current unavailable in simulation

[Ridis]

In the schematic included when I try to simulate with

menu Simulate -> Analyses -> Transient Analisys
a window [Transient Analisys] opens  -> Output tag

1) I don't see the current flowing through R3 e C1. Why ? 

2) I see I(V1) and I(L1) that's the same current.

[yyao]

Hi Ridis,

By default, Multisim (and other SPICE simulators) keep track of only the essential device state variables to save memory. As you know, we tend to think of voltage as the state variable for capacitors and current as the state variable for inductors. This is why by default, you see I(L1) but not I(C1).

None the less, you can still view the current through any component by doing the following:

1 - In Multisim, click Simulate -> Analyses -> Transient Analisys

2 - Click the Output tab

3 - Click the Add device/model parameter

4 - Make sure Device Parameter is selected under Parameter Type

5 - Select your component of interest by selecting the right option under the Device Type and Name fields (e.g. Capacitor and C1)

6 - Under Parameter, select i (current)

7 - You will see I(c1[i]) under your Variables in Circuit list

8 - You can now add I(c1[i]) to your analysis list and plot it like any other variable

Message Edited by yyao on 12-03-2008 08:57 AM

[Ridis · Accepted solution]

Thanks for your detailed description. I tried and it works but I suggest to make easier adding a variable.

A way could be making two lists: one of "primary" variables that we have now already available.

The second list with all the rest of the voltages and currents in every part of the circuit.

[yyao]

Thank you for your suggestion. We will consider implementing it in the future.