaison   Professor & Head

 

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ACKNOWLEDGEMENT (Font: 16, TNR)

We express our deep sense of gratitude to our Guide Mr.D.k.swami, IETE, OU, for his invaluable

guidance and encouragement in carrying out our Project.

We are highly indebted to our Faculty Liaison Mr.T.D.Bhatt, Associate Professor, Electronics

and Communication Engineering Department, who have given us all the necessary technical

guidance in carrying out this Project.

We wish to express our sincere thanks to Dr. E. Nagabhooshanam, Head of the Department of 

Electronics and Communication Engineering, M.G.I.T., for permitting us to pursue our Project in

Cranes Varsity and encouraging us throughout the Project.

Finally, we thank all the people who have directly or indirectly help us through the course of our 

Project.

 

D.MeenakshiG.Silpa

V.Rajitha

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ABSTRACT

The need for a device that can detect and extinguish a fire on its own is long past due.

Many house fires originate when someone is either sleeping or not home. With the

invention of such a device, people and property can be saved at a much higher rate with

relatively minimal damage caused by the fire.

Our task as electronic engineers is to design and build a prototype system that could

autonomously detect and extinguish a fire. Also aims at minimizing air pollution.

In this Project we design a Robot. It is the Robot that can move through a model

structure, find a burning oil derrick (lit candle) and then extinguish it with help of a

Blower. This is meant to simulate the real world operation of a Robot performing a fire

extinguishing function in an oilfield.

We are using the Popular 8 bit Microcontroller the 8051 family Microcontroller. Program

code to control the fire-fighting robot is written in assembly language.

Microcontroller that is being used is Atmel’s AT89C52. The AT89C52 is a low-power,

high-performance CMOS 8-bit microcomputer with 8K Bytes of Flash programmable

and erasable read only memory (PEROM). The on-chip Flash allows the program

memory to be reprogrammed in-system or by a Conventional nonvolatile memory

 programmer. The device is manufactured using Atmel’s high-density nonvolatile memory

technology and is Compatible with the industry-standard 80C51 and 80C52 instruction

set and pin out.

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Table of contents

CERTIFICATE FROM ECE DEPARTMENT (i)

ACKNOWLEDGEMENTS (ii)

ABSTRACT (iii)

LIST OF FIGURES (V)

LIST OF TABLES (vi)

CHAPTER 1. OVERVIEW

1.1 Introduction 2

1.2 Aim of the project 3

1.3 Methodology 3

1.4 Significance and applications 4

1.5 Organization of work 4

CHAPTER 2. 2.1 Introduction

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A microprocessor  is a computer  processor on a microchip. It's sometimes called a logic

chip. It is the "engine" that goes into motion when you turn your computer on. A

microprocessor is designed to perform arithmetic and logic operations that make use of 

small number-holding areas called registers. Typical microprocessor operations include

adding, subtracting, comparing two numbers, and fetching numbers from one area to

another. These operations are the result of a set of  instructions that are part of the

microprocessor design. When the computer is turned on, the microprocessor is designed

to get the first instruction from the basic input/output system (BIOS) that comes with the

computer as part of its memory. After that, either the BIOS, or the operating system that

BIOS loads into computer memory, or an application program is "driving" the

microprocessor, giving it instructions to perform.

 

A microcontroller  is a specialized form of microprocessor that is designed to be self-

sufficient and cost-effective, where a microprocessor is typically designed to be general

 purpose (the kind used in a PC). Micro controllers are frequently found in automobiles,

office machines, toys and appliances.

 

The microcontroller is the integration of a number of useful functions into a single IC

 package. These functions are:

The ability to execute a stored set of instructions to carry out user defined tasks.

The ability to be able to access external memory chips to both read and write data from

and to the memory.

 

Basically, a microcontroller is a device, which integrates a number of the components of 

a microprocessor system onto a single microchip.

So a microcontroller combines onto the same microchip:

The CPU core

Memory (both ROM and RAM)

Some parallel digital I/O

Also, a microcontroller is part of an embedded system, which is essentially the whole

circuit board. The difference is that microcontroller incorporates features of 

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microprocessor (CPU, LU, Registers) along with the presence of added features like

  presence of RAM, ROM, I\O ports, counter etc. Here microcontroller controls the

operation of machine using fixed program stored in ROM that doesn't change with

lifetime.

2.1: AT89C52

The microcontroller that was used in the project is the  AT89C52, which was

manufactured by Atmel Corporation.

2.1.1: Description

The  AT89C52 is a low-power, high-performance CMOS 8-bit microcomputer with 8K 

 bytes of Flash programmable and erasable read only memory (PEROM). It is compatible

with the industry standard 80C51 and 80C52 instruction set and pinout. The on-chip

Flash allows the program memory to be reprogrammed in-system or by a conventional

non-volatile memory programmer. By combining a versatile 8-bit CPU with Flash on a

monolithic chip, the Atmel 89C52 is a powerful microcomputer which provides a highly-

flexible and cost-effective solution to many embedded control applications.

2.1.2: Features:

The features of  AT89C52 are:

Compatible with MCS-51 products

8K bytes of In-System Reprogram able Flash Memory

Endurance: 1,000 Write/Erase cycles

Fully static operation: 0Hz to 24MHz

Three-level Program Memory Lock 

256* 8-bit internal RAM

• 32 Programmable I/O lines

• Three 16-bit Timer/Counters

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• Eight Interrupt Sources

• Programmable Serial Channel

• Low-power idle and power-down modes

2.1.3: Pin Diagram

Fig: 2.1

2.1.4: Pin description

The  AT89C52 consists of 8K bytes of 

Flash memory and 256 bytes of on-chip

RAM. It is a 40-pin DIP (dual in-line

 package). There are 4 I/O ports, which

comprise of a total of 32 pins. The ports

are labeled as: Port ‘0’, Port ‘1’, Port ‘2’ and Port ‘3’. The remaining 8 pins include:

RST (reset), VCC (supply), GND (ground), XTAL1, XTAL2, PSEN (program store

enable), EA/VPP, ALE (address latch enable).

The following are the features of P0-P3:

P0: -

It is a bi-directional 8-bit port, which can be used as an address or data lines depending

on the value of the address latch enable (ALE). If ALE=’1’ then, the lines are used as

address lines. Otherwise, they are used as data lines. The pins from 32 to 39 contribute

for the port ‘0’ lines.

 

P1 and P2: -

These ports are used as simple I/O ports. Port ‘2’ must be used along with Port ‘0’ to

 provide the 16-bit address for the external memory. Port ‘2’ pins are designated as A8-

A15. Pins from 1 to 8 contribute to the port ‘1’ lines. And, pins from 21 to 28 contribute

to the port ‘2’ lines.

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P3:-

Port ‘3’ occupies from pins 10 through 17. It has the additional function of providing

some extremely important signals such as interrupts. The Table: 1 explains the alternate

functions for Port ‘3’: 

Table: 2.1

 

RST:

Pin 9 is the RESET pin. It is an input and is active high. Upon applying a high pulse to

this pin, the microcontroller will reset and terminate all activities.

XTAL1 and XTAL2:

P3 Bit Function Pin

P3.0 RXD 10

P3.1 TXD 11P3.2 INTO_L 12

P3.3 INT1_L 13

P3.4 T0 14P3.5 T1 15

P3.6 WR_L 16

P3.7 RD_L 17

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 The 8051 has an on-chip oscillator but requires an external clock to run it. Most often a

quartz crystal oscillator is connected to inputs XTAL1 (pin 19) and XTAL2 (pin 18).

GND:

 Pin 20 is the ground.

VCC:

 Pin 40 provides supply voltage to the chip. The voltage source is +5v.

EA:

It stands for “external access”, is pin number 31. It is an input pin and must be connected

to either VCC or GND.

ALE:

(ADDRESS LATCH ENABLE) is an output pin and is active high. The ALE pin is used

to demultiplex address and data by connecting to the G pin of the 74LS373 chip.

PSEN:

This is an output pin. It stands for “program store enable”. In an 8031-based system in

which an external ROM holds the program code, this pin is connected to the OE pin of 

the ROM.

CHAPTER-3: COMPARATORS

 

A comparator  is a device, which compares two voltages or currents and switches its

output to indicate which is larger. An operational amplifier has a well-balanced

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difference input and a very high gain, which allows the op-amp to serve as comparators

in some functions.

A standard op-amp operating in open-loop configuration can be used as a comparator.

When the non-inverting input (V+) is at a higher voltage than the inverting input (V-),

the high gain of the op-amp causes it to output the most positive voltage it can. When

the non-inverting input (V+) drops below the inverting input (V-), the op-amp outputs

the most negative voltage it can. Usually, the output of the op-amp oscillates between

two values only i.e., either VCC or VEE. Where, VCC is generally taken in the range of 

5 to 12 volts. And, VEE is taken from 0 to –12 volts. Since the output takes only two

values at any point, the output of the op-amp appears like a square wave. Hence, the op-

amp can be said to function as a A/D converter where, it gives a digital output for 

analog input (such as DC).

The comparator used in the project is a quad-differential comparator (LM 339).

 

3.1: LM 339

The   LM 339 is a quad differential comparator which consists of four independent

 precision voltage comparators with an offset voltage specification as low as 2.0mV max

for four comparators, which were designed specifically to operate from a single power supply over a wide range of voltages.

These comparators are designed for use in level detection, low-level sensing and

memory applications in consumer, automotive and industrial electronic applications.

The pin diagram of the LM 339, quad differential comparator is given in Fig 3.1.

Fig: 3.1

 

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CHAPTER-4: AMPLIFIERS

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4.1:LM358:OPERATIONAL AMPLIFIERS

The LM358 series consists of two independent, high gain ; internally frequency

compensated operational amplifiers which were designed specifically to operate from a

single power supply over a wide range of voltages. Operation from split power supplies is

also possible and the low power supply current drain is independent of the magnitude of 

the power supply voltage.

Application areas include transducer amplifiers, dc gain blocks and all the conventional

op amp circuits, which now can be more easily implemented in single power supply

systems. For example, the LM158 series can be directly operated off of the standard +5V

 power supply voltage, which is used in digital systems and will easily provide the

required interface electronics without requiring the additional ±15V power supplies.

 

ParametersGain Bandwidth

Channels

Input Output Type

Slew Rate

Supply Min

Supply Max

Offset Voltage max, 25C

Supply Current Per Channel

Power Wise Rating 2

Max Input Bias CurrentOutput Current

Voltage Noise

Shut down

Special Features

Function

Temperature Min

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Temperature Max 70 deg C

 

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4.2:FEATURES:

CHAPTER-5: MOTOR DRIVER IC

Available in 8-Bump micro SMD chip sized package, (See AN-1112)

• Internally frequency compensated for unity gain• Large dc voltage gain: 100 dB

• Wide bandwidth (unity gain): 1 MHz (temperature compensated)

• Wide power supply range:

• Single supply: 3V to 32V

• or dual supplies: ±1.5V to ±16V

• Very low supply current drain (500 µA)-essentially independent of supply voltage

• Low input offset voltage: 2 mV

• Input common-mode voltage range includes ground

• Differential input voltage range equal to the power supply voltage

• Large output voltage swing

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The L293D is a monolithic integrated high voltage, high current four channel river 

designed to accept standard DTL or TTL logic levels and drive inductive loads (such asryssolenoides, DC and stepping motors) and switching power transistors. To simplify use

as two bridges is pair of channels is equipped with an enable input. A separate supply

input provided from the logic, allowing operation at a low voltage and internal clamp

diodes are included.

This device is suitable for use in switching applications at frequencies up to 5 KHz. The

L293D is assembled in a 16 lead plastic package, which has 4 center pins connected

together and used for heat sinking.

The L293D is a quadruple half H-bridge bi-directional motor driver IC that can drive

current of up to 600mA with voltage range of 4.5 to 36 volts. It is suitable to drive small

DC-Geared motors, bipolar stepper motor etc.

5.1:SPECIFICATIONS: -

Supply Voltage Range 4.5V to 36V

600-mA Output current capability per driver 

Separate Input-logic supply

It can drive small DC-geared motors, bipolar stepper motor.

Pulsed Current 1.2-A Per Driver 

Thermal Shutdown

Internal ESD Protection

High-Noise-Immunity Input

The L293 has 2 H-Bridges (actually 4 Half H-Bridges), can provide about 1 amp to each

and occasional peak loads to 2 amps.

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5.2:PIN DESCRIPTION:

The L293 contains 4 half H-bridges labeled 1, 2, 3 and 4 in the pin diagram, which can

 be used in pairs as two full H-Bridges.

In this IC there are two different power supplies (Vcc1 and Vcc2). Vcc1 is for logic input

circuit while Vcc2 is supply for the output circuit. This means that you should apply

about 5V to Vcc1 and whatever voltage required by the motor (up to 36V max for this

IC) to Vcc2. Each Half H-Bridge has an individual Ground. So you must ground the

terminal corresponding to the Half H-Bridge you want to use or else you can also just

ground all the 4 terminals.

Each Half H-Bridge has an Input (A) and output (Y). Also there are enable pins to turn

on the Half H-Bridges. (If 1,2EN (Pin1) is given +5V, then the 1 and 2 Half H-Bridges

are turned on. If Pin1 is Ground, then the 1 and 2 Half H-Bridges are disabled. Similar 

for3,4EN.

 

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Let's start with the name, H-bridge. Sometimes called a "full bridge" the H-bridge is so

named because it has four switching elements at the "corners" of the H and the motor 

forms the cross bar. The basic bridge is shown in the figure to the right.

The key fact to note is that there are, in theory, four switching elements within the bridge.

These four elements are often called, high side left, high side right, low side right, and

low side left (when traversing in clockwise order).

The switches are turned on in pairs, either high left and lower right, or lower left and high

right, but never both switches on the same "side" of the bridge. If both switches on one

side of a bridge are turned on it creates a short circuit between the battery plus and

 battery minus terminals. If the bridge is sufficiently powerful it will absorb that load and

your batteries will simply drain quickly. Usually however the switches in question melt.

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To power the motor, you turn on two switches that are diagonally opposed. In the picture

to the right, imagine that the high side left and low side right switches are turned on. The

current flow is shown in green.

The current flows and the motor begin to turn in a "positive" direction. What happens if 

you turn on the high side right and low side left switches? Current flows the other 

direction through the motor and the motor turns in the opposite direction.Actually it is just that simple, the tricky part comes in when you decide what to use for 

switches. Anything that can carry a current will work, from four SPST switches, one

DPDT switch, relays, transistors, to enhancement mode power MOSFETs.

One more topic in the basic theory section, quadrants. If each switch can be controlled

independently then you can do some interesting things with the bridge, some folks call

such a bridge a "four quadrant device". If you built it out of a single DPDT relay, you can

really only control forward or reverse. You can build a small truth table that tells you for 

each of the switch's states, what the bridge will do. As each switch has one of two states,

and there are four switches, there are 16 possible states. However, since any state that

turns both switches on one side on is "bad" (smoke issues forth: P), there are in fact only

four useful states (the four quadrants) where the transistors are turned on.

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High SideLeft High SideRight Low SideLeft Low SideRight QuadrantDescription

On Off Off On Forward Running

Off On On Off Backward Running

On On Off Off Braking

Off Off On On Braking

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CHAPTER 6:LIGHT DEPENDENT RESISTOR:

A light dependent resistor is shaped like a quarter. They are small, and can be nearly anysize. Other names for light dependent resistors are: photoconductors, photo resistor, or a

CdS cell. There are black lines on one side of the light dependent resistor. The overall

color of a light dependent resistor is gold. Usually other electrical components are

attached to the light dependent resistor by metal tubes soldered to the sides of the light

dependent resistor.

BENIFITS:

There are many great benefits to light dependent resistors. They allow less power to be

used in many different kinds of lights. They help lights last much longer. They can be

trigged by several different kinds of triggers, which is very useful for motion lights and

security systems. They are also very useful in watches and cars so that the lights can turn

on automatically when it becomes dark. There are a lot of things that light dependent

resistors can do.

LDRs or Light Dependent Resistors are very useful especially in light/dark sensor 

circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000 000

ohms, but when they are illuminated with light resistance drops dramatically.

There are just two ways of constructing the voltage divider, with the LDR at the top, or 

with the LDR at the bottom:

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The action of the voltage divider is reversed when the LDR is used as  R bottom instead of as

 Rtop.

CHAPTER7:DC MOTOR 

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An electric motor is a device using electrical energy to produce  mechanical energy,

nearly always by the interaction of magnetic fields and current-carrying conductors. The

reverse process, that of using mechanical energy to produce electrical energy, is

accomplished by a generator or dynamo. Traction motors used on vehicles often perform

 both tasks.

As a convention the term electric engine is not used for electric motors, but instead refers

to a railroad electric locomotive.

Electric motors are found in a myriad of applications such as industrial fans, blowers and

 pumps, machine tools, household appliances,  power tools, and computer disk drives,

among many other applications. Electric motors may be operated by direct current from a

 battery in a portable device or motor vehicle, or from alternating current from a centralelectrical distribution grid. The smallest motors may be found in electric wristwatches.

Medium-size motors of highly standardized dimensions and characteristics provide

convenient mechanical power for industrial uses. The very largest electric motors are

used for propulsion of large ships, and for such purposes as pipeline compressors, with

ratings in the thousands of kilowatts. Electric motors may be classified by the source of 

electric power, by their internal construction, and by application.

The physical principle of production of mechanical force by the interaction of an electric

current and a magnetic field was known as early as 1821. Electric motors of increasing

efficiency were constructed throughout the 19th century, but commercial exploitation of 

electric motors on a large scale required efficient electrical generators and electrical

distribution networks.

7.1:PRINCIPLE:

The principle of conversion of electrical energy into mechanical energy by

electromagnetic means was demonstrated by the British scientist  Michael Faraday in

1821 and consisted of a free-hanging wire dipping into a pool of  mercury. A permanent

magnet  was placed in the middle of the pool of mercury. When a current was passed

through the wire, the wire rotated around the magnet, showing that the current gave rise

to a circular magnetic field around the wire[2]. This motor is often demonstrated in school

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 physics classes, but brine  (salt water) is sometimes used in place of the toxic mercury.

This is the simplest form of a class of electric motors called homopolar motors. A later 

refinement is the Barlow's Wheel. These were demonstration devices, unsuited to

 practical applications due to limited power.

7.2:COMPARISION OF MOTOR TYPES:

Type Advantages DisadvantagesTypical

Application

Typical

Drive

AC Induction(Shaded Pole)

Least expensive

Long lifehigh power 

Rotation slips from

frequencyLow startingtorque

Fans Uni/Poly- phase AC

AC Induction

(split-phasecapacitor)

High power 

high startingtorque

Rotation slips from

frequencyAppliances

Uni/Poly-

 phase AC

AC Synchronous

Rotation in-sync

with freq

long-life(alternator)

More expensive

Industrial motors

Clocks

Audio turntablestape drives

Uni/Poly-

 phase AC

Stepper DC

Precision

 positioningHigh holding

torque

Requires a

controller 

Positioning in printers and floppy

drives

MultiphaseDC

Brushless DC

electric motor 

Long lifespan

low maintenanceHigh efficiency

High initial cost

Requires acontroller 

Hard drives

CD/DVD playerselectric vehicles

Multiphase

DC

Brushed DC

electric motor 

Low initial costSimple speed

control (Dynamo)

High maintenance(brushes)

Low lifespan

Treadmillexercisers

automotive starters

Direct PWM

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7.3:EFFICIENCY:

To calculate a motor's efficiency, the mechanical output power is divided by the electrical

input power:

where η is  energy conversion efficiency,  P e is electrical input power, and  P m is

mechanical output power.

In simplest case  P e = VI , and  P m = T ω, where V  is input voltage,  I  is input current, T  is

output torque, and ω is output angular frequency.

7.4:GEAR RATIOS:

The gear ratio is the relationship between the number of teeth on two gears that are

meshed or two sprockets connected with a common roller chain, or the circumferences of 

two pulleys connected with a drive  belt.

In the picture to the right, the smaller gear (known as the  pinion) has 13 teeth, while the

second, larger gear (known as the idler  gear) has 21 teeth. The gear ratio is therefore

21/13, 1.62/1, or 1.62:1.

The ratio means that the pinion gear must make 1.62 revolutions to turn the idler gear 1

revolution. It also means that for every one revolution of the pinion, the idler gear has

made 1/1.62, or 0.62, revolutions. In practical terms, the idler gear turns more slowly.

Suppose the largest gear in the picture has 42 teeth, the gear ratio between the second and

third gear is thus 21/42, or 1/2, and for every revolution of the smallest gear, the largest

gear turns 0.62/2, or 0.31 revolution, a total reduction of about 1:3.23.

Since the intermediate (idler) gear contacts directly both the smaller and the larger gear it

can be removed from the calculation, also giving a ratio of 42/13 = 3.23.

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Since the number of teeth is also  proportional to the circumference of the gear wheel (the

 bigger the wheel the more teeth it has) the gear ratio can also be expressed as the

relationship between the circumferences of both wheels (where d is the diameter of the

smaller wheel and D is the diameter of the larger wheel).

In other words, the gear ratio is proportional to ratio of the gear diameters and inversely

 proportional to the ratio of gear speeds.

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CHAPTER8:IC 7404:HEX INVERTER: : 

8.1:FEATURES:

Output Drive Capability - 10 LSTTL Loads

Outputs Directly Interface to CMOS, NMOS and TTL

Large Operating Voltage Range

Low Input Current

High Noise Immunity

8.2:PIN DESCRIPTION:

Pin Number Description

1 A Input Gate 1

2 Y Output Gate 1

3 A Input Gate 2

4 Y Output Gate 25 A Input Gate 3

6 Y Output Gate 3

7 Ground

8 Y Output Gate 4

9 A Input Gate 4

10 Y Output Gate 5

11 A Input Gate 5

12 Y Output Gate 6

13 A Input Gate 6

14 Positive Supply

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The 7404 IC package contains six independent positive logic NOT GATES

(INVERTERS). Pins 14 and 7 provide power for all six logic gates.

8.2.1:LOGICDIAGRAM:

Outputs of one gate can be connected to inputs of another within the same chip or to

another chip as long as they share the same ground.

The output is the inverse of the input, in other words if the input is HIGH then the output

is LOW and if the input is LOW the output is HIGH.

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flows from the battery to power the regulator itself. The operating temperature is a full-

required range.

9.1:CIRCUIT DIAGRAM:

IC voltage regulators are available in a variety of IC package types.

Dual in-line packages (DIP) can be made of ceramic (CIP) or plastic (PDIP).

Quad flat packages (QFPs) contain a large number of fine, flexible, gull wing shaped

leads.

SC-70, one of the smallest available IC packages, is well suited for applications where

space is extremely limited.

Small outline (SO) packages are available with 8, 14, or 20 pins. Transistor outline (TO)

 packages are commonly available.

TO-92 is a single in-line package used for low power devices.

TO-220 is suitable for high power, medium-current, and fast-switching products.

TO-263 is the surface-mount version of the TO-220 package. Other IC packages for IC

voltage regulators include shrink small outline package (SSOP), small outline integrated

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circuit (SOIC), small outline package (SOP), small outline J-lead (SOJ), discrete package

(DPAK), and power package (PPAK).