Diode

It is an electronic component .Before many years ago ,vacuum tube diode and transistor ,mercury arc values are used in many electronic devices.But they are in bigger in size,very difficult to manufacture and to make the electronics devices ,costly .So it can not be used in protable electronic devices ,it is not so efficient then solid state semiconductor devices .
When solid state semiconductor was invented then there are huge revolution in electronics and communications field because of their smallest in size ,very highly efficient ,easy to manufacture of it and very low cast . So it has wide range of application in this field and become very popular . It make help to invent the transistor and integrate circuit .

They are many type of diode but we are discussed only followings type of diode which are made by silicon and Germanium.

1. Normal diode
2. Zener diode
3. Light emitting diode(LED)
4. Power diode
5. Shocklcy diode
6. Photo diode
7. Varactor diode
8. Optocopler diode
   

Normal diode is used in mainly in rectifier circuits ,signal trapper circuits , power section etc. It conduct only one direction i.e from positive polarities to negative polarities.So it is work in forward bias connection .If it is connected in reverse bias system it may be damage.Silicon diode has 0.3 V breakdown voltage where as Germanium has 0.7 V. After this breakdown voltage it conduct the signal.

Zener diode component only work in reverse bias connection.It is used mostly in voltage regulator , inductor or coil protect circuits ,power section of electronics devices.It allow to pass constant voltage in regulator .After breakdown voltage it is ready to conduct or pass the constant voltage . Most of all electronics devices work in constant range of input power or voltage so is help for this purpose and become popular in this field .

Light emitting diode ,it beautiful diode components .It is work in forward bias connection.This type of diode is not made by Silicon andGermanium but by Galium ,Arsenic,phosphorus etc.Above those silicon and germanium diode change current in to heat But this diode change into light .Colour of light is depends upon the combination of elements in proper quantity.It is very usefully in lightnings system in required places.

Power diode ,it is used in power electronics equipment ,where high power is used .If other diode is used it can be damage so it is used in high power equipment and electrical equipments.It contain heat sink which observe the heat produce in this component.

Shocklcy diode,it is named by inventer.this is PNPN diode of two terminals diode .It is used in switching circuit.It consists of four layer of P- type and N-type of semiconductor in alternate ways.

Photo diode, this type of diode work in reverse -bias connection .It conduct reverse current when it is exposed in the light.

Varactar diode, this is act as variable capacitor by its PN junction in reverse bias.

Optocupler diode, it is combination of LED and Photo diode in one crystal.