FUNDAMENTALS OF ELECTRONICS
 
 
 
ELECTRONICS
Electronics is the branch of physics which deals with development of electron-emitting devices, there use and control of electron flow in electrical circuits. Electronics also deals with semiconductors, diode, rectifiers etc.
p-TYPE SUBSTANCE
If a trivalent element from the IIIrd group such as Gallium (Ga) or Indium (In) is added to pure crystals of germanium (Ge) or silicone (Si), three electrons of impurity form covalent bonds with three atoms of (Ge) or (Si), while there exist a vacancy for an electron in the fourth bond. This vacant space is called Hole. This hole behaves like a positive charge and can move in the structure of substance. Such a substance is called a p-type substance.
n-TYPE SUBSTANCE
  If a pentavalent element from the Vth Group such as Antimony (Sb) is added to pure geranium (Ge) or silicone (Si), then four electrons of (Sb) will form covalent bonds with four (Ge) or (Si) atoms. The fifth electron of 'Sb' is free to move which makes (Ge) or (Si) a good conductor. This type of material is called n-type substance.
RECTIFIER
A rectifier is a device which is used to convert alternating current (AC) into direct current (DC).
PN-junction diode is used as a rectifier.
RECTIFICATION
The process of converting alternating current into direct current is called rectification.
FORWARD BIASING
when n-type end of pn-junction is connected to negative terminal and p-type end with positive terminal of a (DC) supply, then the height of potential barrier reduces and provides easy flow of electric charge that is pn-junction conducts electricity. In this condition pn-junction is said to be Forward Biased.
REVERSE BIASING
When p-type end of pn-junction is connected to the negative terminal and n-type end with positive terminal of a (DC) supply. The height of potential barrier increases to maximum and the flow of electric charge across the junction will become zero. In this condition a pn-junction diode is called Reverse Biasing.
DOPING
 
Addition of an element of group IIIrd-A or Vth-A to Ge or Si crystals to convert them into semiconductor substance (p-type or n-type) is called Doping. Normally impurity is in very small quantity. There are two types of impurities that are added to geranium or silicon:
DONOR IMPURITY
ACCEPTOR IMPURITY
|PHOTOSHOP|FLASH|SWISH|FLAX|INTERNET|PHYSICS|CHEMISTRY|HOME|