Electrical Energy Sources

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Energy sources:

Basic types:

1.       Voltage source:
-          Energy source which gives voltage across its terminals.
-          Ideal voltage source is the energy source which gives constant voltage across its terminals irrespective of the current drawn through its terminals
-          In practical, due to small internal resistance of the voltage source, voltage is dependent on the load.

2.       Current source:
-          Energy sources which gives current across its terminals.
-          Ideal current source is the energy source which gives constant current across its terminals irrespective of the voltage appearing its terminals
-          In practical, every current will have a high internal resistance.

Based upon the dependency, energy sources are classified as:

1.       Independent sources:
-          The value of the energy source is independent on all other characteristics of the circuit.

2.       Dependent sources:
-          Value of the energy source is dependent on the voltage or current elsewhere in the circuit.
a)      Voltage dependent voltage source (VDVS):
§  Provides voltage as a function of voltages elsewhere in the circuit.
b)      Current dependent current source (CDCS):
§  Provides current as a function of current elsewhere in the circuit.
c)       Current dependent voltage source (CDVS):
§  Provides voltage as a function of current elsewhere in the circuit.
d)      Voltage dependent current source (VDCS):
§  Provides current as a function of voltage elsewhere in the circuit.


Note: Four terminals are required to define a controlled source/dependent source whereas two terminals are enough to define a uncontrolled source/independent source.

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