Hi, I'm analysing a largish piece of music gear stage by stage in LTSpice. Each stage is behaving wonderfully and I can tweak the stages as I want to. I'm at the point where I want to see the results of the signal from one being processed by the next. I have each of these stages in separate simulations for clarity so is there a way of chaining each simulation, (I would guess unlikely), or can I just Copy/Paste one into the other?

I should point out, I'm not a total dummy or lazy , I have actually tried to do this unsuccessfully by just copying the whole first schematic but I am not then offered the [paste] option in the second. I have thought about exporting the netlist but can find no [import] function. And I can't find a way of opening up a simulation into an existing one.

(And I have spent time Googling it without finding anything that helps.)

Many thanks.

 

Just to prove I'm not lazy I've proved I'm an idiot! I was changing from one maximised simulation to the next by selecting the appropriate tab above the main window. It seems that this aborts the copy procedure. It works perfectly if you have the two sim windows open side by side and you simply slide from one to the other. I did manage to find the instructions in the LTSpice area: http://www.linear.com/solutions/5519 It said there that this is a standard procedure so I tried again with that in mind and voila!

Thanks anyway, hope this helkps others who may be puzzled by this.

 

Hi

You can copy and paste but you need to ensure that labeled nets are named properly when you do so.
Reference designators will also be re-assigned.

A better way would be to create a hierarchical block for each stage, place each block into a new schematic, wire them together, then simulate.
You can still drill down into each block to view the schematic of each stage for trouble shooting purposes.

 

Wow, seems as though what I had assumed would be impossible is actually very doable. that's great news! I'll look into the hierarchical block approach and adopt that while I'm still at a small enough stage to change to a more robust solution. Is there anywhere you can recommend I start at where the info on how to do this would be? I know Linear Technology has very good info on LTSpice but I can't see it at first glance.

I should have mentioned I'm only using LTSpice IV at the moment.

 

I often use copy-and-paste as a way to focus on one small part of a larger schematic, and then simply add the small part to the larger part once it's working nicely. But I'm not designing anything "big", nothing more than 2 or 3 ICs. The block approach sounds like a good way to handle a large project.

 

hi,
I agree with 'eetech00', that's the way I combine large sim projects.
Take care with the notation's
E

 

I'm seeing the principle of creating a hierarchy of connected blocks, I'm just not sure how to set that up in the first instance. I would guess that if I use the "Hierarchy" -> "Create a new sheet" menu option then the new sheet is connected to the old. It may be simpler than that, any sheets which I have open at the same time become effectively connected, but it doesn't seem to be like that at the moment. I'm going to have to set up a test case here just to establish the process.

In my own case, each stage is a simple single opamp with an overall shared PSU structure but there are a number of component value variables I want to be able to trim for each stage. I'm currently doing this with .op commands altering a number of components at a time according to a simple "channel" selection I make in the .op early on. This works great, but can it work from one sheet to control aspects on another connected sheet? If so I can run the whole sim from a single .op. If not, how can I run .op commands on two or more sheets in the same run?

I'll keep the thread up to date with what I find.