Electronics > Projects, Designs, and Technical Stuff
Conducted emissions issue with multiple Mean Well AC/DC converters
Mr. Scram:
--- Quote from: prasimix on July 16, 2020, 09:43:17 am ---I return to the topic. In the meantime I got the Siglent SVA1015X and built LISN thanks to @Jay_Diddy_B who gave me the schematic and referred me to its design discussed here. LISN has 10 dB attenuator on its outputs. I used a ready made extruded box for which I made a front and rear panel to make construction easier. This is actually the second and wrong revision of the PCB which is 10mm shorter because I misinterpreted the dimensions of the box. If these 10 mm are added, a filter up to 6 A as well as a PCB AC power switch can be installed. Maybe I'll do it once in the future. In this case I had to shorten the box by 10 mm :-/O
--- End quote ---
That LISN looks great! I may have to build one myself at some point.
Jay_Diddy_B:
--- Quote from: prasimix on August 07, 2020, 08:47:42 pm ---
Thanks Jay_Diddy_B, I followed that topic, indeed. However, I haven't done anything about it yet because what is left open is what with the cores. Where to get them?
BTW, I tried to treat this issue as CM only and DM only, applying chokes that address one or another mode. But it seems that both of them are very prominent and need to be handled.
--- End quote ---
Hi,
The cores I used the prototype are hard to get. There is a minimum order quantity.
I have tried a core that I obtained from a P0354NL common mode choke in one of the two locations. This core is too small for one of the locations.
I have also received some ferrite cores that are sold by Digikey. I will test these in the near future.
Regards,
Jay_Diddy_B
prasimix:
Hi all, just to summarize this topic, because a few days ago I passed the conducted emission testing. This of course required adding an AC input filter in front of all Mean Well modules so the scheme now looks like this:
Worst case scenario with the max. load in the lab looks like this:
Probably the peak around 20 MHz could be ironed out, however this is also passing and I am currently having other problems since I found out that my MCU module is doing a serious problem with conducted emission for which I will open a new topic.
Thanks to everyone for the assistance, especially @Jay_Diddy_B who gave me the LISN schematics.
Kean:
Good work!
Any way to modify the original power board on the Crowd Supply units?
Maybe with a daughter board holding the filter components and some track cutting.
Not sure if there is enough space to safely fit it...
prasimix:
Hm, highly unlikely. That was my first approach for test lab, but when I realized that both CM and DM choke is required I gave up and make another revision. The new challenge was to put everything together in the existing PCB dimensions and possibly the same budget. In the end, I succeeded in that by throwing out the triacs and their drivers and heat sink and putting relays, which are used on the BP3C backplane as well. So the audit that passed the conducted emission test now looks like this:
Even this revision isn’t necessarily the last one, because I don’t know how the people in charge of LVD testing will like it. For now, the latest AUX-PS module allows a passing of the EMI conducted emission for the entire BB3 chassis.
I will follow up on CE testing in the main BB3 thread soon.
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