Answer These Five Questions - Daily Questions

1) C- Language is a:
a) High level language                                     b) Low level language
c) High level language with low level features.

2) What is the value of d in the following C-language assignment statement when a is 8, d is 10 and b is 16. {d+=(a>0&a<=10)?++a:a/b}
a) 19            b) 18              c) 9              d) 0.5

3) The value of the arithmetic expression in C
2*{i%5) * (4+(j-3)/(k+2))}
When i is 8, j = 15 and k is 4 is
a) 12            b) 19.2          c) 36              d) 57.6

4) Equivalent hexadecimal number for 69 decimal number in C-programis:
a) 0x45        b) 0x69          c) 0x54          d) 0x96

5) In C, which of the following type of operators have the highest precedence:
a) Relational operator                       b) Logical operator
c) Equality operator                          d) Arithmetic operator

Answer These Above Questions in Comments, Waiting to see who can answer...

Resistor -- Electronic Equipment

RESISTOR:

A resistor is a two – terminal passive electronic component which implements electrical resistance as a circuit element. When a Voltage ‘V’ is applied across the terminals of a resistor, a current ‘I’ will flow through the resistor in direct proportion to that voltage. The reciprocal of the constant of proportionality is known as the resistance R, since, with a given voltage V, a larger value of R further ‘resists’ the flow of current I as given by Ohm’s law.

I = V/R

Resistors are common elements of electrical networks and electronic circuits and also a most important electronic equipment.

Resistor units are measured in the symbol Ω (Ohm), It is the SI unit of Electrical Resistance.

Ohm’s law states that the voltage (V) across a resistor is proportional to the current (I) passing through it, where the constant of proportionality is the resistance.

DIODE LASER ARRAYS -- ENGINEERING / TECHNOLOGY / PHYSICS

DIODE LASER ARRAYS:

In this blog, comprehensive overview of the fundamental principles and applications of semiconductor diode laser arrays. All of the major types of arrays are discussed in detail, including coherent, incoherent, edge- and surface-emitting, horizontal- and vertical-cavity, individually addressed, lattice- matched and strained-layer systems. The initial chapters cover such topics as lasers, amplifiers, external-cavity control, theoretical modeling, and operational dynamics. Spatially incoherent arrays are then described in detail, and the uses of vertical-cavity surface emitter and edge-emitting arrays in parallel optical-signal processing and multi-channel optical recording are discussed. Researchers and graduate students in solid state physics and electrical engineering studying the properties and applications of such arrays will find this book invaluable.
• First comprehensive treatment of this topic

Contributors
1. Monolithic phase-locked semiconductor laser arrays D. Botez
2. High power coherent, semiconductor laser master oscillator power amplifiers and amplifier arrays D. F. Welch and D. G. Mehuys
3. Microoptical components applied to incoherent and coherent laser arrays J. R. Leger
4. Modeling of diode laser arrays G. R. Hadley
5. Dynamics of coherent semiconductor laser arrays H. G. Winfuland and R. K. Defreez
6. High average power semiconductor laser arrays and laser array packaging with an emphasis for pumping solid state lasers R. Solarz
7. High power diode laser arrays and their reliability D. R. Scifres and H. H. Kung
8. Strained layer quantum well heterostructure laser arrays J. J. Coleman
9. Vertical cavity surface emitting laser arrays C. J. Chang-Hasnain
10. Individually addressed arrays of diode lasers D. Carlin.
Soon we will post all releted information on this post topic.

NUMBER SYSTEMS AND CODES - INTRODUCTION

INTRODUCTION:

Number system is a basis for counting various items. On hearing the word 'number', all of us immediately think of the familiar decimal number system with its 10 digits : 0,1,2,3,4,5,6,7,8 and 9.
Modern computers communicate and operate with binary numbers which use only the digits 0 and 1. Let us consider decimal number 18. This number is represented in binary as 10010. In the example, if decimal number is considered, we require only two digits to represent the number, whereas if binary number is considered we require five digits. Therefore we can say that, when decimal quantities are represented in the binary form, they take more digits. For large decimal numbers people have to deal with very large binary strings and therefore, they do not like working with binary numbers. This fact gave rise to three new number systems : Octal, Hexadecimal and Binary Coded Decimal (BCD). These numbers represent binary number in a compressed form. Therefore, these number systems are now widely used to compress long strings of binary numbers.
In this, we discuss binary, octal, hexadecimal, and BCD number systems, and we will see how to convert from decimal to binary, octal and hexadecimal, and vice versa. In the later post of this blog we are going to see binary, hexadecimal, Excess-3 and BCD arithmetic.

FixCleaner -- Softwares

FixCleaner gives you the tools you need for essential PC maintenance. The common errors that people see on a computer have varied causes. FixCleaner was designed to be a multi-form tool. It combines a set of tested, specialized utilities to comprehensively fix errors that cause a lack of performance, slow boot-up speeds and other frustrating problems. A user-friendly interface ties all of these utilities together so that you can get professional maintenance as easily as clicking a mouse.
FixCleaner feature
* Clean your registry to find and fix the discrepancies that cause PC errors.
* Manage the startup sequences on your computer, preventing the overload that makes your bootup slow.
* Customize how you maintain your machine. You can hand-pick errors to remove, or let FixCleaner do it automatically.
* Eliminate program delays to increase PC startup speed
* Download and manage critical updates for Windows Java, Adobe, Internet Explorer, and more.
* Back up your registry state automatically or create a backup whenever you want.
* Wipe away junk files, redundant links, invalid program shortcuts and outdated help files.
* Eliminate program Runtime Errors and program crashes.
* Get rid of Corrupted DLL file paths
* Put an End to IExplorer Errors and optimize your Internet Settings with ease.
* Eliminate File Path Errors and “File Cannot be Found” Errors.
Safely Repair PC Problems Quickly & Easily with FixCleaner:
No one should give in to system errors. A slow PC means lost productivity, lost features, slow browsing and wasted time. Often people think they need a new PC, but these problems can frequently be fixed-given the right tools.
* Windows Installer Problems
* Windows Upgrade Problems
* Scan Disk Problems
* Program Freezes
* Problems with Shutdown
FixCleaner can systematically remove the most frustrating errors:
* Internet Explorer Errors
* Program Run-time Errors
* DLL Errors
* javascript Errors
* Dr. Watson and System32 Utility Errors
* Hardware connection Errors
* Windows Registry Errors
* ActiveX Control Errors
* ActiveX Shield Errors
* Driver Compatibility and Update Errors
* “File cannot be found” Errors
* isass.exe, svchost.exe, & other .EXE Errors

VueScan -- Softwares

VueScan, the world's most popular scanner software, is used extensively by photographers, home users, scanning services and corporations. VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. It is very easy to use, and also has advanced features for restoring faded colors, batch scanning and other features used by professional photographers. VueScan changes nothing on your system, installs nothing in your operating system and all other scanner software will continue to function. VueScan increases your productivity and saves you money. VueScan has advanced scanning options, powerful features, and greatly improves your scans with superior color accuracy and better color balance. VueScan supports more than 700 scanners and 209 digital camera raw files and takes about 5 minutes to download and install.

Features:
• Works with 1200 flatbed and film scanners
• Runs on Mac OS X, Windows and Linux
• Improves your productivity and quality of scans
• Has been downloaded more than 5 million times
• Create raw scan files
• ICC profiles and color spaces
• IT8 color calibration

THYRISTOR

An SCR rated about 100 amperes, 1200 volts mounted on a heat sink - the two small wires are the gate trigger leads.

The thyristor is a solid-state semiconductor device with four layers of alternating N and P-type material. They act as bistable switches, conducting when their gate receives a current pulse, and continue to conduct for as long as they are forward biased (that is, as long as the voltage across the device has not reversed).

Some sources define silicon controlled rectifiers and thyristors as synonymous other sources define thyristors as larger set of devices with at least four layers of alternating N and P-type material, including.

Thyristors have three states:

1) Reverse Blocking Mode -- Voltage is applied in the direction that would be blocked by a diode.

2) Forward Blocking Mode -- Voltage is applied in the direction that would cause a diode to conduct, but the thyristor has not yet been triggered into conduction.

3) Forward Conducting Mode -- The thyristor has been triggered into conduction and will remain conducting until the forward current drops below a threshold value known as the "holding current"

SOFT START OF 3 PHASE INDUCTION MOTOR ELIMINATING THE STAR DELTA & USING THYRISTORS - RC SNUBBERS

RC SNUBBERS:

A simple snubber comprising a small resistor (R) in series with small capacitor(C) is often used. This combination can be used to suppres the rapid rise in voltage across a thyristor, preventing the erroneous turn-on of the thyristor; it does this by limiting the rate of rise in voltage 9dV/dt) across the thyristor to a value which will not trigger it. Snubbers are also often used to prevent arcing across the contacts of relays and switches and the electrical interference and welding/sticking of the contacts that can occur. An appropriately-designed RC snubber can be used with either DC or AC loads. This sort of snubber is commonly used with inductiveloads such as electric motors. The voltage across a capacitor cannot change instantaneously, so a decreasing transient current will flow through it for a small fraction of a second, allowing the voltage across the switch to increase more slowly when the switch is opened. While the values can be optimised for the application, a 100 ohm non-inductive resistor in series with 100 nanofarad, or larger, capacitor of appropriate voltage rating is usually effective. Determination of voltage rating can be difficult owing to the nature of transent waveforms; the actual rating can be determined only by measuring temperature rise of the capacitor. This type of snubber is oftern manufactured as a single component.

SOFT START OF 3 PHASE INDUCTION MOTOR ELIMINATING THE STAR DELTA & USING THYRISTORS - ABSTRACT

ABSTRACT:

A soft starter is another form of reduced voltage starter for A.C. Induction motors. The soft starter is similar to a primary resistance or primary recatance starter in that it is in series with the supply to the motor. The current into the starter equals to the current out. The soft starter employs solid state devices to control the current flow and therefore the voltage applied to the motor. In theory, soft starters can be connected in series with the line voltage applied to the motor, or can be connected inside the delta loop of a delta connected motor, controlling the voltage applied to each winding.

These Solid State Switches are phase controlled in a similar manner to a light dimmer, in that they are turned on for a part of each cycle. The average voltage is controlled by varying the conduction angle of the swithches. Increasing the conduction angle will increase the average output voltage. Controlling the average output voltage by means of solid state switches has a numbger of advantages. One of the major advantages being the vast improvement in efficiency relative to the primary resistance starter, due to its low on state voltage of the solid state switches. Typically, the power dissipation in the starter, during start, will be less than 1% of the power dissipated in a primary resistance starter during start. Another major advantage of the solid state starter is that the average voltage can be easily altered to suit the required starting conditions. By variation of the conduction angle, the output voltage can be increased or reduced, and this can be achieved automatically by the control electronics. After the motor reaches desired speed the semi conductor switches are bypassed to feed full voltage to the motor.

SOFT START OF 3 PHASE INDUCTION MOTOR ELIMINATING THE STAR DELTA & USING THYRISTORS

INTRODUCTION:

Now a days and olden days we are using the starters, because starting current minimization and motor will be safely starting. A soft starter is another form of reduced voltage starter for A.C. induction motors. The soft starter is similar to a primary resistance or primary reactance starter in that it is in series with the supply to the motor. The current into the starter equals the current out. by using START SOFT STARTER when starting morots, it is important and essential that starter enables sufficient torque for the motor and it dynamically accelerates at work speed in spite of different loads, rapid reversals and mechanical vibrations/jerks, etc.

A Start starts the motors effective and automatically without large mechanical jerk or starting current peaks in spite of different loads. Starting does not stres power transmission and machinery and no changes are needed on adjustments. It is possible also for a smooth stop, which removes piping strokes.

The soft starters of 3-phase induction motor by using the back to back (3*2 Thyristors). In this method we are design simple construction and weight is very low than the any another type of starter for example Star / Delta Starter, DOL(Direct on Line Starter) and so on.