Voltage Controlled Current Source (VCCS)


Here is a circuit that contains a Voltage Controlled Current Source (VCCS). The gain of the VCCS can be changed using the scrollbar.


When the gain of the VCCS is equal to 0.25 A/V this is the circuit considered in problem P2.7-2 of Introduction to Electric Circuits, 7e by R.C. Dorf and J.A. Svoboda. In problem P2.7-2 the gain of the VCCS is denoted by the symbol g. Then

Ia = g * Vb

where g is the gain of the dependent source. Notice that the units of g are A/V. The current Ia, in Amps, and voltage Vb, in Volts, are measured using the voltmeter and ammeter. Thus the gain of the dependent source can be determined from the meter readings.

In this circuit

Vb = Vs* R2 / ( R1 + R2 )

where R1 = 50 Ohms, R2 = 25 Ohms and Vs = 24 V. (See, for example, Section 3.3 of Introduction to Electric Circuits, 7e.) Thus

Vb = 8 V

regardless of the value of the gain of the VCCS.



Challenges:

  1. Set the gain of the VCCS equal to 0.25 A/V to check the answer to problem P2.7-2.

  2. Determine the gain of the VCCS required to cause Ia = 6 A. Verify that the meter readings are consistent with the gain of the dependent source.

  3. Predict the value of Ia when the gain of the VCCS is 7.5 A/A. Check your prediction using the scrollbars.

  4. Predict the gain of the VCCS that will cause Ia = 5 A. Check your prediction using the scrollbars.