Mean Well RSP-2000-48 Teardown deep going, ends with EMC stuff - Page 1
Forum section: electronics / general

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 26, 2021, 02:17:35 pm
content: this is my longest teardown video so far.sorry it is over 30mins, but there was quite a lot of details to explain.questions are welcomeSORRY youtube crashed and F--- my file... maybe i re-make it....right now feeling depressedNEW FILE:https://youtu.be/bIP53wtVbcU

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 26, 2021, 04:19:31 pm
content: Yeah, weird isolated converter section!I wonder what effect all the leakage has there. The wiring alone (loose cables from transformer to rectifier) incurs a good 200nH already, maybe more seeing as it's litz.I imagine most of the emissions are from the output side. Have seen plenty of supplies that need a CMC and "Y" cap on the output side to behave. The primary side isn't usually too bad, having ample reference to ground (Y caps), but the output, between being isolated, and cheaping the hell out on filtering (enough to meet the ripple spec, and no need to do anything >20MHz), can be pretty messy.Quote from: oz2cpu on November 26, 2021, 02:17:35 pmOh, I guess that explains the some minutes of black in the middle.Hopefully a reupload or whatever does the trick.Good voice by the way, reasonably good mic, clear narration, just a tinge of Germanic accent?Tim

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 26, 2021, 07:25:10 pm
content: FINALLY, i had to remake the missing minutesi really hope it works nowhttps://youtu.be/bIP53wtVbcU

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 26, 2021, 07:30:49 pm
content: here is a little bit better explain of the filter i madeall things that juse single-point to ground / chassis as well,is the most quiet, since this way all cables refer to that single point = no ac difference = low emi:-)

author: thm_w
author_rank: Super Contributor
timestamp: November 26, 2021, 10:10:56 pm
content: 2kW in that tiny case? incredible.

author: 2N3055
author_rank: Super Contributor
timestamp: November 26, 2021, 11:34:12 pm
content: Nice work Thomas!I agree with Tim, good, clear narration, not to slow. Nice analysis, both circuit and EMC.It was nice and interesting to watch.Interesting PSU, some quite exotic choices.Best,

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 26, 2021, 11:49:22 pm
content: Mean Well does have a reputation of being electrically noisy, I once worked at a place where a specific Mean Well wall wart was the standard for a "noisy PSU".Quote from: thm_w on November 26, 2021, 10:10:56 pmPretty much the same as what rack server PSUs can do, just with a higher output voltage.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 27, 2021, 09:59:59 am
content: funny you mention the noise, and reputation, where i come from, most people thinks : if there is written mean well on it,it is well below limits, and all problems are only implementation and user error..and all the magic i need to do, is to solve that :-)fell free to re-do the radiation experiments in EMC labs, with cables connected to the unit,of course you need to transport the energy to something a few meters away.else it is not a realistic setup, if you power this up, with out cables.Lets say 2-4 meters, on input, and on output.and the cables needs to be on the test table too..here another picture, from another test lab, same curve, same level..

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 27, 2021, 10:05:11 am
content: thanks for the comments on the video..i made a few other teardown videos, but most are made in Danish, the plan is to do some more in English too, specially if they get more likes :-)this design is old and funny, I am sure you get the point even if you dont understand the talk.https://youtu.be/qVu1LMr85fY

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 27, 2021, 03:55:57 pm
content: Quote from: oz2cpu on November 27, 2021, 09:59:59 amHaving the input directly connected to a cord that leaves the end product is reasonable, but having the output directly connected to a length of cable going outside the enclosure of the end product is not the intended use case for that kind of PSU. It's intended to be mounted inside the same enclosure as the load. Most high power 48V loads are electrically noisy so it would be wasteful to try to reduce the noise on the output.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 27, 2021, 05:23:14 pm
content: good input there mike, in my use : the 2kw power go somewhere else, external of the main controller and main case with the powersupply..so of course I need a very effective filter..NEWS : the 2.2uF red cap that handle ALL input peak currents,when i wanted to desolder it, to test its internal resistance and current capeabilities,one pin just fell off ! all by it self, way too easyand i was very carefull with the desoldering, so maybe this was the main cause of death !!ac current overloading !!maybe we can find full datasheet over this cap ?

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 27, 2021, 05:27:52 pm
content: here that capacitor is, picture addedok it is from HJCpartnumber must beMFTD225*0450DB*22*https://www.hjc.com.tw/admin/product_en/images/file/2021-11-09/618a2666a4791.pdfno info about AC current capeabilities at 110kHz