Introduction to Electronics
Praise be to Allah and peace and blessings be upon His Messengers Prophet Muhammad and his family and companions. . As yet, tremendous advances in technologies and witnessed by our time and rapid developments as expected and somewhat in the coming period in all areas of life is closely linked to the progress of science electronics - every day a new development in the world of electronics, for example, a team of US scientists has succeeded from the "Bill Factor "in the development of smaller transistors in the world of the new design allows to continue to minimize the silicon chips were able to double the speed of operations for some of the slides
- The size of the transistor Alljdid 50 nm, which is less than two thousand times the thickness of a single hair on the human head. The new dwarf known in the world of electronics as the vertical transistor because all of its components carefully built on top of each other. He says one of the researchers that the vertical transistor may skip the traditional transistors, which industrialists experts predict it will reach an impasse within ten years is noteworthy that the traditional transistor was discovered by three scientists from the same lab in 1947.
- Built the first computer a letter in the 1940 world and weighed 27 tons and included in his stomach tens of thousands of valves and several kilometers of copper wire and reached its costs millions Ataratbad it and using semiconductors has been the invention of the transistor which has led to a revolution in the science of electronics and rolled inventions Vtm making different types of transistors and then a new revolution appeared in the science of electronics which integrated circuits where he was able group of scientists to arrange a set of electronic elements on a small slice of semiconductor this was the beginning of the tremendous developments that we see today in all electronic devices which led to the production of very large industries, and coming inventions in Electronics and still Electronics surprise the public every day the news of a massive new
Second, the emergence of Electronics
What a concept electronics
Is the science and technology Almokhtassan studying the transmission of minutes charged in the semiconductor or gas or vacuum material
And all electronic devices relies in its work on the oscillatory electrical currents
Fluctuating currents and produces one of two ways
1 - from vacuum tubes
2 - from transistors
First, vacuum tubes
And it relies in its work on the phenomenon of thermal emission ionic or nonionic emission Althermo
Definition of the phenomenon of emission Althermooaona: - are displayed emission of electrons from the surface of a given metal when raising the temperature
Interpretation of the phenomenon of emission Althermooaona: - Free electrons in the metal near the surface of the nucleus specific card linked caused by the strength of attraction between the negative electrons and positive nucleus
To the electron leaves the surface of the metal is not essential for him to get enough energy to overcome the force of attraction between him and the nucleus. The call that energy on behalf of the job function
Job function: - is the energy consumed by the electron to do the filling to escape from the metal surface
The kinetic energy of the electron and fit directly proportional to the temperature. Therefore the emission Althermooaona happen if the degree of the metal warmed to the point of irritation
The vacuum tube is divided into two types
A) Diode
B) triode
First: -alsmam duo: and it was so named because it consists of two parts Hmaalmassad foundations and cathode
elevator
Airstrip
Heated indirectly using priming
Direct heating
priming
There is elevator and cathode inside the glass bubble deflated
1 - elevator: - a plaque purpose of assembling the electrons emitted from the cathode
2 - runway: - The so-called Wick and its purpose to get electrons. In practical applications of his effort to be in the range of 5 volts
How emitted electrons from the cathode? It is raising the cathode temperature in a certain way Vtaathrr electrons from the cathode material
How it works diode
When heated cathode emits electrons Because LED a vacuum, the electrons move freely inside it and because of the difference in voltage between the elevator and the cathode, the electrons emanating from the cathode gravitate toward the elevator
As diode is used? Diode used in the evaluation of current operations by allowing current to pass in only one direction. So-called valve
Methods of delivery of the diode in the electronic circuits
1 - front Delivery: - in which the cathode connects the negative pole of the power source and connects the elevator under the current Vtntaleg electrons from the cathode and is heading to the elevator and going mainstream
(Connecting Front (current flows
(Rear plug (no current flows
Rear delivery: - and it connects the cathode the positive pole of the power source and the elevator connects the negative pole of the power source Vtaatnavr electrons with the electrons and the elevator goes mainstream
Note from the foregoing that the valve allows the passage of current in only one case, which is to be a positive effort the elevator or in the case of the front delivery only.
What are the uses of diode?
AC calendar
( detection of high-frequency carrier waves (or separation of the carrier wave for mobile
Raising the voltage
?(How to use a diode in the evaluation process of AC (alternating
AC be this way
Intended to evaluate the AC power is making passes in only one direction
(Either positive or negative)
- : There are two types of assessment, namely
the network
landing strip
the elevator
AC before Calendar
Calendar half Moggi
Full calendar Moggi
Calendar half Moggi: This is done using only one valve which allows current to pass through in only the positive part
Calendar full waveform: it is using valves together, where each valve evaluate the half-wave
- : Triode
Diode add a third part called
Network so-called triode
And function of the network is controlled in a number
Electrons up to the elevator
If the grid voltage is positive, the number of electrons that link to the elevator
If the grid voltage is negative fewer electrons up to the elevator
If the grid voltage is zero the number of electrons that link to the elevator has not changed
And the network control effort by connecting source suitable for effort
Network and be closer to the airstrip, including the elevator which weakens the effect of the elevator on the runway and become the network is controlling the passage of electrons so-called ruling network
(One of the main uses triode enlarge (or amplified voltage
And using the following formula for calculating the increase in effort or amplification coefficient
Change in the elevator effort
Amplification coefficient
Changes in the network effort
: Semiconductors
It is nonconducting material stream or weak conduction in normal circumstances
And it supports connecting rigid material for electricity on the Bulk density of electrons
: Definition of Bulk density of electrons
Is the number of free electrons per cubic meter of material
In the conductive material Bulk density of electrons reach 1028 electron / m3 in the insulating material of up Bulk density of electrons 10 7 electron / m3. In the semi-conductor materials are volumetric density between these two figures
Among the most famous semiconductor materials germanium and silicon. As it contains the last energy level has four electrons so connecting every atom with four neighboring atoms have to form covalent bonds between atoms to reach the status of installation of Eight
Featuring semiconductors that reduce the temperature leads to make them non-conductive stream because the electrons become more coherent nucleus. At absolute zero electron correlation nucleus what can be greater and when the increase in temperature to get some of the electrons enough energy to overcome the binding energy and leads to the liberation of the electron moves freely inside the nucleus, leaving behind a vacuum-called gap
How important is the gap? The significance of that gap can be considered as carriers of the stream, such as electrons
And working every gap to attract an electron from another atom gives up this and other new electron gap and so on. The gap can be considered a positive charge moving counterclockwise motion of the electron
To make the semiconducting material conductive material is added to the other semiconducting materials called impurities
Gap
Electron
Impurities are trivalent or pentavalent substances are added
The semiconducting material to make it conductive stream
The most famous triple impurities kinds of aluminum
And boron
Impurities quintet of antimony, arsenic
When you add impurities to a semiconductor consists
- : Two types of conductive crystals are
1 - crystallize conductive positive and made up if we add the flawless trilogy (containing three electrons in the outer level) to the semiconductor material consists of three links covalent bond and remain fourth incomplete where remains positive gap attracts free electrons. Examples include adding impurity of aluminum or boron or germanium to silicon element. The symbol of this type of crystals are indicated by (m p) In this type gaps are considered mainstream carriers
2 - crystallize negative conductive consist If we add flawless pentagonal (containing five electrons in the outer level) to the semiconductor material composed in this case four covalent bonds and remains fifth electron electron plus this be a free electron
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