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Hi! Thank you for great videos. Do you have any source of where I can find the smart algoritm for control so that I may pass the flicker standard for household appliances? /Tomas

Excellent video! I’ve finished your Practical EMC Training for Design Engineers course from Fedevel Academy, loved the real scenario experience. On lesson 9 didn’t have the tools to test the radiated immunity so I hope by sending the screen capture of this video and subscribing to the channel and giving thumps up! I hope It still counts as done homework to get the certificate :D and using a stapler to hold the PCB antenna is something I’ll have done too!

Excellent...thank you

Very informative....Thank You Sir!

+A video!

Hello, that is great job 🤩, thank you, much help for my setup.

Hello Min, I can add to your video that, being walkie-talkie test very far from the compliance measurement process, if you check specification for Medical Electrical Devices, EN 60601-1-2, chapter 8.6, the walkie-talkie method is stated as a way of performing Radiated Immunity test in an "in situ" or "post installation" environment... very curious indeed!! Thanks for sharing!

Oh my God, what is up with that horrible looking sinewave if you can even call it that. Are you running off some kind of cheap inverter? The 60Hz sinewave coming out of my outlets has a THD of 0.7%. I can't even imagine what the THD must be on that sinewave.

Thanks Min. Interesting that the mains in the UK is nowhere near sinusoidal, I get a triangular wave in Australia. Also, I definitely see EMC issues caused by CISPR compliant appliances, mainly with intentional receivers. AM radio in particular. I guess the main takeaway is preventing 'unacceptable' interference. So the CISPR limits do work despite a significant amount of subjective judgement. I think you videos would benefit from a 3-6dB increase in audio level. I really enjoy you videos.

I am a bit confused about your claim. From the instrument the signal of interest(123MHz) is suppressed by the ferrite? Also how does 250KHz signal from signal generator gets out from the 60cm length(1/4 wave) antenna? 60cm length(1/4 wave) antenna resonate at around 125MHz but get suppressed by the ferrite but 250KHz is fed into the antenna. Could you explain?

Very informative🌹🙏

Maybe I am just dum but isnt that box just a hi-pass filter? Thanks for great videos! / Tomas

I have some "dimmable" LEDs that sometimes when the dishwasher is running get really blinky. I'd love to see if that is between the dimmer and the bulbs or in the whole circuit. I'd love to have one of these for a week or two!

These videos are great

Hi, why did you use two lisn? One lisn was that enough?

Hello Dr Min, Just making sure, when connecting ( HH, LL , HL, LH ) C.M impedances to the ends of out Coaxe cable, by saying it becomes λ/4 & λ/2 antennas , you mean that it physically becomes Monopole or dipole ? Thanks you.

These videos are great. Thanks for taking the time to make them.

Great video as always! Very informative

What plastic is the ground plane wrapped in?

7:05 can you zoom the blue signal wave next time? It really isn't clear when you have a switching on the 0v pattern with full cycle (period). Why do we see the half of the duty cycle with lower amplitude? Very interesting vid. Thanks. And can you place a "decoupling" cap to reduce this flickering noise on the lines?

Great Video. I'd love to see more of the lab setup. The ground sheets. How they are placed and tied together etc.

This is a very good intro, and the exhibition and conference looks great!😊

Hi Min .. Could you please make some videos on SMPS EMI / EMC

Hello Min, First I want to thank you for sharing your knowledge and experience with the community. This is very valuable because it is valid. I see mach bullshit on the WEB. I can say you contribute positively to the public knowledge and I congratulate you for this. I like your direct style. You two important things. 1st your are young (willing to discover and to be enthusiastic); 2nd you have the knowledge to speak about EMC. So keep up the good work. The future will tell if these videos will stay or leave within the community. In regard to the subject of this video, it is very nice explained one of the most common EMI issue found in practice. Ie in automotive (where I'm activating as EMC eng.) we use 2m length harness between the EUT and various loads. The wires in the harness has different resonances and they always get in to trouble the project. If this is not treated correctly, it can make a difference between pass and fail. So I think it would be a good idea if you can continue this series about cable resonance with another movie demonstrate how can a such problem could be solved (cancel the resonance) in practice. Again, many thanks for what you are doing on this field.

Excellent video as usual. Any comments on how to implement a QPD in the time domain? I notice you have done some recent videos where you do the conducted emissions testing in the time domain and then do some FFTs. Presumably doing the QPD this way is also feasible?

Thanks a lot.

What is the book, Min? Title/Author? ... Edit: Found it! ... "Electromagnetic Compatibility Engineering" by Henry W. Ott.

Thank you for your great Video and for the time you take to share you knowledge.

Thank you for the video, very good explanation

Great content as always. Would love to know more about the TBMR-110M!

Thanks for your high quality video. I wonder when Tekbox will officially announce these receivers. I cannot find any information on them yet.

This was the type of video, electronic engineers want!

Thanks a lot. Very good explanation!

Thanks for the video. My spectrum analyzer is identical to yours. On my analyzer, when I turn on the TG, I have -23dBm, ranging up to -30dBm. But no spikes. The problem is just attenuation. I live in Brazil and I love doing everything myself. Thanks

I think the better reference video to add is this one th-cam.com/video/lBHJ3QamqiA/w-d-xo.html (fairly close to what you have in terms of eval board) where they do show that as soon as you screw something else on the board, the ground cut is useless. Further, did no-one check that their symmetrical layout is based on the assumption that they had 2 ground pins? They seriously assume that everyone will connect the PHASE digital input to ground to get "symmetrical layout", and if you don't, well too bad. They literally made a bad layout for either a product that has 2 ground pins, or for marketing. And in my experience, crappy power inductors will be crappy and not contain fields properly, and good inductors will do, so if you are placing capacitors close to the inductor to "shield" fields, you are already grasping at straws.

really good examples for conducted emission. i always have similar view about ground saparation. thank you for experiment!

Thanks a lot for this video!!! Why the Xc curve at resonance frequency looks so noisy?

you only performed a conductive emissions test which determines if you have any common mode radiation coming in/out of your cables. Also, given that the CM filter did not help means it was poorly specified for the load which makes sense because when you design a CLC + Cd pi filter with damping bulk cap you need to know your load cases. separating grounds is a problem concerning return current paths. the flux coming out of the inductor will hit the top ground plane island and induce eddy currents in the copper layers. the island is to reduce the influence of this effect on neighboring components. the shielding capacitors also help with radiation leakage from the inductor. this test would be more conclusive if you performed a localized radiated emission test using RF probes at various points on the board surface to show how the emission pattern differs between designs.

Hi Min when your SMPS EMC course is coming?

This channel deserves way more attention! It is so hard to find such valuable and rich information nowadays.. Thank you so much for your work, people like you are a huge gain for the community! ❤

great video! continue your work!

A very interesting experiment and one that is in agreement with my personal experience as well. I have found that the difference between using a four layer board with two internal ground planes and a two layer board is very significant when it comes to emissions - after that, subsequent improvements are marginal. However, one reason to use copper ground on the top in a switching regulator layout is for thermal purposes, especially if the MOSFETs are integrated into the controller - I don't think this really needs to extend to the whole of the top layer though.

Interesting. I found this presentation of MPS: media.monolithicpower.com/mps_cms_document/e/m/EMI-Webinar-2.pdf (couple of sheets down: how to utilize a multi layer pcb…), datasheet evaluation board: www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/EVQ4430-L-00A/document_id/9652/ (page 14) and datasheet of the used chip: www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MPQ4430/document_id/4966/ (page 28/29) In the chip datasheet the pgnd on layer 1 is separated, but not the other layers, in the evaluation board layer 1 and 2: in the presentation they claim the vias will act as a filter to “block noise and clean GND”.

Thanks for sharing. one question, how did you get that 0.7 factor?

very useful and clear for understanding as usual.

Well, this seems to be one of those cases where they had multiple engineers in different locations, without their phone numbers, write the datasheet, do the datasheet layout recommendation, and do the evaluation board. The datasheet goes as far as to recommend/suggest not connecting AGND to PGND on the board because they are connected internally, then their example schematics show them connected externally but not in the layouts, and obviously in the EVM someone else decided to actually properly connect them. This is how you create myths, and like James Pawson likes to say "customers". The split results are boring because the split is not actually a split, and no surface current would (in my opinion) have any reason to cross it as everything is probably going through the vias to the second layer. Like others said, the non-power engineer with "I am not a power guy, these people made the part, they are" will blindly copy paste it into a different design where that will actually create issues, and then solder in 4 ferrite beads, 3 X2Y caps, and light a 7 candles in a star around the board with the conclusion "that is how you fix it".

It will be nice you explain the separate grounds for dc/dc isolation converter this is used at industrial applications to filter noise.

I wouldn't consider this a "split" plane in any standard sense, it appears more likely to be a thermal break from the top copper pour and the ground pad on the IC. Supporting this idea is the apparent trouble you had in getting a clean solder bridge between the two regions on the top layer.

Interesting! But is it really separated in this situation, with all those vias and GND at layer 2, 3 and 4? Although if implemented in another stackup/layer configuration, the results could be worse for the split. And depending on the di/dt. Do you have a link to the mps idea behind this cut?

The thing I'm mostly interested here ironically is the tent. I assume the tent is supposed to block radiation like a faraday cage. But from what I gathered, testing in a faraday cage isn't a good idea for radiation testing, because it will reflect the radiation and therefore will give you useless results? So what's the idea here? Also, if the power supply should be stable and you're in an office environment - why not just use an UPS in the office, physically disconnecting it from the grid? You need one anyways for open air testing with the antenna, because there's simply no power cable in the field?