--- In LTspice@..., Arnold Esper <arnold.esper@n...>
wrote:
Thanks to Helmut for the hints to making model-libs and coverting
plain Spice-
Ascii text.
I encounterd problems with the model of the vacuum tube 12AX7
below. Apart from
being rather far from reality, this model seems to produce
convergence problems.
Hello Arnold,
I tried your example also without luck. The next step you normally
would do is testing the transfer function I_A(Ugk).
Ok, I did it for you. The gain was a factor of 1000 to less. I
remembered something with '^' and '**' for the power operator. After
some trial and error I came to the conclusion that LTSPICE has been
guilty for the wrong result.
Hello Mike,
why doesn't LTSPICE follow SPICE3 syntax with the '^' power operator.
LTSPICE only accepts '**' for the power operator. If I tried '^' for
the power, the result seems to be always 1.
Now Arnold, it is clear would you have to do. Replace any '^'
with '**' in all your models. I tested it already with the **
operator and it is then ok.
Example:
BLIM LI 0 V=(URAMP(V(A)-V(K))^1.5 )* 1.6e-5
BLIM LI 0 V=(URAMP(V(A)-V(K))**1.5 )* 1.6e-5
Best Regards
Helmut
