4
\$\begingroup\$

How do I measure the characteristics of a voltage divider in QUCS?

Below is what I have tried thus far, using Qucs 0.0.15 on Ubuntu 10.04

I want to measure how the voltage at the center of a voltage divider changes based on R2 in the schematic below. I am attempting to simulate this in QUCS using a DC simulation and a parameter sweep.

This is how I have it set up below, but the output is constant from what I can tell, which does not make sense.

schematic

graph setup tabular output

\$\endgroup\$
4
\$\begingroup\$

Like SPICE simulators there's a difference between simulation parameters and reference designators.

Here, the reference designator for the lower resistor is R2. The R value of R2 is always 50 ohms. To use a parameter, you must assign it to the parameter name surrounded by curly braces. So the R value of resistor R2 should be {R2} to have resistor R2's R value set to the parameter R2.

To make things a bit more clear, change the parameter sweep param to RLOW and the value of R2 to {RLOW}. The simulation should work as expected and you'll get the correct results (yeah, I realize that my voltage source isn't at the same level as the OP so the actual values will be different).

schematic

results

\$\endgroup\$
  • \$\begingroup\$ Bless you! That worked wonderfully. \$\endgroup\$ – JonnyRo Mar 15 '13 at 5:49
  • \$\begingroup\$ Stack exchange is the coolest system out there! \$\endgroup\$ – JonnyRo Mar 15 '13 at 5:50
  • \$\begingroup\$ I don't think you need the curly brackets in QUCS \$\endgroup\$ – endolith Aug 28 '15 at 19:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.