Do our controllers pose any health risk?

John in CR

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Our bike controller must put out some electronic noise. Other that electrocution or maybe for people with pacemakers, do they pose any health risk? On my main bike the controller is under the seat, but it's a motorcycle seat, so it gives me an extra shell of steel between my controller and the family jewels. I'd rather avoid becoming like Lance Armstrong, no matter how good a cyclist it makes me afterward.
 
Even with 100+ amps flowing through the wiring, the magnetic field generated is rather small compared to what's going on with those spinning magnets in the wheels (even accounting for the 1/(D^2) drop-off of the field with distance. Or the field generated by the magnets in earphones. Your McNuggets are probably safe. YMFMV. If you are concerned, just remove them goolies before each trip and store them in a safe place.
 
Well John the latest Scientific American has an article about using magnetic energy (a lot like 1.5 Teslas) held right near your head to help cure depression. This is MRI strength with cooled magnets but the controller probably does not radiate much. I am sure one of the folks who know electronics well could put a meter on a controller. I am not sure what kind of EMF would be dangerous. A really good question. I hope LFP, Doc or Methods type people could help.
otherDoc
 
Drunkskunk said:
The controller box is metal, right? Its a basic Faraday shield. I'd be more worried about your Computer moniter, Cell phone, and the electrical wires in the wall.

You're right mine was a stupid question. I was thinking it had to be ferrous metal to shield. I should have looked it up. Re: cell phones I used to keep it in my pocket, but when I saw it's affect on a speaker a couple of feet away when a call came in, I thought maybe there is something to the claims they may cause brain tumors.
 
A faraday cage might block electric fields (but your controller box probably won't), but it is almost certainly transparent to magnetic fields. Put a magnet in an aluminum box. Stick one on the outside. Guess what happens?

Also, the high power cables going to and from the controller generate magnetic fields. The 4 gauge cables to my capacitor discharge battery tab welder electrodes want to give you a serious bitch slap when you fire a weld pulse at higher power levels (but then it can crank out over 20,000 amps at 20V) They will jump about a foot.

That said, fields drop off with the square of the distance. The wavelength of the signals involved in controllers (20 KHz) is VERY long... much longer than you... like 10 miles long. The field gradient across your 6 feet is tiny. Cell phones on the other hand operate at a frequency VERY close to that of your microwave oven... It's less than a watt or two, but you stick that puppy in your ear and carry it next to your nads.
 
We're surrounded by devices which radiate EM fields - anything with a brushed electric motor produces a lot of broadband noise, for example (small appliances, hair dryer, power tools...). I don't think a controller would be significantly worse. As has already been mentioned, the inverse square law applies so if you're nervous just move it a little further away. I actually don't think the wires would radiate very much since the current is always flowing in a balanced pair. The currents flowing in and out will tend to cancel each others' fields. The noise generated inside the controller should be at least partially blocked by the metal case.

You are correct that a non-ferrous metal case will not block DC (static) magnetic fields. It will block non-DC fields, such as the switching EMI. For non-DC fields, the electric and magnetic fields are linked (hence the term electromagnetic field), so a conductive shield will block EM even if it is non-ferrous. These metal cases are far from a perfect Faraday cage, but every little bit helps.
 
Yeah, the EM radiation from the controller electronics is trivial. Less that what those TV/radio stations 20 miles away are blasting you with. The only potentially significant source in an ebike is the fields associated with the motor phase currents. Those currents are at a rather low frequency that has a huge wavelength compared to your body size... very unlikely to interact.

Electricity has been hanging around us for over a century now. Somebody would have notice all the three eyed, twelve toed babies by now. (OK, the kid down the road has twelve toes, so does his dad. And a mechanic I know has six fingers on one hand. But they all only have two eyes each)
 
No more health risk than the pulluted air we have to breath from cars...
 
^ Sad but true!
 
By far, our biggest heath risk is when inertial meets concrete. Followed closely by sheet metal (usually in SUV form, driven by some POS soccer mom yammering on her cell phone, oblivious to the rest of the world). :x


I did a quick test of aluminum cases shielding 20 KHz signals. I sealed up a small MC34063 based DC-DC converter, battery, and load in an aluminum case (A very high quality, unused microwave brick. No openings. All seams were either dovetails in slots or overlapped tongue in groove). I used a coil hooked to an oscilloscope to sample the radiation from the converter choke. It was around 12% lower when the unit was sealed in the case.
 
Hi,

There is no conclusive proof of tabacco having a negative impact on health but there is a lot of evidence pointing in that direction.

There is no conclusive proof of EMF having a negative impact on health but there is also a lot of evidence pointing in that direction. I'd say given the evidence its prudent to minimize your exposure as much as possible.

I don't normally trust "research" funded by industry but George Carlo's meticulous and well funded research is an exception. You can view an interview with Dr. Carlo here about the risks posed by Cell Phones here (length 4:40). He states that today there are between 30k and 50k cases of Brain and Eye Cancer (I think annually) due to Cell Phone use. By 2010 close to 500k every year.
[youtube]2GD_BKTWyTY[/youtube]
TV Interview with Dr. Carlo (Campbell Live, TV3)
Dr. Carlo talks about the cell phone industry’s marketing towards children and the epidemic projections from cell phone use.
George Carlo's book:
Cell Phones: Invisible Hazards in the Wireless Age: An Insider's Alarming Discoveries about Cancer and Genetic Damage (Paperback)
http://www.amazon.com/Cell-Phones-I...=sr_1_1?ie=UTF8&s=books&qid=1252875096&sr=1-1
Publishers Weekly Review
In 1993, when the cell phone industry’s chief lobbyist hired epidemiologist and pathologist Carlo to refute claims that cell phones, which had never been subjected to premarket testing, cause cancer, no one thought he would discover otherwise.

But after six years of exhaustive analysis and scrupulous peer review, the results proved, according to this report, that radiation from a cell phone’s antenna can cause the formation of micronuclei red flags for cancer in the brain. Children in particular are more susceptible to the radiation than adults.

Carlo reported his findings to the industry and the FDA and advocated for continued research, but both parties still maintain that cell phones are safe. Here, Carlo and syndicated columnist Schram retrace Carlo’s scientific undertaking and what they cast as a sinister web of corporate greed and masterful PR “spin” that choked his efforts.

Schram provides the primary narrative, with Carlo’s insights and recollections scattered throughout, a format that grows repetitive. Despite the captivating story, many consumers won’t want to slog through the detailed scientific explanations to get to the bottom-line safety recommendations.

More info on Dr. Carlo here:
http://en.wikipedia.org/wiki/George_Carlo

And here:
http://www.hans.org/magazine/349/A-Real-Hero-George-Carlo
A Real Hero: George Carlo, PhD
by Milt Bowling
Source: Health Action Magazine Fall 2006

Webster's Dictionary defines hero as: "a man of exceptional quality who wins admiration by noble deeds, especially deeds of courage." George Carlo is such a man.

In 1993, the wireless industry was sued by a Florida man whose wife died from a brain tumour. He alleged that her fatal illness was caused by her constant use of her cell phone. Although the case was eventually lost years later, the negative publicity caused the US Congress to hold hearings on the subject of cell phones and brain cancer. Through the process of the Congressional hearings, it became clear that the wireless industry had not been required to do pre-market testing or any post market surveillance on health effects of cell phones. The industry had just assumed that the technology was perfectly safe.

After these hearings, they realized that they could only sidestep hard regulation by the Food and Drug Administration by volunteering to conduct research on the scientific verification that cell phones' exposure was benign. The industry cut the deal with the government – the industry puts up the money for the research and the FDA waits for the results before deciding whether or not to regulate. And they needed a scientist with recognized credentials to run the program – to manage not only the research, but also regulatory aspects and the public relations.

The scientist they picked was Dr George Carlo. After all, he was a world recognized medical scientist, author and lawyer. His career spanned thirty years, with more than 150 medical, scientific and public policy publications in the areas of public health, workplace safety and consumer protection. He was well respected in Washington, having served on several government committees, worked with several government agencies, and was often sought by the news media to opine on issues related to public health and consumer safety. He was just the man to oversee the surveillance and conduct the studies. The industry expected that they had found the man who would give them the all-clear.

So, in 1993 Dr. Carlo was put in charge of what became a 6 year, $28.5 million surveillance and research program that in the industry's mind, was to prove that cell phones were safe. It took years to set up the research and to develop proper protocols, and at first the results looked reassuring to the industry. But by 1998, some troubling findings were emerging. Dr Carlo was in the difficult position of having to tell the wireless industry news they didn't want to hear. Their technology could be very dangerous. He also told them they needed to do more research to pursue these troubling findings, to get at the truth.

So that there would be no perceived conflicts regarding his motivation, Dr Carlo clearly indicated that he was going to step down from his position so that the funds could be given to someone "without the perception of an agenda." However, when Dr Carlo rebuffed their offers of financial reward in exchange for being quiet, instead of providing the needed funding to whoever Dr Carlo's successor would be, the industry began an all out program to distance themselves from Dr Carlo and his findings. Rumors were started about both his professional and his personal life. Fabricated stories of impropriety were planted on the Internet. His divorce records were made public. And then the personal attacks began. He was threatened financially and physically. Finally, his house was destroyed by arson.

He was forced to go underground for a few years, for both his personal safety and mental well-being. But by the end of 2004, studies that had been conducted under the oversight of the European Union not only verified Dr Carlo's findings, but added new data making it clear that mobile phones were indeed dangerous.

I first heard of Dr Carlo in 1997, when I became an EMF advocate. In 1998, he wrote a very pointed letter to C Michael Armstrong, Chair of AT&T, and to the other CEOs of the corporations which funded his work, warning them not to take the same route as the tobacco industry did, in buying science and giving falseconfidence that there were no adverse health effects.

This letter was leaked to the media, and eventually made it to the Internet. Television news magazines picked up the story and by the end of 1999, Dr Carlo was in an open war of wills with the entire global wireless industry. When Dr Carlo went public with his findings, and then stood his ground against the attacks of the industry, it gave every activist and advocate a much needed boost in confidence. If Dr Carlo, who had been viewed as an industry "hired gun", saw enough danger to put his contrary opinions in writing, then activists were confirmed in having been right all along.

In 2001, Dr Carlo co-wrote, with Washington syndicated columnist Martin Schram, Cell Phones: Invisible Hazards in the Wireless Age. The acclaimed book, which is printed in five languages, tells the story of this classic clash between science and the politics of power and profits. The work of Dr Carlo, who remains the Chairman of the non-profit Science and Public Policy Institute in Washington, DC, is the subject of a Hollywood docudrama to be released in 2007.

Over the years, I have known Dr Carlo – first as the "industry's hired gun", later as a source of data to help me with my work in furthering the cause of public health, and most recently as a working colleague. When you work next to someone, you get to know what they are made of. Not many people have the courage to stand up for what they believe in. Not many have the courage to stand up to their employer, let alone a trillion dollar industry.

Dr Carlo is, simply put, a hero.

HANS consultant and member Milt Bowling is President of the Clean Energy Foundation, http://www.cleanenergycanada.com, which works with the public, industry and government for better regulations and safer technology.
 
bull, there is no evidence to support this lawyer's retirement plan claim that cell phones cause cancer. period.

there is clear and undeniable evidence that smoking induces cancerous transformation of susceptible cells. period.
 
dnmun said:
bull, there is no evidence to support this lawyer's retirement plan claim that cell phones cause cancer. period.

there is clear and undeniable evidence that smoking induces cancerous transformation of susceptible cells. period.

I heard some very interesting interviews about this very subject on CBC radio a couple months ago, with people from both sides sharing their views.

EDIT: Here's the link to the CBC's site with info links to the story of the "interphone study". The publication of the results from the study had been delayed a long time - lots of contraversy.

Anyone interrested in this subject should listen to the audio clip of the CBC show (part 2 at the top of the page), and maybe read the study results themselves. The three big Canadian cell phone providers declined to comment. The Canadian Wireless Telecommunications Association's president (former New Brunswick Premier Bernard Lord) says there is no risk... but he is a well known industrial politician that of course will say anything for his employer.

I think that "bull" is much too strong a word, unless you know something that the researchers aren't sure about yet, dnmun? The cause and effect relationship using statistics for something like this is the only "proof" we could ever have - just like the link between cigarettes and cancer is statistical only too, right?

As for me, holding a smallish microwave emitter glued to my head for hours a day doesn't sound good for some reason. Ebike controllers are no competition with cell phones in this respect, for one thing the frequencies involved are not anywhere near microwave frequencies and controllers are designed to *not* emit too much - cell phones have nice little antenae just for that purpose!

Pat
 
Anyone want to start smoking cigarettes or cigars now? The evidence is overwhelming regarding carcinogenicity of tobacco products. However, feel free to try them if you think the evidence is bogus. It will definitely win you a Darwin award :evil: Tobacco is the number one preventable cause of death in the world these days. I'm happy to debate this issue (or should I say non-issue) further!!! Regarding emf the jury is certainly out on this one, but it is certainly possible that cellular damage could occur. Just no smoking wires yet!
otherDoc
 
Has anyone heard the dirty EMF noise that come from brushed motors. God that cant be good for anything.
 
docnjoj said:
Anyone want to start smoking cigarettes or cigars now? The evidence is overwhelming regarding carcinogenicity of tobacco products. However, feel free to try them if you think the evidence is bogus. It will definitely win you a Darwin award :evil: Tobacco is the number one preventable cause of death in the world these days. I'm happy to debate this issue (or should I say non-issue) further!!! Regarding emf the jury is certainly out on this one, but it is certainly possible that cellular damage could occur. Just no smoking wires yet!
otherDoc
I hope you didn't understand my post as to say that there is no proven health risk to tobacco use, doc. What I was getting at is that the cause and effect statistical probability relationship is the same thing being studied for both tobacco smoke in the lungs and cell phone microwave radiation close to the brain. The other point is that motor controller radiation is much lower frequency (~1-5Mhz vs ~2.4Ghz), not close to the central nervous system, and not designed specifically as an emitter.

Who likes to stand with their heads close by their microwave ovens while heating food? I'll pass! :lol:
 
Check this video out if you are scared of cell phones.
http://www.dailymotion.com/video/x5odhh_pop-corn-telephone-portable-micro-o_news
 
OMG Arlo!! That's gotta be some kind of trick - cell phones making pop corn! :shock:

But the different groups of people look genuinely shocked/surprised that it worked, so I must check this out better. I have had high speed internet for a few weeks now and I LOVE it for stuff like this!! *EDIT* - Wow! People can be pretty good at doing funny video trickery like this. :)
 
Hey ZapPat. Sorry for the rant. I just react when some of my students apply the "lack of specificity of statistical cause and effect" issue to the tobacco problem. I teach Pathology for a University and many pre-Med and pre-Nursing students smoke. It is quite bizarre when they use that phrase as a justification. I really don't know enough about the various frequecies and wavelengths of little electronic devices to make an informed comment on them. Even high tension steel tower powerlines are suspect as carcinogenic but I have not seen any proof.
otherDoc
 
ZapPat said:
Who likes to stand with their heads close by their microwave ovens while heating food?
My crazy sister leans over with her face against it, staring into it as things cook...but she *is* crazy, and is usually babbling at her own variation on some person she's talked to in the past "for real" at the time, too. :roll:
 
I hesitate to wade into a debate like this, but...

All of this - cell phones, controllers, power lines, etc. emit non-ionizing radiation. That's as opposed to ionizing radiation such as UV, X-rays, gamma rays, etc. Non-ionizing radiation does not cause molecular damage and DNA damage. Ionizing radiation does. UV, X-rays, etc. will give you cancer. A cell phone will not. The EM waves simply do not carry enough energy to do the sort of DNA damage we associate with carcinogens. This is a function of the frequency, not the transmitted power level - so a 1 MW AM station is no more dangerous in this respect than a 1 W cell phone.

Not to say that there aren't health risks. IEEE, OSHA, and several other organizations have exposure safety standards. High levels in the RF spectrum (MHz through 10s of GHz) cause your tissues to heat up. Early warning radar operators in Alaska used to stand in front of their radars to warm up. I'm not kidding. Highly not recommended. But these danger levels are much higher than we experience in everyday life. There are strict regulations and signage requirements, and the limits are also lower for "uncontrolled" areas where members of the general public might wander through.

Is it possible that low-level EM fields have some sort of other long-term effect? Yes. Likely? I don't think so, and I have yet to see any scientific studies which prove it with statistical confidence. It's prudent to take steps to limit your exposure, but I don't think tinfoil hats are called for.

Speaking of bunk, so-called "electrosensitivity" is also a myth. People are not "allergic" to WiFi. I have read of several cases were people complained of various symptoms caused by cell phone towers, neighbors' WiFi, etc. only to be informed that they had been turned off months before. Bogus.
 
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