Re: [Help-gnucap] AC circuit analysis

[al davis]

On Monday 01 May 2006 13:17, Evgeni Dobrev wrote:
> I have the following circuit:
>
> AC VOLTAGE ADDITION
> v1 1 0 ac 15 0 sin
> v2 2 1 ac 12 35 sin
> v3 3 2 ac 22 -64 sin
> r1 3 0 10k
>
> The list command in gnucap results in:
>
> V1  1  0  SIN  offset= 0.  amplitude= 1.  frequency= NA 
> delay= 0. damping= 0.  AC   0.
> V2  2  1  SIN  offset= 0.  amplitude= 1.  frequency= NA 
> delay= 0. damping= 0.  AC   35.
> V3  3  2  SIN  offset= 0.  amplitude= 1.  frequency= NA 
> delay= 0. damping= 0.  AC  -64.
> R1  3  0  10.K
>
> Why can't I see the phase offsets?

The syntax   AC mag phase .. doesn't work in gnucap.
 
To work around it, explicitly specify the phase:

v1 1 0 ac 15 phase=0
v2 2 1 ac 12 phase=35

There's another difference in the printouts:
Gnucap prints phase in degrees by default.
Spice prints phase in radians.

If you want gnucap to print phase in radians (to match spice) 
use the statement ".option phase=radians".

It still reads phase in degrees.

Spice reads phase in degrees, but prints phase in radians.


Also ...

That "sin" suffix doesn't do anything for AC.  It is only for 
transient analysis.

Trying to get exact spice compatibility is a real pain.  
First, "which Spice??".  Then it seems that any extension 
breaks something.