Thank you, Ive been at this a long time and still learning. I expected the first steel plate to have a far more dramatic effect. And if I were EMC debugging I would have thought this trough for any piece of steel - I learned today steel can be anything - so something for me to be aware of. Thx for sharing.
I suspect the plates leave a small gap around the coils and we don't get a complete attenuation. I wonder how much it would change if the plates were slightly larger.
Now i think i understand why we should place telecomunication cables in difrent metal cable tray than power cables (low frequency emf) and why communication cables have copper shielding (hf emf). But still dont understand shielding grounding of telecommunication cables (should it be at one end or both ends). Can you make presentation with shielding plate grounding for high and low frequencies? please please please please please please @LearnEMC :) but wonder where to ground this shielding..
Please repeat the low/high frequency experiment, but this time connect the oscilloscope's second channel directly to the waveform generator input into the transmitting coil. Now compare the phase difference between the transmitting and receiving coil, or channel 1 and 2.
If the coils were separated by a known distsnce it should be possible to measure the speed of propagation of the magnetic field by doing this experiment. Have you or anyone else ever measured this?
At~ 7.14 you say “high permeability encourages the EMF to penetrate the material” attenuator yet permeability of free space is ideal, close or at zero… am i wrong?
Great video! Can you please give any advice for properly shielding PC? What i understood from those 2 videos is that you probably need some universald metal to be safe from both high and low frequencys, so what do you think would be a good choice for practical use?
You probably don't need to shield for low-frequency magnetic fields, so almost any metal would be the appropriate material choice. If (for some reason) you also need need to shield low-frequency magnetic fields, any steel that a magnet will stick too can be used to redirect those fields.
Put a coil of copper between the coils and see what the drop off is when compared to just sheets of copper. Is there a mass correlation here? A correlation to the number of turns?
im about to prime the entire inside of my new home. Do you think adding activated charcoal to the primer (then doing another coat of regular primer, then paint.) be good for emf?
How do you feel about cancer and emf fields being pointed at humans over long periods of time.horrible attachment or passed through minus the temperature just strong emf fields like a subwoofer vs how the exact amp and real reading the directed current being shot In ones direction. Danger levels?
You would have to describe your test set-up before we could offer a definitive explanation. However, a 180-degree phase shift would occur if you passed through a resonance and the coupling changed from inductive to capacitive.
LearnEMC, I've a cell phone app, which is showing that I've magnetic field upto 135 micro tesla, would that be high frequency, or low frequency? What kind of a material would be best for shielding, I need to shield an entire room.
@@LearnEMC It's some kind of a weapon, normal reading is around 25 microtesla on my meter, when this weapon gets turned on it causes headache, tooth aches, and problems breathing. I'm a Diplomat, and it's a weapon being used against us.
@@LearnEMC thanks for the feedback! we have a product (VFD+PMSM Motor) with aluminum housing that is over the limits in about 30MHz to 100MHz range, it seems that metal housing can't surpress high frequency noise completely?
@@xiaosun9111 EMC problems with motor drives are best handled by proper design. That's not something can be done via CZcams comments. I'd recommend you seek advice from someone who can review your current design.
Thank you, Ive been at this a long time and still learning. I expected the first steel plate to have a far more dramatic effect. And if I were EMC debugging I would have thought this trough for any piece of steel - I learned today steel can be anything - so something for me to be aware of. Thx for sharing.
Спасибо за видео, добрый человек! Здоровья и успехов.
This is a very nice demonstration of magnetic field behaviour!
Please keep on going with such kind of videos. Thank You.
I learn a lot from this channel, thank you!
Boa demonstração nesse video High-Frequency Magnetic Field Shielding Demonstration ( Ronaldo Lacerda Diadema )
I'd love to see the same video but using 10 Mhz and, of course, coils designed for the higher frequency. Interesting video. Thank you.
It would be interesting to talk about the loading effect upon the driver with these high frequency and low frequency experiments :)
I would be interested to see how a sheet of bismuth sheilds high frequency vs low frequency.
Hello brother Ilike your video thank you very much
I suspect the plates leave a small gap around the coils and we don't get a complete attenuation. I wonder how much it would change if the plates were slightly larger.
Now i think i understand why we should place telecomunication cables in difrent metal cable tray than power cables (low frequency emf) and why communication cables have copper shielding (hf emf). But still dont understand shielding grounding of telecommunication cables (should it be at one end or both ends). Can you make presentation with shielding plate grounding for high and low frequencies? please please please please please please @LearnEMC :) but wonder where to ground this shielding..
it is possible to shield a home against electromagnetic pulse?
good Demonstration ! if you can share the Electric Field Shielding Demostration,that is perfect!
If I'm not mistaken, silver is a higher conductor than copper. Would be interesting to see the effect.
Please repeat the low/high frequency experiment, but this time connect the oscilloscope's second channel directly to the waveform generator input into the transmitting coil. Now compare the phase difference between the transmitting and receiving coil, or channel 1 and 2.
If the coils were separated by a known distsnce it should be possible to measure the speed of propagation of the magnetic field by doing this experiment. Have you or anyone else ever measured this?
How are you doing I wonder if you could tell How do you detect EM Radiation Thank you
been trying to find a video for EMF sheilding a circuit breaker panel in my bedroom. can this be done and how? thanks
What about trying combination of them at once - like mu-metal along with copper? Will it shield further or not?
At~ 7.14 you say “high permeability encourages the EMF to penetrate the material” attenuator yet permeability of free space is ideal, close or at zero… am i wrong?
Great and helpful. Can you do one for a titanium plate, see if there is any shielding?
At high frequencies, yes, because titanium is a good conductor. At very low frequencies, no, because titanium is not magnetic.
yes
Great video! Can you please give any advice for properly shielding PC? What i understood from those 2 videos is that you probably need some universald metal to be safe from both high and low frequencys, so what do you think would be a good choice for practical use?
You probably don't need to shield for low-frequency magnetic fields, so almost any metal would be the appropriate material choice. If (for some reason) you also need need to shield low-frequency magnetic fields, any steel that a magnet will stick too can be used to redirect those fields.
Put a coil of copper between the coils and see what the drop off is when compared to just sheets of copper. Is there a mass correlation here? A correlation to the number of turns?
Excellent suggestion! We have not done this, but would expect a single-turn loop to be very effective if it were sized similar to the coils.
What material would be best to block 25-100gHz?
Thank you for this video! How effective is ~30um thick copper plane in PCB at typical SMPS frequencies (0.4-2.2MHz)?
Very effective at 2.2 MHz, where the skin depth is 18 um. A little less effective a 0.4 MHz where the skin depth is 42 um.
@@LearnEMC Thanks for you response. And thank you very much for all the resources you share on your site. I wish I could afford your courses!
What is the output power(mA) of the signal generator?
im about to prime the entire inside of my new home. Do you think adding activated charcoal to the primer (then doing another coat of regular primer, then paint.) be good for emf?
No. That is unlikely to make any measurable difference.
what about lead
Does grounding affect magnetic field blocking or lessening the strength of magnetic field - both low and high frequency fields?
Not significantly
Would it be any difference if the shielding was a) built as a box/cage around the coil and/or b) if the shield itself was grounded?
The conductive materials would work better around the whole coil, the non-conductive materials still wouldn't work. Grounding makes no difference.
@@LearnEMC Thanks! Then these guitar shieldings also shouldn't be grounded at all in theory?
czcams.com/video/tcXuVXrCxig/video.html
Sir can you please tell something about your 10khz sinewave generator. I have been trying different oscillator but none of them are stable.
It was a Rigol waveform generator.
How do you feel about cancer and emf fields being pointed at humans over long periods of time.horrible attachment or passed through minus the temperature just strong emf fields like a subwoofer vs how the exact amp and real reading the directed current being shot In ones direction. Danger levels?
Would a mesh sheet have the same attenuating effect?
Yes, to the extent that it allows the free flow of the eddy currents.
Intro Killed me haaaaaaaaa
Try Bismuth.
I noticed a magnetic field polarity reversal at about 800K hz, any explanation ?
You would have to describe your test set-up before we could offer a definitive explanation. However, a 180-degree phase shift would occur if you passed through a resonance and the coupling changed from inductive to capacitive.
@@LearnEMC That give me a field to explore to find my explanation, thank you very much for your response.
Hi,what's about titanium¿ does it shield¿¿
High frequencies, yes. Low-frequency magnetic fields, no. Titanium is conductive, but not magnetic.
@@LearnEMC thank you.
LearnEMC, I've a cell phone app, which is showing that I've magnetic field upto 135 micro tesla, would that be high frequency, or low frequency? What kind of a material would be best for shielding, I need to shield an entire room.
That is likely to be the earth's magnetic field. No need for shielding.
@@LearnEMC It's some kind of a weapon, normal reading is around 25 microtesla on my meter, when this weapon gets turned on it causes headache, tooth aches, and problems breathing.
I'm a Diplomat, and it's a weapon being used against us.
what about MHz?
The magnetic field is blocked by eddy currents at MHz and GHz frequencies also.
@@LearnEMC thanks for the feedback! we have a product (VFD+PMSM Motor) with aluminum housing that is over the limits in about 30MHz to 100MHz range, it seems that metal housing can't surpress high frequency noise completely?
@@xiaosun9111 You don't have a magnetic field shielding issue. Your emissions are due to the common-mode currents induced on the cables.
@@LearnEMC oh, thanks, can i solve the problem by using a ferrite core aroung the cable?
@@xiaosun9111 EMC problems with motor drives are best handled by proper design. That's not something can be done via CZcams comments. I'd recommend you seek advice from someone who can review your current design.