Great video again! 👍👍 I'm just curious, if I want to simulate the effects of the components on the board, such as common mode choke, lc filter, etc., does that mean I have to model the choke as a lumped model? Also, how do you determine the simulation timestep and min decrement to ensure that openems does not crash for a sized grid? From my previous runs with openems, the crashes were influenced by the grid size, the timestep and the min decrement. Is there a formula to determine/calculate the appropriate values for the timestep and min decrement for a given grid size? Looking forward for your far-field sim soon 😊👍
Far Field: I will upload the far field simulation process on udemy this week and will re-comment here once done. Determination of required timesteps: Yes, for many problem types there is a formula for the required timesteps, will upload it on udemy those next days and keep you updated. Min decrement: I sadly dont know a formula for that one, I typically use a very low value and limit the simulation time by the number of timesteps. Inductors / chokes: As of now the lumped inductor models seem not to work. So a choke still need to be modeled by via the 3D geometry. Thats kind of hard to do especially if you want to simulate a specific partnumber of a given manufacturer. I am working on a video for that, but this one is going to take a while.
Hi again :) on udemy now are following updates: Lecture 20: I added an Excel sheet on how to calculate the required timesteps when injecting a step signal. Lecture 19: check this one out regarding crashes. PS: what exactly do you mean with crashes. you mean that you get error messages or do you refer to very long loading times? If its mainly about loading times, then the new lectures 16 and 17 might also be very useful. I will text again once the far field tutorial is uploaded.
@panire3 thanks! Just checked it out yesterday. Haven't gone through but thank you very much for the udemy updates. Regarding the crash, it was not related to the long loading issue. It was more on that, openems immediately terminates the session and an error message code that I have shared with you in previous lectures. It goes something like this: error: openEMS binary exited with error-code -1073740791 However, after playing around with the timesteps and min decrement and maintaining a fine mesh grid, i think i did around 0.05, the error message disappears. When I increase the grid to 0.1, same issue occurs but after playing around with the timestep and min decrement, it disappears. Probably it might have something to do that openems breaks itself due to the fine mesh with to big of a timestep but with small min decrement. So, i came to the conclusion that it has to correlate with the mesh size, timestep and min decrement. So far, that was the issue that i had last year and i think my current workflow was to use a smaller timestep like in your previous video, maintaining default min decrement, grid size of 0.5. The lowest i could try was at 0.3 before the same error code message occurred again. Looking forward on your far field video this week. Need to learn how to use for my current project actually😂.
Many DDR layouts have the GND pulled back, so in a way I agree that its kind of the industry standard for routing in multi-layer PCBs. If thats the "best" way I am not sure. In fact via stitching every signal could cause less emissions (see here: th-cam.com/video/jYVD-8Wgdq8/w-d-xo.html), however vias take up much space, so removing GND from the top layer is often done due to limited board space.
me estoy tomando el tiempo para ver todos tus videos.. no dejes de publicar por favor!!
Great video again! 👍👍 I'm just curious, if I want to simulate the effects of the components on the board, such as common mode choke, lc filter, etc., does that mean I have to model the choke as a lumped model?
Also, how do you determine the simulation timestep and min decrement to ensure that openems does not crash for a sized grid? From my previous runs with openems, the crashes were influenced by the grid size, the timestep and the min decrement. Is there a formula to determine/calculate the appropriate values for the timestep and min decrement for a given grid size?
Looking forward for your far-field sim soon 😊👍
Far Field: I will upload the far field simulation process on udemy this week and will re-comment here once done.
Determination of required timesteps:
Yes, for many problem types there is a formula for the required timesteps, will upload it on udemy those next days and keep you updated.
Min decrement:
I sadly dont know a formula for that one, I typically use a very low value and limit the simulation time by the number of timesteps.
Inductors / chokes:
As of now the lumped inductor models seem not to work. So a choke still need to be modeled by via the 3D geometry. Thats kind of hard to do especially if you want to simulate a specific partnumber of a given manufacturer. I am working on a video for that, but this one is going to take a while.
@@panire3thank you for your hard work to share your knowledge on this. Looking forward on your udemy course update soon👍
Hi again :)
on udemy now are following updates:
Lecture 20: I added an Excel sheet on how to calculate the required timesteps when injecting a step signal.
Lecture 19: check this one out regarding crashes. PS: what exactly do you mean with crashes. you mean that you get error messages or do you refer to very long loading times? If its mainly about loading times, then the new lectures 16 and 17 might also be very useful.
I will text again once the far field tutorial is uploaded.
@panire3 thanks! Just checked it out yesterday. Haven't gone through but thank you very much for the udemy updates. Regarding the crash, it was not related to the long loading issue. It was more on that, openems immediately terminates the session and an error message code that I have shared with you in previous lectures. It goes something like this:
error: openEMS binary exited with error-code -1073740791
However, after playing around with the timesteps and min decrement and maintaining a fine mesh grid, i think i did around 0.05, the error message disappears. When I increase the grid to 0.1, same issue occurs but after playing around with the timestep and min decrement, it disappears. Probably it might have something to do that openems breaks itself due to the fine mesh with to big of a timestep but with small min decrement. So, i came to the conclusion that it has to correlate with the mesh size, timestep and min decrement. So far, that was the issue that i had last year and i think my current workflow was to use a smaller timestep like in your previous video, maintaining default min decrement, grid size of 0.5. The lowest i could try was at 0.3 before the same error code message occurred again.
Looking forward on your far field video this week. Need to learn how to use for my current project actually😂.
Wouldn't it be better to pull back the copper on Layer 1 to control the return path by confining it to layer 2?
Many DDR layouts have the GND pulled back, so in a way I agree that its kind of the industry standard for routing in multi-layer PCBs.
If thats the "best" way I am not sure. In fact via stitching every signal could cause less emissions (see here: th-cam.com/video/jYVD-8Wgdq8/w-d-xo.html), however vias take up much space, so removing GND from the top layer is often done due to limited board space.