Hi Ron I have been following this thread closely to see what people think about Migraines. As a Traumatic Brain Injury (TBI) survivor and Migraine sufferer I understand your employees pain! I love the long dictations of "Other Reasons" for the Migraine and talk of placebo effect. Migraines are no joke, and no fun.
Triggers for Migraines can be many things, strong perfumes are a good one for me. But I will say that inverters are a trigger also. I have 3 different inverters in my power room. I do not have problems with the Magnum or Outbacks, But the new Bergey 10Kw inverter will set me off when it is running at a specific power level with me working close by. I think in that inverter it is the inductors. I find that is is not the "Sound" but a frequency (non-sound) harmonic that is radiated. I am sure you can use a scope to see this, but a easy way to understand this is to lightly hold a large flat NEO magnet in your cupped hand. Then place your hand close to the DC power feed cables running from the battery bank to your inverter. The magnet will vibrate (resonate) at that inverters frequency. I find that when charging from the inverter or inverting heavy from the battery you can have large amounts of harmonics, and it is interesting to see how much the magnet vibrates in your hand. The suggestion of twisting the cables really helps reduce this! On a side note the Magnum inverter has different harmonics than the Outbacks. So, do you have a place that the employee can move to that is not near the inverter? I think that is the simple solution. Logan > Ron Young wrote: >> Mike, >> >> Some interesting points, thank you. I would have attributed the >> problem to several of the mentioned issues, medications (HRT), >> clenching, tension... But what happened a couple of days ago makes me >> wonder. I turned on the inverter without her knowledge and within two >> minutes she was complaining and asked me if it was on. It was right at >> quitting time and she was out of the environment within 7-8 minutes >> but the next day she complained that she had a "migraine" that night. >> >> Ron > > Yep, it's gotta be the sound. I'm 95+% sure... > > If you want to try to tweak things, a decent microphone running into > a higher sample > rate A/D on a laptop with (96 kHz or 192 kHz) and a program with > spectrum analyzer can help > to adjust things to possibly quiet it down some. Maybe if you know > someone into audio you could > have them come over and bring their goodies to help you sorta "see" the > sound in the room. > > Then, you could try tweaking things lik, tightening screws and putting > in a baffle or > something until that 20 kHz frequency spike comes down, say, 10 or 20+ > dB or so. > > Might just work. But, then again..... > boB > > > >> >> On 4-Feb-10, at 6:41 PM, Ron Young wrote: >> >>> forwarded from earth2 >>> >>> >>> Begin forwarded message: >>> >>>> *From: *"Michael Gullo" <mgul...@comcast.net >>>> <mailto:mgul...@comcast.net>> >>>> *Date: *February 4, 2010 5:47:56 PM PST (CA) >>>> *To: *"RE-wrenches" <re-wrenches@lists.re-wrenches.org >>>> <mailto:re-wrenches@lists.re-wrenches.org>> >>>> *Subject: **Re: [RE-wrenches] Inverter causing migraine? >>>> **Reply-To: *RE-wrenches <re-wrenches@lists.re-wrenches.org >>>> <mailto:re-wrenches@lists.re-wrenches.org>> >>>> >>>> Hi Ron and the group, >>>> >>>> The attribution of negative health effects to exposure to >>>> electromagnetic fields or activated electric equipment has not been >>>> confirmed in random double-blind provocation studies involving >>>> persons reporting hypersensitivity to electricity. Before we accuse >>>> are hard-working inverters, let's look at some facts. There are 13 >>>> different categories of headaches which are divided into over 129 >>>> sub-types. Many people call every headache they experience as >>>> migraine when in fact there are specific inclusion criteria to make >>>> diagnosis of migraine. The "rubber band tightening around my head" >>>> is a classic symptom of tension-type headache. Given a mid 50's >>>> female, there are more likely one or more provoking factors: >>>> medications, sleep pattern, hormonal replacement therapy, stress >>>> (clenching, TMJ), smoker, foods (aged cheese, alcohol, caffeine, >>>> chocolate, dairy products, MSGs, etc). Does she work at a computer >>>> using a chair with no arms and no lower back support with a monitor >>>> slightly higher than eye level? This is an extremely common scenario >>>> in which the employee comes to work symptom-free and by 12 or 1:00 >>>> develops a headache or neck ache. If she really wants some answers, >>>> she will need to keep a headache diary for several weeks and seek >>>> professional help. You could cycle the inverter on/off to see if >>>> there is a direct correlation between the incidence of the headaches >>>> and runtime of the inverter. BTW, the placebo effect, as mentioned >>>> in other emails, is between 40-60% effective at resolving symptoms. >>>> Hope this helps a bit. >>>> >>>> Mike >>>> Michael Gullo >>>> Solar Solutions LLC >>>> Marlton, NJ >>>> >>>> NABCEP Certified PV Installer T >>>> Diplomate American Board of Orofacial Pain >>>> >>>> ----- Original Message ----- From: "Ron Young" >>>> <solarea...@solareagle.com <mailto:solarea...@solareagle.com>> >>>> To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org >>>> <mailto:re-wrenches@lists.re-wrenches.org>> >>>> Sent: Thursday, February 04, 2010 1:19 PM >>>> Subject: Re: [RE-wrenches] Inverter causing migraine? >>>> >>>> >>>>> Bob, >>>>> Not a customer, an employee who works for me. She is mid 50's and >>>>> has very good hearing. You may be right about sound. I also think >>>>> there's a significant portion of psychosomatic in the mix but I >>>>> wanted to find out if there were other instances of people >>>>> experiencing distress from inverter operation just to rule out the >>>>> possibility -or take it into account. >>>>> >>>>> I know that some people are becoming more sensitive to >>>>> environmental influences but this inverter is quiet, just the usual >>>>> fan sound occasionally. I used to be able to hear the sound of an >>>>> ultrasonic alarm system back when I was in my 20's & 30's - now I >>>>> just hear ringing in my ears. >>>>> >>>>> Ron >>>>> >>>>> >>>>> On 4-Feb-10, at 1:30 AM, boB Gudgel wrote: >>>>> >>>>>> >>>>>> Dan Fink said: >>>>>> >>>>>> "That's a tricky situation. There are only two possibilities >>>>>> for what's causing the problem; sound or electromagnetic radiation" >>>>>> >>>>>> I'm betting that it's sound. Remember how you could >>>>>> hear televisions singing >>>>>> away at 15 kHz ?? That still gives some people headaches. >>>>>> >>>>>> How old is this customer ?? I'm guessing he's young because >>>>>> it's most likely because he >>>>>> can hear the inverter switching. We just can't normally >>>>>> hear them.... The FX/VFX >>>>>> inverters switch at around 20 kHz which some people can still >>>>>> hear. Especially younger ones >>>>>> with better hearing. >>>>>> >>>>>> It's probably the transformer windings and iron acting as a >>>>>> speaker/ transducer. >>>>>> >>>>>> High frequencies are very directional so will usually respond >>>>>> well to a thin wall of >>>>>> padding between inverter and the rest of the inside of the house >>>>>> or cabin. >>>>>> That should help reduce the acoustical output. >>>>>> >>>>>> boB >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> Dan Fink wrote: >>>>>>> Joel -- >>>>>>> Good points. In a recent newspaper article in Boulder, CO about a >>>>>>> really bad PV install, the direct grid tie inverter was >>>>>>> mounted right on the outside of the wall from the homeowner's >>>>>>> bed. They finally had to have it moved--mostly because of >>>>>>> buzzing, but EMF was a concern too. It was basically less than a >>>>>>> foot from the guy's pillow. >>>>>>> >>>>>>> Also, I forgot to mention that there are fairly inexpensive >>>>>>> EMF meters available from the same places that sell DIY >>>>>>> shielding materials. >>>>>>> >>>>>>> The biggest source of EMF at *my* house is actually the E-Meter >>>>>>> measuring amp-hours. It even interferes with my handheld ham >>>>>>> and fire department radio FM communications on 2 meter. >>>>>>> >>>>>>> DAN FINK >>>>>>> Renewable Energy Consultant >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> Joel Davidson wrote: >>>>>>>> Ron, >>>>>>>> >>>>>>>> Electromagnetic fields are produced any time you have >>>>>>>> current flowing through wire. They are low frequency waves that >>>>>>>> drop off rapidly proportional to the distance from the source. >>>>>>>> Inverters, transformers, fluorescent light ballasts, motors, >>>>>>>> clock radios, power blocks, microwave ovens, kilowatt hour >>>>>>>> meters, service panels all emit EMF. There is no >>>>>>>> practical way to block EMF. It passes through almost everything >>>>>>>> including walls and even lead. There is no U.S. safety >>>>>>>> standard for EMF. Some say 8 milligauss or more is dangerous >>>>>>>> and 2.5 milligauss or less is safe. >>>>>>>> >>>>>>>> I went through our home about 10 years ago using a >>>>>>>> borrowed milligauss meter (thanks David Katz). Our utility >>>>>>>> meter service had significant EMF, but that was not a problem >>>>>>>> since it is mounted on an outside wall and there is a closet >>>>>>>> between the living space and the meter. The EMF had fallen to >>>>>>>> below 2 milligauss between the wall and the closet door. The >>>>>>>> bedroom clock radio was the second largest EMF source in our >>>>>>>> home. Moving the clock 1 foot away from the bed to the other >>>>>>>> side of the night stand brought the EMF levels under 2 >>>>>>>> milligauss. Our SW4048 inverter emitted a field that fell to a >>>>>>>> safe level 2 feet from the inverter. >>>>>>>> >>>>>>>> I tell people not to put their bed against the wall where their >>>>>>>> utility service panel or inverter is mounted. I also tell >>>>>>>> them that the Japanese did a 2 year study of school children >>>>>>>> riding the Tokyo subway (big EMF emitter) and found that there >>>>>>>> was no danger. >>>>>>>> >>>>>>>> Some sounds that most of us take for granted can cause physical >>>>>>>> discomfort and even pain. SW4048 and other transformer and >>>>>>>> electrical and electronic buzzing can be annoying. Also certain >>>>>>>> wavelengths and intensities of light can cause pain and injury. >>>>>>>> >>>>>>>> Joel Davidson >>>>>>> _______________________________________________ >>>>>>> List sponsored by Home Power magazine >>>>>>> >>>>>>> List Address: RE-wrenches@lists.re-wrenches.org >>>>>>> <mailto:RE-wrenches@lists.re-wrenches.org> >>>>>>> >>>>>>> Options & settings: >>>>>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>>>>>> >>>>>>> List-Archive: >>>>>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >>>>>>> >>>>>>> List rules & etiquette: >>>>>>> www.re-wrenches.org/etiquette.htm >>>>>>> <http://www.re-wrenches.org/etiquette.htm> >>>>>>> >>>>>>> Check out participant bios: >>>>>>> www.members.re-wrenches.org >>>>>>> >>>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> List sponsored by Home Power magazine >>>>>> >>>>>> List Address: RE-wrenches@lists.re-wrenches.org >>>>>> <mailto:RE-wrenches@lists.re-wrenches.org> >>>>>> >>>>>> Options & settings: >>>>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>>>>> >>>>>> List-Archive: >>>>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >>>>>> >>>>>> List rules & etiquette: >>>>>> www.re-wrenches.org/etiquette.htm >>>>>> <http://www.re-wrenches.org/etiquette.htm> >>>>>> >>>>>> Check out participant bios: >>>>>> www.members.re-wrenches.org >>>>>> >>>>> >>>>> _______________________________________________ >>>>> List sponsored by Home Power magazine >>>>> >>>>> List Address: RE-wrenches@lists.re-wrenches.org >>>>> <mailto:RE-wrenches@lists.re-wrenches.org> >>>>> >>>>> Options & settings: >>>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>>>> >>>>> List-Archive: >>>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >>>>> >>>>> List rules & etiquette: >>>>> www.re-wrenches.org/etiquette.htm >>>>> <http://www.re-wrenches.org/etiquette.htm> >>>>> >>>>> Check out participant bios: >>>>> www.members.re-wrenches.org >>>>> >>>> >>>> _______________________________________________ >>>> List sponsored by Home Power magazine >>>> >>>> List Address: RE-wrenches@lists.re-wrenches.org >>>> <mailto:RE-wrenches@lists.re-wrenches.org> >>>> >>>> Options & settings: >>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>>> >>>> List-Archive: >>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >>>> >>>> List rules & etiquette: >>>> www.re-wrenches.org/etiquette.htm >>>> <http://www.re-wrenches.org/etiquette.htm> >>>> >>>> Check out participant bios: >>>> www.members.re-wrenches.org >>>> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> List sponsored by Home Power magazine >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Options & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out participant bios: >> www.members.re-wrenches.org >> >> > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
