The source of electrical energy are classified into two group :
- Voltage source
- Current source
These sources are further classified into two types as:
- Ideal sources
- Practical source
Ideal Voltage Source
An ideal voltages sources are defined as the voltage source which provides a constant terminal voltage across the load for any variation of load current lL or load resistances R.
Practical Voltage Source
It is not possible to get the ideal voltage source producing a strictly constant voltage across its terminals while supplying the current.
Voltage source in series
The two practical voltage sources in series can be combined together to get a single equivalent voltage source.
Voltage sources in parallel
For parallel combinations of two ideal sources, their voltages must be same with the same polarities as V1 =V2
Ideal current sources
An ideal current source is defined as the current source which provides a constant current through the load for any variation of load voltage VL or loads resistance RL.
Practical current Practical
Practically it is impossible to visualize the ideal current source supplying a strictly constant current through the load across terminals a and B.
Current sources series
For series combinations of two ideal current sources, their current must be the same in magnitude and directions.
I1 = I2
practical current sources
The two practical current sources in parallel can be combined together to get a single equivalent current source.