Ideal and practical current sources are concepts used in electrical engineering to describe two different types of current sources with varying levels of realism and accuracy in modeling real-world behavior.
Ideal Current Source:
An ideal current source is a theoretical concept used to simplify calculations and analysis in circuit design. It is characterized by providing a constant current regardless of the voltage across it or the load it is driving. In other words, it maintains a fixed current output regardless of the connected circuit elements. Mathematically, an ideal current source is represented by the symbol "I" with an arrow pointing away from it.
Key characteristics of an ideal current source:
It provides a constant current, irrespective of the circuit conditions.
It has infinite internal impedance, meaning it does not drop any voltage across it.
The voltage across its terminals can vary without affecting the output current.
Practical Current Source:
A practical current source takes into account the limitations and real-world behavior of actual current sources. In reality, it's not always possible to achieve a perfectly constant current output under all circumstances. Various factors such as component tolerances, internal resistance, and load variations contribute to deviations from the ideal behavior.
Key characteristics of a practical current source:
It provides a relatively constant current within certain operating conditions but might exhibit variations under certain circumstances.
It has a finite internal impedance or output resistance that can cause voltage drops across the source itself.
The output current may be affected by changes in the load resistance or variations in the power supply voltage.
In summary, the main difference between ideal and practical current sources lies in their level of realism and accuracy in representing real-world behavior. Ideal current sources are theoretical constructs that provide a constant current output regardless of the surrounding conditions, while practical current sources account for real-world factors and might exhibit some deviations from the ideal behavior.