Ideal Voltage Sources
An electrical device which can generate prescribed voltage irrespective of the current supplied to other elements is called an ideal voltage source. The ability to provide constant voltage will not be harmed by any other means like heavy load. Since load always destabilizes voltage sources and at full load no source can produce prescribed voltage so ideal voltage sources are imaginary. Ideal voltage sources are not available in real world. We use this idea of Ideal voltage source to make comparison among other voltage sources.
In summary we can say, An ideal voltage source is an electric device which maintains a constant voltage whether we change the load or not, or we can say irrespective of the current flowing throw it. The amount of the current supplied by the source depends on the circuit connected to it.
Ideal Current Sources
An electrical device which can generate prescribed current irrespective of the circuit or other elements connected to it, is called an ideal current source.To maintain a constant current the voltage in the circuit will vary. Thus it will produce arbitrary voltage across its terminals. The figure below shows symbol of ideal current sources.
We can say: An ideal current source maintains a prescribed or constant current irrespective of the circuit connected to it. The circuit connected to the ideal current source determines the voltage generated.
