Re: [Help-gnucap] Problems with C charge ¿?

[al davis]

On Wednesday 27 August 2008, Jesus Genicio wrote:
> The problem is thath the gnucap make analysis without
> "power-on" period, ¿it is ok?.

I understand now.

"uic" completely skips the initial DC analysis, just like 
the "uic" option in Spice.  Often it leads to nonsense results, 
so I do not recommend it.

The way to see the power on transient is to, like 
Jacques said, to adapt your voltage sources. 

To see an example of where I did this, look at the example on 
our wiki "Phase Shift Oscillator".  

http://wiki.gnucap.org/dokuwiki/doku.php?id=gnucap:phase_shift_oscillator

I used a "pulse" source, but this is not the only way.  
The "fit" source that Jacques recommended works too.

That example ultimately measures the oscillating frequency and 
distortion of an oscillator.  To get there, it also models the 
start-up behavior.  In this case, the oscillator doesn't start 
oscillating until about 1 second after power is applied, and 
takes over 5 seconds to stabilize, so we wait 10 seconds to 
make distortion measurements.