Dear All,

I am using the attached diacs.lib from STMicroelectronics. However, there is a warning on the image file.
After I inspected the .lib file, I deleted "*{Tr}" from this line: R_R1 N02098 TRG 1.462*{Tr}, and the simulation worked fine.
It seems like the LTSpice doesn't recognize the "*" sign. However, doing so will make R1 be independent from the rise time (Tr).
I searched the .lib file elsewhere, but can't find R1. So, I would like to know what should I do with the parameter R1?

Sincerely,
BlackMelon

 

hi BM,
In LTS the '*' is a Comment marker.
R_R1 N02098 TRG 1.462*{Tr}

For R1 why don't you find the Tr for the device, multiply by 1.462 and enter the value in uS into the Lib file.

Save the Lib and restart LTS.

E
Update:
Checking thru that Lib.
+Tr=0.342

R_R1 N02098 TRG 1.462*{Tr}

1.462*0.342 = 0.500004

So.
R_R1 N02098 TRG 0.500004

 

In LTS the '*' is a Comment marker.

Yes, if it starts a line.
It's also the floating point multiplication symbol, so the 1.462*{Tr} looks valid to me, providing Tr has been defined as a parameter.

Edit: Oops. My bad. It's not valid, but {1.462*Tr} is.

 

hi alec,.
The +Tr=0.342 is that Lib header.
But LTS burps at the '*' symbol.
E

 

So, I would like to know what should I do with the parameter R1?

The designator isn't R1, it's R_R1. (Note the underscore).

But LTS burps at the '*' symbol.

Yes, if only Tr is inside the curly braces, Move the left curly brace so that both multiplier and multiplicand are inside the braces and it doesn't burp.

 

Dear All,

I am using the attached diacs.lib from STMicroelectronics. However, there is a warning on the image file.
After I inspected the .lib file, I deleted "*{Tr}" from this line: R_R1 N02098 TRG 1.462*{Tr}, and the simulation worked fine.
It seems like the LTSpice doesn't recognize the "*" sign. However, doing so will make R1 be independent from the rise time (Tr).
I searched the .lib file elsewhere, but can't find R1. So, I would like to know what should I do with the parameter R1?

Sincerely,
BlackMelon

You shouldn't change anything. You are using the wrong model.
The DIAC model is a template subckt that is used by the "real" models tuned for specific devices.
Do not use the DIAC model.

Use one of the subckt model names defined under the description "Standard DIACs definition", like "DBT3G" for example.