SwitcherCAD - no thyristor?

On Sat, 25 Mar 2006 16:02:09 +0200 in sci.electronics.basics, Seeker wrote,

There are generic SCR and TRIAC under Misc.

Yes but I don't know how to use it without the model.

After a while trying, I can't figure it out either. So, I'm crossposting this response to sci.electronics.cad. Of course, if you had posted there to begin with you might have the answer already.

I can find thyristor models on the web. But how does one connect such a model to the TRIAC or SCR symbols in LTspice?

On Tue, 28 Mar 2006 17:34:58 -0600 in sci.electronics.cad, John Fields wrote,

Nope, nothing there but "Members Only" and a form to sign up for more Yahoo Spam.

I had hoped that somebody who knows the answer to "Seeker"'s question might just post it. Mike Engelhardt has posted some great answers right here in the past. I would have liked to know, also. But if I have to sign up for more junk mail, I'll wait until I _have to_ know.

Nothing against you, John, but...

To hell with all Yahoo groups and the yahoos who create them. We have a perfectly good newsgroup for Spice topics right here. Please keep the discussion open and public here on the real Usenet.

David,

There's an example typically installed as

C:\\Program Files\\LTC\\SwCADIII\\examples\\Educational\\dimmer.asc

that uses the SCR and DIAC symbols. The models don't have to be on the schematic, they just are in the example. Normally you'd .lib/.inc them or program the symbol to automatically include the appropriate library file.

I've never, ever received spam from Yahoo and rely on one of their free e-mail addresses while on the road.

These days I often either don't see or simply ignore posts here. The Yahoo group works well. It's still a bit like Usenet so you have people occasionally talking about what they ought to be talking about, but overall, it's a good forum if you want LTspice help and don't want to use the offical support address for the program.

--Mike

On Sun, 02 Apr 2006 07:49:34 GMT in sci.electronics.cad, "Mike Engelhardt" wrote,

Good example. Thanks for answering. I hope I wasn't picking on you and that you don't have to be the only one who can answer those questions.

The main point I didn't get was the link from the symbol to the subckt via the Value=TRIAC parameter. For some reason I thought it would be SpiceModel=TRIAC, perhaps because something I read said that the spice model for so-and-so is a subckt. What is the SpiceModel attribute for?

With examples it's hard to tell what things must be done a certain way and what things are only that way by coincidence.

As I see in the Educational\\opamp example. Hmmm, I should try finding more relevant examples by greping the .asc files.

But there I see parameters being set by SpiceLine1 & SpiceLine2 instead of Value2 like for the DIAC. What's the difference? I did not find anything in the LTSpice help file at the LINE/WINDOW/SYMATTR directive level. Nor do I see any .param parameter declarations in opamp.sub.

Still learning stuff.