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    EMI and Ferrite Cores

    Scheduled Pinned Locked Moved IT Discussion
    ferriteelectromagnetic inemiferrite coreferrite choke
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    • gjacobseG
      gjacobse @Brains
      last edited by

      @Brains said:

      Also when I worked for the cable company we had "Signal Leakage" meters. Is there a similar meter that can assist me in pinpointing the source or direction the interference is coming from?

      I see that you have dimmers - these themselves can be noisy. if they are off, they should not generate noise.

      scottalanmillerS 1 Reply Last reply Reply Quote 2
      • scottalanmillerS
        scottalanmiller @gjacobse
        last edited by

        @g.jacobse said:

        @Brains said:

        Also when I worked for the cable company we had "Signal Leakage" meters. Is there a similar meter that can assist me in pinpointing the source or direction the interference is coming from?

        I see that you have dimmers - these themselves can be noisy. if they are off, they should not generate noise.

        So much that you can actually HEAR them!

        1 Reply Last reply Reply Quote 1
        • BrainsB
          Brains
          last edited by

          any other ideas or suggestions guys? This is pretty far out of scope, and I have limited experience this deep in.

          scottalanmillerS 1 Reply Last reply Reply Quote 0
          • scottalanmillerS
            scottalanmiller @Brains
            last edited by

            @Brains said:

            any other ideas or suggestions guys? This is pretty far out of scope, and I have limited experience this deep in.

            Unfortunately this is an electrical engineering thing and not an IT thing. While we know of the issues, I don't think that anyone here is trained or qualified to help. Have you looked into bringing in an EE for this?

            1 Reply Last reply Reply Quote 1
            • BrainsB
              Brains
              last edited by

              Im talking to some of my EE friends from college, but they havent been of any significant help yet. I would like to pass this off to a professional qualified to deal with it, but I dont even know where to start. Any ideas?

              1 Reply Last reply Reply Quote 0
              • MattSpellerM
                MattSpeller
                last edited by MattSpeller

                Did some EE, still do for a hobby.

                Having trouble figuring out what the actual problem is in your post - 180hz signal shouldn't be there? What should? How do you know it's 180hz?

                Could you link to the products you're using? From below you didn't really give what model etc. I found these, but not sure.
                http://www.jjengineering.com/C6.htm

                1 Reply Last reply Reply Quote 1
                • BrainsB
                  Brains
                  last edited by Brains

                  @MattSpeller said:

                  didn't really give what m

                  Thanks Matt. I appreciate the offer of help.
                  I have attached a screenshot from the monitoring software. Yes the 180Hz signal should not be present, or at least prevalent in the pictures. He is reading very low frequency electrical impulses and this signal is throwing off the tests.

                  upload-8fc07b6b-92ec-4579-a70f-9ebce53df9f5

                  He is sending me the model numbers of the equipment in the morning. In the meantime, could you help me pick out some ferrite cores that may be able to help filter this 180Hz (3rd Harmonic?) interference? I was about to order some, but then I noticed that there were different types for different frequencies, and I cant make heads or tails of which one I need.

                  MattSpellerM 1 Reply Last reply Reply Quote 0
                  • MattSpellerM
                    MattSpeller @Brains
                    last edited by

                    @Brains Alright, well from what I remember I don't think chokes work that way - at least how you want it to in this instance. I will have to read up on them again to make sure I'm correct there!

                    Onwards; 180hz is super low and an odd one. 3rd harmonic of the 60hz powerline, no doubt that could be the source. Unusual to only see the harmonic though, do you also see 120 & 60? (60 should be a huge spike if it's AXT (alien cross talk) from a transformer or something nasty). You've already tried isolating it from outside noise and it sounds like you did a pretty good job of it.

                    Next up I'd look at the device it's self and read it's manual. I'm willing to bet it has internal filters for this kind of thing - if not I'm almost certain that it'll mention how to deal with AXT as it's such a sensitive device you won't be alone in having issues with interference.

                    1 Reply Last reply Reply Quote 0
                    • BrainsB
                      Brains
                      last edited by Brains

                      Thanks for the followup Matt.

                      I went through some of the logs of tests performed. When there was a transformer close, it definitely cycled every 60/120/180, but with everything turned off, this is what we see

                      upload-08302f62-e439-4105-9d53-4bb27c212692

                      He has spoken with the manufacturers of both devices and they have been of no help unfortunately. When I get the model#'s tomorrow, I will try to give them a call and see if we can have a detailed conversation about our options. I do not expect this to be productive as the user using this equipment is pretty intelligent and understands some of this better than I do and was not able to glean any information. I am very good at cutting through red tape and double talk from tech support, so maybe I will be able to get something helpful.

                      FYI he is usually using a desktop to perform these tests, and the problem is apparent on both the PC and laptop (Laptop is unplugged of course)

                      1 Reply Last reply Reply Quote 1
                      • MattSpellerM
                        MattSpeller
                        last edited by

                        Very interesting

                        If you have access to an oscilloscope or a signal gen you could probe it out a bit further... very intrigued and I hope you let us know how it plays out!

                        BrainsB 1 Reply Last reply Reply Quote 0
                        • BrainsB
                          Brains @MattSpeller
                          last edited by

                          @MattSpeller

                          The models are:

                          Thought Technology: ProComp Infinity Model SA7500
                          J&J: I-330 C2 Plus

                          1 Reply Last reply Reply Quote 1
                          • MattSpellerM
                            MattSpeller
                            last edited by

                            Page 5, try self calibration
                            http://www.thoughttechnology.com/pdf/manuals/SA7510 rev. 7 ProComp Infiniti User Manual.pdf

                            Try replacing the fiber - that shit breaks so easily and I'm guessing the Doc isn't familiar with using it

                            BrainsB 1 Reply Last reply Reply Quote 0
                            • BrainsB
                              Brains @MattSpeller
                              last edited by

                              @MattSpeller so you think there may be a small break in the fiber that could be letting the EMI in, its just not bad enough to cause the unit to stop working?

                              Ill send this over to the user and ask him to try it

                              MattSpellerM 1 Reply Last reply Reply Quote 0
                              • MattSpellerM
                                MattSpeller @Brains
                                last edited by

                                @Brains just trying to think of the most common things to break - fiber is always top of the list.

                                BrainsB 1 Reply Last reply Reply Quote 1
                                • BrainsB
                                  Brains @MattSpeller
                                  last edited by

                                  @MattSpeller awesome. He is receptive and will take care of that this weekend or Monday. I am open to any ideas, I was also wondering if it might be a case of "dirty power" in the building? Maybe we have some feedback from the AC Units being sent back along the line? Since this happens in many different places in the building, maybe we could install something to "clean up" the power. Before today I always considered those power cleaners a scam, but this seems like the intended usage if I ever saw one

                                  MattSpellerM 2 Replies Last reply Reply Quote 0
                                  • MattSpellerM
                                    MattSpeller @Brains
                                    last edited by

                                    @Brains Power cleaners won't help you*, but I do recommend you try it outside the building in a big field or something.

                                    *the units are battery powered IIRC

                                    1 Reply Last reply Reply Quote 0
                                    • MattSpellerM
                                      MattSpeller @Brains
                                      last edited by MattSpeller

                                      @Brains said:

                                      @MattSpeller Maybe we have some feedback from the AC Units being sent back along the line?

                                      I've seen huge underground transformers cause bullshit like this before with testing gear.
                                      Edit: they're not typically under the building though...

                                      1 Reply Last reply Reply Quote 0
                                      • BrainsB
                                        Brains
                                        last edited by Brains

                                        I know it has been a while since I last updated, but we finally came to a resolution a few weeks ago and I haven't had a chance to update yet.

                                        And....... it completely disappeared without a trace. haha well that is typically my luck so I wasn't too surprised.

                                        We were able to walk around with the equipment and a laptop across the entire property, and believe we did identify the cause as our next door neighbors. They are a medical facility with some MRIs, so maybe their equipment was failing and they replaced a part.

                                        One piece of additional information, I was able to have some really good conversations with their tech support and learned that they do have internal filters for 60Hz so that explains the absence of a 60Hz signal. I appreciate all the help from everyone on this forum. It was my beacon of light in a sea of confusing data.

                                        Hope you guys are having a good April 1st. Don't trust everything you read

                                        1 Reply Last reply Reply Quote 1
                                        • ?
                                          A Former User
                                          last edited by

                                          I've used Ferrite cores a lot with cat5e on cell towers to block RF from the cellular antennas.

                                          1 Reply Last reply Reply Quote 2
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