The Design And Construction Of 2kva Inverter

THE BASE: This is the lead responsible to activate the transistor
THE COLLECTOR: This is the positive lead
THE EMITTER: It is the negative lead of the transistor
The PNP transistor is the exact opposite of the NPN transistor. Also all the polarities for a PNP transistor are reversed which means that it “sinks” current into its bas as opposed to the NPN transistor which source current through it base.
The main difference between the two types of transistor is that holes are majority carriers for PNP transistors while electrons are the majority carries NPN transistors.
There are two main categories of transistor:
1.    Bipolar junction transistor (BJT): it also divided into NPN and PNP transistors.
2.    Field effect transistor (FET): it has three terminal unipolar solid state device in which current is controlled by an electric field as is done in vaccum tubes (http://www.amplifieredparts.com/2017/05/27 product/transistor.tip416-npn-epitaxial-transistors).
There are two types of FETs.
a.    Junction field effect transistor (JFET)
Metal-oxide semi-conductor field effect transistor (MOSFET) is also called insulated gate FET(IGET). MOSFET require very careful handling particularly when out of circuit. In circuit a MOSFET is as rugged as any other solid-state device of similar construction and size.
 It is essential not to permit any stray or static voltage on the gate otherwise the ultra-thin siO2 layer between the channel and the gate will get ruptured. Since the gate-channel junction looks like a capacitor with extremely high resistance. It requires only a few electrons to produce high voltage across it. Generally, grounding rings are used to short all leads of a MOSFET for avoiding any voltage build up between them. These grounding or shorting rings are removed after between them. These grounding or shoring rings are removed after MOSFET is securely wired into the circuit. Sometimes, conducting foam is applied between the leads instead of using shorting rings. Some MOSFET have back-to-back zener diodes internally formed to protect them against stray voltage. (Tharaja B.L (1997), A test book of electrical technology, (23rd Edition), S. Chand & company Ltd. Ram Nagar, New Delhi). These MOSFET can be further sub-divided into: FET (IGET)
i.    Deflection-enhanced MOSFET (DEMOSFET)
ii.    Enhancement only MOSFET (DEMOSFET)
ADVANTAGE OF FET OVER BJT   
i.    FET has high input impendence
ii.    FET has loss noisy compared to BJT
iii.    It’s smaller in connection
iv.    FET is les affect by radiation
v.    It is bipoler transistor