ELECTRONICS KERALAM

Sunday, July 31, 2011

ബേസിക് ഇലക്ട്രോണിക്സ്





കാസര്‍ഗോട് ജില്ലയിലെ ബദിയടുക്കയിലുള്ള ക്രിഷ്ണകുമാര്‍ ലോകത്തിലെ ഏറ്റവും

ചെറിയ ഫിലിം ക്യാമറ നിര്‍മ്മിച്ച് ശ്രദ്ദേയനായ വിവരം അറിഞ്ഞിരിക്കുമല്ലോ. ബഹു

മുഖപ്രതിഭയായ ഈ ചെറുപ്പക്കാരന്‍ ഇലക്ട്രോണിക്സിലും അതീവ തല്‍പ്പരനാണ് .

ക്രിഷ്ണകുമാറിന്റെ വെബ് സൈറ്റിലെ ബേസിക് ഇലക്ട്രോണിക്സ് പാഠങ്ങള്‍ കാണൂ

Electronics deals with electrical circuit with companents like ICs,Transistor, Capasitor, Resistor..
.which conected by wires or traces through which electric current can flow. The combination

of companents trought connector allows various simple and complex operation like
amplification, computaton, data tranformation etc can be performed, they are catageriesed as
Analog, Digital and Mixed signal types of circuits.
The Basic Electronic Companents
Resistors
A resistor is a two-terminal passive electronic component which "resist" the flow of electrical
current with in it . Resistors are color coded, and resistance are calculated based on the color
rings on it. Their measuring unit is Ohms.

From the above Resisitor
Resistance is 5(Green)/1(Brown)/0(Black)/00(Red-Value is 2 so Two Zeros)
51000ohms
ie, 51Kohms
Flow of current I as given by (Ohm's law) I=V/R Ohms
I-Current, V-applied Voltage and R-resistance of resistor.
Other types of Resistors are Carbon Composition, Metal Oxide Film, Precision Metal Film,
Foil Resistors, Filament Resistors, Power Film, Precision Wire Wound, High Power Wire
Wound, Photoresistors and Thermistors Variable Resistors.

Capacitors
Is a device used to store charge in an electrical circuit. A basic capacitor is made up of two
conductors separated by an insulator, or dielectric. The dielectric can be made of paper, plastic,
mica, ceramic, glass, a vacuum or any other nonconductive material. They are measured in Farads.

One Farad = 6,280,000,000,000,000,000
Capacitors usually measured in microfarads (uF = 0.000,001F) and
picofarads (pF = 0.000,000,000,001F ).
C = t/[(Vo/V)R], in Farad
Initial Voltage, Vo = voltage of power source, in Volt
Resistance, R = Resistance of the resistor used, in ohm
Final voltage, V = voltage reference, in Volt
Time taken, t = The time when the stopwatch stop counting, in seconds
Electrolytic, Ceramic, Mylar, Mica, Variable Capacitors are other kind of Capacitors.

Transistors
Is a semiconductor and are used amplify current or electronic signal and may be used as a switch
Using a small amount of electricity to control a gate on a much larger supply of electricity,
It having least three terminals for connection to an external circuit. there are two main types;
NPN and PNP.


The Junction Transistor , A Bipolar Junction Transistor ( BJT) is an active
semiconductor device formed by two P-N junctions whose function is amplification of
an electric current and are made from 3 sections of semiconductor material , with 2
resulting P-N junctions.
The Field-Effect Transistor the function is similar to bipolar transistors but there are a
few differences. They have 3 terminals. Two general types of FETs are the 'N' channel and
the 'P' channel MOSFETs.

Diodes
Diode or semiconductor Diode is a two-terminal electronic component that conducts electric current in only one direction while blocking current in the opposite direction. The arrow of the circuit symbol shows the direction in which the current can flow. It used to convert alternating current to direct current, and to extract modulation from radio signals in radio receivers.
Other Diodes - LED- emit light when an electric current passes through them Laser Diode, Schottky Diodes, Zener diode, Photodiode, Varicap Diode or Varactor Diode, Rectifier Diode.

ICs
They are an entire electrical circuit with numerous transistors, wires, and other electrical devices which etched onto a square chips of silicon semiconductor . The pins are numbered anti-clockwise around the IC and starting near the notch or dot.
There are Analog (or linear) which are used as amplifiers, timers and oscillators, Digital (or logic) which are used in microprocessors and memories and Some ICs are combinations of both analog and digital.

Relays
A relay is an electrically operated switch, some relays works based on electromagnetism, current flowing through the coil of the relay creates a magnetic field, which attracts a lever and changes the switch contacts. Relays are used where it is necessary to control a circuit by a low-power signal or where several circuits must be controlled by one signal.
The relays switch connections: COM= Common, NC = Normally Closed and NO= Normally Open

Inductors
Made from a copper wire, when current flowing through these coil ( inductor) creates a magnetic field which transmit and measure current in relation to the amount of voltage applied, electromagnets store and release an electrical current, Inductors are commonly used in radio frequency applications 





Coupled Inductors: Two coils that are linked by electromagnetic induction called Coupled
inductor. When an alternating current allow to flows through one coil, the coil sets up a
magnetic field which is coupled to the second coil and induces a voltage in that coil.
The phenomenon of one inductor inducing a voltage in another inductor is known as
mutual inductance.
Multi-Layer Inductors: This particular type of inductor consists of a layered coil,
wound multiple times around the core. As a result of the multiple layers and the insulation
between them, multi-layer inductors have a high inductance level.
Ceramic Core Inductors: Is unique in having a dielectric ceramic core, meaning
it cannot store a lot of energy but has very low distortion and hysteresis.
Molded Inductors: These inductors are molded using plastic or ceramic insulation

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