Entertaining Electronics

15/04/2013

Want to be in two places at once..??...well u can at least pray to God to make u an electron in ur next life.....:p

22/09/2012

OPTICAL COMMUNICATION


Optical communications, in various forms, have been used for thousands of years. The Ancient Greeks polished their shields to send signals during battle. In the modern era, semaphores and wireless solar telegraphs called heliographs were developed, using coded signals to communicate with their recipients.
Many fields of technology have found use for the narrow,concentrated,sharply directed light beams produced with the aid of lasers (Light Amplification By stimulated Emission Of Radiation) . Lasers are being used for maintaining communication with objects in space. True, direct communication between the earth and space is always made difficult because light is dispersed by clouds,fog,snow and rain. Because of that,the laser is installed in the satellites and the ordinary radio stations maintain communication between satellite and the earth.
A beam sent into space by a laser travels straight to its destination.
For communicating with Mars an ordinary radio station must have a power amounting millions of watts,whereas in the case of the laser,one watt power is sufficient,i.e.less than the power of a pocket electric torch or flashlight!
Lasers can be of great service not only in space,but also under water. Ordinary radio waves are greatly attenuated (weakened) in water,therefore ultrasound is now being used for underwater communications. Light is also poorly propagated through water , but light waves whose length corresponds to blue and green colours freely pass through water-hence the specific colour of sea-water.
Communication and radar under water are now realized by means of radar beams of the "sea-water colour".

21/09/2012

21/09/2012

LIGHTENING IN A JAR

In Faraday's time the science of electricity developed tempestuously. Any discovery soon found its application and served as food for new research and ideas.
Coulomb investigated the properties of charges several decades earlier. At that time no one knew what to do with charges: there were no sources of electricity as yet and no one even imagined that charges could be transported by wires. But mechanics at that time was a well-known subject.So it was decided that the first and wisest thing to do was to turn to mechanics for aid. Instead of rubbing the amber rod by hand,a special wheel was used for the purpose. The rod itself was replaced by a large glass jar,which was lined inside and outside with lead. Thus,in laboratories of the Dutch city of Leyden were developed the first condensers (capacitors) which came to be known as Leyden jars. It was expected that the machine would produce an invisible "electric liquid" which would fill the Leyden jar to the brim.
Mechanics proved its worth. If a comb rubbing against one's hair could produce electric sparks which were barely visible in the dark,the wheel made it possible to obtain large charges in the Leyden jar. These experiments became so fashionable tat they were conducted not only in laboratories ,but even in the reception-rooms of aristocrats and kings' palaces.
Louis XV would form a chain of soldiers and amused himself watching the grimaces of the men,when the discharge current of a Leyden jar passed through this living circuit. The amazed public watched lightening-like sparks obtained from the jars. The aristocracy were astounded: "What a wonder-lightening in a jar! What science is capable of!" But things went no further.
Such was not the case in Faraday's time. Progressive scientific thought was focused on electric and magnetic phenomena. Ampere and Davy,Volta and Ohm,Oersted and Helmholtz approached the same problems from different angles. Ideas permeated the air like electricity before a thunder-storm. This was no longer science for the sake of science,not the curiosity of single men-practical life set aims for the science,and kept demanding solutions to more and more problems.
And if science comes across something unknown when solving these problems? So much the better! This means that there will be new grounds for new practical tasks.
Thus,electrolysis which was developed to obtain pure metals and gases helped discover the electron. The same chemical process formed the basis for the first current sources which were developed as the result of the discoveries made by Galvani and Volta and which came to be known as galvanic or voltaic cells.
With the advent of these sources the interest in electricity grew still more. Man learned to transmit charges along wires and noticed immediately that the current flowing along a wire produced heat. And heat could be made to work. This thought was well assimilated, and it gave birth to a whole revolution in engineering, which brought glory to the 19th century.

19/09/2012

Where Does Radio Begin?

Now,we have radio and electronics-two fields of engineering closely linked together.Where is the borderline between them?
Electronics deals with the development of electronics devices:valves,cathode-ray tubes,semiconductors.The role played by radio needs no explanations.And yet...
Can radio exist without electronics? It is hard to imagine a modern transmitter or receiver without semiconductors or valves.But now it turns out that communication can be realized by means of photonic devices.In this case it is light rays and not radio waves that are employed.
Is this radio or is it not? We shall have to go once more deep into the meaning of the word "radio" to answer this question.The word "radio" comes from latin word "radius" which means "ray". Radio can operate with various rays.The more so,as the waves employed by radio up till now and light are of one and the same nature.
Maxwell established this truth about a 150 years ago.Why is it that only recently systems employing light rays have come into being?
The thing is that in the early years of the development of communication engineering it was easier to deal with longer wavelengths.After Maxwell's discoveries science was persistently seeking ways of obtaining these invisible waves.What for? Not simply to confirm or refute Maxwell's ideas.Many understood that having studied these waves,science would be able to apply them for practical purposes.For what purposes precisely? Who could know what possibilities were latent in the waves that no one had yet observed? It was hard to predict anything,when their properties were totally unknown.
Even heirich hertz,who was the first to obtain the waves,asserted that his discovery was of no practical value.
Nevertheless,it was precisely in Hertz' experiments that the principle was born which subsequently became the basis of all kinds of wireless communication: radiation and reception.
"A device should be invented which would substitute electromagnetic sense that man lacks"-that is how the problem was posed by the prominent Russian scientist Alexander Popov.
And soon he proved that such devices really could be developed.On the 7th of May 1895.A. popov expounded in his epoch-making report the results of his first experiments in wireless communication.Two years later in the course of his report delivered at the St. petersburg University A. popov demonstrated the possibility of transmitting radio signals over a distance of 250 metres which separated the chemical laboratory,where the transmitter was set up,from the physics room in which the signals were received.At that time the navy was in great need of such a communication. On land wires could do the task.But one cannot stretch wires from the shore to a ship that has put out to sea!
Two more years passed and radio station built by A.popv was already keeping up communication between two ships lying forty kilometres apart,and in the year 1900 the operations involved in the salvage of the battleship "GENERAL-ADMIRAL APRAKSIN",which had run aground near the island of Gogland,were coordinated by means of wireless communication between Kronstadt and the island.
By using the same station Popov transmitted to the captain of icebreaker "Ermak" a message of the Admiralty that a storm had set adrift an ice floe on which 27 fishermen were stranded.The ship that went to their rescue arrived in time.Wireless communication helped to save human lives.
Thus radio began to be acknowledged,but nobody had yet heard of electronics.

09/09/2012

This page is for all those who are interested in studying d electronics and also for those who are curious about dis very known word ELECTRONICS......

30/04/2012

"THE HISTORY OF LIGHT"
PART 2

Approximately in the 11th century A.C. the famous Arabian scientist Abu-Ali Al Hasan Ibn Al-Haytham (he is known in history by the name of Alhazen) was the first who proclaimed that we see the light reflected by objects.
But just what is this light?
The great Newton has left us his theory of light in which the ideas of the philosophers of antiquity are revived.He also believed that light consists of particles.Truly,his particles (he called them corpuscles) are not radiated by the eye,nor by objects......Newton understood well that visible objects only reflect light.
And then Maxwell advances his electromagnetic theory of light which fascinates the minds of scientists to such an extent that no one thinks of the light corpuscles any longer.But now scientists begin remembering Huygens and Fresnel,Newton's contemporaries and opponents,who had asserted that on encountering obstacles light behaves as if it consists not of particles,but of waves.
And then,several decades later,science comes across a phenomenon which demands again that the ideas about light be reviewed.
Under the action of light,metal emits electrons,as if it were bombarded by a hail of particles.Maxwell's waves cannot explain such phenomenon.Studying this effect (it has become known as photoelectric effect),Einstein has taken up anew Newton's corpuscle idea and added a particle of light--the photon-to the formerly discovered series of elementary particles of matter.
This is a typical example of dialectics.......revaluation of former views and former ideas at a new stage of development.From Newton's corpuscles of light to Huygens' and Fresnel's waves,from these,to Maxwell's ideas about electromagnetic waves,and then,to Einstein's photons which have eliminated the "white spots" in the wave theory of light--such are the main stages marking the evolution of views held by the science of light.
And now,finally,the modern theory of light--yet another vivid example of the dialectical unity of conflicting qualities of phenomena.....in some phenomena light manifests its wave properties and in others,behaves like a stream of minuscule particles.

30/04/2012

"THE HISTORY OF LIGHT"
PART 1

The science of light had covered a long and thorny way before maxwell's ideas linked with electromagnetic waves.
people have been curious about light since time immemorial.No special instruments have been required to discover it.The universe is filled with sunbeams and it is only due to light that man has been able to learn about this sunny world.That is why the first "scientific debate" about light was held as far back as three and a half thousand years ago.The sponsor of the "debate" was pharaoh Amenophis 4,who lived in the 14th century B.C.
Rejecting the then existing theories that light is radiated by the eyes of god Amun,Amenophis 4 came to the conclusion that light is emitted by the sun.The sun was also considered a god known by the name of Aten.Amenophis 4 legalized the new concepts.........he ordered that Aten should be worshiped instead of Amun and in honour of this reform he changed his mane of Amenophis for that of IKHNATON.....Amenophis means "pleasing to Amun",and Ikhnaton means "welcome to Aten".The new name was in full accord with the spirit of the new ideas.
The ancient greeks had different views.Having established the fact that man can see objects only because of light,they concluded that light is radiated by the objects themselves."particles of light" reach the human eyes and because of these particles a thing can be seen.
However,in the works of the ancient philosophers one can also find different ideas.Plato,for example,in his famous "Dialogues" says that of all organs it is the light carrying eyes that the gods have created first of all.
Compared to Amenophis-Ikhnaton this is already some progress.According to Plato,not only the gods possess "light carrying vision",but even man himself.
But then it is hard to say whether Ikhnaton claims that light exists outside man and Plato,that the source of light is man himself.It is as if his eyes feel object with the beam they emit.


To Be Continued........

28/04/2012

Just what happens to amber rod when it is rubbed with wool? Only at the end of the 18th century did science provide more or less clear answer....the rod becomes charged with electricity.And what is electricity? Where has it come from?
In 1775 coulomb made the first quantitative experiment.His aim was to determine what is it that the forces of mutual attraction of two point charges depend on (Coulomb called these forces"electric fluids") and what is the magnitude of these forces and what is a point charge? May it not be that coulomb meant an electron?
No.Coulomb hadn't the slightest idea about the electron.By the point charge he meant any charged body,the size of which was many times less than the distance to other bodies.He wanted to determine how the force of mutual attraction of point charges depends on distance.At the same time it was necessary to take into account the quantity of the charge given to reach body.....the force is the greater the larger each charge.At that time force could be measured with sufficient accuracy.In particular,coulomb measured the force of interaction of two charges with a specifically designed torsion balance.To measure the distance between the charges was not hard at all.But what about the charges? Before coulomb no one had attempted to measure them.There were neither measuring units nor instruments which could compare charges.
Coulomb's method was most ingenious.He took two charged balls and determined the force with which they attracted each other.Then he took a third,uncharged ball and made it touch a charged one.At the moment of contact the charged ball gave up half its charge to the uncharged one,since both balls were made up of the same material and size.After this the force was halved.Then coulomb began increasing the distance between the charged balls 2,3,4 and 5 times.The force began decreasing 4,9,16 and 25 times,respectively.
Int this way the law of interaction between two point charges was established.THE FORCE OF INTERACTION IS PROPORTIONAL TO THE MAGNITUDE OF BOTH CHARGES AND INVERSELY PROPORTIONAL TO THE SQUARE OF THE DISTANCE BETWEEN THEM.
In honour of this experiment the law was called COULOMB'S LAW and the units which were subsequently used for measuring charges were also called as coulombs.Compared to the charge of a single electron a coulomb is a veritable giant;a body must accept 6.29*10^18 electrons(q=ne) to acquire a charge of one coulomb.The figure is enormous.If every second a body is given one million electrons,a charge of one coulomb accumulate only in 200 years...:p

25/04/2012

do watch it.....it's more informative than anything else...:p

Rappin' about CERN's Large Hadron Collider! Links below... Apparently YouTube fixed the sound! Still, Will Barras made two options trying to get around the o...