LT Spice challenge

On Sun, 22 Aug 2021 11:00:46 -0400, legg <legg@nospam.magma.ca> wrote:

>On Sat, 21 Aug 2021 11:24:21 -0700, jlarkin@highlandsniptechnology.com
>wrote:
><snip>
>>>>>>>Sounds like a table, rather than a plot.
>>>>>>
>>>>>>I want a plot.
>>>>>>
>>>>>>LT Spice now has the ADG1208 analog mux. Three of them lets me scan 24
>>>>>>points. I can drive them from a 1 Hz counter or a few pulse
>>>>>>generators.
>>>>>>
>>>>>
>>>>>This topic on the LTspice forum may be addressing your 'challenge':
>>>>>
>>>>>https://groups.io/g/LTspice/topic/measure_voltage_at_periodic/85037428?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,85037428
>>>>>
>>>>>
>>>>>RL
>>>>
>>>>Interesting, but that's not what I want to do.
>>>
>>>Not sure I see it.
>>>
>>>Do you want a visual display similar to a bar spectrun analyser
>>>output?
>>
>>I've explained it. X-axis is node number. Y axis is voltage on each of
>>those nodes. Since node numbers are discrete, it would probably look
>>stairstepped, like a DAC output.
>
All this talk about how LTspice encourages your instincts;

....and here you are wanting to load the poor circuit with 
twenty voltmeters.

RL

On Sun, 22 Aug 2021 11:03:54 -0400, legg <legg@nospam.magma.ca> wrote:

>On Sun, 22 Aug 2021 11:00:46 -0400, legg <legg@nospam.magma.ca> wrote:
>
>>On Sat, 21 Aug 2021 11:24:21 -0700, jlarkin@highlandsniptechnology.com
>>wrote:
>><snip>
>>>>>>>>Sounds like a table, rather than a plot.
>>>>>>>
>>>>>>>I want a plot.
>>>>>>>
>>>>>>>LT Spice now has the ADG1208 analog mux. Three of them lets me scan 24
>>>>>>>points. I can drive them from a 1 Hz counter or a few pulse
>>>>>>>generators.
>>>>>>>
>>>>>>
>>>>>>This topic on the LTspice forum may be addressing your 'challenge':
>>>>>>
>>>>>>https://groups.io/g/LTspice/topic/measure_voltage_at_periodic/85037428?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,85037428
>>>>>>
>>>>>>
>>>>>>RL
>>>>>
>>>>>Interesting, but that's not what I want to do.
>>>>
>>>>Not sure I see it.
>>>>
>>>>Do you want a visual display similar to a bar spectrun analyser
>>>>output?
>>>
>>>I've explained it. X-axis is node number. Y axis is voltage on each of
>>>those nodes. Since node numbers are discrete, it would probably look
>>>stairstepped, like a DAC output.
>>
>All this talk about how LTspice encourages your instincts;
>
>....and here you are wanting to load the poor circuit with 
>twenty voltmeters.
>
>RL

In this case, that graph is what I want to train my instincts.

Spice doesn't care about loading. I sometimes have to force myself to
not care about kilowatt resistor power dissipation, or megavolt
potentials. 



-- 

Father Brown's figure remained quite dark and still; 
but in that instant he had lost his head. His head was
always most valuable when he had lost it.



  

On Thursday, August 19, 2021 at 4:08:23 PM UTC-7, John Larkin wrote:
> Suppose I have a circuit with 20 nodes, N1 ... N20. 
> 
> I want to plot the node voltages, left to right on the screen. 
> 
> Any ideas? 
> 
> Clumsy ways: 
> 
> Build an analog mux and clock it with a counter, plot with time as 
> x-axis 
> 
> Push a pulse into a tapped transmission line to sequence a bunch of 
> switches 
> 
> Export a file and do it in a separate program

I would use python. The script could present a GUI of the output and any input control of the circuit (values, voltages, frequencies, whatever).
Spice can be pretty slow, of course, so the GUI controls wouldn't be "live"; Instead, there would be a "Do it" button to start the cycle:
 * write a file of parameter values for inclusion into the spice model
 * run Spice
 * process the raw file using the ltspice python library
 * plot the nodes of interest. If you're trying to get a "feel" for the transfer functions, plot little trails of the previous runs.

I had a project that required LTSpice to verilog test vectors to Vivado to vcd dump files (vddvcd python library) to final processing (to verify the verilog). 
The GUI would probably take the most time to code. Perhaps just columns of numbers would be ok?

HTH,
Bob

"legg"  wrote in message news:pnp4igh0oujoc5dn6cslfahlmrn5m8h37f@4ax.com... 


>>
>>I've explained it. X-axis is node number. Y axis is voltage on each of
>>those nodes. Since node numbers are discrete, it would probably look
>>stairstepped, like a DAC output.

Rotate your laptop 90 degs.

http://www.anasoft.co.uk/ SuperSpice
http://www.kevinaylward.co.uk/ee/index.html