Electrical engineering

LED is an optical semiconductor device that converts electrical energy into light energy.  Also known as light emitting diode. And it also varies in different colors.       A semiconductor diode that emits light when current flow through it. When electrons in semiconductor recombine with electron wholes than an energy release in form of photon. Light emitting diodes emit either visible light or invisible infrared light when forward biased. The LEDs which emit invisible infrared light are used for remote controls.   LEDs A diagram of the inside of an LED is shown in Figure  The chip at the heart of the LED consists of a p-n junction --- two different solid materials that have been joined together. It is surrounded by a transparent, hard plastic that protects the LED from vibration and shock. The LED is constructed in such a way that the light emitted by the chip is reflected off the base it sits on and i...

Capacitor is an electrical component in which we store Electrical energy electric field. A capacitor behavior like a battery for little bit time. It's unit is FARAD, and it represented by F. It consists of two parallel plates separated by an insulating material called the dielectric • In the neutral state, both plates have an equal  number of free electrons • When a voltage source is connected to the  capacitor, electrons are removed from one plate and an equal number are deposited on the other plate • No electrons flow through the dielectric (insulator) Capacitance of capacitor : The capacitance of a capacitor -- how many farads it has -- depends on how it's constructed. More capacitance requires a larger capacitor. Plates with more overlapping surface area provide more capacitance, while more distance between the plates means less capacitance. The material of the dielectric even has an effect on how many farads a cap has. The total c...

It's Electronic device in which we measure current in amperes (A)in close Circuit. It is connected in series with circuit. The effective resistance of ammeter is low The Resistance of an ammeter is zero. A moving coil of galvanometer is converted in to an ammeter by connected a suitable low resistance in parallel to it. Circuit must be disconnected in order to attach the ammeter. Ammeter considered as less accurate value. Type of ammeter There are 7 type of ammeter. 1.Moving coil  2-Moving magnet  3-Electrodynamic  4-Moving iron  5-Hot wire  6-Digital  7-Integrating Moving coil ammeter:                                   The D'Arsonval galvanometer is a moving coil ammeter. It uses magnetic deflection, where current passing through a coil causes the coil to move in a magnetic field. The modern form of this instrument was devel...

Single phase Energy meter    Single phase induction type energy meter is also popularly known as watt-hour meter. This name is given to it. This article is only focused about its constructional features and its working. Induction type energy meter essentially consists of following components:   1. Driving system  2. Moving system  3. Braking system and  4. Registering system   Driving system                            It consists of two electromagnets, called “shunt” magnet and “series” magnet, of laminated construction. A coil having large number of turns of fine wire is wound on the middle limb of the shunt magnet.   This coil is known as “pressure or voltage” coil and is connected across the supply mains. This voltage coil has many turns and is arranged to be as highly inductive as possible. In other words, the voltage coil produces a hig...

  DC  Circuits:   Prerequisites:                                    A  DC  circuit  (Direct  Current  circuit)  is  an  electrical  circuit  that  consists  of  any     combination  of  constant  voltage  sources,  constant  current  sources,  and  resistors.  In  this  case, the  circuit  voltages  and  currents  are  constant,  i.e.,  independent  of  time.  More  technically, a  DC  circuit  has  no  memory.  That  is,  a  particular  circuit  voltage  or  current  does  not  depend on  the  past  value  of  any  circuit  voltage  or  current.  This...

Voltage : -                            Voltage  is  electric  potential  energy  per  unit  charge,  measured  in  joules  per coulomb.  It  is  often  referred  to  as  "electric  potential",  which  then  must  be  distinguished  from electric  potential  energy  by  noting  that  the  "potential"  is  a  "per-unit-charge"  quantity.  Like mechanical  potential  energy,  the  zero  of  potential  can  be  chosen  at  any  point,  so  the  difference in  voltage  is  the  quantity  which  is  physically  meaningful.  The  difference  in  voltage  measured when  moving  from  poi...

Resistors  are one of the basic building blocks of electrical circuits.  Resistance occurs in  all materials, but resistors  are discrete components manufactured  to create an exact amount of intended resistance in a circuit.   Resistors are made of a mixture  of clay and carbon, so they are part conductor part insulator.   Because of this, they conduct electricity, but only with a set amount of resistance added.   The value of the resistance is carefully controlled.  Most resistors have four  color bands. The first band reveals the first digit of the value.  The second band reveals the second digit of the value.  The third band is used to multiply the value digits.  The fourth band  tells the tolerance of  the accuracy of the total value.  If no fourth band is present, it is assumed that the tolerance is plus or minus 20%.  Resistance color code Here are the ...

The Current is flow of Electric charge Carrier in which we can harness to do work.  Current is the rate at which charge is flowing. Electric charge also known as electron. There is two type of current : 1. DC current. (Direct current) 2. AC current. ( Alternating current) 1. Direct current                       In  Dc Current flow of Electric charge in one direction. It is steady state of constant voltage circuit. 2. Alternating current                         In  Alternating current  ( AC ) is the flow of electric charge that periodically reverses direction.    

                            Diode Diode is a two- terminal   electronic component  that conducts  current  primarily in one direction. it has low (ideally zero)  resistance  in one direction, and high (ideally infinite)  Resistance  in the other. A diode  vacuum tube  or  thermionic diode  is a vacuum tube with two  electrodes , a heated  cathode  and a  plate , in which electrons can flow in only one direction, from cathode to plate. A  semiconductor diode , the most commonly used type today, is a  crystalline  piece of  semiconductor  material with a  p–n junction  connected to two electrical terminals.Semiconductor diodes were the first  semiconductor electronic devices . The discovery of asymmetric electrical conduction across the contact between a crystalline mineral and a metal was made by Ge...

AC Instantaneous  and  RMS Value:  Instantaneous  Value:                   The  Instantaneous  value  of  an  alternating  voltage  or  current  is  the  value  of  voltage  or current  at  one  particular  instant.  The  value  may  be  zero  if  the  particular  instant  is  the  time  in  the cycle  at  which  the  polarity  of  the  voltage  is  changing.  It  may  also  be  the  same  as  the  peak  value, if  the  selected  instant  is  the  time  in  the  cycle  at  which  the  voltage  or  current  stops  increasing  and starts  decreasing.  There  a...

AC Circuits :.                              Prerequisites:   An  alternating  current  (AC)  is  an  electrical  current,  where  the  magnitude  of  the current  varies  in  a  cyclical  form,  as  opposed  to  direct  current,  where  the  polarity  of  the  current stays  constant. The usual  waveform  of  an  AC  circuit  is  generally  that  of  a  sine  wave,  as  this  results  in the  most  efficient  transmission  of  energy.  However  in  certain  applications  different  waveforms are  used,  such  as  triangular  or  square  waves. Introduction :  Used  ge...