Sunday, February 15, 2009

number systems(code conversion) AND BINARY CODED DECIMAL

CLICK HERE TO VIEW AND EXPERIMENT


One of the most widely used representations of numerical data is the binary coded decimal (BCD) form in which each integer of a decimal number is represented by a 4-bit binary number (see conversion table). It is particularly useful for the driving of display devices where a decimal output is desired. BCD usually refers to such coding in which the binary digits have their normal values, i.e., 8421. Sometimes it is written "8421 BCD" to clearly distinguish it from other binary codes such as the 4221 Code, but when BCD is used without qualification, the 8421 version is assumed.

Thursday, February 12, 2009

POWER SUPPLY

There are many types of power supply. Most are designed to convert high voltage AC mains electricity to a suitable low voltage supply for electronics circuits and other devices. A power supply can by broken down into a series of blocks, each of which performs a particular function.
For example a 5V regulated supply:





  • Transformer - steps down high voltage AC mains to low voltage AC.
  • Rectifier - converts AC to DC, but the DC output is varying.
  • Smoothing - smooths the DC from varying greatly to a small ripple.
  • Regulator - eliminates ripple by setting DC output to a fixed voltage.
.








FOR MORE INFORMATION CLICK HERE

Tuesday, February 10, 2009

TRANSISTOR CODES

Transistor codes


There are three main series of transistor codes used in the UK:

  • Codes beginning with B (or A), for example BC108, BC478

    The first letter B is for silicon, A is for germanium (rarely used now).
    The second letter indicates the type; for example C means low power audio frequency;
    D means high power audio frequency; F means low power high frequency.
    The rest of the code identifies the particular transistor.
    There is no obvious logic to the numbering system.
    Sometimes a letter is added to the end (eg BC108C) to identify a special version
    of the main type, for example a higher current gain or a different case style.
    If a project specifies a higher gain version (BC108C) it must be used,
    but if the general code is given (BC108) any transistor with that code is suitable
    .

  • Codes beginning with TIP, for example TIP31A

    TIP refers to the manufacturer: Texas Instruments Power transistor.
    The letter at the end identifies versions with different voltage ratings.

  • Codes beginning with 2N, for example 2N3053

    The initial '2N' identifies the part as a transistor and the rest of the code
    identifies the particular transistor.
    There is no obvious logic to the numbering system.

Monday, February 9, 2009

HELLO MRITS ECE!

Hello freinds and lecturers!

This blog can have maximum 100 authors,and if you want to be one of them leave yor Gmail address in the chat box at the left.

In two days you will be able to write to this blog,any article,post any link and do lot more.Please do not post offensive content.Post more technical posts.
This blog contains many posts which may give you some idea about how to write to this blog?

You can see blog archive at the left bottom for the earlier posts..

Thank you!

Gautam Kaundinya




Wish to Kiss the Sky!

I am the man who is thirsty of kissing the sky.
Help me please.
At least in the year 2009, let me kiss the sky.
Please don’t ask me why.
Some wishes why and how they generate nobody knows.
If you know please tell me.
From childhood I had this wish, the wish to kiss the
sky.
I felt it keeps my pride very high, just equal to sky.
Several times, I stretched my hands to touch the sky.
I didn’t succeed, so went to the terrace of a 10 storied building and tried again.
No…I didn’t get success. What a disappointment!!
What we desire, we never get…oops.
Wright brothers understood real pain in my disappointment.
They worked hard and developed a toy, which we call now an airplane.
I felt very happy while boarding on to it.

Yeah…I am going to kiss the sky.
But alas…when I looked out from my side window, I saw clouds well below my plane.
Many times I thought clouds were the sky, so touching clouds keeps my pride so high.
But I was in the plane which was well above the clouds.

So sky does not mean could, it is above the clouds.
I looked up from the window; everything appeared bluish black, just like the one I saw from my lawn.
I felt desperate. I wish to kiss the sky. Huh…Huh!
My next seat person was Wernher Von Braun. He observed how my eyes glued to the window studying the sky and how I said Huh…Huh several times.
He asked me the reason. While controlling tears, I told him my wish…a wish to kiss the sky.
He didn’t laugh like my friends. He nodded his head with deep understanding of my wish.
Later he invented a Rocket and presented it to me. He told me “My friend…Go and fulfill your wish.” His team mates and many others joined together and constructed a spacecraft.
They said unanimously “Friend…Go and fulfill your wish.”
You can’t understand how much happiness I felt.
I thought of celebrations after coming back after kissing the sky.
I sat in the spacecraft which was launched successfully.
My spacecraft reached thousands of kilometers away from the earth.
Strange…first of all my spacecraft reached another globe like earth.
No…finding another globe was not my wish.
I wish to kiss the sky.
Moved further, my spacecraft was roaming like a weapon in the hands of mad dog.
I found several globes but didn’t succeed to touch the sky to kiss it.
After fuel was over, my spacecraft threw me to my lawn again.
Every one congratulated me for roaming around the earth and touching all the planets.
They made big celebrations.
But I was with uncontrollable tears.
Every one thought those tears were due to successful space journey.
But I only know that I faced utter failure. I lost interest in everything.
Some people thought I became mad.
Ordinary people never understand the scientist’s mind.
No I can’t leave it. I have to develop something else.
That something else should help me to kiss the sky and keep my pride so high.
Don’t ask me its name now. You are going to know it very soon.
Millions of people realized pain in my heart.
They determined to help me in fulfilling my wish of kissing the sky.
They formed groups, forgot their personal lives, working on this mission day and night.
Very soon they will present me something else which helps me in kissing the sky.
Let that invention of something else takes place in 2009.
I pray for it. You too pray for it please.

I heard somebody murmuring “What we wish we never get and what we get never satisfies us.”
I say “if there is a guarantee of fulfillment, it is not a wish. Mystery creates curiosity and becomes a wish. It is there from the days of Adam and Eve and solution to every mystery became a history.”

Happy Happy New Year to You All Dear Students.
May all your dreams come true in this year 2009.















Pushpa

Sunday, February 8, 2009

LOGIC FAMILIES AND GATES

Logic Families


The types of logic devices are classified in "families", of which the most important are TTL and CMOS. The main families are:





Logic Gates



AND

OR

XOR

NAND

NOR

XNOR

BUFFER

INVERTER BUFFER OR SIMPLY, INVERTER

TRUTH TABLE FOR ALL GATES


BISTABLE MULTIVIBRATOR



As the name implies, the bistable multivibrator has two stable states. If a trigger of the correct polarity and amplitude is applied to the circuit, it will change states and remain there until triggered again. The trigger need not have a fixed prf; in fact, triggers from different sources, occurring at different times, can be used to switch this circuit.

The bistable multivibrator circuit and the associated waveforms are shown in figure 3-17, views (A) and (B), respectively. In this circuit, R1 and R7 are the collector load resistors. Voltage dividers R1, R2, and R5 provide forward bias for Q2; R7, R6, and R3 provide forward bias for Q1. These resistors also couple the collector signal from one transistor to the base of the other. Observe that this is direct coupling of feedback. This type of coupling is required because the circuit depends on input triggers for operation, not on RC time constants inside the circuit. Both transistors use common emitter resistor R4 which provides emitter coupling. C1 and C2 couple the input triggers to the transistor bases.
MORE INFORMATION.....



BISTABLE MULTIVIBRATOR JAVA APPLET

Friday, February 6, 2009

DOWNLOAD PSPICE

PSPICE 9.1 STUDENT VERSION(ALREADY AVAILABLE ON WEB FOR FREE)

DIRECT DOWNLOAD

Sunday, February 1, 2009

ECE SYLLABUS

Hello! we are the students of a college,under JNTU ECE.Currently the topics covered in 7 semesters of ECE course are:

First year:

1)C&data structures
2)Electronics devices and circuits
3)Mathematics-1
4)Mathematics-2
5)English
6)Engineering drawing
7)Network analysis
8)Applied Physics

Second Year:

1)Electrical Technology
2)Pulse and Didgital circuits
3)Electronic Circuit Analysis
4)Signals and Systems
5)Environmental Sciences
6)Analog Communications
7)Control Systems
8)Mathematics-3
9)Probability Theory and Stochastic Processs
10) Switching Theory and Logic design
11)OOPS throygh JAVA
12)Electromagnetic waves and transmission lines

Third Year:

1)Managerial Economics and financial Analysis
2)Antennas and Wave Propagation
3)Linear Integrated Circuits
4)Digital Integrated Circuits
5)Digital Communications
6)Management Science
7)Digital Signal Processing
8)Very Large Scale Integration(VLSI)
9)Telecommunication and Switching Systems
10)Microwave Engineering
11)Computer Organization

Computer networks
electronics measurement and instrumentation
Cellular and mobile communications
radar systems
satellite communications
digiatl image processing
wireless communciations and networks

GATE SYLLABUS ACCORDING TO GATE 2009

ENGINEERING MATHEMATICS
Linear Algebra: Matrix Algebra, Systems of linear equations, Eigen values and eigen vectors.

Calculus: Mean value theorems, Theorems of integral calculus, Evaluation of definite and improper integrals, Partial Derivatives, Maxima and minima, Multiple integrals, Fourier series. Vector identities, Directional derivatives, Line, Surface and Volume integrals, Stokes, Gauss and Green�s theorems.

Differential equations: First order equation (linear and nonlinear), Higher order linear differential equations with constant coefficients, Method of variation of parameters, Cauchy�s and Euler�s equations, Initial and boundary value problems, Partial Differential Equations and variable separable method.

Complex variables: Analytic functions, Cauchy�s integral theorem and integral formula, Taylor�s and Laurent� series, Residue theorem, solution integrals.

Probability and Statistics: Sampling theorems, Conditional probability, Mean, median, mode and standard deviation, Random variables, Discrete and continuous distributions, Poisson, Normal and Binomial distribution, Correlation and regression analysis.
Numerical Methods: Solutions of non-linear algebraic equations, single and multi-step methods for differential equations.

Transform Theory: Fourier transform, Laplace transform, Z-transform.

ELECTRONICS AND COMMUNICATION ENGINEERING


Networks:
Network graphs: matrices associated with graphs; incidence, fundamental cut set and fundamental circuit matrices. Solution methods: nodal and mesh analysis. Network theorems: superposition, Thevenin and Norton�s maximum power transfer, Wye-Delta transformation. Steady state sinusoidal analysis using phasors. Linear constant coefficient differential equations; time domain analysis of simple RLC circuits, Solution of network equations using Laplace transform: frequency domain analysis of RLC circuits. 2-port network parameters: driving point and transfer functions. State equations for networks.

Electronic Devices:

Energy bands in silicon, intrinsic and extrinsic silicon. Carrier transport in silicon: diffusion current, drift current, mobility, and resistivity. Generation and recombination of carriers. p-n junction diode, Zener diode, tunnel diode, BJT, JFET, MOS capacitor, MOSFET, LED, p-I-n and avalanche photo diode, Basics of LASERs. Device technology: integrated circuits fabrication process, oxidation, diffusion, ion implantation, photolithography, n-tub, p-tub and twin-tub CMOS process.

Analog Circuits:

Small Signal Equivalent circuits of diodes, BJTs, MOSFETs and analog CMOS. Simple diode circuits, clipping, clamping, rectifier. Biasing and bias stability of transistor and FET amplifiers. Amplifiers: single-and multi-stage, differential and operational, feedback, and power. Frequency response of amplifiers. Simple op-amp circuits. Filters. Sinusoidal oscillators; criterion for oscillation; single-transistor and op-amp configurations. Function generators and wave-shaping circuits, 555 Timers. Power supplies.

Digital circuits:

Boolean algebra, minimization of Boolean functions; logic gates; digital IC families (DTL, TTL, ECL, MOS, CMOS). Combinatorial circuits: arithmetic circuits, code converters, multiplexers, decoders, PROMs and PLAs. Sequential circuits: latches and flip-flops, counters and shift-registers. Sample and hold circuits, ADCs, DACs. Semiconductor memories. Microprocessor(8085): architecture, programming, memory and I/O interfacing.

Signals and Systems:

Definitions and properties of Laplace transform, continuous-time and discrete-time Fourier series, continuous-time and discrete-time Fourier Transform, DFT and FFT, z-transform. Sampling theorem. Linear Time-Invariant (LTI) Systems: definitions and properties; causality, stability, impulse response, convolution, poles and zeros, parallel and cascade structure, frequency response, group delay, phase delay. Signal transmission through LTI systems.

Control Systems:

Basic control system components; block diagrammatic description, reduction of block diagrams. Open loop and closed loop (feedback) systems and stability analysis of these systems. Signal flow graphs and their use in determining transfer functions of systems; transient and steady state analysis of LTI control systems and frequency response. Tools and techniques for LTI control system analysis: root loci, Routh-Hurwitz criterion, Bode and Nyquist plots. Control system compensators: elements of lead and lag compensation, elements of Proportional-Integral-Derivative (PID) control. State variable representation and solution of state equation of LTI control systems.

Communications:

Random signals and noise:
probability, random variables, probability density function, autocorrelation, power spectral density.
Analog communication systems:
amplitude and angle modulation and demodulation systems, spectral analysis of these operations, superheterodyne receivers; elements of hardware, realizations of analog communication systems; signal-to-noise ratio (SNR) calculations for amplitude modulation (AM) and frequency modulation (FM) for low noise conditions. Fundamentals of information theory and channel capacity theorem. Digital communication systems:
pulse code modulation (PCM), differential pulse code modulation (DPCM), digital modulation schemes: amplitude, phase and frequency shift keying schemes (ASK, PSK, FSK), matched filter receivers, bandwidth consideration and probability of error calculations for these schemes. Basics of TDMA, FDMA and CDMA and GSM.

Electromagnetics:

Elements of vector calculus: divergence and curl; Gauss� and Stokes� theorems, Maxwell�s equations: differential and integral forms. Wave equation, Poynting vector. Plane waves: propagation through various media; reflection and refraction; phase and group velocity; skin depth.
Transmission lines:
characteristic impedance; impedance transformation; Smith chart; impedance matching; S parameters, pulse excitation. Waveguides: modes in rectangular waveguides; boundary conditions; cut-off frequencies; dispersion relations. Basics of propagation in dielectric waveguide and optical fibers.
Basics of Antennas: Dipole antennas; radiation pattern; antenna gain.

Any further queries on the topics can be written in the chat box or post a comment......