I need to spend a few days just studying LTSpice. I'm studying diff. amps and so if I want to display on screen Vd and Vc , I could make 2 arbitrary sources and put the math in for Vd and Vc. But's that's making a circuit to display a value from another circuit.

So using .op or text commands or whatever, how do I make a desired value appear on the schematic view, where ever I place it ?
So as for displaying functions (or in general making functions for VS/CS), how complicated can you make the equations ?

The more I use spice the more I like it and appreciate it, thanks

 

LTSpice allows you to place probes on the schematic wherever you want. You decide if they are voltage or current probes.

While the values are not displayed on the schematic, there is another page that displays a graph of the probe values over time.

Check out the graphing tutorials. It takes some getting used to, but is a basic skill required for simulation.

 

I need to spend a few days just studying LTSpice. I'm studying diff. amps and so if I want to display on screen Vd and Vc , I could make 2 arbitrary sources and put the math in for Vd and Vc. But's that's making a circuit to display a value from another circuit.

So using .op or text commands or whatever, how do I make a desired value appear on the schematic view, where ever I place it ?
So as for displaying functions (or in general making functions for VS/CS), how complicated can you make the equations ?

The more I use spice the more I like it and appreciate it, thanks

The value(s) cannot be displayed on the schematic (except for DC operating point). But for transient simulations they can be displayed on the waveform viewer. You can also use a "measure" statement to compute the value, and then, either, view the result in the waveform viewer, or, view it in the error log.

eT

 

The value(s) cannot be displayed on the schematic (except for DC operating point).

To display the DC operating voltage values on the schematic, run the .OP (DC op pnt) and then left click on the node you want to display the voltage.

 

You can also use a "measure" statement to compute the value, and then, either, view the result in the waveform viewer...

How do you view measure results in the waveform viewer? I would love to see my measure results there instead of having to manually open the error log every time. The only way I knew was using drop down menus to view the error log.

 

How do you view measure results in the waveform viewer? I would love to see my measure results there instead of having to manually open the error log every time. The only way I knew was using drop down menus to view the error log.

There are a couple of ways.

1. If you have used a "stepped" simulation, you can open the error log, find the measurement of interest, right-clk, then select "plot step'ed .meas data". A new waveform window will open. Rht-click in the new window and select "view->visible traces". These will be the measured values you can choose to display.

2. You can also perform a calculation using an equation. Specify the equation in a B device. Label the B device output node.
You can then click the label at the output node to display in the result in the waveform window.

There are probably more ways but those are a couple...

eT

 

LTSpice allows you to place probes on the schematic wherever you want. You decide if they are voltage or current probes.

While the values are not displayed on the schematic, there is another page that displays a graph of the probe values over time.

Check out the graphing tutorials. It takes some getting used to, but is a basic skill required for simulation.

Yeah I know you can take the difference with the probes

But ok so no one has said LTSpice can do what I hoped.

Ok and it wasn't till later that day I calculated/realized a DC diff.amp really is like a comparator, so I moved onto the AC of that for the 1st time