Simulation Error in Circuit Lab with 2 Dependent Sources

Question

^{simulate this circuit – Schematic created using CircuitLab}

I'm practicing some problems and came across this circuit. It asks for the Thevenin equivalent with respect to terminals A and B. I solved it by hand and have the correct answer and also verified it in the back of the book.

I wanted to simulate it in Circuit Lab to verify the results but I keep getting a simulation error.

The text says:

Error building graph: TypeError: Cannot read property 'u' of undefined
Simulations will not run and values will not be displayed, until you return to Build mode and fix these errors.

Is there something blatant that I'm missing? I've attached a picture of the circuit in the text book.

Answer 1

(CircuitLab developer here.) Sorry for the cryptic error message. On CCCS1, you're specifying the control current as R5 when it should be R5.nA. With this change, the simulation runs:

^{simulate this circuit – Schematic created using CircuitLab}

The .nA suffix is needed to uniquely specify the current going into a particular terminal of resistor R5. In this case, as drawn, it's the terminal on the left, so R5.nA picks up the current flowing left-to-right through R5, which matches your book's labeling for \$i_b\$.

See also Labeling Voltages, Currents, and Nodes (specifically the "Terminal Voltages and Currents" heading). And many more working CircuitLab examples with dependent sources on Dependent (Controlled) Sources and Dependent Source Feedback.