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Lewis,

If the old file does not exist, then it is not possible for LTspice to load up a nonexistent file.

If it still starts up with the old file, then the old file exists. ?Contrary to popular belief, LTspice doesn't do magic; it doesn't come configured with a time portal. ?If you had this problem earlier too, that mysteriously went away, I think you need to consider the possibility that you should not be as certain as you are about the nonexistence of the file.

This is easy enough to verify, by editing the standard.dio file to remove all but one entry. ?If LTspice doesn't immediately see the difference the next time it starts, then you haven't successfully edited LTspice's file;?i.e., the old file still exists.

Andy

partha wrote:

? "the lib file i got from CREE site has the temperature at 25 degree C . but i need to increase the junction temperature to 125 degree C . What modification i need to do ?"

Hopefully, nothing.

SPICE models are capable of being temperature dependent. ?If they made them right, they will be.

What makes you say the lib file "has the temperature at 25 degrees C"? ?In what form did you see this? ?What you saw might have been the parameter that sets the nominal temperature of the model, meaning that it is the temperature against which the temperature-dependent relationships are anchored. ?In that case it would not mean it is the only temperature at which the model works in a simulation.

While it isn't proof that your models are correct, you could try simulations at 25 C and at 125 C and see if they differ.

If LTspice still opens on the old standard.dio file, then it must still exist, right?

If worse comes to worst, you could?do?a reboot. ?I think it shouldn't change anything, but see if it does.

Andy

Lewis wrote:

? "I sorted the part numbers in the standard.dio file and added a couple of new .model descriptions. ?When I access it, I still get the old order and cannot see the added models.

? "Why?"

I am guessing you have run into the way Microsoft Windows works, which is why people are asked not to tamper with their LTspice installations and anything in the "C:\Program Files\" area. ?Windows tries to protect that area by various devious means.

It's possible the file you thought you were editing is not the one actually in that directory. ?Windows may have given you a copy (physically located in another folder) and made it appear to you as if you saved it, but it was saved somewhere else. ?Even having Admin privileges doesn't always save you from this.??Windows doesn't trust you.

ahmedkq.work asked:

? "I downloaded this file:
? "Files > Examples > Books > Chris Basso's files > ChrisBasso.zip
? "and extracted it into a directory on my Desktop.
? "-
? "I want to be able to see the symbols (*.asy files) from inside the LTspice to be able in instantiate them into new schematic. But I don't know how to put the folder I extracted file in it into the program path such that it sees it?"

It is always recommended that you NOT add models, symbols, etc. into the LTspice program path. ?There are complications if you do.

Instead, anything you download or create, should be put into your working directory or directories, where you have the schematics you are working on. ?Those directories should be no-where near the Windows "C:\Program Files" (or whatever it is called on your computer) directory structure.

Yes it is somewhat less convenient than having them come up automatically in LTspice's "Select Component" menus, but you will be better off if you avoid that.

When you bring up the "Select Component" menu (F2), the very top of the pop-up window lets you choose the "Top Directory". ?The two choices are LTspice's own symbol directory, or your current working directory for schematics. ?By selecting your working directory, any symbols that you have put in your working directory, should appear as choices in the menu.

Andy