RC charge not working

[c_bauer]

Hi!

For some rason, I cannot get Multisim to show the capacitor voltage as it increases exponentially over time.

The time constant R*C is 100us but the scope shows "u_c" to be at 5V from the very start. No exponential rise...

I attached the simulation if somebody wants to take a closer look (Multisim 12 Power pro).

Thank you!

Chris

[c_bauer]

Interestingly, NI has a knowledgebase entry "How do I see the charging of a capacitor" at

http://digital.ni.com/public.nsf/allkb/030CDBEF18515D6486257199006AEF56

that discusses the changes to Multisim to make it simulate the cap charging.

Unfortunately, I get the same result as before.

As an aside, the release notes say I can run Multisim v12 on WinXp, Vista and Win7 x64 (I have Win10 x64). Still, everything else has worked OK so far.

I don't know what else to look at.

best,

Chris

[vlad3156]

In the simulation menu, set the option "Set to zero"

[c_bauer · Accepted solution]

Thanks Vlad!

I re-checked all settings I might have changed and there it was: I had deliberately set

a short circuit to the series resistor but forgot to undo that (double-click on a component, tab "Fault"). Obviously, without the resistor in effect, the upper node of the cap would immediately carry 5V no matter what.

So the only change needed is to apply the option "Set to zero".

Chris