Voltage controlled voltage sources: This is a voltage source whose output can be controlled by changing the controlling voltage (Fig.3.11). This is a voltage amplifier if we consider the VCVS to be a box which takes the input as voltage and then at the output generated the amplified voltage. In the figure, 20 will be the gain of voltge amplifier.
Voltage controlled current sources: In case the control variable is voltage and the output of the source is current, it is VCCS. The unit of gain factor (20 in the Fig.3.12) will of siemens. This is transconductance amplifier.
Output current can be modified by changing .
Current controlled voltage sources: shown in figure 3.13.
Current controlled current sources (Fig.3.14: A current amplifier, the gain is current gain (dimensionless, as in voltage amplifier).