Noise from a Toroidal Transformer

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RJS100
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Noise from a Toroidal Transformer

Post by RJS100 »

I am adding an ATC, and running out of space in my enclosure. The enclosure originally had high voltage and low voltage nicely separated. The only place I could find to add the Ether1616 board is on the door of the enclosure.

The only space I can find for the inputs/outputs from the Ether1616 board to exit the enclosure is in close proximity to the toroidal transformer. See attached, the red circle is where the wires would exit the enclosure. Does this usually cause issues?
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Red Circle - Wire Exit.jpg


eng199
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Re: Noise from a Toroidal Transformer

Post by eng199 »

Toroidal transformers radiate less noise than EI core, so that is working in your favor. Separating the signal wires from power will also increase your chance of success (don't strap all the wires to the bundle that is already there).


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Re: Noise from a Toroidal Transformer

Post by RJS100 »

Thanks! The wires that are already there are AC wires that power the coil of a contactor that turns on the power for the whole panel. I was able to move them to the back of the cabinet.

Thanks for your suggestions!

Richard


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Re: Noise from a Toroidal Transformer

Post by RJS100 »

I finally finished pulling all the wires for ATC. I guess I didn't expect them to take up as much space as they did :cry:

My concern is that when the door to the enclosure is closed, it pushes the wires closer to the toroidal transformer than I expected.

Do you think it is worth moving the toroid to a separate enclosure or is there anything I can put between the transformer and ATC wires to minimize EMI?

I am not really a happy the way this worked out. The panel was nicely organized before adding the ATC. In hindsight, I would have been better off using something like a 12-conductor shielded cable to handle the wires going directly to the ATC. This would significantly reduce the bulk of the wires.

Richard
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20250718_133151.jpg


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Re: Noise from a Toroidal Transformer

Post by cnckeith »

Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html


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Re: Noise from a Toroidal Transformer

Post by suntravel »

Yes, great video.

There are some discussions in German forums how to ground the shield, and Joey showed single ending to a common terminal is ok... :D

After posting this no one replied, maybe because I am a show better or shut up guy :mrgreen:

Uwe


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Re: Noise from a Toroidal Transformer

Post by RJS100 »

Thanks guys. I did indeed use shielded wire and ground according to the video. Perhaps I am overthinking it. I just didn't like the fact that the wires are so close to the toroid.


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Re: Noise from a Toroidal Transformer

Post by ShawnM »

So many builders use unshielded wire on critical connections and then wonder why they have noise and communication issues. Or I've even seen builders use shielded cable and not ground the drain wire. :shock: Guys will spend thousands and thousands of dollars and sometimes tens of thousands of dollars on a table and controller and then buy crappy wire on Amazon. Blows the mind. :o

Stepping down off my soapbox now. :D

I typically only ground one end of the shield and do this near the Acorn in the control cabinet on my ground bus bar. I've had two instances where I needed to ground both ends of a VFD cable to keep the noise out.

Thanks for sharing this Keith.


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Re: Noise from a Toroidal Transformer

Post by Muzzer »

suntravel wrote: Mon Jul 21, 2025 5:00 pm There are some discussions in German forums how to ground the shield, and Joey showed single ending to a common terminal is ok... :D
ShawnM wrote: Wed Jul 23, 2025 10:45 am I've had two instances where I needed to ground both ends of a VFD cable to keep the noise out.
This question of whether to ground one end or both ends of a screen is one of the oldest and hottest chestnuts. There is no right or wrong answer for all situations, as it depends on the installation. Some VFD manufacturers (eg Yaskawa) recommend both ends, while others recommend one end. Unless you are struggling to meet tight EMC test limits, it barely matters. As ShawnM says, it's a miracle many of the "spider's web" wiring schemes we see work in the first place, so the question of how to connect the screen is in the right zone.


ShawnM
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Re: Noise from a Toroidal Transformer

Post by ShawnM »

Muzzer wrote: Sat Jul 26, 2025 3:45 pm
suntravel wrote: Mon Jul 21, 2025 5:00 pm There are some discussions in German forums how to ground the shield, and Joey showed single ending to a common terminal is ok... :D
ShawnM wrote: Wed Jul 23, 2025 10:45 am I've had two instances where I needed to ground both ends of a VFD cable to keep the noise out.
This question of whether to ground one end or both ends of a screen is one of the oldest and hottest chestnuts. There is no right or wrong answer for all situations, as it depends on the installation. Some VFD manufacturers (eg Yaskawa) recommend both ends, while others recommend one end. Unless you are struggling to meet tight EMC test limits, it barely matters. As ShawnM says, it's a miracle many of the "spider's web" wiring schemes we see work in the first place, so the question of how to connect the screen is in the right zone.
I agree 100%, grounding the shields/drain wire can be machine/build specific but you have to at least ground ONE END for it to even be beneficial. Hell, you have to use shielded wire to EVEN have the shield/drain wire to ground. :D

The first thing I look at is someone's report when they come on here with weird "gremlins" in their build is the error log to see if they have noise/communication issues and what do you know, they do. Then I look at their build pics and there are unshielded wires everywhere with no dedicated ground bus. :o

We all know this isn't a cheap hobby so why would you treat it as one? I know we are all on a budget of some sort but wire isn't the place to try to go cheap. Spend a few extra bucks up front on good quality wire and save yourself a ton of wasted time and headaches later on chasing your tail around the electrical enclosure looking for those gremlins. :D


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