I have been trying to build a very simple schematic to simulate in gspiceui. I've never actually seen spice run, though, and I have not been able to actually find any examples on the net that don't start off with something like "import your schematic". I have a simple voltage doubler schematic built, but now what? gspiceui won't do anything with it, and I gather it's because I don't have a voltage source.

Rather than continue to whine like this, I'll just ask for help. If you've got a pointer to a very very VERY simple example schematic, I'd really appreciate it to help me get a running start. Even some verbiage telling me how to set the source device to be a source accepted by gspiceui would help, as well.

I guess, you will have to specify the voltages.

.. using spice ..
http://www.linuxjournal.com/article/2169

.. create a netlist
http://littletux.homelinux.org/knowhow/ngspice.pdf

http://sourceforge.net/projects/asco/

Odd is, that Googling .. using gspice ..
provides no hits.
.....

Tell me about it. The real problem is that I'm so ignorant about this that I wouldn't have recognized what I'm looking for if it was staring me in the face. Could it be something as simple as not giving netnames to my networks? I'll give that a shot, and if that doesn't help, I guess I'll follow the example in the pdf from start to finish.

One more question, on naming: if I name the schematic xxx.sch, then gspiceui complains that it can't find a .ckt file. But if I name it .ckt then gschem doesn't see it unless I click on show all files. What's up with that (i.e. what am I screwing up)?

.. I didn't find an answer for " .ckt file. "
There are some text in the Manual ( The 'Help button')
describing .ckt files.

Did you read this thread from today
http://www.linuxquestions.org/questi...igning-770316/
↓
Debian geda packages ..
http://packages.debian.org/sid/geda
.....

Oregano is easy to use : I draw a simple scematic yesterday,
got a netlist created, but was stopped by "missing executable"
when attempting to run the simulation.
.....

No, you don't need netnames in order to simulate. It may be a very worthwhile convenience when it comes to observing what is going on, otherwise there is a tendency not to be absolutely sure which node you are monitoring, but node names are not necessary, as you can use the node numbers.

You do need a node 0 though (ground); without that nothing will work.

You probably do have something wrong about the set up of your voltage source; its easy to do, whether its getting the amplitude or frequency wrong, but whether its the only problem in your circuit...

That is probably the best idea.

Geda comes with examples, but I can't remember if any of them are what you might call trivial; there are certainly some that are closer to useful than trivial. And, in general, Geda doesn't do as much as it might to shorten the learning curve.

I think my best suggestion to you is to try LTSpice; I know that it is a Windows program (boo!, hiss!, etc!) but Linear Technology do take care that it works under wine. Schematic capture looks a bit crummy under wine (I'm only guessing that it looks better under some other OS), but it does all work and it is rather more user friendly (at least in the sense of giving you error messages that point you directly to the problem and setting up stuff for you in sensible ways...I'd hate to tell you how much time I wasted trying to get a noise sim working once just because I wasn't clear about the syntax) than any of the capable Linux-native options that I can think of.

And another thing; the best thing that I can tell you is that however you do this, don't expect it to be as easy as you think it should be (over time, I must have learned between half a dozen and a dozen different schematic capture programs, and I don't think that a single one was without some hair-tearing frustrations during the learning phase...and schematic capture is the easy part!). It won't be, and if you don't have a bit of time to 'waste' on getting going, you probably won't get anywhere useful.

I was starting to think this was the case. Thanks for confirming it for me, as this is a show-stopper. I've already had too many projects that lost momentum and failed because learning a "better" tool crowded out the actual project. I've got a bunch of caps and a breadboard coming from Mouser on Monday. I'll get out the scope and do it the old-fashioned, easy, way. After all, my goal is to create a clean, working power supply from a problematic source, not to learn to play with spice.

Thanks for the posts to this thread, guys!

Now I'm feeling a little guilty for maybe having been a bit too negative (not wrong...just too much emphasis on the negative side). If your circuit is simple and if you can use one of the simpler options you still might have time to do something useful before your parts arrive.

This sounds like a small collection of capacitors and small signal diodes hooked up to an AC source. That should be fairly easy to simulate (but, in that case, I don't understand why you are having the "it's because I don't have a voltage source" part; just add an AC voltage source with an appropriate series resistance). It may be more difficult if you are generating the input voltage yourself from a switching circuit, as you may have to simulate the generating part (...or not, if you feel that a source does it adequately...).

Yeah, I know. It SHOULD be easy to simulate. You just add the source component, give it values, and off you go. Except, that it won't go. I'm sure it's because I haven't set some flag or some esoteric thing it needs, but there ya go.

The latest issue of QST (ham radio club magazine) mentions LTspice. I think I'll go ahead and download that today and give it a try. From the description, it sounds like it's more targeted toward the neophyte. I'll report back the results.

Come to think of it, though, maybe you can help with the way I have the source defined. Here's what I have. Is there something obvious? What I want is a source with 0V DC offset, 6.3 VAC, at 60 Hz. Anything else I need to post? Does it need to be surrounded by quotes or parens or something else that isn't obvious to the most casual observer?

Well, I got something going pretty quickly in LTspice! It's not exactly what I expected to see, but it gives me something to play with.

Added:
D'oh! Peak voltage, not RMS voltage. OK, I got this thing going with LTspice.

Hmm, I'm not sure that anyone else was ever likely to spot that one from the information given...always difficult to do some remote debugging remotely, while it might have been obvious if we had had a conversation, just casually discussing what you were doing.

One of the problems is that there is an enormous number of potential "D'ohs".

Anyway, glad that you started with LTSpice...can be used for quite serious stuff, but it does have a shallower learning curve than any of the serious, Linux-native, options. When you are just getting started, "plots", and "coloured" and "easy" can be an enormous help if you aren't even sure of which problem you are fighting.

Actually, when I opened the thread I hadn't even gotten that far. I was stuck so badly that there was simply no hope. With LTspice, I started getting results from the start with none of those mysterious errors. The answers were wrong, though, until I read something somewhere and realized that spice uses peak, not RMS, voltages for AC.

It's a very intuitive product; easily learned by an old fart like me. There are a number of things that made the difference for me.

1. It's a single integrated tool. Everything is done from one place, whether it's drawing the schematic or running the simulation.

2. Since it's an IDE, the errors are also integrated, which makes finding their cause much easier.

3. The popup for the source device gives you all the options for the different types of source voltages. You don't have to look through a manual to discover the syntax for a 6.3VAC 60Hz supply.

4. It has a pretty good list of components, and it's not that hard to add new components of a type, such as a new diode not on the list.

5. Building a schematic is less time-consuming than gschem and more forgiving, and you don't have to go back and forth from one program to another to make updates and run a simulation.