Knowledge Exchange...: 20091025

Lecture Notes - Electromagnetism and Optics

File : pdf, 1.4 MB, 260 pages

Lecture Notes by Richard Fitzpatrick,
The University of Texas at Austin
1 Introduction
2 Vectors
2.1 Vector Algebra
2.2 Vector Area
2.3 The Scalar Product
2.4 The Vector Product
2.5 Vector Calculus
2.6 Line Integrals
2.7 Surface Integrals
2.8 Volume Integrals
3 Electricity
3.1 Historical Introduction
3.2 Conductors and Insulators
3.3 Electrometers and Electroscopes
3.4 Induced Electric Charge
3.5 Coulomb's Law
3.6 Electric Fields
3.7 Worked Examples
4 Gauss' Law
4.1 Electric Field-Lines
4.2 Gauss' Law
4.3 Electric Field of a Spherical Conducting Shell
4.4 Electric Field of a Uniformly Charged Wire
4.5 Electric Field of a Uniformly Charged Plane
4.6 Charged Conductors
5 Electric Potential
5.1 Electric Potential Energy
5.2 Electric Potential
5.3 Electric Potential and Electric Field
5.4 Electric Potential of a Point Charge
6 Capacitance
6.1 Charge Storage
6.2 Breakdown
6.3 Capacitance
6.4 Dielectrics
6.5 Capacitors in Series and in Parallel
6.6 Energy Stored by Capacitors
7 Electric Current
7.1 Electric Circuits
7.2 Ohm's Law
7.3 Resistance and Resistivity
7.4 Emf and Internal Resistance
7.5 Resistors in Series and in Parallel
7.6 Kirchhoff's Rules
7.7 Capacitors in DC Circuits
7.8 Energy in DC Circuits
7.9 Power and Internal Resistance
8 Magnetism
8.1 Historical Introduction
8.2 Ampere's Experiments
8.3 Ampere's Law
8.4 The Lorentz Force
8.5 Charged Particle in a Magnetic Field
8.6 The Hall Effect
8.7 Ampere's Circuital Law
8.8 Magnetic Field of a Solenoid
8.9 Origin of Permanent Magnetism
8.10 Gauss' Law for Magnetic Fields
8.11 Galvanometers
9 Magnetic Induction
9.1 Faraday's Law
9.2 Lenz's Law
9.3 Magnetic Induction
9.4 Motional Emf
9.5 Eddy Currents
9.6 The Alternating Current Generator
9.7 The Direct Current Generator
9.8 The Alternating Current Motor
9.9 The Direct Current Motor
10 Inductance
10.1 Mutual Inductance
10.2 Self Inductance
10.3 Energy Stored in an Inductor
10.4 The RL Circuit
10.5 The RC Circuit
10.6 Transformers
10.7 Impedance Matching
10.8 Worked Examples
11 Electromagnetic Waves
11.1 Maxwell's Equations
11.2 Electromagnetic Waves
11.3 Effect of Dielectric Materials
11.4 Energy in Electromagnetic Waves
12 Geometric Optics
12.1 Introduction
12.2 History of Geometric Optics
12.3 Law of Geometric Propagation
12.4 Law of Reection
12.5 Law of Refraction
12.6 Total Internal Reflection
12.7 Dispersion
12.8 Rainbows
13 Paraxial Optics
13.1 Spherical Mirrors
13.2 Image Formation by Concave Mirrors
13.3 Image Formation by Convex Mirrors
13.4 Image Formation by Plane Mirrors
13.5 Thin Lenses
13.6 Image Formation by Thin Lenses
13.7 Chromatic aberration
14 Wave Optics
14.1 Introduction
14.2 Huygens' principle
14.3 Young's Double-Slit Experiment
14.4 Interference in Thin Films

Download : link

Network Protection and Automation Guide (Electrical Power System)

File : pdf, 11.2 MB, 452 pages

TOC
Introduction
Fundamentals of Protection Practice
Fundamental Theory
Fault Calculations
Equivalent Circuits and Parameters of Power System Plant
Current and Voltage Transformers
Relay Technology
Protection: Signalling and Intertripping
Overcurrent Protection for Phase and Earth Faults
Unit Protection of Feeders
Distance Protection
Distance Protection Schemes
Protection of Complex Transmission Circuits
Auto-Reclosing
Busbar Protection
Transformer and Transformer-Feeder Protection
Generator and Generator-Transformer Protection
Industrial and Commercial Power System Protection
A.C. Motor Protection
Protection of A.C. Electrified Railways
Relay Testing and Commissioning
Power System Measurements
Power Quality
Substation Control and Automation
Distribution System Automation
Appendix 1 Terminology
Appendix 2 ANSI/IEC Relay Symbols
Appendix 3 Application Tables

download : zip1 zip2 zip3 ch4.pdf app2

PHP Tip: Add Custom Google Search Results to Your Site with PHP

Have you ever wanted to integrate a custom google search on your site, and style it to your liking? Today, I will take you through adding custom google search results to your site with php.

What you need

Quickly...

Mike Migurski's PHP JSON decoder
allow_url_fopen set to On in your PHP.INI (many hosts have this on by default)
A desire to learn to be even more awesome than you already are

You'll end up with 2 files to make things work: search.php that shows a search form and results and querygoogle.php that pulls search results from Google. Put the CSS used in this tutorial wherever you want... if you want it.

How will this make your life better?

Being the awesome Web developer/designer/jack-of-all-tradeser you are and your clients know you are, you receive frequent requests to add a "little search box" as a part of your client's Web site. What follows is a twitch you disguise as a sneeze because you know you haven't got a solid easy-to-impliment custom solution that the client won't groan at.
But that'll all change now. Armed with a little PHP wizardry, we can turn you into a star. This is a ridiculously easy to implement solution for adding CSS-able custom results straight from Google to your client's Web site. And, we'll do it all in 3+1 easy steps. (note: please read Google's Terms of Use).

Step 1: The search form/page - search.php

Since computers can't yet read minds, we'll have to create a simple search form that includes a text field for the search query and a search button. This should be pretty ho-hum to you, but it's important nonetheless.
Notice the form posts to querygoogle.php. We'll create that script in step 2.

<form method="post" action="querygoogle.php"> 

<label for="searchquery"><span class="caption">Search this site</span> <input type="text" size="20" maxlength="255" title="Enter your keywords and click the search button" name="searchquery" /></label> <input type="submit" value="Search" /> 

</form>

Yeah baby! We've created a simple search form ready for any daunting search challenge. Let's create the real muscle be your custom search engine, the famed querygoogle.php.

Step 2: The script to query Google - querygoogle.php

Now the fun stuff you've been skip scrolling to see (I know your scanning tendancies!). I wrote this PHP script to take advantage of Google's AJAX Search API to provide a transparent, usable, branded experience to end-users. My customers were happy, and yours will be too. Save this PHP as querygoogle.php.
Here's what the code is doing:

Includes the JSON library
Sets up the URL that you will give you Google's search results. The URL includes your domain to make it a site specific search and the user's search query. The search uses Google's "site:domain.com keywords" search syntax
Uses fopen and fread to grab the JSON that results from a call to Google
Decodes the JSON into a PHP object with Mike's JSON library
Iterates through the object, creating custom HTML-formatted results
Sets a session variable that contains the custom HTML-formatted results to send to your custom results page
Uses PHP's header function to send the browser to your custom results page

<?php 

session_start(); 

  

// if you use an Mike Migurski's JSON library, include it like I did 

require_once('JSON.phps'); 

  

// Here's the Google AJAX Search API url for curl. It uses Google Search's site:http://www.yourdomain.com/ syntax to search in a specific site. I used $_SERVER['HTTP_HOST'] to find my domain automatically. Change $_POST['searchquery'] to your posted search query 

  

$url = 'http://ajax.googleapis.com/ajax/services/search/web?rsz=large&;v=1.0&q=' . urlencode('site:' . $_SERVER['HTTP_HOST'] . ' ' . $_POST['searchquery']); 

  

// use fopen and fread to pull Google's search results 

  

$handle = fopen($url, 'rb'); 

$body = ''; 

while (!feof($handle)) { 

$body .= fread($handle, 8192); 

} 

fclose($handle); 

  

// now $body is the JSON encoded results. We need to decode them. 

  

$json = new Services_JSON(); 

$json = $json->decode($body); 

  

// now $json is an object of Google's search results and we need to iterate through it. 

  

foreach($json->responseData->results as $searchresult) 

{ 

if($searchresult->GsearchResultClass == 'GwebSearch') 

{ 

$formattedresults .= ' 

<div class="searchresult"> 

<h3><a href="' . $searchresult->unescapedUrl . '">' . $searchresult->titleNoFormatting . '</a></h3> 

<p class="resultdesc">' . $searchresult->content . '</p> 

<p class="resulturl">' . $searchresult->visibleUrl . '</p> 

</div>'; 

} 

} 

  

$_SESSION['googleresults'] = $formattedresults; 

header('Location: ' . $_SERVER['HTTP_REFERER']); 

exit; 

?>

Important Note

We are having a small issue with the code syntax formatting, be sure the '&' signs in the url on line 9 above do *not* have a semicolon after them. Please see 'Renes' comment below for more. Apologies for the inconvenience!

Step 3: The results page - back to search.php

I know you're itching to see the results. So was I! Boy I wish I could do it all over again for the first time...
Anyway, the HTML formatted results are now stored in a PHP session variable from querygoogle.php. Groovy. All we have to do is display them and add some more CSS to make the results look sexy.
Make sure you can pull the results from the session by verifying that you are starting the session at the beginning of search.php and then echo the results. See below for the final search.php code (we started it in Step 1):

&lt;?php 

session_start(); 

?&gt; 

  

<form method="post" action="querygoogle.php"> 

<label for="searchquery"><span class="caption">Search this site</span> <input type="text" size="20" maxlength="255" title="Enter your keywords and click the search button" name="searchquery" /></label> <input type="submit" value="Search" /> 

</form> 

  

&lt;?php 

if(!emptyempty($_SESSION['googleresults'])) 

{ 

echo $_SESSION['googleresults']; 

unset($_SESSION['googleresults']); 

} 

?&gt;

Your search results work! But they're ugly. Here's some sexy CSS like I promised to get your started.

body 

{ 

background-color: #000; 

color: #ccc; 

font: .75em/1.5em Arial, sans-serif; /* EMs calculated with pxtoem.com */

padding: 1.5em; 

margin: 0; 

width: 40em; 

} 

  

.searchresult 

{ 

padding: 1.5em 0; 

border-bottom: 1px solid #333; 

} 

  

.searchresult h3, .searchresult p 

{ 

margin: 0; 

} 

  

.searchresult h3 a 

{ 

font: italic 1em Georgia, serif; 

color: #f30; 

border-bottom: 1px solid #900; 

text-decoration: none; 

font-weight: bold; 

font-size: 1em; 

} 

  

.searchresult .resultdesc b 

{ 

color: #fff; 

} 

  

.searchresult .resulturl 

{ 

color: #666; 

font-size: .75em; 

}

If you'd like to style your own results your way, each result will be placed in the following HTML format:

<div class="searchresult"> 

<h3><a href="page-url">Page Title</a></h3> 

<p class="resultdesc">Page description/highlights</p> 

<p class="resulturl">URL that google always shows in green</p> 

</div>

Step 3+1: Celebrate!

Congratulations! Your clients are happy. You've worked hard and you should take some "you time."

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Beginners Introduction to the Assembly Language of ATMEL AVR Microprocessors

File : pdf, 1.1 MB, 58 pages
Content
Why learning Assembler

Short and easy
Fast and quick
Assembler is easy to learn
AT90Sxxxx are ideal for learning assembler
Test it

Hardware for AVRAssemblerProgramming

The ISP Interface of the AVR processor family
Programmer for the PC Parallel Port
Experimental board with a AT90S2313
Readytouse
commercial programming boards for the AVR family

Tools for AVR assembly programing

The editor
The assembler
Programming the chips
Simulation in the studio

What is a register?
Different registers
Pointerregister
Recommendation for the use of registers

Ports

What is a Port?
Details of relevant ports in the AVR
The status register as the most used port
Port details
SRAM
Using SRAM in AVR assembler language
What is SRAM?
For what purposes can I use SRAM?
How to use SR15
Use of SRAM as stack
Defining SRAM as stack
Use of the stac
Bugs with the stack operation

Jumping and Branching

Controlling sequential execution of the program
What happens during a reset?
Linear program execution and branches
Timing during program execution
Macros and program execution
Subroutines
Interrupts and program execution

Calculations

Number systems in assembler
Positive whole numbers (bytes, words, etc.)
Signed numbers (integers)
Binary Coded Digits, BCD
Packed BCDs
Numbers in ASCII format
Bit manipulations
Shift and rotate
Adding, subtracting and comparing
Format conversion for numbers
Multiplication
Decimal multiplication
Binary multiplication
AVRAssembler
program
Binary rotation
Multiplication in the studio
Division
Decimal division
Binary division
Program steps during division
Division in the simulator
Number conversion
Decimal Fractions
Linear conve
Example 1: 8 bit AD converter
with fixed decimal output
Example 2: 10 bit AD converter
with fixed decimal output

Annex

Commands sorted by function
Command list in alphabetic order
Assembler directives
Commands
Port details
Status Register,
Accumulator flags
Stackpointer
SRAM and External Interrupt control
External Interrupt Control
Timer Interrupt Control
Timer/Counter 0
Timer/Counter 1
Watchdog Timer
EEPROM
Serial Peripheral Interface SPI
UART
Analog Comparator
I/O Ports
Ports, alphabetic order
List of abbreviation

download : pdf1

Handbook of instrumentation and controls

MODUL 1 TEMPERATUR DETECTOR

RESISTANCE TEMPERATURE DETECTORS (RTDs)
Temperature
RTD Construction
THERMOCOUPLES
Thermocouple Construction
Thermocouple Operation
FUNCTIONAL USES OF TEMPERATURE DETECTORS
Functions of Temperature Detectors
Detector Problems
Environmental Concerns .
TEMPERATURE DETECTION CIRCUITRY
Bridge Circuit Construction
Bridge Circuit Operation
Temperature Detection Circuit
Temperature Compensation
MODUL 2 PRESSURE DETECTORS
PRESSURE DETECTORS
Bellows-Type Detectors
Bourdon Tube-Type Detectors
Summary
PRESSURE DETECTOR FUNCTIONAL USES
Pressure Detector Functions
Detector Failure
Environmental Concerns
PRESSURE DETECTION CIRCUITRY
Resistance-Type Transducers
Inductance-Type Transducers
Capacitive-Type Transducers
Detection Circuitry
MODUL 3 LEVEL DETECTORS
LEVEL DETECTORS
Gauge Glass
Ball Float
Chain Float
Magnetic Bond Method
Conductivity Probe Method
Differential Pressure Level Detectors
DENSITY COMPENSATION
Specific Volume
Reference Leg Temperature Considerations
Pressurizer Level Instruments
Steam Generator Level Instrument
LEVEL DETECTION CIRCUITRY
Remote Indication
Environmental Concerns
MODUL 4 FLOW DETECTORS
HEAD FLOW METERS
Orifice Plate
Venturi Tube
Dall Flow Tube
Pitot Tube .
OTHER FLOW METERS
Area Flow Meter
Displacement Meter
Hot-Wire Anemometer
Electromagnetic Flowmeter
Ultrasonic Flow Equipment
STEAM FLOW DETECTION
FLOW CIRCUITRY
Circuitry .
Use of Flow Indication
Environmental Concerns
MODUL 5 POSITION INDICATORS
SYNCHRO EQUIPMENT
Synchro Equipment
SWITCHES
Limit Switches
Reed Switches
VARIABLE OUTPUT DEVICES
Potentiometer
Linear Variable Differential Transformers (LVDT)
Summary
POSITION INDICATION CIRCUITRY
Environmental Concerns
MODUL 6 RADIATION DETECTORS
OBJECTIVES
RADIATION DETECTION TERMINOLOGY
Electron-Ion Pair
Specific Ionization
Stopping Power
Summary
RADIATION TYPES
Alpha Particle
Beta Particle
Gamma Ray
Neutron .
GAS-FILLED DETECTOR
Summary
DETECTOR VOLTAGE
Applied Voltage
Summary
PROPORTIONAL COUNTER
MODUL 7 PROCESS CONTROLS
PRINCIPLES OF CONTROL SYSTEMS
Introduction
Terminology
Automatic Control System
Functions of Automatic Control
Elements of Automatic Control
Feedback Control
CONTROL LOOP DIAGRAMS .
Terminology
Feedback Control System Block Diagram
Process Time Lags
Stability of Automatic Control Systems
TWO POSITION CONTROL SYSTEMS
Controllers
Two Position Controller
Example of Two Position Control
Modes of Automatic Control .
PROPORTIONAL CONTROL SYSTEMS
Control Mode
Proportional Band
Example of a Proportional Process Control System
RESET (INTEGRAL) CONTROL SYSTEMS
Reset Control (Integral)
Definition of Integral Control
Example of an Integral Flow Control System
Properties of Integral Control
PROPORTIONAL PLUS RESET CONTROL SYSTEMS
Proportional Plus Reset
Example of Proportional Plus Reset Control
Reset Windup
PROPORTIONAL PLUS RATE CONTROL SYSTEMS
Proportional-Derivative
Definition of Derivative Control
Example of Proportional Plus Rate Control
Applications
PROPORTIONAL-INTEGRAL-DERIVATIVE CONTROL SYSTEMS
Proportional-Integral-Derivative
Proportional Plus Reset Plus Rate Controller Actions
CONTROLLERS
Controllers
Control Stations
Self-Balancing Control Stations
VALVE ACTUATORS
Actuators
Pneumatic Actuators
Hydraulic Actuators
Electric Solenoid Actuators
Electric Motor Actuators

download : pdf1 pdf2

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