Monday, November 2, 2009

Bishmillah


The Basmala has a special significance for Muslims, who are to begin each task after reciting the verse. It is often preceded by Ta'awwudh. In Arabic calligraphy, it is the most prevalent motif, more so even than the Shahadah. The three definite nouns of the Basmala, Allah, ar-Rahman and ar-Rahim correspond to the first three of the traditional 99 names of God in Islam. Both ar-Rahman and ar-Rahim are from the same triliteral root, R-Ḥ-M "to feel sympathy or pity". According to Lane, ar-raḥmān is more intensive, including in its objects the believer and the unbeliever, and may be rendered as "The Compassionate", while ar-raḥīm has for its peculiar object the believer, considered as expressive of a constant attribute, and may be rendered as "The Merciful".

In a commentary on the Basmala in his Tafsir al-Tabari, al-Tabari writes:
“The Messenger of Allah (the peace and blessings of Allah be upon him) said that Jesus was handed by his mother Mary over to a school in order that he might be taught. [The teacher] said to him: ‘Write “Bism (In the name of)”.’ And Jesus said to him: ‘What is “Bism”?’ The teacher said: ‘I do not know.’ Jesus said: ‘The “Ba” is Baha’u'llah (the glory of Allah), the “Sin” is His Sana’ (radiance), and the “Mim” is His Mamlakah (sovereignty).”[2]


About Me

I am Muhammad Ahsan Iqbal, from Multan.
I am student of Electronics Engineering, from Institute of Engineering & Technology Multan.

Any one can contact me;

ahsaniqbal815@gmail.com

ahsaniqbal815@yahoo.com

Its Me (Ahsan Iqbal)


It's My Own Little Electronics Lab


About My Institute (NFC-IET)




Department of Electronics Engineering

Department of Computer System Engineering


Department of Checmical Engineering


NFC Institute of Engineering & Technology,

Is one of the established institute for the engineering qualification and affiliated with the Bahau din Zikriya Univeristy Multan. 

IET offers the degree in the disciplines of the;

Checmical Engineering,
Electronics Engineering,
Computer System Engineering,
BS Computer Sciences.

Electronics Engineering Univeristies in Pakistan

Government College Univeristy Lahore


Naval Engineering College Karachi


Hamdard Univeristy Faisalabad


International Islamic Univeristy Islamabad


Air Univeristy Islamabad


BUITMS Quetta


Muhammad Ali Jinnah Univeristy Islamabad


Mehran Univeristy Jamshoro


Usman Institute of Technology Karachi


Electronics

Electronics is the study an uise o electrical components an circuits that controls the flowe o electrons or ither electrically chairged pairticles.

The fairmaist components uised in electronics is resistors, capacitors, an ticht or lowse wund hanks o wire cried inductors. Aulder electronics uised gless or metal vacuum tubes for tae control the flowe o electrons. By the late 1960's an early 1970's the transistor, a semiconductor, begoud tae tak the steid o vacuum tubes as control components. At aboot the same time, integratit circuits (meeniatur semicondutor circuits conteenin lairge nummers o awfu wee transistors pitten on gey an thin skelfs o seelicon) cam intae ordinar uiss. Integratit circuits made it possible tae seegnificantly reduce the nummer o components needit tae mak electronic products.

Fowk interestit in pheesics aften studies hou an whit for thir electronic components wirks. By their studies they can find, cleck, or better electronic components. Ither fowk designs an constructs electronic circuits for tae redd practical problems. This is pairt o electrical, electronic an computer ingineerin. Maist electronics seestems faws intae ane o thir twa categories:
Some electronic circuits process an caw aboot information. Thir are communications seestems.
Ither electronic circuits converts an distributes energy. Thir are control seestems.

Ae wey o leukin at an electronic seestem is tae separate it intae three pairts:
Inpits - Electrical or mechanical sensors (or transducers) that taks seegnals (in the form o temperatur, pressur, etc.) frae the pheesical warld an converts them intae current an voltage seegnals.
Seegnal processin circuits - Thir conseests o electronic components connectit thegether for tae manipulate, interpret an transform the information conteened in the seegnals.
Ootpits - Actuators or ither devices (transducers an aw) that transforms current an voltage seegnals back intae uissefu pheesical form.

Tak as an example a televeesion set. A televeesion set's inpit is a braidcast seegnal received frae an antenna, or a wire cable providit by a cable televeesion vendor. Seegnal processin circuits inside the televeesion set uises the brichtness, colour, an soond information athin the received seegnal tae control the televeesion set's ootput devices. The display ootpit device micht be a cathode ray tube (CRT) or a plasma or liquid creestal display screen. The audio ootpit device micht be a magnet driven audio speaker. The display ootput devices converts the seegnal processin circuits' brichtness an colour information intae the veesible eemage displayed on a screen. The audio ootput device converts the processed soond information intae soonds that can be heard by listeners.

Analog circuits


Analog circuits is uised for segnals that haes a reenge o amplitudes. For odinar, analog circuits meisurs or controls the amplitude o seegnals. In the early days o electronics, aw electronic devices uised analog circuits for seegnal processin an control.

Pulse circuits



Pulse circuits is uised for seegnals that requires swith pulses o energy. For example, aircraft an grund radar equipment wirks by uisin pulse circuits for tae create an send heich pouered brusts o radio energy frae radar transmeeters. Special antennas (cried "bauk" or "dish" antennas acause o their shape) is uised for tae send the heich pouered brusts in the airt the bauk or dish antenna is pyntit.

The radar transmeeter's pulses or brusts o radio energy hit an stot back frae haurd an metallic objects. Haurd objects is things like biggins, hills, an muntains. Metallic objects is ocht made o metal, like aircraft, brigs, satellites, or e'en objects in space. The reflectit radar energy is detectit by radar pulse receivers that uises baith pulse an deegital circuits thegither. The pulse an deegital circuits in radar pulse receivers is uised for tae shaw the location an distance o objects that haes reflectit the radar transmeeter's heich pouered pulses.

By controllin hou aften the rapid pulses o radar energy is sent oot by a radar transmeeter (cried the transmeeter's "pulse timin"), an hou lang it taks for the reflectit pulse energy tae come back tae the radar receiver, a body can tell no juist whaur objects is, but hou faur awa they are. Deegitial circuits in a radar receiver calculates the distance tae an object by knawin the time interval atween energy pulses. The radar receiver's deegital circuits coonts hou lang it taks atween pulses for an object's reflectit energy tae be detectit by the radar receiver. Syne radar pulses ais sent an received at aboot the speed o licht, the distance tae an object can be easy calculate. This is duin in deegital circuits by dividin the speed o licht by the time it taks tae receive the radar energy reflecteit back frae an object.

The time atween pulses (aften cried "pulse rate time", or PRT) sets the leemit on hou faur awa an object can be detectit. That distance is cried the "reenge" o a radar transmeeter an receiver. Radar transmeeters an receivers uises lang PRT's for tae find the distance tae objects that's faur awa. Lang PRT's maks it possible tae accurately determine the distance tae the muin, for example. Fast PRT's is uised for tae detect objects that's a hail sicht closer, like ships at sea, hie fleein aircraft, or for tae determine the speed o fast muivin caurs on motorweys.

Digital circuits



Digital circuits is uised for seegnals that aye turns on an aff. Active components in deegital citcuits for ordinar haes a constant amplitude whan turnt on, an zero amplitude whan turnt aff. Tae the maist pairt, deegital circuits coont the nummer o times a component is sneckit on an aff. Computers an electronic clocks is examples o electronic devices that's maistly made o deegital circuits.

Basic blocks:
Logic yetts
Flip-flops
Coonters
Resistors

Complex devices:
Microprocessors
Microcontrollers
Digital seegnal processors

History of Electronics










Military equipment, toys, communication, home electronics, computing, cars, satellites and others. This is only a partial list of products, which contain electronics. Actually electronics won our world. We wake up with the ring of electronic clock, drink coffee from a electronic coffee machine, work with computers, learn by using video conferences, listen to the music from a sound system and go to sleep while adjusting our electronic watch for tomorrow morning. It is hard even to think that only a hundred years ago our world seemed different at all from this point of view. But how did the electronics revolution begin? Which research and discovery was the basis for this modification? Why was it so fast, relatively to other developments in history? I will try to answer these questions in this observation. 

Theoretical and experimental studies of electricity started in the 18th and 19th centuries enabled the development of the first electrical machines and the wide use of electricity. During that time the first theory was founded and the rules of electricity was formulated. The event of identification of the electron in second half of 19th century by the English physicist J.J. Thompson and the measurement of its electric charge in 1909 by the American physicist A. Millikan were the point of turning the electronics evolution separately from that of electricity. Another coarse of interest to electronics was the observation of the American inventor Thomas A. Edison. He noticed that the current of electrons would flow from one electrode to another, if the second one was with relatively positive charge. This discovery led to the development of electron tubes. Electron tubes became very useful for manufactory at that time. X-ray tube, the radio signal detectors and transmitters, and the first power systems were based on electron tubes. The development of the vacuum tube and later the three-electrode tube by adding the grid between the anode and the cathode (Negative and positive electrodes in the tube) improved the characteristics of the tube by far and made it more useful for different electronic applications. 

The first half of the 20th century was the era of the vacuum tubes in electronics. Using the tube permitted the development of radio, long-distance telephony, television and even the first computers. The most known one was the ENIAC (Electronic Numerical Integrator and Computer) completed in 1946. 

The first and the second World Wars gave a considerable boost to the way the electronics science has advanced. Governments of rival countries invested a lot of money in the technology of military industry. On other hand they wanted the quick solution and were looking for long-range developments. Therefore the varieties of vacuum electron tubes were the central device in the electronics system of that time. 

There are several limitations to the tube. Its big size, slow working paces, bad accuracy, and very hard and high cost of production it. These limitations of the tube motivated to the “Solid-State” revolution with the invention of the transistor in 1947 by Bell Laboratories scientists: John Bardeen, Walter H. Brattain, and William B. Shockley. The vacuum tube hasn’t disappeared from the world until today. All kind of displays (except the liquid crystal one), laser systems, some measurement equipment include the tube and there is no alternative product to be used instead of the tube until now. 

Recently we have witnessed the biggest event in the history of electronics – the invention of the semiconductor devices. It made a real revolution in the world of electronics. The semiconductors are small, accurate and low cost devices. Transistors and diodes are made of crystalline solid materials, which have electrical properties that are capable of variations, an extremely wide range, by the addition of little quantities of other elements like resistors, inductors and capacitors. Early semiconductors were produced using germanium as the material, but since 1960 silicon quickly became the preferred material, because it was less expensive and it could operate in wide range of the temperatures. For instance, silicon diodes work at temperature up to 200°C (392°F), whereas germanium diodes cannot work above 85°C(277°F). 

Since 1960 transistors have quickly supplanted vacuum tubes. Electronic system became more complex and smart. Computers included hundred of thousands of transistor each (This without counting of other devices). This fact, together with the need for compact, lightweight electronic missile guidance systems, led to the invention of the integrated circuit (IC). This invention was the result of independent research of Jack Kilby of Texas Instruments Incorporated in 1958 and of Jean Hoerni and Robert Noyce of Fairchild Semiconductor Corporation in 1959. Early ICs contained about 10 individual semiconductor elements but the their number rapidly increased during next ten years. In 1970 the number was 1,000 in a chip and the result of hard work of physicists, electronics and mechanical engineers was developing and producing of first microprocessor with memory interface in 1971. This event was the beginning of computerization and smart digital electronics. 

0 and 1. Those two small numbers changed our world. Computers, data communication, the Internet understand only two numbers, 0 and 1. Digital electronics (Microprocessors and it’s surrounding) based on Boolean algebra that represent the numbers to the base of two. Since 1970 until today the digital ICs have been in constant development. Everywhere we hear about new microprocessor, which are that quicker, more complex, smarter and less expensive than the previous one. We can state that ever since the first computers electronics were improved it self. The calculation became simpler. The measurement equipment becomes more accurate. 

In conclusion, I can say that the science of electronics is one of most important science today. We all witness the influence of electronics on our life in good and bad side as well. The process of development was relatively quick and interesting. The best brains of 20th century were the of this process. But the history of electronics has not ended, as we see, and our using of electronics is the best evidence for it.


Electronic Devices

Solid state devices



Solid-state electronics are those circuits or devices built entirely from solid materials and in which the electrons, or other charge carriers, are confined entirely within the solid material.[1] The term is often used to contrast with the earlier technologies of vacuum and gas-discharge tube devices and it is also conventional to exclude electro-mechanical devices (relays, switches and other devices with moving parts) from the term solid state.[2][3] While solid-state can include crystalline, polycrystalline and amorphous solids and refer to electrical conductors, insulators and semiconductors, the building material is most often crystalline semiconductor.[4][5] Common solid-state devices include transistors, microprocessor chips, and DRAM. There is a considerable amount of electromagnetic and quantum-mechanical action takes place within the device. The expression became prevalent in the 1950s and the 1960s, during the transition from vacuum tube technology to semiconductor diodes and transistors. More recently, the integrated circuit (IC), the light-emitting diode (LED), and the liquid-crystal display (LCD) have evolved as further examples of solid-state devices.

In a solid-state component, the current is confined to solid elements and compounds engineered specifically to switch and amplify it. Current flow can be understood in two forms: as negatively-charged electrons, and as positively-charged electron deficiencies called electron holes or just "holes". In some semiconductors, the current consists mostly of electrons; in other semiconductors, it consists mostly of "holes". Both the electron and the hole are called charge carriers.

For data storage, solid-state devices are much faster and more reliable but are usually more expensive. Although solid-state costs continually drop, disks, tapes, and optical disks also continue to improve their cost/performance ratio.

The first solid-state device was the "cat's whisker" detector, first used in 1930s radio receivers. A whisker-like wire was moved around on a solid crystal (such as a germanium crystal) in order to detect a radio signal.[6] The solid-state device came into its own with the invention of the transistor in 1947.

Examples of non-solid-state electronic components are vacuum tubes and cathode-ray tubes (CRTs).

Semiconductor device


Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium, and gallium arsenide. Semiconductor devices have replaced thermionic devices (vacuum tubes) in most applications. They use electronic conduction in the solid state as opposed to the gaseous state or thermionic emission in a high vacuum.

Semiconductor devices are manufactured both as single discrete devices and as integrated circuits (ICs), which consist of a number—from a few to millions—of devices manufactured and interconnected on a single semiconductor substrate.

Semiconductor device fundamentals

The main reason why semiconductor materials are so useful is that the behavior of a semiconductor can be easily manipulated by the addition of impurities, known as doping. Semiconductor conductivity can be controlled by introduction of an electric field, by exposure to light, and even pressure and heat; thus, semiconductors can make excellent sensors. Current conduction in a semiconductor occurs via mobile or "free" electrons and holes, collectively known as charge carriers. Doping a semiconductor such as silicon with a small amount of impurity atoms, such as phosphorus or boron, greatly increases the number of free electrons or holes within the semiconductor. When a doped semiconductor contains excess holes it is called "p-type", and when it contains excess free electrons it is known as "n-type", where p (positive for holes) or n (negative for electrons) is the sign of the charge of the majority mobile charge carriers. The semiconductor material used in devices is doped under highly controlled conditions in a fabrication facility, or fab, to precisely control the location and concentration of p- and n-type dopants. The junctions which form where n-type and p-type semiconductors join together are called p-n junctions.
[edit

List of common semiconductor devices




Two-terminal devices:

Avalanche diode (avalanche breakdown diode)
DIAC
Diode (rectifier diode)
Gunn diode
IMPATT diode
Laser diode
Light-emitting diode (LED)
Photocell
PIN diode
Schottky diode
Solar cell
Tunnel diode
VCSEL
VECSEL
Zener diode


Three-terminal devices:

Bipolar transistor
Darlington transistor
Field effect transistor
GTO (Gate Turn-Off)
IGBT (Insulated Gate Bipolar Transistor)
SCR (Silicon Controlled Rectifier)
SGCT (Switched Gate Commuted Thyristor)
Thyristor
TRIAC
Unijunction transistor

Four-terminal devices
Hall effect sensor (magnetic field sensor)

Multi-terminal devices:
Charge-coupled device (CCD)
Microprocessor
Random Access Memory (RAM)
Read-only memory (ROM)


Semiconductor device applications
All transistor types can be used as the building blocks of logic gates, which are fundamental in the design of digital circuits. In digital circuits like microprocessors, transistors act as on-off switches; in the MOSFET, for instance, the voltage applied to the gate determines whether the switch is on or off.

Transistors used for analog circuits do not act as on-off switches; rather, they respond to a continuous range of inputs with a continuous range of outputs. Common analog circuits include amplifiers and oscillators.

Circuits that interface or translate between digital circuits and analog circuits are known as mixed-signal circuits.

Power semiconductor devices are discrete devices or integrated circuits intended for high current or high voltage applications. Power integrated circuits combine IC technology with power semiconductor technology, these are sometimes referred to as "smart" power devices. Several companies specialize in manufacturing power semiconductors.


Micro Electronics


Microelectronics is a subfield of electronics. Microelectronics, as the name suggests, is related to the study and manufacture, or microfabrication, of electronic components which are very small (usually micrometre-scale or smaller, but not always). These devices are made from semiconductors. Many components of normal electronic design are available in microelectronic equivalent: transistors, capacitors, inductors, resistors, diodes and of course insulators and conductors can all be found in microelectronic devices.

Digital integrated circuits (ICs) consist mostly of transistors. Analog circuits commonly contain resistors and capacitors as well. Inductors are used in some high frequency analog circuits, but tend to occupy large chip area if used at low frequencies; gyrators can replace them in many applications.

As techniques improve, the scale of microelectronic components continues to decrease. At smaller scales, the relative impact of intrinsic circuit properties such as interconnections may become more significant. These are called parasitic effects, and the goal of the microelectronics design engineer is to find ways to compensate for or to minimize these effects, while always delivering smaller, faster, and cheaper devices.

Transistor



A transistor is a semiconductor device commonly used to amplify or switch electronic signals. A transistor is made of a solid piece of a semiconductor material, with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current flowing through another pair of terminals. Because the controlled (output) power can be much more than the controlling (input) power, the transistor provides amplification of a signal. Some transistors are packaged individually but most are found in integrated circuits.

The transistor is the fundamental building block of modern electronic devices, and its presence is ubiquitous in modern electronic systems.




Capacitor



A capacitor or condenser is a passive electronic component consisting of a pair of conductors separated by a dielectric. When a voltage potential difference exists between the conductors, an electric field is present in the dielectric. This field stores energy and produces a mechanical force between the plates. The effect is greatest between wide, flat, parallel, narrowly separated conductors.

An ideal capacitor is characterized by a single constant value, capacitance, which is measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them. In practice, the dielectric between the plates passes a small amount of leakage current. The conductors and leads introduce an equivalent series resistance and the dielectric has an electric field strength limit resulting in a breakdown voltage.

Capacitors are widely used in electronic circuits to block the flow of direct current while allowing alternating current to pass, to filter out interference, to smooth the output of power supplies, and for many other purposes. They are used in resonant circuits in radio frequency equipment to select particular frequencies from a signal with many frequencies.

Inductor



An inductor or a reactor is a passive electrical component that can store energy in a magnetic field created by the electric current passing through it. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries. Typically an inductor is a conducting wire shaped as a coil, the loops helping to create a strong magnetic field inside the coil due to Faraday's law of induction. Inductors are one of the basic electronic components used in electronics where current and voltage change with time, due to the ability of inductors to delay and reshape alternating currents.

Resistor



A resistor is a two-terminal electronic component that produces a voltage across its terminals that is proportional to the electric current through it in accordance with Ohm's law:
V = IR

Resistors are elements of electrical networks and electronic circuits and are ubiquitous in most electronic equipment. Practical resistors can be made of various compounds and films, as well as resistance wire (wire made of a high-resistivity alloy, such as nickel/chrome).

The primary characteristics of a resistor are the resistance, the tolerance, maximum working voltage and the power rating. Other characteristics include temperature coefficient, noise, and inductance. Less well-known is critical resistance, the value below which power dissipation limits the maximum permitted current flow, and above which the limit is applied voltage. Critical resistance depends upon the materials constituting the resistor as well as its physical dimensions; it's determined by design.

Resistors can be integrated into hybrid and printed circuits, as well as integrated circuits. Size, and position of leads (or terminals) are relevant to equipment designers; resistors must be physically large enough not to overheat when dissipating their power.

Diode



In electronics a diode is a two-terminal electronic component which conducts electric current asymmetrically or unidirectionally; that is, it conducts current more easily in one direction than in the opposite direction. The term usually refers to a semiconductor diode, the most common type today, which is a two-terminal semiconductor P-N junction. A vacuum tube diode, which was the first type of diode invented but is now little used, is a vacuum tube with two electrodes; a plate and a cathode.

The most common function of a diode is to allow an electric current in one direction (called the forward direction) while blocking current in the opposite direction (the reverse direction). Thus, the diode can be thought of as an electronic version of a check valve. This unidirectional behavior is called rectification, and is used to convert alternating current to direct current, and remove modulation from radio signals in radio receivers.

However diodes can have more complicated behavior than this simple on-off action, due to their complex non-linear electrical characteristics, which varies with the construction of their P-N junction. These are exploited in special purpose diodes that perform many different functions. Diodes are used to regulate voltage (Zener diodes), electronically tune radio and TV receivers (varactor diodes), generate radio frequency oscillations (tunnel diodes), and produce light (light emitting diodes).

Early semiconductor diodes, called cat's whisker diodes were made of crystals of galena. Today most diodes are made of silicon, but other semiconductors such as germanium are sometimes used.

Insulator



Insulator (electrical), a substance that resists the flow of electric current
Insulator (genetics), an element in the genetic code
Thermal insulation, a material used to resist the flow of heat
Building insulation, a material used in building construction to prevent heat loss
A Mott insulator, a type of electrical insulator