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Lab Manual For ELECTRONICS SOFTWARE LAB

EXPERIMENT NO. 01

INTRODUCTION OF MATLAB

Theory:-

MATLAB is a high-performance language for technical computing. It integrates

computation, visualization, and programming in an easy-to-use environment where

problems and solutions are expressed in familiar mathematical notation.

Typical uses include Math and computation Algorithm development, Data acquisition

Modeling, simulation, and prototyping Data analysis, exploration, and visualization

Scientific and engineering graphics Application development, including graphical user

interface building MATLAB is an interactive system whose basic data element is an

array that does not require dimensioning. This allows you to solve many technical

computing problems, especially those with matrix and vector formulations, in a fraction

of the time it would take to write a program in a scalar non-interactive language such as

C or Fortran.

The name MATLAB stands for matrix laboratory. MATLAB was originally written to

provide easy access to matrix software developed by the LINPACK and EISPACK

projects. Today, MATLAB engines incorporate the LAPACK and BLAS libraries,

embedding the state of the art in software for matrix computation.

In university environments, it is the standard instructional tool for introductory and

advanced courses in mathematics, engineering, and science. In industry, MATLAB is the

tool of choice for high-productivity research, development, and analysis. MATLAB

features a family of add-on application-specific solutions called toolboxes.Very important

to most users of MATLAB, toolboxes allow you to learn and apply specialized

technology. Toolboxes are comprehensive collections of MATLAB functions (M-files)

that extend the MATLAB environment to solve particular classes of problems.

Areas in which toolboxes are available include signal processing, control systems, neural

networks, fuzzy logic, wavelets, simulation, and many others. The MATLAB system

SVERI’S College Of Engineering, Pandharpur. 1




consists of five main parts : Desktop Tools and Development Environment. This is the set

of tools and facilities that help you use MATLAB functions and files. Many of these tools

are graphical user interfaces. It includes the MATLAB desktop and Command Window, a

command history, an editor and debugger, a code analyzer and other reports, and

browsers for viewing help, the workspace, files, and the search path. The Command

Window is one of the main tools you use to enter data, run MATLAB functions and other

M-files, and display results. The MATLAB Mathematical Function Library, This is a vast

collection of computational algorithms ranging from elementary functions, like sum, sine,

cosine, and complex arithmetic, to more sophisticated functions like matrix inverse,

matrix eigen values, Bessel functions, and fast Fourier transforms. The MATLAB

Language, This is a high-level matrix/array language with control flow statements,

functions, data structures, input/output, and object-oriented programming features.

Graphics MATLAB has extensive facilities for displaying vectors and matrices as graphs,

as well as annotating and printing these graphs. It includes high-level functions for two-

dimensional and three-dimensional data visualization, image processing, animation, and

presentation graphics. It also includes low-level functions that allow you to fully

customize the appearance of graphics as well as to build complete graphical user

interfaces on your MATLAB applications. The MATLAB External Interfaces/API, This

is a library that allows you to write C and Fortran programs that interact with MATLAB.

It includes facilities for calling routines from MATLAB (dynamic linking), calling

MATLAB as a computational engine, and for reading and writing MAT-files.

In MATLAB, a matrix is a rectangular array of numbers. Like most other programming

languages, MATLAB provides mathematical expressions, but unlike most programming

languages, these expressions involve entire matrices .The building blocks of expressions

are Variables Numbers Operators Functions.

Expressions use familiar arithmetic operators and precedence rules.

+ Addition

- Subtraction





* Multiplication

/ Division

\ Left division

^ Power

' Complex conjugate transpose

( ) Specify evaluation order

The MATLAB commands you will encounter in this exercise are as follows:

Operators and Special Characters

: .

+ -

* /

; %

Elementary Matrices and Matrix Manipulation

Ones pi

rand randn

zeros

Elementary Functions

cos exp

imag real

Data Analysis

Sum

Two-Dimensional Graphics

axis grid

legend plot





stairs stem

title xlabel ylabel

General Purpose Graphics Functions

clf subplot

Signal Processing Toolbox

sawtooth square

CONCLUSION:------------------------------------





EXPERIMENT NO. 02

GENERATION OF VARIOUS SIGNALS

Aim: Program to generate various Continuous time and Discrete Time signals

Software Tool: MATLAB 7

Theory:

Generation of Sequences:-

The purpose of this section is to familiarize you with the basic commands in MATLAB

for signal generation and for plotting the generated signal. MATLAB has been designed

to operate on data stored as vectors or matrices. For our purposes, sequences will be

stored as vectors. Therefore, all signals are limited to being causal and of finite length.

The steps to follow to execute the programs listed in this book depend on the platform

being used to run the MATLAB.

1) Sinusoidal & Cosine Sequences

Another very useful class of discrete-time signals is the real sinusoidal sequence of theform of

Such sinusoidal sequences can be generated in MATLAB using the trigonometric

operators cos and sin.

2) Exponential Signals

Another basic discrete-time sequence is the exponential sequence. Such a sequence can

be generated using the MATLAB operators. ^ and exp.





where A and α are real or complex numbers. By expressing

3) Unit Sample

This signal is represented as δ(n).

This signal is also called as Delta signal or Unit Impulse signal.

The Functional Representation of unit sample signal is as given below

Unit sample signal is having Amplitude equal to 1 at n=0 only & it is zero elsewhere.

A unit sample sequence u[n] of length N can be generated using the MATLAB command

u = [1 zeros (1, N -1)];

4) Unit Step Sequences

This signal is represented as u(n).

The Functional representation of unit step signal is as given below

This signal is having amplitude equal to 1 at n≥ 0 & it is zero for negative values of n.

A unit sample sequence ud[n] of length N and delayed by M samples, where M < N, can

be generated using the MATLAB command

ud = [zeros(1,M) 1 zeros(1,N - M - 1)];

Likewise, a unit step sequence s[n] of length N can be generated using the MATLAB

command

s = [ones (1, N)];





5) Ramp Signal

This signal is represented as r (n).

The Functional representation of ramp signal is as given below.

If w tends to zero the ramp becomes a step signal. This relationship is important because

we cannot differentiate a step signal because it is discontinuous. However, the ramp

signal is continuous and therefore differentiable.

Conclusion:---------------------------------





Program:

1)%$$$$$$$$ Generation of a sine sequence $$$$$$$$$$

n = 0:40;f = 0.1;

phase = 0;A = 1.5;

%----------- Generate Cosine sequence ---------- arg = 2*pi*f*n- phase;x = A*sin(arg);

%----------- Plot CT Sinusoidal sequence-------- subplot(2,1,1);plot(n,x);title('CT sine Sequence');

xlabel('Time index n');ylabel('Amplitude');

%------------ Plot DT Sinusoidal sequence -------

subplot(2,1,2);stem(n,x);axis([0 40 -2 2]);grid;title('DT sine Sequence');xlabel('Time index n');

ylabel('Amplitude');Output: 1)

0 5 10 15 20 25 30 35 40-2

-1

0

1

2CTSinusoidal Sequence

Timeindex n

A m p l i t u d e

0 5 10 15 20 25 30 35 40-2

-1

0

1

2DTSinusoidal Sequence

Timeindex n

A m p l i t u d e





2)%$$$$$$$$$$ Generation of a Cosine sequence $$$$$$$$$

n = 0:40;f = 0.1;phase = 0;

A = 1.5;

%----------- Generate Cosine sequence ---------- arg = 2*pi*f*n- phase;x = A*cos(arg);

%---------- Plot CT Cosine sequence -------------

subplot(2,1,1);plot(n,x);title('CT Cosine Sequence');xlabel('Time index n');

ylabel('Amplitude'); %----------- Plot DT Cosine sequence ----------

subplot(2,1,2);stem(n,x);axis([0 40 -2 2]);grid;title('DT Cosine Sequence');xlabel('Time index n');ylabel('Amplitude');

Output: 2)

0 5 10 15 20 25 30 35 40-2

-1

0

1

2CTCosineSequence

Timeindexn

A m p l i t u d e

0 5 10 15 20 25 30 35 40-2

-1

0

1

2

DTCosineSequence

Timeindexn

A m p l i t u d e





3)%%%%%%%%%%% Generation of Ramp signal %%%%%%%%%%%%%

% ---------Input the Variables ----------------- a=input('Enter any number=');N= input('Type in length of sequence=');

n= 0:N;

%---------- Generate Ramp sequence ---------- x= a*n;

%--------- Plot CT Ramp sequence -----------

subplot(2,1,1);plot(n,x);title('CT Ramp Sequence');xlabel('Time index n');

ylabel('Amplitude'); %--------- Plot DT Ramp sequence ---------

subplot(2,1,2);stem(n,x);title('DT Ramp Sequence');xlabel('Time index n');ylabel('Amplitude');

Enter any number=4Type in length of sequence=10

Output: 3)

0 1 2 3 4 5 6 7 8 9 100

10

20

30

40CTRampSequence

Timeindexn

A m p l i t u d e

0 1 2 3 4 5 6 7 8 9 100

10

20

30

40DTRampSequence

Timeindexn

A m p l i t u d e





4)

% ****** Generation of a Unit Impulse Sequence *******clf;

% !!!!!!!!!! Generate a vector from -10 to 20 !!!!!!!!!!! n = -10:20;

% !!!!!!!!!!! Generate the unit Impulse sequence !!!!!!!!!! u = [zeros (1, 10) 1 zeros (1, 20)];

% !!!!!!! Plot the DT unit Impulse sequence !!!!!!!

subplot(2,1,1);stem(n,u);xlabel('Time index n');ylabel('Amplitude');title('DT Unit Impulse Sequence');axis([-10 20 0 1.2]);

% !!!!!! Plot the CT unit Impulse sequence !!!!!!!!

subplot(2,1,2);plot(n,u);xlabel('Time index n');ylabel('Amplitude');title('CT Unit Impulse Sequence');axis([-10 20 0 1.2]);

Output: 4)

-10 -5 0 5 10 15 200

0.5

1

Timeindexn

A m p l i t u d e

DTUnit sampleSequence

-10 -5 0 5 10 15 200

0.5

1

Timeindexn

A m p l i t u d e

CTUnit SampleSequence





5)

% ****** Generation of a Unit Step Sequence *******clf;

% !!!!!!!! Generate a vector from -10 to 20 !!!!!!!!!!

n = -10:20; % !!!!!!!!! Generate the unit step sequence !!!!!!!!!!!!!

u = [ones (1, 10) 1 ones (1, 20)];

% !!!!!!!!!!!! Plot the DT unit step sequence !!!!!!!!!!!

subplot(2,1,1);stem(n,u);xlabel('Time index n');ylabel('Amplitude');title('DT Unit step Sequence');axis([-10 20 0 1.2]);

% !!!!!!!!!!! Plot the CT unit step sequence !!!!!!!!!

subplot(2,1,2);plot(n,u);xlabel('Time index n');ylabel('Amplitude');title('CT Unit step Sequence');axis([-10 20 0 1.2]);

Output: 4)

-10 -5 0 5 10 15 200

0.5

1

Timeindexn

A m p l i t u d e

DTUnit stepSequence

-10 -5 0 5 10 15 200

0.5

1

Timeindexn

A m p l i t u d e

CTUnit stepSequence





EXPERIMENT NO. 03

OPERATIONS ON SIGNALS

Aim: Program to perform various operations on Signals


Theory:Following Operations we can perform on the signal.

1) Amplitude Scaling

2) Time Scaling

3) Folding/Reflection

4) Shifting

1) Amplitude Scaling:-

Consider x (t) as an original signal and y (t) as the amplitude scaling signal with;

y(t) = B x (t); B is a constant

2) Time Scaling:

Time scaling compresses and expands a signal by multiplying the time variable by some

amount. If that amount is greater than one, the signal becomes narrower and the operation

is called compression, while if the amount is less than one, the signal becomes wider and

is called dilation. It often takes people quite a while to get comfortable with these





operations, as people's intuition is often for the multiplication by an amount greater than

one to dilate and less than one to compress.

Consider f (t) as an original signal and y (t) as the time scaling signal with;

y (t) = f (at); a is a real constant

3) Time Reversal:

A natural question to consider when learning about time scaling is: What happens when

the time variable is multiplied by a negative number? The answer to this is time reversal.

This operation is the reversal of the time axis, or flipping the signal over the y-axis.

Consider x (t) as an original signal and y (t) as the time reversal signal.Hence;

y (t) = x (-t)

4) Time Shifting:

Time shifting is, as the name suggests, the shifting of a signal in time. This is done by

adding or subtracting the amount of the shift to the time variable in the function.

Subtracting a fixed amount from the time variable will shift the signal to the right (delay)

that amount, while adding to the time variable will shift the signal to the left (advance).





Figure 1: f (t −T ) moves (delays) f to the right by T .

Consider x (t) as an original signal and y (t) as the time shifting signal. It can then be

written as:

y (t) = x (t-to)

where to is a constant.

Let y(t) = x(t-to)

“





Program: 1)

%@@@@@@ SCALING - AMPLITUDE SCALING @@@@@@@@ %@@@@@@ y(n) = A*x(n) @@@@@@@@

n = -5:5;

% ***** Generate the unit sample sequence ********

x = [zeros (1, 5) 1 ones (1, 5)];axis ([-5 5 0 1.2]);

% ******** Plot the unit sample sequence ********

subplot (2,1,1);stem (n,x);xlabel('Time index n');ylabel('Amplitude');title('Unit Sample Sequence');

% ***** Generate the Amplitude Scaled signal ******

d=input ('Enter the Amplitude scaling factor');y= d*x;subplot (2,1,2);stem (n,y);xlabel('Time index n');ylabel('Amplitude');title ('Amplitude scaled signal');

Output: 2)

Enter the Amplitude scaling factor 4

-5 -4 -3 -2 -1 0 1 2 3 4 50

0.2

0.4

0.6

0.8

1

Timeindexn

A m p l i t u d e

Unit SampleSequence

-5 -4 -3 -2 -1 0 1 2 3 4 50

1

2

3

4

Timeindexn

A m p l i t u d e

Amplitudescaledsignal





Program: 2)

%&&&&&&&&&&& TIME SCALING &&&&&&&&&&&&&&

clf;

clc;n= 0:20;n1=0:40;t=0.1*pi*n;t1=0.1*pi*n1;

%^^^^^^^^^^^ Sinusiodal Signal ^^^^^^^^^^^^^^

x=2*sin(t);subplot(3,1,1);plot(n,x);

axis([0 20 -1 1]);xlabel('Time');ylabel('Amplitude');Title('Original Signal');grid;

%^^^^^^^^^^^^^ Compressed Signal ^^^^^^^^^^^^^

a=input('Enter scaling factor a>1');x1=2*sin(a*t);subplot(3,1,2);plot(n,x1);xlabel('Time');ylabel('Amplitude');Title('Compressed Signal');axis([0 20 -1 1]);grid;

%^^^^^^^^^^^^ Expanded Signal ^^^^^^^^^^^^^^^^

a1=input('Enter scaling factor a<1');x2=2*sin(a1*t1);subplot(3,1,3);plot(n1,x2);xlabel('Time');ylabel('Amplitude');Title('Expanded Signal');axis([0 40 -1 1]);grid;





Output: 2)

Enter scaling factor a>1 2

Enter scaling factor a<1 0.5

0 2 4 6 8 10 1 2 1 4 1 6 18 20-1

0

1

T ime

A m p l i t u d e

Or ig ina l S igna l

0 2 4 6 8 10 1 2 1 4 1 6 18 20-1

0

1

T ime

A m p l i t u d e

Co m p re s s e d S ign a l

0 5 1 0 15 20 25 30 35 40-1

0

1

T ime

A

m p l i t u d e

E x p a n d ed S ig na l





Program: 3)

%_******* GENERATION OF A FOLDING SEQUENCE ********

%********** Generate a vector from -5 to 5********

n = -5:5; %***** Generate the unit sample sequence ***********

u = [zeros (1, 5) 1 ones (1, 5)];axis ([-5 5 0 1.2]);

%******* Plot the unit sample sequence *************

subplot(2,1,1);stem(n,u);

xlabel('Time index n');ylabel('Amplitude');title('Unit Sample Sequence');

%******* Generate the unit sample sequence ******

subplot(2,1,2);x=fliplr(u);stem(n,x);xlabel('Time index n');ylabel('Amplitude');title('Folded signal');

Output: 3)

-5 -4 -3 -2 -1 0 1 2 3 4 50

0.2

0.4

0.6

0.8

1

Timeindexn

A m p l i t u d e

Unit SampleSequence

-5 -4 -3 -2 -1 0 1 2 3 4 50

0.5

1

Timeindexn

A m p l i t u d e

Foldedsignal





Program:4)

%@@@@@@@@ SHIFTING OPERATION ON SIGNAL @@@@@@@@@

%^^^^^^^^^^^^ Plot Original Signal ^^^^^^^^^^^^^^^^^^^

n = [-2:5];x = [4 3 1 0 1 2 3 2]; %input sequencesubplot(3,1,1);stem(n,x);xlabel('Time');ylabel('Amplitude');Title('Original Signal');

%^^^^^^^^^^^^ Delayed Signal ^^^^^^^^^^^^^^^^^^

n11=input ('enter the n0 > 0')

m=n11+n;y=x;subplot(3,1,2);stem(m,y);xlabel('Time');ylabel('Amplitude');Title('Delayed signal');

%^^^^^^^^^^^^^^^^ Advanced Signal ^^^^^^^^^^^^^^^^

n12=input('enter the n0 < 0');

m1=n12+n;y=x;subplot(3,1,3);stem(m1,y);xlabel('Time');ylabel('Amplitude');Title('Advanced signal');





Output: 4)

enter the n0 > 0 3

enter the n0 < 0 -3

- 2 - 1 0 1 2 3 4 50

2

4

T i m e

A m

p l i t u d e

O r i g i n a l S i g n a l

1 2 3 4 5 6 7 80

2

4

T i m e

A m

p l i t u d e

D e l a y e d s i g n a l

- 5 - 4 - 3 - 2 - 1 0 1 20

2

4

T i m e

A m

p l i t u d e

A d v a n c e d s i g n a l

CONCLUSION:--------

This module will look at two signal operations, time shifting and time scaling. signaloperations are operations on the time variable of the signal. These operations are verycommon components to real-world systems and, as such, should be understoodthoroughly when learning about signals and systems.





EXPERIMENT NO. 04

LINEAR CONVOLUTION OF SIGNAL

Aim: Program to perform Linear Convolution of Signal.


Theory:

The response of a discrete-time system to a unit sample sequence {δ[n] } is called the unit

sample response or, simply, the impulse response , and denoted as {h[n] }.

Correspondingly, the response of a discrete-time system to a unit step sequence {μ[n] },

denoted as {s[n] }, is its unit step response or, simply the step response.

The response y[n] of a linear, time-invariant discrete-time system characterized by

an impulse response h[n] to an input signal x[n] is given by

……………………………(1)

which can be alternately written as

…………………………….(2) by a simple change of variables. The sum in Eqs. (1) and (2) is called the convolution

sum of the sequences x[n] and h[n], and is represented compactly as:

…………………………….(3)

where the notation denotes the convolution sum.

Convolution

The convolution operation of Eq. (3) is implemented in MATLAB by the command conv,

provided the two sequences to be convolved are of finite length. For example, the output

sequence of an FIR system can be computed by convolving its impulse response with a

given finite-length input sequence. The following MATLAB program illustrates this

approach.





Program: %!!!!!!!!!!!!!!!!! Linear Convolution !!!!!!!!!!!!!!!!!!!!!!!!!!

clc;clear all;

close all;

% ******** Input & Impulse Sequences ********

x = input('Enter the first sequence');h = input('Enter the second sequence');

% ******** Convolution of two sequences *******

y = conv(x,h);

% ************* Input sequence **************

subplot(3,1,1);stem(x);ylabel('Amplitude ');xlabel('fig.(a) n----->');title('First sequence');

%************* Impulse sequence **************

subplot(3,1,2);

stem(h);ylabel('Amplitude ');xlabel('fig.(b) n----->');title('Second sequence');

%************* Output sequence **************

subplot(3,1,3);stem(y);ylabel('Amplitude ');xlabel('fig.(c) n----->');

title('Convolution of two sequences');disp('The resultant signal is');disp(y);





Enter the first sequence [3 2 1 2]

Enter the second sequence [2 1 2 1]

Output:

The resultant signal is

6 7 10 12 6 5 2

1 1 .5 2 2 .5 3 3 .5 4

0

2

4

A m p l i t u d e

f ig.(a) n----->

F i r s t s e q u e n c e

1 1 .5 2 2 .5 3 3 .5 40

1

2

A m p l i t u d e

f ig.(b) n----->

S e c o n d s e q u e n c e

1 2 3 4 5 6 70

1 0

2 0

A m p l i t u d e

f ig.(c) n----->

Convo lu t i on o f two sequences

Conclusion:----------------------------





EXPERIMENT NO. 05

SAMPLING THEOREM

Aim: Program to Implement Sampling Theorem.


Theory:

Sampling Theorem – Let ga(t ) be a bandlimited signal with Ga( jΩ) = 0 for |Ω| >Ωm.

Then ga(t ) is uniquely determined by its samples ga(nT ) , n = 0 , 1 , 2 , 3 , . . . , i

Where

Given {g [n] } = {ga(nT ) }, we can recover ga(t ) exactly by generating an impulse train

gp(t ) of the form

and then passing gp(t ) through an ideal lowpass filter Hr ( jΩ) with a gain T and a cutoff

frequency Ωc greater than Ωm and less than ΩT − Ωm, that is,

The highest frequency Ωm contained in ga(t ) is usually called the Nyquist frequency as it

determines the minimum sampling frequency ΩT > 2Ωm that must be used to fully

recover ga(t ) from its sampled version. The frequency 2Ωm is called the Nyquist rate. If

the sampling rate is higher than the Nyquist rate, it is called oversampling . On the other

hand, if the sampling rate is lower than the Nyquist rate, it is called undersampling .

Finally, if the sampling rate is exactly equal to the Nyquist rate, it is called critical

sampling .





Program:

% !!!!!!!! Sampling Process in the Time Domain !!!!!!! clf; % ^^^^^^^^^^ Continuous- Time Signal ^^^^^^^^^^^^

t = 0:0.0005:1;f = 13;xa = cos(2*pi*f*t);subplot(4,1,1)plot(t,xa);gridxlabel('Time, msec');ylabel('Amplitude');title('Continuous-time signal xa(t)');

% ^^^^ Continuous- Time Signal sampled at T=0.1 ^^^^^subplot(4,1,2);T=0.1;

n = 0:T:1;xs = cos(2*pi*f*n);k = 0:length(n)-1;stem(k,xs); gridxlabel('Time index n');ylabel('Amplitude');

title('Continuous-time signal xa(t)sampled at T=0.1');% ^^^^ Continuous- Time Signal sampled at T=0.1 ^^^^^

subplot(4,1,3);T1=0.01;n1 = 0:T1:1;

xs1 = cos(2*pi*f*n1);k1 = 0:length(n1)-1;stem(k1,xs1); gridxlabel('Time index n');ylabel('Amplitude');

title('Continuous-time signal xa(t)sampled at T1=0.01');% ^^^^ Continuous- Time Signal sampled at T=0.1 ^^^^^^

subplot(4,1,4);T2=0.2;n2 = 0:T2:1;xs2 = cos(2*pi*f*n2);k2 = 0:length(n2)-1;stem(k2,xs2); gridxlabel('Time index n');ylabel('Amplitude');

title('Continuous-time signal xa(t)sampled at T2=0.2');





Output:

0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1- 1

0

1

T i m e , m s e c

A

m

p l i t u d e

C o n t i n u o u s - t i m e s i g n a l x a ( t )

0 1 2 3 4 5 6 7 8 9 1 0

- 1

0

1

T i m e i n d e x n

A

m

p l i t u d e

C o n t i n u o u s - t i m e s i g n a l x a ( t ) s a m p l e d a t T =

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0- 1

0

1

T i m e i n d e x n

A

m

p l i t u d e

C o n t i n u o u s - t i m e s i g n a l x a ( t ) s a m p l e d a t T 1

0 0 . 5 1 1 . 5 2 2 . 5 3 3 . 5 4 4 . 5 5- 1

0

1

T i m e i n d e x n

A

m

p l i t u d e

C o n t i n u o u s - t i m e s i g n a l x a ( t ) s a m p l e d a t T 2

Conclusion:-----------------------





EXPERIMENT NO. 06

MONOSTABLE MULTIVIBRATOR USING 555

Aim : To simulate an Monostable Multivibrator using IC 555.

Software Tool: MULTISIM 10

Components:-

Name EDWinComponents Used

Description Number of componentsrequired

RES RC05 Resistor 1

CAP CAP Capacitor 2

555 LM555 Timer 1

VDC VDC Dc voltage source 1

GND SPL0 Ground 3

VGEN VGEN Pulse Generator 1

Theory :-

The 555 timer configured for monostable operation is shown in the figure.





Monostable Multivibrator often called a one shot Multivibrator is a pulse generating

circuit in which the duration of this pulse is determined by the RC network connected

externally to the 555 timer. In a stable or standby state, the output of the circuit is

approximately zero or a logic-low level. When external trigger pulse is applied output is

forced to go high ( 2/3 V CC ). The time for which output remains high is determined by the

external RC network connected to the timer. At the end of the timing interval, the output

automatically reverts back to its logic-low stable state. The output stays low until trigger

pulse is again applied. Then the cycle repeats. The Monostable circuit has only one stable

state (output low) hence the name Monostable.

The internal diagram for a 555 timer is shown in the figure.

Pin1: Ground . All voltages are measured with respect to this terminal.

Pin2: Trigger . The output of the timer depends on the amplitude of the external trigger

pulse applied to this pin. The output is low if the voltage at this pin is greater than 2/3

V CC . When a negative going pulse of amplitude greater than 1/3 V CC is applied to this pin,

comparator 2 output goes low, which inturn switches the output of the timer high. The

output remains high as long as the trigger terminal is held at a low voltage.

Pin3: Output . There are two ways by which a load can be connected to the output

terminal: either between pin 3 and ground or between pin3 and supply voltage +V CC .

When the output is low the load current flows through the load connected between pin3

and +V CC into the output terminal and is called sink current. The current through the





grounded load is zero when the output is low. For this reason the load connected between

pin 3 and +V CC is called the normally on load and that connected between pin 3 and

ground is called normally off-load . On the other hand, when the output is high the current

through the load connected between pin 3 and +V CC is zero. The output terminal supplies

current to the normally off load. This current is called source current. The maximum

value of sink or source current is 200mA.

Pin4 : Reset . The 555 timer can be reset (disabled ) by applying a negative pulse to this

pin. When the reset function is not in use, the reset terminal should be connected to +V CC

to avoid any possibility of false triggering.

Pin5: Control Voltage. An external voltage applied to this terminal changes the threshold

as well as trigger voltage. Thus by imposing a voltage on this pin or by connecting a pot between this pin and ground, the pulse width of the output waveform can be varied.

When not used, the control pin should be bypassed to ground with a 0.01µF Capacitor to

prevent any noise problems.

Pin6 : Threshold . This is the non-inverting input of comparator 1, which monitors the

voltage across the external capacitor. When the voltage at this pin is greater than or equal

to the threshold voltage 2/3 V CC , the output of comparator 1 goes high, which inturn

switches the output of the timer low.

Pin7 : Discharge. This pin is connected internally to the collector of transistor Q1. When

the output is high Q1 is OFF and acts as an open circuit to external capacitor C connected

across it. On the other hand, when the output is low, Q1 is saturated and acts as a short

circuit, shorting out the external capacitor C to ground.

Pin8: +V CC . The supply voltage of +5V to + 18V is applied to this pin with respect to

ground.





Operation:-

Initially when the circuit is in the stable state i.e , when the output is low, transistor Q1 is

ON and the capacitor C is shorted out to ground. Upon the application of a negative

trigger pulse to pin 2, transistor Q1 is turned OFF, which releases the short circuit acrossthe external capacitor C and drives the output high. The capacitor C now starts charging

up towards VCC through R. When the voltage across the capacitor equals 2/3 VCC,

comparator 1’s output switches from low to high, which inturn drives the output to its

low state via the output of the flip-flop. At the same time the output of the flip-flop turns

transistor Q1 ON and hence the capacitor C rapidly discharges through the transistor. The

output of the monostable remains low until a trigger pulse is again applied. Then the

cycle repeats.

The pulse width of the trigger input must be smaller than the expected pulse width of the

output waveform. Also the trigger pulse must be a negative going input signal with

amplitude larger than 1/3 VCC.

The time during which the output remains high is given by

where R is in Ohms and C is in Farads.

Once triggered, the circuit’s output will remain in the high state until the set time, t

elapses. The output will not change its state even if an input trigger is applied again

during this time interval t . The circuit can be reset during the timing cycle by applying

negative pulse to the reset terminal. The output will remain in the low state until a trigger

is again applied.

Procedure:-

Multisim -> Schematic Editor : The circuit diagram is drawn by loading components

from the library. Wiring and proper net assignment has been made. Values are assigned

for relevant components.





Multisim -> Simulator: The circuit is preprocessed. The waveform marker is placed at

the output of the circuit. GND net is set as the reference net. The Transient Analysis

parameters are also set and the Transient Analysis is executed. The output waveform is

observed in the Waveform Viewer.

CIRCUIT DIAGRAM:-

A1

555_VIRTUAL

GND

DIS

OUTRST

VCC

THR

CON

TRI

C11uF

C21uF

R11kΩ

R21kΩ

VCC

5V

VCCXSC1

A B

Ext Trig+

+

_

_ + _

2

3

I1

1kHz

1 A

1

0

4

Monostable Multivibrator using

IC 555

Observation Table:-

C(µf) Theoretical(T=1.095 RC(ms))) Practical T(ms)





Output:-

The output waveform may be observed in the waveform viewer.

Conclusion:-----------------------------





EXPERIMENT NO. 07

ASTABLE MULTIVIBRATOR USING 555

Aim : To simulate an Astable multivibrator using IC 555.

Software Tool: MULTISIM 10

Components:-

Name EDWinComponents Used

Description Number of componentsrequired

RES RC05 Resistor 2

CAP CAP Capacitor 2

555 LM555 Timer 1

VDC VDC Dc voltage source 1

GND SPL0 Ground 3

Theory:-

The circuit diagram for the astable multivibrator using IC 555 is shown here. The astable

multivibrator generates a square wave, the period of which is determined by the circuit





external to IC 555. The astable multivibrator does not require any external trigger to

change the state of the output. Hence the name free running oscillator. The time during

which the output is either high or low is determined by the two resistors and a capacitor

which are externally connected to the 555 timer.

The above figure shows the 555 timer connected as an astable multivibrator. Initially

when the output is high capacitor C starts charging towards V cc through R A and R B.

However as soon as the voltage across the capacitor equals 2/3 V cc, comparator1 triggers

the flip-flop and the output switches to low state. Now capacitor C discharges through R B

and the transistor Q1. When voltage across C equals 1/3 V cc, comparator 2’s output

triggers the flip-flop and the output goes high. Then the cycle repeats.

The capacitor is periodically charged and discharged between 2/3 V cc and 1/3 V cc

respectively. The time during which the capacitor charges from 1/3 V cc to 2/3 V cc is equal

to the time the output remains high and is given by

where R A and R B are in ohms and C is in Farads. Similarly the time during which the

capacitor discharges from 2/3 V cc to 1/3 V cc is equal to the time the output is low and is

given by





Thus the total time period of the output waveform is

Therefore the frequency of oscillation

The output frequency, f is independent of the supply voltage V cc.

Procedure:-

Multisim -> Schematic Editor: The circuit diagram is drawn by loading components

from the library. Wiring and proper net assignment has been made. Values are assigned.

For relevant components.

Multisim-> Simulator:The circuit is preprocessed. The waveform marker is placed at




Circuit Diagram:-





U1

LM555CM

GND

1

DIS7

OUT 3RST4

VCC

8

THR6

CON5

TRI2

R1

2.2kΩ

R23.9kΩ

C1100nF C2

10nF

VCC

5VVCC

1

2

00

XSC1

A B

Ext Trig+

+

_

_ +

_

4

3

ASTABLE MULTIVIBRATOR USING

IC LM555

Observation Table:-

C (µf) Theoreticaltime period(us)

Practical time period(us)

Theoretical freq(kHz)

Practicalfreq(kHz)

Output:-






Conclusion:-------------------

EXPERIMENT NO. 08

RC PHASE SHIFT OSCILLATOR





Aim: Simulation of RC Phase Shift Oscillator .

Software Tool: - MULTISIM 10

Theory:-

Oscillator Fundamentals:

An oscillator is a circuit that is capable of a sustained AC output signal obtained by

converting input energy. Oscillators can be designed to generate a variety of signal

waveforms, and they are convenient sources of sinusoidal AC signals for testing, control,

and frequency conversion. Oscillators can also generate square waves, ramps, or pulses

for switching, signalling, and control.Simple oscillators produce sinewaves, but another form, the multivibrator, produces square or sawtooth waves. These circuits were

developed with vacuum-tubes, but have since been converted to transistor oscillators.

Figure 1. is a simple block diagram showing an amplifier and a block representing the

many oscillator phase-shift methods. Regardless of its amplifier, an oscillator must meet

the two Barkhousen conditions for oscillation:

1 - The loop gain must be slightly greater than unity.

2 - The loop phase shift must be 0° or 360°.

To meet these conditions the oscillator circuit must include some form of amplifier, and a

portion of its output must be fed back regenerative to the input. In other words, the





feedback voltage must be positive so it is in phase with the original excitation voltage at

the input. Moreover, the feedback must be sufficient to overcome the losses in the input

circuit (gain equal to or greater than unity). If the gain of the amplifier is less than unity,

the circuit will not oscillate, and if it is significantly greater than unity, the circuit will be

over-driven and produce distorted (non-sinusoidal) waveforms.

The typical amplifier--vacuum tube, BJT, or field-effect transistor--imparts a 180° phase

shift in the input signal, and the resistive-capacitive (RC) feedback loop imparts the

additional 180° so that the signal is returned in phase. Energy coupled back to the input

by inductive methods can, however, be returned with zero phase shift with respect to the

input.

RC Oscillators:

Figure 2. is the schematic for a phase-shift oscillator , a basic resistive-capacitive

oscillator. Transistor Q1 is configured as a common-emitter amplifier, and its output

(collector) signal is fed back to its input (base) through a three-stage RC ladder network,

which includes R5 and C1, R2 and C2, and R3 and C3.

Each of the three RC stages in this ladder introduces a 60° phase shift between its input





and output terminals so the sum of those three phase shifts provides the overall 180°

required for oscillation. The phase shift per stage depends on both the frequency of the

input signal and the values of the resistors and capacitors in the network.

The values of the three RC ladder network capacitors C1, C2, and C3 are equal as are the

values of the three resistors R5, R2, and R3. With the component values shown in Fig. 2,

the 180° phase shift occurs at about 1/14 RC or 700 Hz. Because the transistor shifts the

phase of the incoming signal 180°, the circuit also oscillates at about 700 Hz.

At the oscillation frequency, the three-stage ladder network has an attenuation factor of

about 29. The gain of the transistor can be adjusted with trimmer potentiometer R6 in the

emitter circuit to compensate for signal loss and provide the near unity gain required for

generating stable sine waves. To ensure stable oscillation, R6 should be set to obtain a

slightly distorted sine wave output.The amplitude of the output signal can be varied with

trimmer potentiometer R4. Although this simple phase-shift oscillator requires only a

single transistor, it has several drawbacks: poor gain stability and limited tuning range.

Procedure:-








Circuit Diagram:-





Q1

2N2219

R112kΩ

R239kΩ

R32.2kΩ

R4470Ω

R5

100kΩ

R65.6kΩ

R73.3kΩ

R85.6kΩ

C147uF

C2

100nF

C3

100nF

V1

6 V

0

2

C4

100nF

4 5

0

3

C5

47uF

1

XSC1

A B

Ext Trig+

+

_

_ + _

9

6

7

0

RC PHASE SHIFT OSCILLATOR

Output:-






Conclusion:-----------------------

EXPERIMENT NO. 09





WEIN BRIDGE OSCILLATOR

Aim:- Simulation of Wein Bridge Oscillator

Software Tool: - MULTISIM 10

Theory:-

There are ways to overcome the drawbacks of the phase-shift oscillator, and one of them

is to include a Wien-bridge or network in the oscillator's feedback loop. The concept is

illustrated in the Fig. block diagram. A far more versatile RC oscillator than the phase-

shift oscillator, its operating frequency can be varied easily.

As shown within the dotted box in Fig. A Wien Bridge consists of a series-connected

resistor and capacitor, wired to a parallel- connected resistor and capacitor. The

component values are "balanced" so that R1 equals R2 and C1 equals C2.

The Wien Network is exceptionally sensitive to frequency. That shift is negative (to a

maximum of -90°) at low frequencies, and positive (to a maximum of +90°) at high

frequencies. It is zero a center frequency of 1/6.28RC. At the center frequency, network

attenuation is a factor of 3. As a result, the Wien network will oscillate if a non-inverting,

amplifier with a gain of 3 is connected as shown between the amplifier's output and input

terminals. The output is taken between the output of the amplifier and ground.

A basic two-stage Wien-Bridge oscillator schematic is shown in Fig. Both transistors Q1





and Q2 are configured as low-gain common-emitter amplifiers. The voltage gain of Q2 is

slightly greater than unity, and it provides the 180° phase shift required for regenerative

feedback. The 4.7K resistor R4, part of the Wien bridge network, functions as the

oscillator's collector load.

Transistor Q1 provides the high input impedance for the output of the Wien network.

Trimmer potentiometer R5 will set the oscillator's gain over a limited range. With the

component values shown, the Wien bridge oscillator will oscillate at about 1 KHz.

Trimmer R5 should be adjusted so that the sinewave output signal is just slightly

distorted to achieve its maximum stability.

Many different practical variable-frequency Wien-bridge oscillators can be built with

operational amplifier integrated circuits combined with an automatic gain-control

feedback network. No inductors are needed in these circuits.

Procedure:-












Circuit Diagram:-

Q1

2N3904

Q2

2N3904

R127kΩ

R24.7kΩ

R339kΩ R4

4.7kΩ

R61kΩ

R722kΩ

R83kΩ

R94.7kΩ

C233pF

C333pF

9R5

1kΩ

Key=A

90%6

38

V19 V

XSC1

A B

Ext Trig+

+

_

_ + _

1

C5

1uF

C110uF

2

Wein Bridge Oscillator

0

4 5

10

Output:-






Conclusion:--------------------

EXPERIMENT NO. 10

MOSFET AS A SWITCH





Aim: Simulation of MOSFET as A Switch.

Software Tool:- MULTISIM 10

Theory:-

The N-channel, Enhancement-mode MOSFET operates using a positive input voltage and

has an extremely high input resistance (almost infinite) making it possible to interface

with nearly any logic gate or driver capable of producing a positive output. Also, due to

this very high input (gate) resistance we can parallel together many different MOSFET's

until we achieve the current handling limit required. While connecting together various

MOSFET's may enable us to switch high current or high voltage loads, doing so becomes

expensive and impractical in both components and circuit board space. To overcome this

problem Power Field Effect Transistors or Power FET's where developed.

By applying a suitable drive voltage to the gate of an FET the resistance of the drain-

source channel can be varied from an "OFF-resistance" of many hundreds of kΩ's,

effectively an open circuit, to an "ON-resistance" of less than 1Ω, effectively a short

circuit. We can also drive the MOSFET to turn "ON" fast or slow, or to pass high

currents or low currents. This ability to turn the power MOSFET "ON" and "OFF" allows

the device to be used as a very efficient switch with switching speeds much faster than

standard bipolar junction transistors.

In this circuit arrangement an Enhancement-mode N-channel

MOSFET is being used to switch a simple lamp "ON" and





"OFF" (could also be an LED). The gate input voltage VGS is

taken to an appropriate positive voltage level to turn the

device and the lamp either fully "ON", (VGS = +ve) or a zero

voltage level to turn the device fully "OFF", (VGS = 0).

If the resistive load of the lamp was to be replaced by an

inductive load such as a coil or solenoid, a "Flywheel" diode

would be required in parallel with the load to protect the

MOSFET from any back-emf.

Above shows a very simple circuit for switching a resistive

load such as a lamp or LED. But when using power

MOSFET's to switch either inductive or capacitive loadssome form of protection is required to prevent the MOSFET

device from becoming damaged. Driving an inductive load

has the opposite effect from driving a capacitive load. For

example, a capacitor without an electrical charge is a short

circuit, resulting in a high "inrush" of current and when we

remove the voltage from an inductive load we have a large

reverse voltage build up as the magnetic field collapses,

resulting in an induced back-emf in the windings of the

inductor.

For the power MOSFET to operate as an analogue switching

device, it needs to be switched between its "Cut-off Region"

where VGS = 0 and its "Saturation Region" where VGS(on) =

+ve. The power dissipated in the MOSFET (PD depends upon

the current flowing through the channel ID at saturation and

also the "ON-resistance" of the channel given as R DS(on).

Procedure:-

Multisim -> Schematic Editor: The circuit diagram is drawn

by loading components from the library. Wiring and proper





net assignment has been made. Values are assigned. For

relevant components.

Multisim-> Simulator:The circuit is preprocessed. The

waveform marker is placed at the output of the circuit. GND

net is set as the reference net. The Transient Analysis

parameters are also set and the Transient Analysis is

executed. The output waveform is observed in the Waveform

Viewer.

Circuit Diagram:-

R11MΩ

VDD

5V

LED2

Q2

BS170

MOSFET AS A SWITCH

V2

1MHz

5 V

1

0

XSC1

A B

Ext Trig+

+

_

_ + _

VDD

2





Output:-

The output waveform may be observed in the waveformviewer.





Conclusion:--------------------------

EXPERIMENT NO. 11

PCB DESIGN USING CAD TOOL

Aim: Prepare layout for various circuits using CADTOOL .

Software Tool:- EAGLE 5.2.0 (MULTISIEM 10 ,

PROTEUS)

Theory:-

Tool Box:





Control Panel:-

After starting EAGLE, the Control Panel will be opened. It

allows you to load and save projects as well as to setup

certain program parameters. A right mouse click to an entry

in the Projects branch of the tree view opens a context menu

that allows to start a new project ( New/Project).





The tree view allows a quick survey of EAGLE's libraries. If

you expand one of the library entries in this branch, for

example 40xx.lbr , the content of the library will be shown.

Select a Device or Package entry to display the preview of

this object on the right.

The Control Panel offers also an overview of User Language

programs, Script files, and CAM jobs. Try selecting various

entries. On the right you will get the referring description.

The Control Panel supports Drag & Drop in usual manner. A

right mouse click on any entry in the tree view opens a

context menu that offers options like Print, Open, Copy,

Rename etc.

The cursor keys allow you to navigate efficiently within the

tree view. The cursorright key expands a branch. Cursorleft

jumps back to the superior node. Hit Cursorleft again to close

the branch. Cursorup/ down leads you to the previous/next

entry. The paths for each branch of the tree view are set in

Options/Directories.

EAGLE Files

The following table lists the most important file types that can be edited with EAGLE:

EAGLE uses only lower case letters for file extensions!





PROCEDURE:-

Create EAGLE Projects:-

Lets create a new project first. After starting the program,

first

• The + character of the Projects path, then

• The + character of the entries examples and tutorial

in the tree view. The contents of the tutorial directory

appears.

• Tutorial with the right mouse button.

• Select the option New Project in the popup menu.

Name the new project MyProject , for example and hit

the Enter key.

• This way you are creating a subdirectory of tutorial

that is named MyProject .

• This directory should contain all data files that belong

to your project. Of course you may define additional

subdirectories.

• To define the path where your project directories will

be stored, click => Options/Directories and enter it in

the Projects field.

• A right mouse click on the project entry and you can

open new schematics,

layouts and libraries. Each project directory contains a

file named eagle.epf which stores project specific

settings, window positions etc.

• Click this icon and then mark a rectangular area

by dragging the mouse cursor while the left mouse

button is pressed. Then release the mouse button. The

marked area will now be displayed. It's possible to





define a certain area of the drawing as a so called

alias.

Create EAGLE Schematic:-

First a new schematic file is to be created. Close all of the

editor windows and select => File/New/Schematic from the

Control Panel.

A new file with the name untitled.sch is now created.

Normally you should

never save a file with the name untitled , but should use

=> File/Save as... to

choose a different name.

Wire properties like Width, Style or Layer can be altered

through the Properties entry of the context menu. Select the

wire in question by a right mouse click to open the context

menu. As an alternative use the INFO command to open die

properties dialog.

Setting up Grid and Unit:-

Schematics should always be drawn on a grid of 0.1 inches

(2,54 mm) since the libraries are defined this way. The grid

for boards is determined by the components used and by the

complexity of the board. Grid and unit are setup by clicking

on the GRID icon in the parameter toolbar. Clicking with

the right mouse button on the GRID icon opens a popup

menu. It contains the entry Last which switches to the grid

used before. With New.. you are allowed to define so called

aliases representing certain grid settings. The alias name can





be used as a parameter with the GRID command. Quick

switches from one grid setting to another are possible now.

All values are given in the currently selected unit.

For all settings in the Design Rules window (= > Edit/Design

Rules...) one can use values in mil or in Millimetres (1 mil =

1/1000 inch). The default unit is mil.

Selecting Layers for Display:-

EAGLE Drawings contain objects in different drawing layers.

In order to obtain a useful result several layers are combined

for the output. For example, the combination of Top, Pad, and

Via layers is used to generate a film for etching the

component side of the printed circuit board. Consequently the

combination of Bottom, Pad, and Via layers is used to

generate the film for the solder side of the board. The Pad

layer contains the

throughholes for the component connections and the via layer

contains the viaholes

which are needed when a signal track changes to another

layer.

Completing the Schematic:-





Use the ADD command to add the remaining components and

the symbols for +5V, V+, and GND from supply1.lbr.

Search pattern: *supply*.

Supply symbols represent the power signals in your

schematic and cause the ERC (Electrical Rule Check)to use

special checks for them. Remember that you can use the

MOVE command to move objects around and that you can

rotate objects attached to the mouse with a right mouse click.

Using the NET command, connect the pins of the components

according to the schematic and connect the supply symbols to

the related pins. Use the right mouse button to alternate

between the orthogonal and diagonal modes while using the

NET command.

If you place a net exactly on a connection point, the net is

terminated at this location. Otherwise the net keeps following

the mouse.

The Electrical Rule Check (ERC):-





If you haven't entered the complete schematic yourself you

can now load the file demo1.sch.

The ERC command is used to test schematics for electrical

errors. The results are warnings and error messages listed in

the ERC window. To start the Electrical Rule Check click the

ERC icon in the command toolbar.

The ERC finds two warnings in our sample:

POWER Pin IC1 VSS connected to GND

POWER Pin IC1 VDD connected to +5V

These messages inform you that the power pins are connected

to other signals than expected. The power pins were named

VSS or VDD in the library but are connected to GND and

+5V. In our case this has been done on purpose. Click on one

of the message entries and EAGLE will show where the

reason for the problem is located in the schematic. Both

warnings don't cause any problems and could be avoided by

changing

the names of the power pins in the library definition. But you

could also Approve these warnings. The messages are now

shown in the Approved branch, no longer in the Warnings

branch of the menu.

Please note that the ERC can only discover possible error

sources. It is up to you to properly interpret the ERC

messages!

Generating a Board from a Schematic:-

After loading a schematic from which you would like to

design a board, click on the BOARD icon in the action





toolbar: A board file will be generated in which the packages

are positioned next to an empty board.

If you have the Schematic Editor and the schematic is already

drawn, you only need a few steps to get the same result as

described in the previous section:

A board containing parts that have already names and values

and whose pads

or SMDs are connected through airwires.

Generating a Board File:-

Load the file demo1.sch and click the BOARD icon :

With this command you create a board file with the same

name as the loaded schematic (demo1.brd ).. Maximize the

Layout Editor window. The white frame on the right of the

window symbolizes the board outlines. It is made up of wires

in the layer 20, Dimension.

Component Placement:-

Select MOVE, the biggest IC somewhere in its center and

move the cursor inside the board outlines. The component

and the airwires remain attached to the cursor. Press the right

mouse button if you want to rotate the component & fix the

position of the component. Place all of the components using

the MOVE command.

Click the RATSNEST icon to calculate the airwires so that

they show the shortest possible connections. Repeat this

command whenever you want to check how good your

current placement is (short airwires, no twisted buses etc.)

Board Changes:-





Once you have completed the routing of the board you can

make changes, e.g. you can:

1) press move and arrange wire segments and components

with MOVE and SPLIT ,

2) use the RIPUP command to change routed tracks to

airwires,

3) use DELETE to erase signals (only without

Forward&Back annotation),

4) replace package variants with CHANGE PACKAGE (also

PACKAGE)

5) modify the Design Rules (for example, Restring settings),

Copper Pouring with the POLYGON Command:-

The POLYGON command enables you to define areas which

belong to a signal, connecting all of the related pads to this

signal with Thermal symbols. Such a signal retains a user

defined distance to any other signal path. You can design

layers that contain multiple polygons such as different ground

areas, and you can design polygons on multiple layers.

Autorouter:-If you would like to see a small demo of the Autorouter, click

the icon for the AUTO command in the command toolbar.

Choose a finer Routing Grid (default 50 mil), if necessary and

press OK . It should be finished in no time at all, provided the

placement is not too bad (watch the status bar). If it is taking

too long, interrupt the Autorouter by

clicking the stop sign icon. Confirm the question Interrupt?

with press Yes.





If you don't like the result, reverse it with the command

RIPUP. If you would like to change certain routed tracks into

airwires, click these tracks and start the ripup process by a

click on the traffic light icon in the action toolbar. If you

would like to change all routed tracks into airwires, press the

RIPUP icon and then press the traffic light icon. Confirm the

question Ripup all signals? with press OK .

You can start the Autorouter at any time, regardless of

whether there are routed tracks or only airwires on the board.

Typically, supply signals and other critical signal paths are

routed manually, before the Autorouter is used. Tracks which

are layed out before starting the autorouter won't be changed.

No Autorouter on earth will lay your board out exactly as you

would like. But it can free you of a lot of boring work. In this

section we want to demonstrate that you can easily combine

manual and automated routing.

Load the board hexapodu.brd .

Switch off layers 21, tPlace, 23, tOrigins, 25 tNames, 27,

tValues, and 51, tDocu, using the DISPLAY command, so

that the components are not shown any more. This board

contains manually routed signals named AC1 and AC2.

Rectangles in the layers 41, tRestrict , and 42, bRestrict , have

been used to create restricted areas for the Autorouter. Within

these areas the Autorouter is not allowed to route tracks on

the Top or Bottom layers. Component B1 is covered by a

restricted area drawn in layer 43, vRestrict . This means the

Autorouter must not set vias there.





Start the Autorouter by clicking the AUTO icon in the

command toolbar. A popup menu appears where you can

enter individual settings You should choose a routing grid of

10 mil (0.254 mm) for hexapodu.brd . As we want to route all

of the unrouted signals OK .

Watch the status messages appearing in the status bar. They

inform you, for instance, of how many signals have been

routed, or of how many vias have been placed at the moment.

You will notice that the number of vias goes down during the

Optimize passes.

If you want to interrupt the Autorouter click on the stop icon.

A protocol of the routing run is stored in the file

hexapodu.pro. Load it into a Text Editor window to have a

look at it. The autorouter uses the width given in the Design

Rules (=> Edit/Design Rules, Sizes tab, Minimum width) for

his tracks. If there are values given in the CLASS command

to define various net classes (as in the example file

hexapod.brd ) the autorouter will also take care of them. In

this case the greater value will be taken.

To define restricted areas for the autorouter use layer 41,

tRestrict , for the Top layer, respectively layer 42, bRestrict ,

for the Bottom layer.

Restricted areas in layer 43, vRestrict , forbids setting vias.

Conclusion:------------------------------





Circuit Diagram:-

1)

LAYOUT:-





2) CIRCUIT DIAGRAM:-

LAYOUT:-






LAYOUT:-





LAYOUT:-


LAYOUT:-


esl lab manual1[1]

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