Different types of sources.
Sources are classified as Independent sources and Dependent sources.
Independent sources are further classified as voltage sources and current sources.
Dependent sources are further classified as
- Voltage controlled voltage source
- Voltage controlled current source
- Current controlled voltage source
- Current controlled current source
Independent ideal voltage source:
In an ideal voltage source, we have the internal resistance as zero whereas practically we do have some internal resistance.
The ideal voltage source acts as shown in the graph.
In this circuit, we have a variable resistor where when we change the resistance value we get the constant voltage with the change in the load current.
When the resistance changes, the load voltage remains constant. Hence the load voltage does not depend on the load current.
As the resistance increases current decreases and still the voltage remains constant as VL = VS
Here we have load voltage is equal to the source voltage.
Practical Voltage Source:
In a practical voltage source, we do have some internal resistance as shown in the circuit. Here the load voltage depends on the load current as we have one resistor added up in the circuit.
Here the load voltage depends on the load current.
Ideal current source:
In an ideal current source, the load current does not depend on the load voltage.
Whenever the resistance changes, the load voltage increases respectively but the load current remains constant.
This can be seen in the graph shown below.
Practical current source:
In a current source, we have internal resistance in parallel with the current source.
Here the load current depends on the load voltage as the current divides in the parallel circuit.
As per the current division rule, we can easily find out the load current. Whereas when the load resistance changes the load voltage increases and hence the load current decreases as shown in the graph.