Summary of Power and Dependent Sources
The article explains how to calculate the power absorbed by a Voltage-Controlled Voltage Source (VCVS). It determines the controlling voltage $v_c$ across a 2-ohm resistor as 2V, resulting in a controlled source voltage of 4V. With a current of 1.5A flowing through the source, the total power absorbed is calculated as 6W using the passive convention.
Parts used in the VCVS Power Calculation:
- Open circuit
- Controlled-voltage source
- 2 ohm resistor
- 4 ohm resistor
Determine the power absorbed by the VCVS in the figure. Solution: The VCVS consists of an open circuit and a controlled-voltage source. There is no current in the open circuit,
so no power is absorbed by the open circuit. The voltage vc across the open circuit is the controlling signal of the VCVS. The voltage Vc (across 2 ohm resisitor) measures vc to be vc = 2V. The voltage of the controlled voltage source is vd = 2 vc = 4V. The current in the controlled voltage source is 6V/4 ohm= 1.5A. The element current id and voltage vd adhere to the passive convention. Therefore, p = id*vd = (1.5)(4) = 6W is the power absorbed by the VCVS.
For more detail: Power and Dependent Sources
- What is the voltage vc across the open circuit?
The voltage vc measures 2V. - How is the voltage of the controlled voltage source determined?
The voltage vd equals 2 times vc, which results in 4V. - What is the current flowing in the controlled voltage source?
The current is calculated as 6V divided by 4 ohms, equaling 1.5A. - Does the open circuit absorb any power?
No, there is no current in the open circuit so it absorbs no power. - Why does the element current and voltage adhere to the passive convention?
This adherence allows the calculation p = id*vd to determine the absorbed power. - What is the final power absorbed by the VCVS?
The power absorbed is 6W. - Which component acts as the controlling signal for the VCVS?
The voltage vc across the open circuit serves as the controlling signal.
