Hi Jesper,
Does post #549 and the reply by jcx give you any clues.
http://www.diyaudio.com/forums/soft...ng-ltspice-beginner-advanced.html#post4552196
If you have nodes V(+) and V(-), you can plot them differentially by writing V(+,-). However you cannot do an FFT on V(+,-) - instead you must do an FFT on both nodes and then in the FFT window add V(+,-). Inconvenient, but it works.
You can also use the differential notation with the .four statement and almost anywhere else.
I'm as guilty as anyone after looking back at the last couple of dozen posts.
If Sk8Ter has no objections then these later posts can be split off to a new thread.
No...absolutely I do not mind please put link in this thread
Can you make the new thread called ( amplifiers for the musical truth ) something like that
I would like very much to continue the conversation
Lawrence
All posts on the Harmon discussion split off to here,
http://www.diyaudio.com/forums/solid-state/288096-amplifiers-musical-truth.html
http://www.diyaudio.com/forums/solid-state/288096-amplifiers-musical-truth.html
when using the ".four" LTSpice directive, how can I have it calculate the FFT across an expression? I've tried ".four 1khz 0 10 V(out+)-V(out-)" but it just adds V(out+) to the error log. I've tried to add quotes, that doesn't help, either. It works if I go to the graph and edit the expression, but I'd like the data go to textual output via the error log.
Hi all here.
I've some questions on LTSpice. As you can see in my threads, i use it not too extensively, but it is the clearest way to show how a circuit works. But sometimes I obtain strange results from it.
As an example, when trying a full wave rectifier with input choke filter, as in the image below, and placing the prove at both sides of the inductor, I have:
Note 0V DC ‼
Why?
Suggestions will be appreciated.
Many thanks in advance.
I've some questions on LTSpice. As you can see in my threads, i use it not too extensively, but it is the clearest way to show how a circuit works. But sometimes I obtain strange results from it.
As an example, when trying a full wave rectifier with input choke filter, as in the image below, and placing the prove at both sides of the inductor, I have:
Note 0V DC ‼
Why?
Suggestions will be appreciated.
Many thanks in advance.
Attachments
Inductors without DC resistance don't have DC V across them
to get the difference you left click the node, hold the left button down and move the probe to other node you want to difference
the waveform label should look like V(n001,n002)
you can add series R to a Spice Inductor - either a added R or invisibly to the schematic in the L model dialog box by right clicking the L body
you can probe the current directly too if that's what you really want to see
to get the difference you left click the node, hold the left button down and move the probe to other node you want to difference
the waveform label should look like V(n001,n002)
you can add series R to a Spice Inductor - either a added R or invisibly to the schematic in the L model dialog box by right clicking the L body
you can probe the current directly too if that's what you really want to see
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Thanks, but it is obvious, is a simple piece of wire. When I put the prove, i'm measuring between any of the filter inductor and ground. The circuit has a rectified senoidal wave, but appears to not have DC at the output. In both of them I must have the same DC voltage.
The filter inductor has a non visible 700DCR, and I tryied both tube and SS rectifiers in the simulation. The same strange end.
THanks for your inputs.
I've a hunch what Osvaldo is getting at here...
Because the only voltage source in the simulation is an AC one (and also because this design is transformer coupled) the only 'simulation type' that will run is the 'Transient' one. So you are viewing all the points in the circuit as if you were using a scope probe.
The DC voltage is shown as zero at all points because the circuit can not run the 'DC op Point' solution because there is no DC voltage source present.
Does that make sense
When you run a 'Transient' simulation, the program automatically does a DC operating point solution as well. The result of that is always going to be zero on circuits like this because there is NO dc source present.
You can disable it attempting to do this by ticking this box.
Because the only voltage source in the simulation is an AC one (and also because this design is transformer coupled) the only 'simulation type' that will run is the 'Transient' one. So you are viewing all the points in the circuit as if you were using a scope probe.
The DC voltage is shown as zero at all points because the circuit can not run the 'DC op Point' solution because there is no DC voltage source present.
Does that make sense
When you run a 'Transient' simulation, the program automatically does a DC operating point solution as well. The result of that is always going to be zero on circuits like this because there is NO dc source present.
You can disable it attempting to do this by ticking this box.
Attachments
OK, excellent guy. Many thanks ;-D
I must to recognize that I don't like "software solutions" as much as real circuits, with real oscilloscopes and feeling the heaters warm. But, as you know, it is a good tool to demonstrate (or better, to show) how a piece of circuit works, as I did in many of my threads.
Many thanks again.
I must to recognize that I don't like "software solutions" as much as real circuits, with real oscilloscopes and feeling the heaters warm. But, as you know, it is a good tool to demonstrate (or better, to show) how a piece of circuit works, as I did in many of my threads.
Many thanks again.
.lib files on Mac version
This is my first day trying LTspice on the mac. I don't know anything at all but have some .asc files to run that came with .lib files. Going to the ltspice package files I found a file titled lib but no .lib files inside. Where do I put them?
PS. Looking at the LTspice tutprials I didn't find anything specifically for the mac,. I did look!
Thanks very much
This is my first day trying LTspice on the mac. I don't know anything at all but have some .asc files to run that came with .lib files. Going to the ltspice package files I found a file titled lib but no .lib files inside. Where do I put them?
PS. Looking at the LTspice tutprials I didn't find anything specifically for the mac,. I did look!
Thanks very much