Independent Source and Dependent Source

Today we discuss about Sources, Electrical Sources.

Electrical Source: who provides enrgy to do some workdone.
There are two type of sources.
¡) Independent Source
¡¡) dependent source

Independent Source:  Those Voltage or current source, which do not depend on any other quantity in the circuit.

Dependent Source: a dependent voltage or current source is one which depends on some other quantity in the circuit which may be either a current or voltage source. It is represented by diamond-shaped symbol to avoid confusion with independent source.
4 possible dependent sources are-
   A) Voltage dependent Voltage source/ Voltage controlled Voltage source[ VCVS]
   B) Voltage controlled Current source
   C) Current controlled Voltage source
   D) Current controlled Current source

Independent sources exist as a battery, a dc generator and an alternator etc. And you know little or more about that.
But dependent sources are parts of models that are used to represent electrical properties of electronic devices such as operational amplifiers and transistors etc.
example of dependent sources are operational amplifiers, BJT ,MOSFETs, Voltage and Current regulator , Piezoelectric device etc.

VCVS- A dependent source depends on an input to determine output. For example, A vcvs's input tells it what the output should be.
Gain is Vout/Vin. If gain=1
Vout= Vin

VCCS- here gain= I(out)/ V(in).
vcvs has a constant of propotionality called transconductance(gm).
Unit is Siemens.

CCVS- here gain= V(out)/ I(in)
Unit is Ohn. ccvs has a constant of propotionality called trans resistance.

CCCS- has a constant of propotionality called Current gain.
gain = I(out)/ I(in).