EMI Causes & Cures

[@rossn5186]

I've created the very best antenna by powering a 4 meter long 24 vdc rgbw strip with + power in at one end and - power out (rgbw) at the other to prevent voltage drop, now I get shocking high frequency noise through my home theatre speakers whenever pwm is working to mix colours,dimming etc. Great advice , going to completely rewire (with shielded cable) all from one end of led strip keeping ALL cabling together and same length.

[@tfoxwa]

Glad the video helped..TFox

[@yashnu]

Brilliant series.

[@cct19840608]

Very good tutorial. Thanks a lot!!!

[@tpoppy9303]

Great info

[@christianbpperez6044]

I understood nothing, I’m not an electrician but I need help. I have a home recording studio and there’s a lot of emi in my room. What can I do to get rid of it??

[@tfoxwa]

You need to find a profession who does understand it and have the pro go through your entire environment.

[@christianbpperez6044]

Terry Fox i don’t want to pay 5,000 dollars to redo the whole room just something that I can do today that can help reduce EMI

[@zanekaminski]

@@christianbpperez6044 Unplug stuff until you find the main sources of interference. Then analyze the problems with those devices using the principles Terry has discussed in his videos

[@varunhajela9498]

Sir, Like you explained formation of Dipole by IC noise source at center, are there other ways antennas are formed on PCB (maybe monopole , patch etc)? Basically could you make a small video on link between SI and EMC (for example you told signal crosstalk can lead to radiation through LED ) , Inter relation between SI and EMC is not well understood by most people as they are treated as different streams. Maybe throw some light on how ringing eventually leads to radiation. Or why CM mode radiates so easily, You can list some examples per your experience.

[@varunhajela9498]

@@tfoxwa Sir, . I have seen and tried to analyze all your videos, Hope you wont mind answering some questions 1) In ringing of signal, we have basically inging frequency , which leads to increase in amplitude of the ringing freq element and its harmonics which can be clearly seen in Fourier transform. Now question is how this amplitude say 100 dbuV after doing fourier math will give me far field amplitude level that we see in any standards (say CISPR etc) while doing RE. Is there some thumb rule that this 100 dbuV of harmonics relate to this much emission (and is above CISPR or FCC levels). Can we roughly calculate , that if I have this much voltage of doing Fourier math - this will be emission seen after doing RE test say for 10m or 3m. To make it short is there a way to find that this many mV or dbuV of signal when measuring on say scope will give me what amplitude of emission at far field. 2) As per your one of the lectures via resonance can cause phase reversal and you mentioned it causes detection problems. Could you elaborate on this as phase reversal of signal causes issues in recovering data. 3) Could you provide some more examples of monopole antenna formed on the board like you did for dipole. Thanks !