Diode

DIODE

Diode is a passive device.It is a two-terminal semiconductor (rectifying) device tat allows current in one direction and blocks current in the opposite direction. To say it precisely it is an electrical component acting as a one-way valve for current.

Diode has wide range of applications which starts from simple rectifier, clippers,clampers, logic circuits, mixer circuits and it’s application areas go beyond our imagination……

DIODE

diode is a electronic semiconductor device.the first diode is called as cat's whiskers diode,it is developed in the year 1906.which is made up mineral crystals such as galena.generally now a days the diode is made up of semiconductor such as germanium ,silicon etc.
diode is a two terminal electronic semiconductor component .one terminal is cathode and another one is plate.

the common function of diode is used to allow electric current in one direction(forward direction) and also blocks the current flows in the other direction(reverse direction).it is mostly used convert ac(alternating current) to dc(direct current).the unidirectional behaviour of diode is called as rectification.

the another name of semiconductor diode is a schotty diode.

*electronically tune radio and tv reciever is (varactor diode).
*high voltage is protected by the avalanche diode.
*zener diode is used for regulate voltage.

LED-LIGHT EMITTING DIODE

LED LIGHT EMITTING DIODE IS INTRODUCED IN 1962.IT IS A PRACTICAL ELECTRONIC COMPONENT. IN EARLY DAYS IT IS A ONLY LOW DENSITY RED LIGHT IS USED.BUT IN MODERN VERSION USING VISIBLE,ULTRAVIOLET AND INFRARED HIGH WAVELENGTHS,WITH HIGH BRIGHTNESS.LED IS A SEMICONDUCTOR LIGHT SOURCE.WHEN LED IS FORWARD BIASED IT IS SWITCHED ON AND ELECTRONS ARE RECOMBINE WITH HOLES AND PRODUCE IN THE FORM OF PHOTONS THIS EFFECT IS CALLED AS ELECTROLUMINESCENCE.THE COLOR OF LED DEPEND ON THE ENERGY OF THE PHOTON (I.E) ENERGY GAP OF SEMICONDUCTOR.


*IT HAS MORE LIFE TIME
*IT IS RELIABLE

capacitor

capacitor is also known as condensor .it is a passive electronic component, which is used for storing eletric charge .the practical capacitor consits of two conductors seprated by non conductor,it consits of pair of conductors seprated by insulator.when eletric charge flows through this dielectric one plate consits of positive charge and another plate consits of negative charge .

capacitors are widely used for block the dc(direct current) and allow the ac(alternating current) current to pass.for smooth output of resonant circuits capacitors are used.it is stored in electro staticfield.its units in farads

photo resister

A photoresistor or light dependent resistor (LDR) is a resistor whose resistance decreases with increasing incident light intensity. It can also be referred to as a photoconductor.

A photoresistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron (and its hole partner) conduct electricity, thereby lowering resistance

TRANSISTOR

TRANSISTOR are the building block of an electronic device.it has three terminals base,collector,and emmiter these three terminals have the capacity to work in different voltage levels.it is used in our daily life like computers,cellphones and even cars.
Before transistor has been introduced engineers used vaccum tubes and electronic switches to complete a electronic device but these tubes were very large and occupied much space,for getting back from this hurdle transistor is introduced,it is fomed from the basic silicon chip.
TRANSISTOR was first introduced in bell telephone system instead of vacuum tubes to enhance its communication system