Lock vertical axis in LTspice?

Hi,

Spice changing the scale of the axis for every new simulation has become a areal pain in the a** for me. Trying to find input impedances by dividing V/I causes division by zero and the impedance rises to infinity, rescaling the axis to 100's of megaohms instead of 10's of kiloohms. I've hade the same problems when designing filter curves. Spice seems to think i'm interested in a high pass filters response below 100 dB every time i change a resistor value and re-simulate. Well, I'm not, +-18 dB is fine! 

Does anybody know how I can just set the limits once and for all and prevent LTspice from changing them?  ???

Thanks 
/SkunkFunk

Are you closing the simulation pane each time you make a change? Don't. Just change the resistor value and hit run again. Everything should stay as it was in the simulation pane.

gemini86 said:

Are you closing the simulation pane each time you make a change? Don't. Just change the resistor value and hit run again. Everything should stay as it was in the simulation pane.

Click to expand...

I'm not closing any panes, just changing values and clicking run with the graph pane already up. I have also unboxed the "autoranging" button, but I can honestly not notice any differences to when it is selected  ???

+1 here.

Here's the answer, from the horse's mouth (Hemut at the LTSpice forum):

The solution is using plot settings.

Run the simulation. Set the scale.

Plot Settings -> Save Plot settings

Next simulation run.

Plot Settings -> Reload Plot settings

Next simulation run.

Plot Settings -> Reload Plot settings

...

You can set a hot key for "Reload Plot Settings".

It seems several user have set the spacebar as hot key.

OT, but if you want to see a "relationship" or how a diff. component value effects your circuit performance, I find it the eaisest to just .STEP the param(s) and then select the "best fit" ones via the right click menu (iirc, "visible traces").

Definitely more useful display compared to individual runs, if you don't mind to type a command.

Otoh I'm lazy, and never really used "plot settings", but only typed the values in the "range" popup (l-click in the plot pane).

abbey road d enfer said:

Here's the answer, from the horse's mouth (Hemut at the LTSpice forum):

The solution is using plot settings.

Run the simulation. Set the scale.

Plot Settings -> Save Plot settings

Next simulation run.

Plot Settings -> Reload Plot settings

Next simulation run.

Plot Settings -> Reload Plot settings

...

You can set a hot key for "Reload Plot Settings".

It seems several user have set the spacebar as hot key.

Click to expand...

Thank you so much for this!

tv said:

OT, but if you want to see a "relationship" or how a diff. component value effects your circuit performance, I find it the eaisest to just .STEP the param(s) and then select the "best fit" ones via the right click menu (iirc, "visible traces").

Definitely more useful display compared to individual runs, if you don't mind to type a command.

Otoh I'm lazy, and never really used "plot settings", but only typed the values in the "range" popup (l-click in the plot pane).

Click to expand...

For some purposes, like potentiometer travelling or just having one variable parameter I'd agree with you. But this time i was looking at all 7 responses of a switched high pass filter simultaneously, using steps aswell would have made it impossible to distinguish any traces  ;D

You can select which ones to display, so in the end it's still the "cleanest" option I know of.

Hey Y'All

I know this is an old thread, but a similar search brought me here.

And it looks like this answers my question;

"The solution is using plot settings.
Run the simulation. Set the scale.
Plot Settings -> Save Plot settings
Next simulation run."

But, where in the world is said "Plot Settings"?

I'm on LTSpice XVII

JohnR (aka Stagekraft)

Right-click on the plot pane, then you see these menus

Select the plot then :File --> Save Plot Settings or Save Plot Settings As

You don't see these options unless you select the plot.

Cheers

Ian

Ahhh... that's the problem, I wasn't selecting the plot panel...

Got 'er figured out now.

Thanks

stagekraft said:

Ahhh... that's the problem, I wasn't selecting the plot panel...

Got 'er figured out now.

Thanks

Click to expand...

Took me several years to discover that.

Cheers

Ian