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

where g is the gain of the dependent source. Notice that the units of g are A/V. The current I_a, in Amps, and voltage V_b, 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

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

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 I_a = 6 A. Verify that the meter readings are consistent with the gain of the dependent source.

3. Predict the value of I_a 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 I_a = 5 A. Check your prediction using the scrollbars.