36) DIY TEM Cell for EMC Pre-Compliance Testing
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- Опубликовано: 9 апр 2018
- Today I’m attempting to make a TEM cell or transverse electromagnetic cell - used for doing EMC precompliance measurements. If you are trying to sell a product (legally), you must have your product reviewed and certified by an “EMC lab” for lack of a better term. This device will allow you to take some preliminary measurements to check and see if your whiz-bang product is radiating massive amounts of electromagnetic interference - before you dish out the big bucks at the certification lab. Happy testing!
Article referenced in the video:
eagle.chaosproject.com/sandbox...
Other interesting articles:
www.emcturkiye.org/papers/Sess...
journals.tubitak.gov.tr/elektr...
www.saelig.com/supplier/tekbox...
www.eetimes.com/document.asp?...
www.compliance-club.com/
www.hottconsultants.com/
www.amazon.com/Electromagneti... 
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I think you did a great job. From my experience even when you go to the test lab half the gear looks home brew. I’m going to have a go at making one it’s a nice project
This is an awesome video. Thanks for the info and links, very useful
Dropped by to say this is awesome... You are awesome!
Thank you so much man. Awesome content
Informative video, good music, high production values, thanks for another great episode! Now I'm curious how well this would work for understanding the behavior of digital circuits too, by looking at the overall emissions on a software defined radio... hmm!
Thanks Micah. I've been wanting to do this project for years. You bring up an interesting point. I'll probably use it in future videos for looking at clocks / switching and how to reduce noise - still pondering that one.
wow, thanks. never thought about it like that
Learn a lots from you .
Nice video buddy
Very informative. Thanks!
No, thank you!
Nice video. I have a GTEM cell I use at work. Been thinking about making one at home to check household LED bulb emissions. Your video will be helpful.
Awesome! I hope you get some usage out of it. Thanks for commenting
Thanks for a great video! You helped bridge the gap on some of the principles for me when you used the whiteboard, many thanks.
Did you happen to find any reference that permitted the septum distance to be different heights from the outer shields? The equations are dumbed down quite a bit, but I can imagine that moving the septum closer to the top to fit larger DUT's will keep the characteristic impedance the same if there is some small adjustment to the cross section of the septum. I read somewhere that a large DUT (>1/3 of the septum height) will significantly skew the open TEM cell results. Still good for troubleshooting, but unable to do go-nogo comparisons for large DUT's.
"I don't have any friends."
"Shit."
That's why I bought a welder.
😂
Thank you very much for showing testing .... could you please share all dimensions for metal cutting and assembly?
Small devices give radiation mainly from cables. I use a self-made (from a ferrite-clamp with 4 turns) Current probe to measure and then recalculate in excel to the radiation. Gives very good results, with accuracy will the device pass Class B or A.
its really helpfull .but i have some doubt in dimensions and thickness of septum and outer aluminium sheet.can u suggest better dimensions for 0- 300 mhz range ???
I'd been trying to characterize a short monopole (6cm) antenna in a TEM cell ELNA dc-1Ghz. Shows a beautiful ~6db/oct high pass response. That is then coupled to a filtered amplifier for an also beautiful flat response from about 20Mhz - >640Mhz to get a predictable AF for field strength measurements. Then tried an independent lab $$$ with a GTEM, not even close to the same results let alone repeatable. OATS is ridiculously expensive and then EMC laws take out the little guy........
Hi .. nice video . I'm from Brazil and I'm build the same TEM cell. One doubt at the begin of the video the septum center is made of copper plate ? Or was used PCB 2 sheet ? thank you
joao henrique angelo I used a double sided pcb, but etched off one side. You may have better performance with copper sheet, but I didn’t have any. Good luck!
@@AmRadPodcast thank you very much.
Hi Joao, I made many TEMs and GTEM in Brazil, you can use any conductive materials: copper, brass, aluminum (in this case you fix the pin soldered at yellow electric fastener with an M3 screw.... One face PCB or 2 faces doesn't change the performance, Some tricks are necessary to match properly the impedance: Columns to stabilize mechanically the structure, and try to change the angle of the screen near the connector, it helps to reduce the return loss ..Good work!!
Hi, do you still remember the thickness of aluminium and septum you used?
which factor is Dependant upon tapered angle of the TEM Cell?
I think it looks good. Grind it off and voila.
What material did u use? Looks like aluminum
ha perfect suggestion, thanks algorythm that will do...
Hey, I know you