Hi everyone,
I am freshman in LTspice. I make a circuit (as attachment) to simulate what it will be affected with 1kV surge voltage, but the LTspice was simulating very slow. I checked the error file and found many "Heightened Def Con..." message (as screenshot below).


I try to make one of following change, and then the simulated speed become to normal.

• The V2 is set 100V.
• The C3 is set to 0.3uf.
• Instead the D2 with short circuit

I do not know why it was.
Is anyone can kindly help to give a suggestion or solution to let the circuit can run simulation in normal speed but not change the circuit structure or components value?

Many thanks for your kindly help in advance.

 

Why didn't you upload the diagram in LTspice format?

 

Sorry, I only attached the specfic component file in last post but lost to attached the asc file. Here is the file.

 

See

Total elapsed time: 0.117 seconds.

 

I do not know why it was.

I think it was because of the particular SCR models you used. I didn't have those models so tried different SCR models and the sim ran quickly without problems.

 

See
View attachment 317376
Total elapsed time: 0.117 seconds.

Many thanks for the reply but I do not understand why the raising/falling time of V2 will affect the simulation speed in this circuit. What is the reason?

 

Many thanks for the reply but I do not understand why the raising/falling time of V2 will affect the simulation speed in this circuit. What is the reason?

The thyristor is turned on by an increase in voltage if the rate of voltage rise is above a certain value. I thought 1 µs was too long. I don't think the counting rate depends much on the front. I used the UIC option.

 

The thyristor is turned on by an increase in voltage if the rate of voltage rise is above a certain value. I thought 1 µs was too long. I don't think the counting rate depends much on the front. I used the UIC option.

Thanks a lot for the explanation.
I made this simulation is for EMC surge test. The test waveform must be 8/20us or 10/1000us. Therefore, your suggestion cannot resolve my problem. Anyway, thanks for your time and suggestion.
Attached the new file is with the test waveform B1.

 

I think it was because of the particular SCR models you used. I didn't have those models so tried different SCR models and the sim ran quickly without problems.

Could you kindly help to provide the SCR library you used so that I can try?

 

Hi CH,
Check out these links.
E
http://bordodynov.ltwiki.org/

https://forum.allaboutcircuits.com/...-of-ltspice-free-download.133690/post-1112695

 

Hi CH,
Check out these links.
E
http://bordodynov.ltwiki.org/

https://forum.allaboutcircuits.com/...-of-ltspice-free-download.133690/post-1112695

Many thanks for the information, Eric.