# Regulated Headlights - Health Impact ( EMF )



## madcat108 (Sep 10, 2008)

I've been wondering about one of the not so popular aspects of regulated Headlights:

How strong would be the electromagnetic field created by a 3-4 Watt Switching Mode Power supply in an unshielded case ?

I have only ELF (50Hz) testing equipment which is not suitable for this case, but i suspect that mounting this power supply so close to the brain is not the best idea.

As an example i can say that a simple 12v 1A linear power supply (with transformer) The kind we use for our WiFi router etc... creates over 1000 mili Gauss field at 5cm from it. That's about 1000 times more than the recommended value. If we would mount such thing on our forehead, that would be a straight way to the graveyard !

Regulated headlights use a high frequency switchnig power supplies with much smaller induction coils and possibly create lower feilds (but with higher frequency). Unfortunately i can not measure it with my equipment.

I have a Prinecton Tec Apex and hadn't seen any FCC labels on it. I guess they could avoid the FCC EMI tests due to the product type which is 'just' a Headlamp.

Maybe some of the tech guys here have access to some measurement equipment and can put some light on this topic...


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## ambientmind (Sep 10, 2008)

interesting....i'll keep my eyes on this thread.


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## TorchBoy (Sep 11, 2008)

*Re: Regulated Headlamps - Health Impact ( EMF )*

Elf testing equipment. Heh heh. Heh. A quick test of an external hard disk switched power supply showed it doesn't affect my CRT computer monitor at all. Does that mean the power supply is shielded?

:tinfoil: on all our headlamps from now on?


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## madcat108 (Sep 11, 2008)

*Re: Regulated Headlamps - Health Impact ( EMF )*

Huge effort is being put to shield CRT monitors from external interference so actually the monitor is shielded in this case and not the power supply. Modern CRT monitors are not susceptible to most high frequency EMI.

Switching power supply on the contrary can even block radio stations in your entire apartment if one of its noise harmonics falls near the radio station frequency. 

And no... you can not measure EMF with a radio  First you don't know the frequency it works on. Second watching the influence of the interference ( on CRT screen, radio etc ) will not give you a precise value and you will never know if it's above the accepted standards or not.

I guess that if you move away about 0.5-1 meter from your power supply you are safe. But the headlamp is just on our head (or worse on our children head) and sometimes for a long time...

And no, don't fall in the "if they sell it - its safe" trap. I have a tabletop (small) fan. The ELF from it drops to 1mG only about 3 meters away ! Imagine how many people sleep within 1 meter away from it for many months/years... And yes. it kills. My large floor fan on the contrary is safe already at 30cm. So you never know unless you measure.


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## TorchBoy (Sep 11, 2008)

*Re: Regulated Headlamps - Health Impact ( EMF )*



madcat108 said:


> Huge effort is being put to shield CRT monitors from external interference so actually the monitor is shielded in this case and not the power supply. Modern CRT monitors are not susceptible to most high frequency EMI.


On the other hand, my non-emitting half metre steel ruler gives it conniptions.



madcat108 said:


> I have a tabletop (small) fan. The ELF from it drops to 1mG only about 3 meters away !


I didn't think radiation was measured in gauss. Can you explain, please?


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## madcat108 (Sep 11, 2008)

*Re: Regulated Headlamps - Health Impact ( EMF )*



TorchBoy said:


> On the other hand, my non-emitting half metre steel ruler gives it conniptions.



Can you check if it is magnetized ? I guess it is. I is extremely difficult to shield somth against a constant magnetic field. When you put a magnet near a CRT screen you divert the electron beam and distort the picture. By moving the magnet you create alternating magntic feild same like in electric motor, which is basically ELF.



TorchBoy said:


> I didn't think radiation was measured in gauss. Can you explain, please?



Radiation is just a general word. Basically it is divided to :


Ionizing - Gamma rays (like in nuclear reactors), X-Rays etc...
Non ionizing - Electromagnetic fields (EMF) below 300 Ghz
The EMF spectrum also divides into few categories and each one has its own properties and standards. But all are dangerous.

You can read about ELF (Extremely low frequency) here for example : 
http://www.icswebsite.com/emf/emfissues/emfissues5.html

That one i can measure, i gave just just as an example and this is NOT the one we are talking here. Switching power supply uses much higher frequency (possibly few Mhz ) it also can be dangerous and i don't have measurement equipment for it. 
After having a good gauss meter for some time i can guess the danger of nearly any household appliance from the point of view of ELF even without measuring. But i have no idea at all about higher frequency appliances like switching power supplies, laptops, computers and so on. What puts the regulated headlight out of all is its direct proximity to the head for a prologed time.
Thus i was asking if anyone knows anything on this topic.


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## sORe-EyEz (Sep 11, 2008)

what if the headlamp is strapped on, near the heart? i use it mostly on a shoulder strap.


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## jayflash (Sep 11, 2008)

We humans sit near walls with Romex inside or, worse yet, knob & tube wiring with strong 60Hz fields. Some of us live near million volt transmission lines or million watt transmitters. I'm curious about those, too. 

How vulnerable are we? I wish we had more data.


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## madcat108 (Sep 11, 2008)

sORe-EyEz said:


> what if the headlamp is strapped on, near the heart? i use it mostly on a shoulder strap.



First, we don't know yet if indeed there is any significant EMF involved. Of course it is there but maybe it's negligible. I've never said that regulated headlights are dangerous. Only that it is possible and someone has to measure it. 
Second, you've touched the most difficult part of the topic : the influence of EMF on human body. Many research institutes are working on this for many years. There are many results published. Some are funded by the manufacturers... So the official picture is pretty complicated. But here we have an advantage of not being "official" so we can say it simple.
If you'll ask my personal (and unscientific) opinion. I'd guess that mounting it on the shoulder is safer. And on your leg even more safe... provided its far from your OO :laughing:

Btw... i'm curious... how do you mount it on your shoulder ? Do you use the stock strap ? I tried to remove the top strap from my Apex and mount it on the shoulder but it does not feel convenient, falling off and the wide angle leds light into my eyes.


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## MorePower (Sep 11, 2008)

*Re: Regulated Headlamps - Health Impact ( EMF )*



madcat108 said:


> Radiation is just a general word. Basically it is divided to :
> 
> 
> Ionizing - Gamma rays (like in nuclear reactors), X-Rays etc...
> ...



If anyone cares to look further into the web site to which you linked, they'll find that it's run by a company that sells a keyboard (?) which supposedly blocks EMF from your computer, as well as cell phone batteries which purport to do the same.

There is some interesting reading in this link, which debunks many of the claims.


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## madcat108 (Sep 11, 2008)

jayflash said:


> We humans sit near walls with Romex inside or, worse yet, knob & tube wiring with strong 60Hz fields. Some of us live near million volt transmission lines or million watt transmitters. I'm curious about those, too.
> How vulnerable are we? I wish we had more data.



There is no reason to panic. But also only you and yourself can ensure your own and your family's safety on this regard.
If your concern is ELF ( i.e. field from power lines, transformers, home appliances) just buy a good tri-axial gaussmeter which is very easy to operate and will show you everything you need on the ELF topic.
Try to google on the topic. I don't want anyone here start accusing me in selling gaussmeters


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## madcat108 (Sep 11, 2008)

*Re: Regulated Headlamps - Health Impact ( EMF )*



MorePower said:


> If anyone cares to look further into the web site to which you linked, they'll find that it's run by a company that sells a keyboard (?) which supposedly blocks EMF from your computer, as well as cell phone batteries which purport to do the same.



Oh... gosh... Here it starts...... 
The guy asked a general question about the Gauss unit. I just googled to find a site with a simple and good explanation on what is ELF and why it is measured in Gauss. The top part of that page gives a nice explanation to that. If you can give a better explanation you could answer his question as well. 
Additionally if anyone has a doubt that EMF / ELF is a health hazard... well... I wont even tell you to start reading on the topic... some people smoke, some use drugs what to do ? Just skip this thread then.
But when an office worker gets cancer we just sigh... And no one pays attention on the electrical cabinet on the back side of the wall behind his desk that put 300 mG into him through the wall for the past 5 years.



MorePower said:


> There is some interesting reading in this link, which debunks many of the claims.


I don't deal with, don't sell and don't discuss here any "EMF eliminating" equipment. So it Looks OT to me and i don't know what "claims" are you talking about.


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## hopkins (Sep 11, 2008)

Fact: chemical exposure and cancer risk is a generally accepted fact
and avoidable in easily understandable ways i.e. don't breathe the fumes, don't touch the liquid, and don't eat more than (X)ppm etc.

But EMI exposure and cancer risk is something that folks can panic
over because its invisible and radiating from all the powered items around you.
Some a lot more than others!
People understand that they cannot avoid EMI, but dislike the reality so keeping EMI sources a safe distance from the body is something easily understandable. So a direct drive headlamp seems sane while ones with 
boost/buck regulation that radiate EMI is nuts.


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## sORe-EyEz (Sep 11, 2008)

madcat108 said:


> If you'll ask my personal (and unscientific) opinion. I'd guess that mounting it on the shoulder is safer. And on your leg even more safe... provided its far from your OO :laughing:
> 
> Btw... i'm curious... how do you mount it on your shoulder ? Do you use the stock strap ? I tried to remove the top strap from my Apex and mount it on the shoulder but it does not feel convenient, falling off and the wide angle leds light into my eyes.


 
hmmm... luckily i don't use a pacemaker.:nana: mounting on legs would be safer but the beam bobbing up & down like a tiny boat on choppy waters.:green:

mounting Apex on shoulders will be more tricky because there 2 parts to the light. like my Pelican 2630. i used polyester strap sold per length, trail guides (those plastic accessories commonly used for packs for adjusting length). to fit the battery unit & lamp unit into one combined unit, den finally use snap on/off buckle to attach to a back pack strap. a little basic sewing is needed for some of the trail guides. works better for SL Argo HP.:thumbsup:


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## Lynx_Arc (Sep 12, 2008)

lets see.... don't use electric blankets because a wire with electricity going through it produces a magnetic field. Don't sleep on a spring bed for fear the springs are magnetized. Don't drive a car because the alternator and distributor and dash and car stereo produce tiny magnetic fields. Don't watch tv, don't use an electric dryer or range. don't use CCFL lamps.... nothing metal or electric allowed.... lol
I seriously doubt the electronics in a headlamp is going to hurt you even a fraction as much as cholesterol in your diet does and breathing the air outside and mowing your lawn etc.


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## hopkins (Sep 12, 2008)

Hei Lynx arc - I know its a bit of tongue in cheek on this EMI from regulated headlamps. But...The inverse square law is real. NO one watches the food cook
in a microwave oven with their nose pressed against the door. Why I wonder?
http://en.wikipedia.org/wiki/Inverse-square_law

A high power example for sure , unlike the very small headlamp EMI. How could such a small power level hurt and trigger cancer? Some say because its so close to the head. Here's a link to a report about tumors growing around RFID
implanted chips inside lab animals. Now *this* is in the same power range as regulated headlamps ie portable scanner to read the implanted RFID chip. 
Makes me think.
http://www.washingtonpost.com/wp-dyn/content/article/2007/09/08/AR2007090800997_pf.html


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## Lynx_Arc (Sep 12, 2008)

could it be tumors grow around the RFID chips because they are foreign matter? RFID chips are in there 24/7, I doubt anyone uses a headlamp 24/7 and how much cancer does headphones give folks with the magnetic drivers?


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## LED-holic (Sep 12, 2008)

This reminds me of the debate about cellphones and possible brain cancer. So far nothing's proven there is a link.

There needs to be more scientific study over these things, but I won't be losing sleep until there's concrete evidence that this stuff will be more harmful than the things we know for sure are bad for us (smoking, pollution, bad diets, etc).


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## hopkins (Sep 12, 2008)

Lynx, I hear you but foreign bodies such as pace makers and breast implants do not have a 1-10% cancer (sarcoma) incidence! Consider that for a moment. 

EMI and cancer risk is a complex issue that medical experts do not understand
fully. Believe in the Inverse square law and keep *unshielded* EMI sources away from the body to be safe. An annoying burden added to the others in my life 



............


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## Lynx_Arc (Sep 12, 2008)

yup.... get rid of the cellphone and keep the headlamp it is safer LOL


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## TorchBoy (Sep 12, 2008)

*Re: Regulated Headlamps - Health Impact ( EMF )*



madcat108 said:


> By moving the magnet you create alternating magntic feild same like in electric motor, which is basically ELF.


It still throws the picture out when it isn't moving, just close to the front of the screen (but not the sides), so I don't think it's generating electric currents.



madcat108 said:


> Radiation is just a general word. Basically it is divided to :
> 
> 
> Ionizing - Gamma rays (like in nuclear reactors), X-Rays etc...
> ...


I didn't think either of those was measured in gauss. From that link you gave:


> Electric ELF fields are related to the voltage in conductors and are measured in volts per meter (V/m). ...
> Magnetic field strengths are measured in the unit of milligauss (mG, 1/1000 of a gauss) since the gauss is a very big unit.


My conclusion is the table fan ELF in post 4 is not measured in mG. Should I presume it was a typo? But the page goes on to contradict its own information.


> Table 2: Typical ELF levels in mG (50/60 Hz) emitted by appliances and devices.


My conclusion now is that this isn't a very good source of information, especially since one of table 2's columns says 46 inches is 1.17 cm (instead of 1.17 m). Just another typo?



hopkins said:


> NO one watches the food cook
> in a microwave oven with their nose pressed against the door. Why I wonder?


I don't want to belittle the inverse square law, but one good reason is that the glass in both microwave and conventional ovens can shatter unexpectedly. It's thankfully quite rare, but you don't want your face up against it if it does.



hopkins said:


> Here's a link to a report about tumors growing around RFID
> implanted chips inside lab animals. Now *this* is in the same power range as regulated headlamps ie portable scanner to read the implanted RFID chip.
> Makes me think.
> http://www.washingtonpost.com/wp-dyn/content/article/2007/09/08/AR2007090800997_pf.html


Makes *me* think of Rev 16:2. oo:


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## hopkins (Sep 12, 2008)

Hey! Keep the cell phone but put it on the table and use a wired earphone/mic.


Are there any shielded i.e. all metal headlamps? hmmm...that metal caving lamp?
Do the cables to the remote battery pack radiate and need shielding also ?
Or is it direct drive and does not radiate EMI ?


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## madcat108 (Sep 12, 2008)

When i posted my original post i had no intention to open a discussion of whether EMF can be dangerous or not. The answer is clear and it is on the paper. There are various standards set (although different in different countries) by bodies like FCC (Federal Communications Commission), ICNIRP (International Commission on Non-Ionizing Radiation), IRPA (International Radiation Protection Association), EPA (Environmental Protection Agency) and so on.... These standards are set to protect the general public from dangerous levels of EMF and other types of radiation. They are set as they are, because there is a solid scientific proof that with higher dosage there is a definite or a very likely chance of damage to living tissues. If a product does not comply with these standards it is prohibited for sale in the developed world.
Current arguments & debates in the world are about lowering these maximum permitted values (because even lower dosage can damage) and i'm not going into this right now. 
For example : most recommendations regarding ELF are in the range of 1-4 mG. So if you've got 100 make you own conclusions. Some need a "proof". Some are just not friends enough with Google and some will continue smoking even they will got a "POISON" note on each of the cigarettes. So i'm here not to be the babysitter of these who decide to ignore danger.
I just asked if someone can measure the EMF of regulated headlights or at least similar switching power supplies to compare it with the official standards. And then each one will decide if the official standards are enough for him or he wants to take a factor of 10 or 100 or whatever as a precaution.

So actually i don't see any topic for an argument here and i think its better to put the effort on finding the information or the right people to provide this information.


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## baterija (Sep 12, 2008)

hopkins said:


> But...The inverse square law is real. NO one watches the food cook in a microwave oven with their nose pressed against the door. Why I wonder?



It's kind of uncomfortable to lean over and stick my nose against the door. I hear it's a violation of the Geneva Convention to force prisoners to stay in that position. More importantly, it's astoundingly dull. Mind numbingly dull. People I knew in college who ingested things that made them look at the pretty colors on the wall never wanted to do it. My food rarely does anything interesting in the microwave. It's just round and round till I start to get sick. :green: ...except for marshmallows. They are pretty cool. They blow up like the Stay-puft marshmallow man.





> Some say because its so close to the head. Here's a link to a report about tumors growing around RFID implanted chips inside lab animals. Now *this* is in the same power range as regulated headlamps ie portable scanner to read the implanted RFID chip.


Interesting quote from your linked article:


> Caveats accompanied the findings. "Blind leaps from the detection of tumors to the prediction of human health risk should be avoided," one study cautioned. Also, because none of the studies had a control group of animals that did not get chips, the normal rate of tumors cannot be determined and compared to the rate with chips implanted.


 It definitely sounds like a RFID tags should be looked into. Order of magnitude difference in the cancer rates between two of the tests seems odd though. Right now they haven't done any testing that show statistical significance versus a control group. They also haven't tried to isolate what aspect of the chips might be causing the effect - chip material, EMI, etc.

To return to the start of the thread. It would be interesting to see what the EMI from a headlamp is. I don't have anything remotely like the equipment to do so.


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## madcat108 (Sep 12, 2008)

*Re: Regulated Headlamps - Health Impact ( EMF )*



TorchBoy said:


> It still throws the picture out when it isn't moving, just close to the front of the screen (but not the sides), so I don't think it's generating electric currents.


Thats right. Even a constant magnetic field can divert the electron beam. That is according the Lorentz force



TorchBoy said:


> I didn't think either of those was measured in gauss. From that link you gave:


Thats right. They are not. Only the ELF. But dont confuse between the EMF and ELF. EMF is a general name for Electromagnetic Field ( of all frequencies) and ELF is a small part of these frequencies and stands for "Extremely low frequency" usually that is below 3KHz and in most cases it is related to 50/60 Hz from the power lines or devices.



TorchBoy said:


> My conclusion is the table fan ELF in post 4 is not measured in mG. Should I presume it was a typo? But the page goes on to contradict its own information.


?! It does measures in mG (mili Gauss). How could you conclude with somth else ? I do own this fan and a masurement device and can easily repeat the test 10 times and get the same value.



TorchBoy said:


> My conclusion now is that this isn't a very good source of information, especially since one of table 2's columns says 46 inches is 1.17 cm (instead of 1.17 m). Just another typo?


i guess they didn't meant to put the dot. (Actually looks like a comma). Anyway the distance in inches is correct and the values are pretty logical and even on the lower side from my experience. So i don't see any problem with that. But of course that was just an example and i gave this page for the sake of it's pretty good answer to the "gauss" question. Of course you can use any other sources of information.



TorchBoy said:


> I don't want to belittle the inverse square law, but one good reason is that the glass in both microwave and conventional ovens can shatter unexpectedly. It's thankfully quite rare, but you don't want your face up against it if it does.


Another reason is that both the ELF and the RF in front of many microwave ovens can be at least tens of times above safety levels. I can confirm the ELF side with my "Brother" microwave. Also seen videos that confirmed the RF side of this claim.


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## madcat108 (Sep 12, 2008)

baterija said:


> My food rarely does anything interesting in the microwave. It's just round and round till I start to get sick. :green:


Have you tried to put an egg in ? :duck:


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## TorchBoy (Sep 12, 2008)

hopkins said:


> Hey! Keep the cell phone but put it on the table and use a wired earphone/mic.


But there are those who say those things just direct the radiation into the brain along a wire instead of having it spread out in all directions, meaning the headset actually results in a higher intensity! :tinfoil:



madcat108 said:


> The guy asked a general question about the Gauss unit. I just googled to find a site with a simple and good explanation on what is ELF and why it is measured in Gauss. The top part of that page gives a nice explanation to that. If you can give a better explanation you could answer his question as well.


For the record it's "gauss" with a small g, and the SI unit for magnetic flux density is the tesla (T); gauss (G) is a cgs unit. As I've said, I'm not completely satisfied with what that page says, and not just because I have to bump up the text size a couple of times before it's big enough to read. I just consulted an electrical engineer who said the field strength of an RF signal is always measured in V/m. Not tesla (or gauss). So any other explanations gratefully accepted.



madcat108 said:


> For example : most recommendations regarding ELF are in the range of 1-4 mG. So if you've got 100 make you own conclusions.


ELF is (according to Wikipedia) "the band of radio frequencies from 3 to 30 Hz" although some people apparently take it to be as high as 85 Hz. Quite apart from the V/m vs T issue, why would a buck regulator running at several kilohertz make *any* ELF radiation to worry about? It just doesn't appear to be running at a suitable frequency. And doesn't ELF transmission need aerials kilometres long? Not in *my* headlamp, thanks.

Here's another thought. Earth's magnetic field is about 30-60 microtesla (30-60 µT, or 300-600 mG) depending on latitude. (This compares to about 0.1 pT [picotesla] generated by electrical activity in the human brain.) Any time we move, being 75% water and therefore a conductor, we will be inducing electric currents in our bodies. No wonder we all die of cancer before we hit puberty.  Seriously, though, I've heard that the electric field strength at the base of power pylons can be high enough that cows are big enough to have a large enough voltage difference between their two ends that it's permanently not-good for them.

Anyway, is there anywhen we might get strong varying magnetic fields at the frequencies of ELF radio waves? (Which somehow gets abbreviated to "strong ELF magnetic fields" - that's what I don't understand.) How about listening to subsonic pipe organ music on a good stereo system? :sick2:


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## hopkins (Sep 12, 2008)

Hei madcat108 - thats for the confirmation on the u-wave oven RF field.
The AM radio in our kitchen will hiss and buzz if placed within a few inches of the
u-wave but is fine several feet away.

The medical insurance industry is trying to categorize the diseases individuals
are prone to suffering (and writing into the policy they will not cover your
high risk ones without a big deductible)

I wonder if there is a genetic test for being susceptible to RF induced cancer? Maybe I've got nothing to worry about from regulated headlamps.


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## hopkins (Sep 13, 2008)

Just had a thought on a way to (very roughly) test the Rf strength out of
a regulated headlamp. Compare how *loud* the headlamp makes a cheap portable AM radio buzz compared to how loud it buzzes when held to the door of a u-wave oven (cooking something). ie volume control at same level and cheap radio's do not have a lot of circuitry to reject unwanted RF which is what we're looking to measure.:devil:

Note: I just did this test with a Rayovac Sportsman Extreme 1AA headlamp
and it made the radio buzz much louder than the u-wave oven! 
Holy RF terror Batman!
Not a real accurate test but its a data point and not a guess or opinion.


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## TorchBoy (Sep 13, 2008)

hopkins said:


> Just had a thought on a way to (very roughly) test the Rf strength out of
> a regulated headlamp. Compare how *loud* the headlamp makes a cheap portable AM radio buzz compared to how loud it buzzes when held to the door of a u-wave oven (cooking something). ie volume control at same level and cheap radio's do not have a lot of circuitry to reject unwanted RF which is what we're looking to measure.:devil:


Nice idea, but it's not the RF strength (in V/m) that madcat was getting worried about, er, wanting to measure, but the magnetic field strength (in T).



hopkins said:


> Note: I just did this test with a Rayovac Sportsman Extreme 1AA headlamp
> and it made the radio buzz much louder than the u-wave oven!
> Holy RF terror Batman!


:laughing: Maybe I should rethink what backup light I want on my caving helmet. Ain't CPF a great place. :thumbsup:


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## hopkins (Sep 13, 2008)

Yup. Fun...
I'm watching hurricane Ike's eye-wall make landfall on Texas on the TV and 
one of the idiot news people, leaning into the wind has a headlamp: think a PT Quad.
So good evidence thats it waterproof.


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## madcat108 (Sep 13, 2008)

TorchBoy said:


> But there are those who say those things just direct the radiation into the brain along a wire instead of having it spread out in all directions, meaning the headset actually results in a higher intensity! :tinfoil:


There are headsets that keep the speaker and electrical wires far from the head and bring the sound to the ear by using an air pipe. Similar to the security guys headsets... (the curly thin transparent pipe that goes to the ear)



TorchBoy said:


> For the record it's "gauss" with a small g, and the SI unit for magnetic flux density is the tesla (T); gauss (G) is a cgs unit. As I've said, I'm not completely satisfied with what that page says, and not just because I have to bump up the text size a couple of times before it's big enough to read. I just consulted an electrical engineer who said the field strength of an RF signal is always measured in V/m. Not tesla (or gauss). So any other explanations gratefully accepted.


The engineer u've consulted is completely right. However I'm doubt you've asked the right question. As you can see in my posts i talk about gauss units only when i speak about ELF and not RF. V/m is a unit for electrical field and guass for magnetic field. Electro magnetic field consist of both of them (even the name says) but when i wrote about the ELF i mentioned only the magnetic component of the field that is mesured in gauss.



TorchBoy said:


> ELF is (according to Wikipedia) "the band of radio frequencies from 3 to 30 Hz" although some people apparently take it to be as high as 85 Hz. Quite apart from the V/m vs T issue, why would a buck regulator running at several kilohertz make *any* ELF radiation to worry about? It just doesn't appear to be running at a suitable frequency. And doesn't ELF transmission need aerials kilometres long? Not in *my* headlamp, thanks.


Apparently you didn't read my posts throughly. Each time i talk about ELF (and guass units) i give it only as an *example* (and i do use this word) to EMF that i can mesure and see it is way above standards from many popular devices as well as it is recognized as causing serious health issues. 
Of course the regulator in the headlight which i guess works more in the MHz band emits negligible ELF. But maybe it emits a strong EMF on higher frequencies that i can not mesure with my gaussmeter of course. That was my original question and it remains.



TorchBoy said:


> Here's another thought. Earth's magnetic field is about 30-60 microtesla (30-60 µT, or 300-600 mG) depending on latitude. (This compares to about 0.1 pT [picotesla] generated by electrical activity in the human brain.) Any time we move, being 75% water and therefore a conductor, we will be inducing electric currents in our bodies. No wonder we all die of cancer before we hit puberty.  Seriously, though, I've heard that the electric field strength at the base of power pylons can be high enough that cows are big enough to have a large enough voltage difference between their two ends that it's permanently not-good for them.


You are mixing lots of stuff in one. What we are talking about here is an *alternating* field (magnetic or electrical) When we refer to ELF from household devices it is 50/60 Hz in contrast to earths magnetic field that is constant. 
When you travel through a constant magnetic field you create a potential (not a current) on both ends of the conductor. 
About the cows - yep. I've heard it can even electro-shock them or even a human if he makes a large step and the power lines are very low thats becaue a difference in the potential. 



TorchBoy said:


> Anyway, is there anywhen we might get strong varying magnetic fields at the frequencies of ELF radio waves? (Which somehow gets abbreviated to "strong ELF magnetic fields" - that's what I don't understand.) How about listening to subsonic pipe organ music on a good stereo system? :sick2:


Sound is a sound wave = simple air movement contrary to EMF that is an electromagnetic field and can perfectly move with a speed of light in the vaccum.
You can get radiation of all kinds in many even unexpected places and occations. No need to be a paranoiac but simple precautions may save life.


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## madcat108 (Sep 13, 2008)

hopkins said:


> Just had a thought on a way to (very roughly) test the Rf strength out of
> a regulated headlamp. Compare how *loud* the headlamp makes a cheap portable AM radio buzz compared to how loud it buzzes when held to the door of a u-wave oven (cooking something). ie volume control at same level and cheap radio's do not have a lot of circuitry to reject unwanted RF which is what we're looking to measure.



You can not use this method to test anything. Microwave oven transmits at 2.5 Ghz and about 1000 W. And the ELF part is 50/60 Hz from the transformer & motors. Few other frequencies possible from the electronic boards but much less powerful. Then all this has harmonics on many other frequencies some of these are being received by your radio but that tells you nearly nothing about the HUGE power transmitted at 2.5Ghz.



hopkins said:


> Note: I just did this test with a Rayovac Sportsman Extreme 1AA headlamp
> and it made the radio buzz much louder than the u-wave oven!
> Holy RF terror Batman!
> Not a real accurate test but its a data point and not a guess or opinion.


Probably that means that your radio is more susceptible to the headlamp regulator frequencies. That is pretty obvious because i guess the regulator works somewhere in the lower Mhz band which is closer to the radio band. But that does prove one thing : There is an EMF emitted from the headlight (was obvious to me) but the question remains : How much ?


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## rantanplan (Sep 13, 2008)

RFID tags and cancer ... RFID chips are passive devices which are powered by the energy of the scanner, therefore they are only active for seconds and the range of their signal is very limited, weak thus. In modern times of cellphones, wireless communication and everything else this should be a risk?

Dangerous electromagnetical fields from headlamps ... wow .. we´ve gone beyond the cellphone discussion!  I haven´t read every post here ... what should be the dangerous effect of a switching regulator in a headlamp be? Cancer, damaged nerve cells in the brain ... ???

Electric field ... year for year "scientific" studies are claiming to´ve found the "smoking gun" with cellphones and cancer ... and then all the "data" was "manufactured" by a assistant again.

Magnetic fields ... ever looked at the tesla values of a MRT. Lying in there your body gets up to 3 Tesla ... yumme 

I don´t have a problem with the radiation of my headlamps ... even though they are glowing in the dark


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## hopkins (Sep 13, 2008)

madcat108 said:


> You can not use this method to test anything.


.
...except a test for the presence of EMR. Wonder if you thought about the fact that the human head acts as broadband RF absorption media. No notch filter circuits inside to reject a given frequency. Now strap on a regulated headlamp.

A complex subject. Seems much study has already been done. Is it being
ignored because the answers are unprofitable? Ask Motorola.

If you want to be worried check out this paper: raises many questions.
Thermal and Nonthermal Mechanisms of the Biological Interaction of Microwaves.

http://arxiv.org/vc/physics/papers/0102/0102007v2.pdf


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## gajslk (Sep 14, 2008)

You all are making me really glad that I wear my tinfoil hat!

Gordon


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## TorchBoy (Sep 14, 2008)

50/60 Hz mains and high tension AC is SLF - super low frequency. It is not ELF.



madcat108 said:


> Sound is a sound wave = simple air movement contrary to EMF that is an electromagnetic field and can perfectly move with a speed of light in the vaccum.


You forget how that sound wave is produced. :tinfoil:



madcat108 said:


> You can get radiation of all kinds in many even unexpected places and occations. No need to be a paranoiac but simple precautions may save life.


Of course, anyone genuinely worried about SLF - and consistent in their application of avoidance of it - would live in the wilderness using candles for light and log fires for heating/cooking. But then, all that soot wouldn't be good for you.



rantanplan said:


> I don´t have a problem with the radiation of my headlamps ... even though they are glowing in the dark


Mine too, since you mention it. Glow o-rings and glow paint!


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## hopkins (Sep 15, 2008)

in case you missed this:
Research in the past on the biological effects of microwaves often has been based
on faulty assumptions. The major flaw has been the premise that microwaves only
produce thermal effects in tissue. This premise easily may be proven illogical and
physically incorrect. Furthermore, assuming only thermal effects leads one to an
optimist's error of quantification in which calories are counted instead of joules.
Past investigations have been misled both by these assumptions and by stereotyped
experiments using only narrow-band radiation sources. Recent studies show that
wide-band microwaves bring out biological effects which are unrelated to those
caused by heat flow. 
But nothing to panic about.
]
........--EMR is nothing to worry about as long as you're immortal.


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## ventur154 (Sep 16, 2008)

Interesting question. Just upgraded my cell phone and briefly flipped through the SAR rating pamphlet. Probably should have read it more carefully, then I could worry about the exact amount emf that is being radiated into my skull while I was using it.

Hope the following pic helps to answer your question about the Apex. Borrowed this meter from a buddy, not sure how reliable, accurate or even relevant the readings are. Got some interesting readings from the breaker box though.


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## TorchBoy (Sep 16, 2008)

That's _very_ interesting, but I guess not completely surprising. Is that meter more sensitive out to the sides where the arrows point? Does it make any difference if you turn it sideways to the breaker box?


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## madcat108 (Sep 16, 2008)

TorchBoy said:


> 50/60 Hz mains and high tension AC is SLF - super low frequency. It is not ELF.


Yep. But ELF is more common name for low frequency fields. I do realize i write on a "Candle" rather than an "electo-tech" forum. So not all here are electronic engineers. We also say RF for all the higher frequencies which includes a very large spectrum.



TorchBoy said:


> You forget how that sound wave is produced. :tinfoil:


I believe you are safe, unless you stick your face into a speaker.
Headphones are a different topic for conversation. 



TorchBoy said:


> Of course, anyone genuinely worried about SLF - and consistent in their application of avoidance of it - would live in the wilderness using candles for light and log fires for heating/cooking. But then, all that soot wouldn't be good for you.


Not at all ! I like technology and there are a lot of electronic devices in my room (just believe me) Yet the place i sit / sleep is well below 1mG ELF (SMF) wise. What about other EMF ? Probably worse but i can't measure this yet. I do however believe that it is reasonably clear on the RF part as well. In short : If you put enough thought you may protect yourself even in the modern world while enjoying all of its advantages. I do admit however that from day to day it becomes a more difficult task.
For example : if you buy a destop PC with a nice "window" on the side (for the EMF devil to go out...:devil: ) with cool blue lights etc... you make it to be your own problem


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## madcat108 (Sep 16, 2008)

oops. sorry for double posting. CPF goes down frequently


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## madcat108 (Sep 16, 2008)

ventur154 said:


> Hope the following pic helps to answer your question about the Apex. Borrowed this meter from a buddy, not sure how reliable, accurate or even relevant the readings are. Got some interesting readings from the breaker box though.


Actually not very relevant. There is no reason that switching power supply in the Apex (that works in the high Khz or more likely in the MHz band) will radiate 50/60 Hz that this gaussmeter can measure. That's the problem. I do have gaussmeter also but nothing to measure the higher frequency EMF from Apex.
Another note: This looks like a single axis meter means you have to turn it physically in the 3D space to find the maximum reading. Thus you can not post a picture of its reading as a proof for "no ELF" in any case because we don't know if you hold it int the maximum field intensity direction.
Regarding he electrical board : yep. it does radiate. The larger boards can radiate even 300+ mG and to distances of few meters and more. Many due to incorrect wiring (large loops of single direction current).


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## Illum (Sep 16, 2008)

regulated headlights does not necessary imply that the design of the assembly is limited to building the regulation module on your head, why not a regulation uint built into the battery pack and, in term, seperate the battery pack/electronics away from the light source [I.E. your head ]?

EMF shielding isn't expensive to do...but its most likely going to increase the size and dimension of the light in question.


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## madcat108 (Sep 16, 2008)

Illum_the_nation said:


> regulated headlights does not necessary imply that the design of the assembly is limited to building the regulation module on your head, why not a regulation uint built into the battery pack and, in term, seperate the battery pack/electronics away from the light source [I.E. your head ]?


Yeah... we already had the idea to mount the light on the leg 

But serious speaking, i guess most use the light with the battery pack attached. Not with an external one. So such solution would be inconvenient.



Illum_the_nation said:


> EMF shielding isn't expensive to do...but its most likely going to increase the size and dimension of the light in question.


Sure i'd like the Apex with an aluminum case! That would improve the durability, water sealing and EMF shielding. All this without significant size/weight increase. And i don't mind to pay few $ more for an aluminum version. Additionally a small EMF filter is needed for the cable but thats not a big deal.
I just don't think anyone really considered EMF while developing a headlight. Thats the problem. ( or maybe they did measure and found nothing... who knows... but i bet they didn't or did & keep mouth zipped as usual.)


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## hopkins (Sep 16, 2008)

Wow! great pictures. The high cost of some EMF meters is a problem.
Found a circuit that looks cheap to build.


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## TorchBoy (Sep 16, 2008)

madcat108 said:


> I believe you are safe, unless you stick your face into a speaker.


:laughing: I now have the mental image of being slapped in the face 30 times a second by the speaker cone. I meant the permanent magnet and electromagnetic production of the movement.



madcat108 said:


> Not at all !


Well, you saw ventur154's reading - the mains can give quite a high result.



madcat108 said:


> Actually not very relevant. There is no reason that switching power supply in the Apex (that works in the high Khz or more likely in the MHz band) will radiate 50/60 Hz that this gaussmeter can measure. That's the problem. I do have gaussmeter also but nothing to measure the higher frequency EMF from Apex.


What happened to ELF/SLF being the main worry?


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## asdalton (Sep 16, 2008)

hopkins said:


> in case you missed this:
> Research in the past on the biological effects of microwaves often has been based on faulty assumptions. The major flaw has been the premise that microwaves only produce thermal effects in tissue. This premise easily may be proven illogical and physically incorrect.



How and by whom?



> Furthermore, assuming only thermal effects leads one to an
> optimist's error of quantification in which calories are counted instead of joules.



This makes no sense. Calories and joules both measure the same thing: energy.



> Past investigations have been misled both by these assumptions and by stereotyped experiments using only narrow-band radiation sources. Recent studies show that wide-band microwaves bring out biological effects which are unrelated to those caused by heat flow.



_Which_ studies show _what_?


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## hopkins (Sep 16, 2008)

Asdalton - Here are some answers to your questions. This paper says
in a nutshell that if you ask flawed questions concerning EMF effects on living tissue the answers will also be flawed. The author lists citations.


http://arxiv.org/vc/physics/papers/0102/0102007v2.pdf


Joule: A unit of electrical energy equal to the work done when a current of one ampere is passed through a resistance of one ohm for one second.
Calorie: The quantity of heat required to raise the temperature of 1 gram of water by 1°C from a standard initial temperature.
EMF exposure to living tissue need not raise the temperature. The argument
that if the temp stays the same there's no danger is questioned.


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## asdalton (Sep 16, 2008)

Joules and calories measure the same thing (energy), just in different units. The thermal definition of the calorie exists for reasons of convenience and tradition. It is incorrect to frame any argument about physics in terms of joules versus calories.

That article that you linked to, as far as I can tell, at most shows that electric fields could induce temporary elastic distortions in dipole layers. But this kind of energy storage is going to become rapidly thermalized due to collisions with nearby water molecules once the field is relaxed or reversed. So the energy ends up as heat anyway.

(By the way, it would be nice if this were a peer-reviewed and published article. At the very least, it would be purged of smug phrases such as, "Errors of agreement can add nonlinearly with errors of understanding to produce unwarranted noncontroversy."  )


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## hopkins (Sep 17, 2008)

Would not 2 different pieces of test gear be needed to measure calories and 
joules ( from a given EMF) in living tissue? 

* In most cases, it is not clear how EMF actually produces the effects observed in some experiments. *
A rather worrisome statement from this report:
http://www.niehs.nih.gov/health/docs/emf-02.pdf

from an organization a bit more respected in the community.


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## baterija (Sep 17, 2008)

hopkins said:


> Would not 2 different pieces of test gear be needed to measure calories and
> joules ( from a given EMF) in living tissue?



Simply ...no. The two measures of energy have a directly linear relationship based on their separate definitions:


> the International Steam Table Calorie - defined as exacty 4.1868 joules



Any measured quantity of energy in one unit can be simply converted to a quantity in the other unit. Saying differently is like saying a measurement in meters is somehow substantially different than a measurement in yards. If we wanted we could express battery capacity (watt-hours) in joules (by definition watt-seconds) or calories. It doesn't change the amount of chemical potential energy in the battery.


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## hopkins (Sep 17, 2008)

Baterija - got to agree with you that on paper the conversion is simple but
we are concerned with the real world. If the test setup only has a device to measure the increase in temperature (say inside a living rat) and it measures
zero change during application of a given EMF at x distance, the conversion to joules absorbed by the rat will be difficult. 

from the study:
http://www.niehs.nih.gov/health/docs/emf-02.pdf
Using criteria developed by the International Agency for Research on
Cancer, a majority of the members of the working group concluded that
exposure to power-frequency EMF is a possible human carcinogen.


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## baterija (Sep 17, 2008)

hopkins said:


> Baterija - got to agree with you that on paper the conversion is simple but
> we are concerned with the real world. If the test setup only has a device to measure the increase in temperature (say inside a living rat) and it measures
> zero change during application of a given EMF at x distance, the conversion to joules absorbed by the rat will be difficult.



Conversion is simple 0 calories = 0 joules = 0 watt-hours= 0 foot-pounds = 0 BTU = 0 ergs. I could even do the math in my head. :naughty:

Measuring temperature change allows them to compute energy that gets converted to heat. It doesn't matter what unit you use to state that energy in. Could there be energy delivered that is not converted to heat and included in the measurement? That seems like the root of your disagreement of the current studies. That has absolutely nothing to do with the unit energy is expressed in. It has everything to do with only measuring energy converted to heat and not measuring possible other forms of energy.


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## hopkins (Sep 17, 2008)

So you disagree with the studies findings that electromagnetic fields cause cell membrane amplification (work) and eliciting biological effects? (And not seen as heat).

Here is yet another report noting this observation:
http://www.radiationresearch.org/goldsworthy_bio_weak_em_07.pdf
from this report:
*The strange non‐thermal biological effects of electromagnetic fields have puzzled
scientists for decades and, until now, there has been no clear explanation. In this article, I will outline a new theory, based on experimental evidence*


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## baterija (Sep 19, 2008)

hopkins said:


> So you disagree with the studies findings that electromagnetic fields cause cell membrane amplification (work) and eliciting biological effects? (And not seen as heat).



I said nothing of the kind.  I am simply saying that the *units* the heat energy is expressed in *is **completely irrelevant*. Measuring the heat will only get you a measurement of heat, even if you express it in joules. They could measure non-heat energy and express it in calories.  Don't confuse the units a measurement is expressed in, with the item being measured.


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## hopkins (Sep 19, 2008)

I think John Michael Williams idea to use joules rather than calories was
its easier to understand joules for this subject. 
( consider how confusing a cereal box label would be if it listed joules instead of calories for the energy per serving). 



Discussion about energy conversion may possibly spark a
new thought and an informative post. For instance if a AA battery is held
near a compass the magnetized needle moves towards the battery.
Work has been done obviously but has the needle increased in temperature?
Has the battery? 

Concerning EMR, EMF and cancer here's a new youtube interview by a doctor
who's been doing research on this topic for years. He suggests we're in trouble.

http://www.youtube.com/watch?v=2GD_BKTWyTY


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## asdalton (Sep 19, 2008)

hopkins said:


> I think John Michael Williams idea to use joules rather than calories was its easier to understand joules for this subject.
> ( consider how confusing a cereal box label would be if it listed joules instead of calories for the energy per serving).



It's not confusing at all. In fact, it's what they already do in Europe.

http://en.wikipedia.org/wiki/Food_energy


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## asdalton (Sep 19, 2008)

By the way, it is wise to have a very long time constant, so to speak, on all of these hypothetical health risks that we are bombarded with through the news (and by activists) on a weekly basis. The vast majority of them amount to far less than their hype, or are contradicted by later research. 

And I definitely reject the whole "We don't know for sure that it's safe, therefore we should worry" line of argument. (This is usually called the "precautionary principle.") This kind of thinking amounts to treating _imagination _as a standard of knowledge, and in practice it is impossible to apply since there will always be an unlimited number of things that _could_ be a health risk.


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## hopkins (Sep 19, 2008)

asdalton said:


> By the way, it is wise to have a very long time constant, so to speak, on all of these hypothetical health risks that we are bombarded with through the news (and by activists) on a weekly basis. The vast majority of them amount to far less than their hype, or are contradicted by later research.
> 
> And I definitely reject the whole "We don't know for sure that it's safe, therefore we should worry" line of argument. (This is usually called the "precautionary principle.") This kind of thinking amounts to treating _imagination _as a standard of knowledge, and in practice it is impossible to apply since there will always be an unlimited number of things that _could_ be a health risk.



so if you needed to use a headlamp right now would you grab a regulated
or direct drive (assuming equal initial outputs, beam patterns, fresh charged NimH batteries, weight, etc.) for a 1 hour task... everynight for the next ten years? Just asking.


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## gajslk (Sep 21, 2008)

hopkins said:


> so if you needed to use a headlamp right now would you grab a regulated
> or direct drive (assuming equal initial outputs, beam patterns, fresh charged NimH batteries, weight, etc.) for a 1 hour task... everynight for the next ten years? Just asking.



I'd choose the one that fit over my tinfoil hat the best!:nana:

Actually there are way too many retired RF engineers and technicians dying of old age for me to get too cranked up about this stuff. Then there's all the folks who sit surrounded by high power switchers for entire careers, most of them get old without incident. Then there are the folks in their 80s who slept most of their nights under electric blankets. Life expectancy hasn't been going down with the proliferation of electronics, it's actually gone up. 

Or maybe the damage isn't cumulative, in which case we're all f***ed anyway unless we've lived in a cave our whole life.

Gordon


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## hopkins (Sep 21, 2008)

Oh I agree. Humans are tough. I'm thinking that EMR affects are in the same ballpark as smoking cigarettes. It won't make you sick statistically before some
other thing more dangerous gets you. 
Anyone remember how many years were doctors saying smoking was 'good' for you?
EMR health effects is an interesting subject. Also got to wonder if the scare mongers are in it only to secure more funding to finance their labs or
what?


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## r-s (Jan 23, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



madcat108 said:


> I have a tabletop (small) fan. The ELF from it drops to 1mG only about 3 meters away ! Imagine how many people sleep within 1 meter away from it for many months/years... And yes. it kills. My large floor fan on the contrary is safe already at 30cm. So you never know unless you measure.



Oh, Lord... mercy!

PURE woo-woo!

The "ELF" from your airblow-fan "kills"? It KILLS?

Oh, yes -- it certainly DOES kill!

I feel really sorry for the poor fly that gets brainsmacked by the spinning blade!

Now, if you want to back up your claim that "it kills" PEOPLE -- who DIE because they have a desk fan on the nightstand (or some such), then I ask but ONE thing of you: EVIDENCE.

How about showing me some dead folk -- and, since we ALL die -- and, since MOST of us have been around desk fans -- how about narrowing it down a tad, and ONLY showing us dead folk who BECAME dead folk DUE to the "it kills" power of a desk fan?

And, no offense, but I'd appreciate it if you could *substantiate* any "death by proximity to desk fan" assertions.

Thanks, etc.


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## likeguymontag (Jan 23, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



r-s said:


> The "ELF" from your airblow-fan "kills"? It KILLS?
> 
> Oh, yes -- it certainly DOES kill!
> 
> ...



It happens in Korea.


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## r-s (Jan 23, 2009)

hopkins said:


> A high power example for sure , unlike the very small headlamp EMI. How could such a small power level hurt and trigger cancer? Some say because its so close to the head. Here's a link to a report about tumors growing around RFID
> implanted chips inside lab animals. Now *this* is in the same power range as regulated headlamps ie portable scanner to read the implanted RFID chip.
> Makes me think.



Wow, MORE woo-woo!

Do you have ANY idea of HOW those things work?

Hint: they have NO battery on-board.

They are "passive" re-radiators. That means that a fairly HIGH output RF beam is aimed at the area containing the grain-of-rice sized HARD pellet, which is then rectified (via a diode), and used to power a tiny transmitter with a MINISCULE output, which is then sent to the scanner, which has a VERY sensitive receiver, capable of detecting the INCREDIBLY *tiny* amount of RF that is transmitted for a VERY short amount of time.

These things MAY be scanned once or twice during the entire life of an animal. Once, when inserted, to verify operation, and, once again, if the animal is lost -- and found -- WITHOUT a physical tag -- and is thus scanned in the hopes that it will have an implanted device.

Grand total exposure is likely in single-digit seconds over the entire lifespan of the animal.

Now, as to the issue of cancer being triggered by them -- and NOT being triggered by breast implants?

Some things to consider: Breast implants are 1) large and soft, rather than small, hard, and IRRITATING to soft tissue, and, 2) used in HUMANS, whereas the rice-grain sized HARD devices are implanted in ANIMALS, which have DIFFERENT responses to things than humans.

While you're considering, you might want to ALSO consider that there's something ELSE that when injected into animals will trigger that cancer problem.

The thing is, I think you'll have a hard time finding *any* RF output -- even in the *nanosecond* range -- for VACCINATIONS.

That's right -- certain VACCINES are very common cancer triggers in certain breeds of animal. There are a lot of cats with cancer due to vaccine -- so many, that the have instructed vets to AVOID injecting under the shoulder blade, but rather, to inject in a leg, so that WHEN a malignancy is triggered, the poor creature can be saved via amputation.

It's curious how certain irritants will cause malignant tumors in certain animals -- but it's no reason to go all woo-woo on us, and, for example, rant about the "need" to prohibit tetanus shots for people, because the evil woo-woo-waves cause cancer.


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## r-s (Jan 23, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



likeguymontag said:


> It happens in Korea.



Now *that's* funny!

That is, it's funny in the same sense that belief in *other* bad juju/voodoo stuff is funny... that poor people, scraping together their last amount of coin, take it to hand over to The Mojo Man, in exchange for a "bag" with "a root."

That would be, it's funny in a sad, tragic, surreal way.


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## hopkins (Jan 23, 2009)

Hi r-s , keep going with your thinking on this subject. I've found, and sited, many diverse studies that turned my knee jerk disbelief around. Some are fairly technical and not easy to understand but the sense is there can be an impact.
Lots of mechanisms involved. Fascinating meld of biology and RF sciences. 
cheers
hopkins


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## LLCoolBeans (Jan 23, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



likeguymontag said:


> It happens in Korea.



Bwaaaaaaaaaaaaaaaaaa ha ha ha ha ha ha ha!!!!

That just got passed around the office, what a great Friday afternoon belly laugh.


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## madcat108 (Jan 23, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



r-s said:


> Oh, Lord... mercy!
> 
> PURE woo-woo!
> 
> ...



Indeed no offense and sorry, but your thinking is a bit primitive.
Do you really expect to turn on your TV and hear a "Breaking News CNN Story" about a man who got killed by his fans ELF ? 

Things happen much more slowly... For example in my country the main cause of death that recently took its 1st place from heart diseases is CANCER.
And the prognosis is that eventually it may happen in all industrialized countries in the world.
You wont hear a CNN story about every man or woman what got cancer ! You don't need to... Even no need to dig deep in your memory to remember a name of a person who died from this poop.

Then why does it happen ? Why does it increase ? What will happen when current young generation will reach their 60s ?

It happens (among other reasons) because we are getting radiated by different artificially created fields more than our body can tolerate. Because we take into our body (drink, eat , breath, touch) carcinogens (but that's another story)

For example you can make a search and see what is the worldwide accepted standard for ELF exposure. In short: you will find values in the range of 1-4 mG (modern standarts).

Here are few examples (you can search for the official sources. if you have more time than me) : 

http://www.tcodevelopment.com/pls/nvp/Document.Show?CID=4146&MID=262



> *Emissions*
> ...
> Alternating magnetic fields must be a maximum of:
> - Band I: 5 Hz to 2 kHz, <= 200 nT, measured at 30 cm in front of and 50 cm around the display.


http://en.wikipedia.org/wiki/Tesla_(unit)



> 200 nanotesla (nT) = US Congress and WHO Recommended limit for constant human exposure = 2 mG


Now just to illustrate the "PURE woo-woo" here is a fresh photo of this fan ( nothing special... just a usual made in china small fan. like millions of others...

And together with a reading of the ELF in mG at about 15cm :











So ? Does it look like "woo-woo" now ?

Yes. no one sticks their face 15cm from the fan. Its just hard to photograph but it drops to 1mG at around 3m. (at 1m its around 20 or so... yes. 10 times above standard. )

And before you jump and say that i'm showing you a fan together with calculator, here is a proof that it is not "calculator" :








So you may ask what about electrical blankets, hair driers, drills, micro ovens, power supplies, electrical boxes, power lines, etc.... 
Some are ok and some are not. Depends on their construction, power and your distance from them.

Did i show you a guy who died from his fan ? 
Obviously no. But i did show enough to understand that it may influence on your health. Excess ELF causes cancer. It is not a secret. Cancer kills. 
So make your own conclusions.


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## LLCoolBeans (Jan 23, 2009)

:eeksign: :sweat:


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## r-s (Jan 24, 2009)

hopkins said:


> Hi r-s , keep going with your thinking on this subject. I've found, and sited, many diverse studies that turned my knee jerk disbelief around. Some are fairly technical and not easy to understand but the sense is there can be an impact.



Your "disbelief" -- yes, that's it in a nutshell.

Sorry, I already have a religion -- and it does not need any woo-woo, pseudo-"scientific" mumbo-jumbo, neo-luddite fear of that which, albeit SIMPLE science, is unknown, and scary to the victims of government education.

Spare me the condescending veiled insults. I have been designing and building RF devices since quite likely before you were born. I know a thing or two about what I say, and I also know BLATANT flapdoodle when I see it waving in my face.

Save your breath for Coast to Coast AM. The only thing you'll convince ME to do is laugh at your woo-woo "beliefs" -- and cry for our future generations, "educated" to "feel good about themselves" -- and run screaming into the night, calling for the space-suit guys, because a mercury thermometer -- or CFL bulb -- fell on the floor and broke.


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## r-s (Jan 24, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



madcat108 said:


> Indeed no offense and sorry, but your thinking is a bit primitive.



Oh. My. God.

YOU are calling MY thinking "a bit primitive"?

Someone pinch me!

Sorry, friend, but *I* am not the one running around like a chicken with its head cut off screeching Look! Look! Look! I have PROOF!!!!! (that there's (*GASP!*) sixty cycle HUM in the air!

Oh, the vapors!




madcat108 said:


> So ? Does it look like "woo-woo" now ?



Are you serious?

I mean, is Allen Funt hiding around the corner?

Are you bleeping SERIOUS?

You show me that there's sixty cycle hum in the air, and I'm supposed to freak out and believe Oh, NOOOOO, we're all gonna DIIIIEEEEEE?

Get real. Get help.

Or, get in line behind the other guy. Art Bell will be glad to hear from you.


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## r-s (Jan 24, 2009)

People who are terrified of the 60 cycle hum from a desk fan -- while remaining oblivious to the MUCH greater amount of hum (and that's all it is, kids -- sixty cycle HUM) from all around them -- remind me of the "audiophiles" who will plunk down THOUSANDS of dollars for a power cord to run from the stereo to the wall outlet -- yet, NEVER stop to think that once it hits the two dollar Leviton power socket, it then runs through fifty feet of the cheapest Romex wire the contractor could find, from whence it runs into the cheapest cable the utility company could find, etc., etc., etc.

P.T. Barnam had it right, that's all I can figure.

But, if you people REALLY want to do something about a GENUINE toxin -- a chemical that is PROVEN to KILL -- and, in fact is DOCUMENTED to cause *countless* deaths each year -- a deadly chemical that is finding its way into nearly *all* foods and drinks sold to unsuspecting consumers -- it is even given to BABIES -- then why don't you stop all this silly supersititious fear of the Demon Electricity, and try to do something about the KNOWN toxin dihydrogen monoxide?

You can start here: http://www.dhmo.org/


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## r-s (Jan 24, 2009)

And if anyone doesn't think this is serious, here is an excerpt from the Dihydrogen Monoxide FAQ on that website:

* What is Dihydrogen Monoxide?*

Dihydrogen Monoxide (DHMO) is a colorless and odorless chemical compound, also referred to by some as Dihydrogen Oxide, Hydrogen Hydroxide, Hydronium Hydroxide, or simply Hydric acid. Its basis is the highly reactive hydroxyl radical, a species shown to mutate DNA, denature proteins, disrupt cell membranes, and chemically alter critical neurotransmitters. The atomic components of DHMO are found in a number of caustic, explosive and poisonous compounds such as Sulfuric Acid, Nitroglycerine and Ethyl Alcohol. 

For more detailed information, including precautions, disposal procedures and storage requirements, refer to one of the Material Safety Data Sheets (MSDS) available for DHMO:
[snip]


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## yellow (Jan 24, 2009)

1st thing when one believes that crap, is to throw away is ones's cellular 

while a regulated headlamp has no power for _making_ frequenzys at all, rides on the strongest part of the skull and is a bit elevated from it, Your cellular is _built_ to send 0.5 W of really threatening frequenzy directly through a hole in a weak part of the skull and rides pressed against the skin
(PS: double distance halves "pollution")


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## traplight (Jan 24, 2009)

i distill my DHMO first.. unless i'm up in the hills, and then i prefer to have a beaver turd or two floating in my veins 

Electricity is everywhere. Minute atomic collisions happen with such frequency that we don't even have a number, let alone the brain capacity to augment an equation to find that number, to define their scale!

Humans will adapt (mutate for all those biochemists) or die.

The universe exists in a state of perfect unity. 1=1


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## Jagge (Jan 24, 2009)

Health impact or not, if a DIY headlamp builder wants not not get affected by this, what type of drivers he should use or should not use. Resistors? How about AMC7135 boards? buck, boost, PWM dimmers?


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## Guy's Dropper (Jan 24, 2009)

That was quite an outburst r-s, but I'm going have to agree with Wildcat that such an amount of RF coming from such a small and common device is concerning.


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## r-s (Jan 24, 2009)

Guy's Dropper said:


> That was quite an outburst r-s, but I'm going have to agree with Wildcat that such an amount of RF coming from such a small and common device is concerning.



Good Freaking Grief.

Stick a fork in us, folks, we're done.

R.I.P. Rational Society -- the Age of Voodoo reigns supreme. Our inboxes overflow with spamverturds touting peeeniepillz -- why? Because people BUY them! -- and, our otherwise-rational web fora are frittered with people scaredy of mystery-waves, stirred to a paranoic froth by hucksters and shamans.

Ashes to ashes, dust to dust, sic semper selene.


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## r-s (Jan 24, 2009)

PS: Sort of ironic, ME being lectured on electronics by a self-described "*Knowledge of electronics*: Newbie(sorry)"


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## gillestugan (Jan 24, 2009)

This is great news! Now I finally have something real to blame for my failing memory. People just laugh when I say it is because of dementia.


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## traplight (Jan 24, 2009)

Well, Jagge, determine the frequency that you want to stop, and create an alternate out of phase frequency. Noise cancellation is a form of this. There's a VERY good chance that EMF cancellation (on a much larger scale) has been in development by the big three war-mongers for quite awhile.

Do a little research into it and you'll find some fascinating self-discovered principles behind frequencies.

Gillestugan - HaHa... "Where's my headlamp" - "it's on your head honey"


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## madcat108 (Jan 24, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



r-s said:


> “I have been designing and building RF devices since quite likely before you were born.”


 

That explains all.

Being an Engineer myself I’ve noticed this incredible fact that "RF people" are always first to jump and debunk the "danger of EMF" myth.

Is it a kind of self-deception ?

At this point it already looks like pretty hopeless case (i.e. further conversation may result in no agreement from either of the sides) But I’ll write some more "woo woo" just for other people who read this and may get mislead. 

“pseudo-scientific" ? Go read some scientific material. Not some nonsense written by a crazy RF hobbyist who sleeps while hugging his 1Kw transmitter and says "hooray! I'm still alive!" at the morning. 
Instead of moaning that we are all hypochondriac - Go check some statistics. If you don't believe that all safety rules (in whatever area) are written with blood - You can even swim with your 1Kw transmitter in the bathtub. I won’t really care.

My point is: If you are 90 and smoke 2 packs a day that does not mean that smoking does not kill. And no one (oh well... almost) will argue with it. Everything is a matter of probability. When you drive a car you have some chance to die. When you drive without seat belt - more chance. When you talk on your mobile while driving in this car - more. High speed ? even more. Bad weather - more ... All sums up... 
So when you sleep 1 meter from a fan from my example - that does not mean you won’t reach 90. It just makes this probability considerably lower. Especially if you smoke, talk 5hr a day on mobile and so on.......

DHMO - Out of topic here so I won't discuss it and other additives here.

"sixty cycle HUM" uh? I'll tell you that its even 50 cycle "HUM". The only difference is that you are not dealing with sound waves here. This 50/60 cycle "HUM" transfers MEGAWATS of energy per hour inside transformers. Enough to turn you into ash in a few seconds.
So the point is not only in frequency but also in power. So how much is 500 mG for your body? What about 50 000 mG at same 50Hz still just a “HUM”? Anyway you can't see smell or touch. But it may come in surprise for "realistic" people like you : not only bullets and baseball bat kills ! What about gamma rays? Will you also argue? 

Mobile... "yellow" if you are goin to throw your mobile better give it to me. I'll find it a better use  Surprise! i do believe this “crap” and have more than 1 mobile ! And yes I even talk on them! It’s just that I don’t talk for hours. When I can I use landline phone ( wired ) or switch to loudspeaker... when I can't I make the conversation short or at least keep a few cm between the mobile and my head. Not a big deal.

Talking about mobiles... also little OT. There are certain standards and these mobiles mostly do comply with them. (for now but not for long). But on my fan example you see somth that is 250 times higher that the current standard! (at that distance). So we talk about different things here.... Possibly you think that the standards are too strict and should be loosened? In such case you are free to set your own standards in *your own* bedroom.


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## madcat108 (Jan 24, 2009)

r-s said:


> PS: Sort of ironic, ME being lectured on electronics by a self-described "*Knowledge of electronics*: Newbie(sorry)"



Sorry to interfere. I really don't like to get personal here... And in no way put myself into the equation... But could you possibly enlighten us all regarding that capital "ME"... ?


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## codypop (Jan 24, 2009)

madcat108

Thanks for the thought provoking inquiry. I for one hadn't even considered the implications of whacking a switching regulator on my head, or conducting switched currents halfway around my skull. I have a feeling that this line of inquiry will influence the design of a headlamp I'm thinking of building.

Let us know if you can find a way of measuring the power radiated by switching headlamps. It may be next to nothing, but you're right - we should be at least interested.


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## LLCoolBeans (Jan 24, 2009)

Is it possible that EMF causes negative health effects? Yes. Is it scientifically proven? I don't know, but it certainly warrants research and I don't think it's outside the realm of common sense to entertain the idea.

Kudos to madcat for remaining perfectly calm amidst such vehement opposition. He makes a very lucid argument and frankly I'm more inclined to believe the guy who can keep his cool.

Some here argue that there is no hard data to back madcat's position. That may be true, but is there hard evidence that proves the opposite?

I may not be an RF expert, or even a novice, but I'd like to think I have a fair amount of common sense and this does not seem so outlandish to me. 

I'm not saying I believe 100% that EMF can be harmful, but I'm certainly open to the idea and I'm definitely game to read more on the subject. It wasn't so long ago that X-Rays were thought to be harmless. Shoe stores used to have X-Ray machines for fitting shoes. Well, guess what, X-Rays are harmful and it's been proven.


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## madcat108 (Jan 24, 2009)

Jagge said:


> Health impact or not, if a DIY headlamp builder wants not not get affected by this, what type of drivers he should use or should not use. Resistors? How about AMC7135 boards? buck, boost, PWM dimmers?



We don't know yet if the amount of EMF from such regulators is dangerous when put directly on the head. Maybe it's negligible ? And maybe large enough to be considered as hazardous. I don't know.
Meantime we discuss if EMF is dangerous to health or not. If the worldwide accepted standards should be followed or not. And more OT stuff.
My initial question was simple : If someone has an equipment that can measure the EMF of Apex (as an example) at zero range. So we can see if it is above or below the common standards. (no intention to put them in question here).

Regarding your question... if your circuit does not use any switching - probably there is nothing to worry about ( except efficiency). If it does: watch the coils. they should be in a closed magnetic case. Avoid large current loops - Place forward and return current conductors as close to each other as possible. Try to use shielded case or at least around the switching element and coils. And any other emf-decreasing techniques...


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## gsegelk (Jan 25, 2009)

LLCoolBeans said:


> Kudos to madcat for remaining perfectly calm amidst such vehement opposition. He makes a very lucid argument and frankly I'm more inclined to believe the guy who can keep his cool.



+1!! I was seriously impressed with the restraint madcat used after all that! If there were any valid points in the original disagreement, it was lost in the tact used in the delivery! 

I'm interested in looking into this more and would've never seen this thread had it not been revived (now that's kind of ironic!). I hope this thread can get back to rational discussions on the subject (and also getting a measurement)...


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## r-s (Jan 25, 2009)

Pseudoscientific twaddle -- superstition masquerading as rational discourse -- does not merit a dignified response.

A neo-voodoo "believer" who "keeps his cool" may gain some followers... but then, so did Jim Jones.


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## Marduke (Jan 25, 2009)

Those who know the least know it the loudest. 

With that in mind and reading the above posts....


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## r-s (Jan 25, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



madcat108 said:


> DHMO - Out of topic here so I won't discuss it and other additives here.



ROTFLMAO!

Thank you, thank you very much, for demonstrating the depth and breadth of your scientific knowledge!

DHMO is _*water*_!

You read world-class "scarystuff" couched in the exact same spookytalk used to terrify the NAIVE of basic electricity --- and you swallowed it whole!

There were NO lies, NO deception on that website -- unlike the "fan death" idiocy and the rest of the mumbojumbo nonsense being piped into this thread.

The facts were there for anyone to read -- those capable of critical thought would read it and get a chuckle out of it, because they realize that the woo-woo-susceptible will read it and go "OMG! A deadly TOXIN! AIEEEEE!!!!!" -- while reading about WATER!

In another culture, folks believe that the camera will capture their soul. Same brand of "logic" -- but, OUR charlatans employ high-sounding flapdoodle, to persuade those who lack the most basic education in the most elementary scientific FACTS.

I am SO tempted to tell you that "gullible" is not found in any dictionary...


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## r-s (Jan 25, 2009)

madcat108 said:


> Sorry to interfere. I really don't like to get personal here... And in no way put myself into the equation... But could you possibly enlighten us all regarding that capital "ME"... ?



But of course!

I apologize for using such arcane terminology, and shall attempt to clarify it for the benefit of those not versed in the depths of the lexicon.

It (the word in question) is a "personal pronoun" of sorts, used as a token, so to speak, syntactically positioned in place of my actual name, which I elect to maintain as a confidential fact owing to a "belief" (if I may employ that term) in the principle of privacy (which being off-topic in this thread, I shall not further expound upon, however, google is your friend -- a basic query for the word "privacy" or its trunk form "private" will likely return a wealth of information should you wish to explore the concept further).


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## r-s (Jan 25, 2009)

LLCoolBeans said:


> Some here argue that there is no hard data to back madcat's position. That may be true, but is there hard evidence that proves the opposite?



That's not how it works.

Anyone can claim anything they want -- but it is NOT accepted as FACT until someone ELSE _disproves_ it. (And I won't even bother explaining that whole "prove a negative" fallacy.)

I can assert that there is a purple goblin on the tip of my nose that provides a lifetime of bad luck to anyone who argues with me, with a 90 day latency period. Can you prove I'm wrong? Hah! I didn't think so! So, it MUST be TRUE!

See how it works?

By the way, extraordinary claims require extraordinary evidence. It's one thing to claim that failure to look both ways while crossing the street increases one's risk of being flattened by a bus. It's something entirely different to claim that the evil waves coming out of a desk fan will kill you.




LLCoolBeans said:


> It wasn't so long ago that X-Rays were thought to be harmless. Shoe stores used to have X-Ray machines for fitting shoes. Well, guess what, X-Rays are harmful and it's been proven.



Ah, but audio frequency oscillators do NOT emit ionizing radiation. Your example is SO far into the "apples and oranges" realm as to merit no serious consideration -- at all!


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## r-s (Jan 25, 2009)

About twelve or fifteen years ago, I found myself trying to reason with a Usenet poster who was convinced that the IR sensor on his television -- nay, on ALL televisions -- (you know, the phototransistor that detects the "radiation"  from the remote control's LED) -- was actually a CAMERA that the government used for the purposes of spying on anyone it chose to observe in their homes.

NO amount of logic, reason, or calm, patient explanation could breach his paranoia. He had an answer for everything -- in his mind, it was proven fact.

It was not long after that -- and a few more encounters with those who were easily led by the nose by hucksters, charlatans, and neo-luddites -- that I gave up trying to be patient with those who embrace folly.

I'm getting the same "good lord, why do I even BOTHER?" feeling in the pit of my gut, so I'll leave you kids to your selenary endeavors in peace.

Rave on!


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## LLCoolBeans (Jan 25, 2009)

r-s,

I just went back through the entire thread and re-read each of your posts. Not once do you make an actual argument for your case. Just flames and childish insults. I would be just as likely to believe your side of the argument, if you would only make it.




r-s said:


> Ah, but audio frequency oscillators do NOT emit ionizing radiation. Your example is SO far into the "apples and oranges" realm as to merit no serious consideration -- at all!



Obviously, you've missed my point. So, here is another apples to oranges example. Once upon a time, most sophisticated, intelligent, well educated and experienced people were certain the earth was flat and that if one were to sail far enough away on the ocean one could fall off. Those who thought to the contrary, were of course CRAZY.


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## rushnrockt (Jan 25, 2009)

LLCoolBeans said:


> So, here is another apples to oranges example. Once upon a time, most sophisticated, intelligent, well educated and experienced people were certain the earth was flat and that if one were to sail far enough away on the ocean one could fall off. Those who thought to the contrary, were of course CRAZY.



That was more than two thousand years ago and most educated people did not believe that nonsense many centuries before Magellan got to prove it.

In this case you are talking about an area with quite a bit research and experience of many different companies. EMI is a concern for any switching circuit not only at the source, but also its interference with the rest of the electronic and non electronic devices. Many of the electronic devices are more sensitive to EMI than organic cells and even a simple plastic enclosure lowers the already negligible EMI by orders of magnitude.

As far as measuring any sort of signal coming from a fan, consider what type of motor is in there. Then consider its power. Then look at your ceiling far and consider the power of its motor. I won't even mention your A/C, fridge and washing machine, or you might want to move out to Yukon


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## hopkins (Jan 25, 2009)

Hei r-s 
I wonder why you're so emotional on this subject? Are you a VP in Samsung or 
Singular? $$$ makes peeps so obvious!

As others have noted here, you sound like one who knows a lot , but maybe does not know everything yet like the rest of humanity.
You're surely not Grand Inquisitor R-S (Bring out the instruments of torture!) but a seeker of knowledge! 

Its simply about RF oscillators strapped to the forehead powering a LED. (Inverse Square Law etc.)

Join us and welcome! Advance this threads knowledge! :thumbsup:


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## HarryN (Jan 25, 2009)

You know, its really not that hard to design an LED light that only uses nominal resistance as the driver / current limiter. The efficiency and output consistency is actually not that bad over a substantial portion of the run time.

I have built a couple of them - example 2 x Li Ion w/ 2 ohm resistor into a Lux V - works fine. Yes, I do need to buy binned LEDs, but it is still cheaper than a driver, and I would buy a binned LED anyway. With some care, it can be close to 80% effiicient - which is not that far from some drivers. The resistor is also a heck of a lot quieter than some RF setups I have seen.

I am not sure about the EMI from a health perspective for civilian use, but I can imagine that a soldier with an EMI emitting flashlight (even in standby) might be detectable. Now that would definitely fit the health hazard criteria.

OTOH, try to get someone to buy a resistored flashlight these days - it is dang tough. Partly because of the misunderstanding of how to match LED VF vs current curves against V bat vs time curves to maintain relatively flat output.

In any event, resistors are an easy way to cut way down on EMI if it is a concern. DC and no coils make it easy to shield.


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## hopkins (Jan 25, 2009)

Good points harryn -direct drive is a quiet drive.

The Inverse Square Law protects us from many RF sources..... 0.1meter-to- infinity???
The special case of a RF radiating headlamp: a hazard to health?
This crosses over to cellphone users too. So much money invested in that market that they need it to be safe
no matter if its not.


The old Petzl MYO XP does not radiate and is one of the reasons its still my favorite.


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## yellow (Jan 25, 2009)

why not simply build a lamp with an aluminium housing that shields possible threats,
instead of argueing on a topic You know _from the beginning _(and Your experience with how ppl react to it) what way it will take...

like to flame? :thinking:


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## madcat108 (Jan 25, 2009)

*Re: Regulated Headlamps - Health Impact ( EMF )*



r-s said:


> ROTFLMAO!



As my main motive in spending time on this discussion is to possibly help some people to save their health and i do enjoy making people happy in general - i am glad i made you so happy in this unexpected way.

When i say something - i mean it. I never (even until now) followed your link. Because it is really not in my interest right now and does not belong to this thread. I've mentioned "Additives" just because it sounded like one of them from your post.

In your posts you just laugh at all people who are concerned from effects of EMF. 
There are 2 topics actually : 
1. Worldwide accepted standards of EMF exposures. ( set & supported by various scientific, medical and government structures). If you don't know it and expect me to start googling for you and and throwing links for your "examination" you are very wrong in your expectations. I do have life, family, work etc... but very less time for stupborn beople. So if you want to get knowledge - that is a good intention... Let me suggest you to start with google.
If you want to argue with that ....well... it's not with me.... print a poster and go down to the street....
2. The possibility that the above limits are too high and these supposedly safe levels are still risky for general public. ( History has shown that most standards were lowered (i.e. get more strict) over time due to new medical evidences. This is Out of topic in this thread. I've never wanted to start this discussion. Only wanted to measure and compare the values to the known and accepted standards. (if someone want to take a personal precaution factor of 2, 5, 10 etc... its their business.)

So can you tell in plain language which one of these are you talking about ? #1 or #2 ? in either of the cases.... you should know what to do (see above ).


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## -LightOn- (Jan 25, 2009)

I'm a RF engineer so I think I know what I am talking about. And while I understand the concern of the people here, I'm afraid I have to agree with r-s about the dangers of low frequency EMR. (Though not his flaming)

Take for example microwave ovens. They operate at around 2.4GHz and use hundreds of watts to warm the food by getting the water molecules to vibrate. Now cell phones operate at frequencies of roughly 1, 2 and 2.4GHz. The GSM power amplifiers put out about 2W maximum (33dBm) and these things are designed to radiate that energy out of the antenna. As was stated previously, the phone is held to the ear which is the weakest part of the skull and still no one has been able to prove that prologned use would actually cause tissue alteration or anything else.

Now, lets think about switching DC-DC converters (boost or buck). First they operate at switching frequencies bellow 1MHz which is very low in terms of EMR. The wave length of 1MHz signal is 3 meters in air, to actually couple energy from that frequency one would need a dipole-antenna 1.5 meters long. So the electric field which could couple across the brain is very weak, because the 'antenna' or our brain is too small. Second, the operating power of a power led nowadays is around 10-12 W (e.g. the P7). With drivers that have efficiency of 80-90% that means that 1-2 W is dissipated by the driver. The important difference to cell phones is that most of that energy is turned into heat which is why we need heatsinking. So the actual power that is radiated is in the order of milliWatts which is still enough to be catched by a AM-radio, but nothing dangerous.

I hope someone can sleep their nights little easier now :candle:.


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## Marduke (Jan 25, 2009)

Microwaves are also heavily shielded. That's what the black grid on the front window is.


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## -LightOn- (Jan 25, 2009)

Marduke said:


> Microwaves are also heavily shielded. That's what the black grid on the front window is.



I know, I was trying give perspective of powers and frequencies.


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## Guy's Dropper (Jan 25, 2009)

r-s said:


> PS: Sort of ironic, ME being lectured on electronics by a self-described "*Knowledge of electronics*: Newbie(sorry)"


I'm not lecturing you on electronics. It's sort of ironic, you lecturing us when you are not a medical doctor and have provided no evidence that backs up your claims that EMF, in any amount, is perfectly safe. It's a well known fact that powerful EMF can kill people. The real question is, at what point does it become dangerous.


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## gsegelk (Jan 25, 2009)

r-s said:


> NO amount of logic, reason, or calm, patient explanation could breach his paranoia. He had an answer for everything -- in his mind, it was proven fact.


 
It sounds like some level of self reflection is starting to show through??




r-s said:


> I'm getting the same "good lord, why do I even BOTHER?" feeling in the pit of my gut, so I'll leave you kids to your selenary endeavors in peace.


 
Thanks! It's really not a big deal seriously...not like I'm declaring WW3 running out to get aluminum foil. It's just an interesting topic just like any other that claims (DHMO not included although funny) something is a risk to our health.

Please feel sorry for us although you don't even know who we are and what our professions are.


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## r-s (Jan 25, 2009)

I told you people I was done trying to reason with your looney nonsense. You're not interested in debate, you're not interested in facts... the craziest part of all is that you're HERE, on a TECHNOLOGY venue, railing against... technology.

You're like rabid vegetarians camping out at a BBQ forum raving endless screeds against the deadly effects of meat-eating.

One last time, and then I am DONE with you crazies.

Hear this, and hear it well -- or, don't. I don't care.

Read the linked material -- or, don't. I don't care.

(You probably won't, as demonstrated by one of your number, who, while dismissing a link I provided earlier -- with much grand handwaving, declaring it off-topic, WITHOUT EVEN KNOWING WHAT IT WAS(!!!!!), illustrated beautifully the sort of proud ignorance that grows indigant when confronted with fact. Outcome-based "understanding" -- the mind already made up, all facts that challenge are dismissed BECAUSE they challenge, and then, in the most absurd insult of all, they declare that their crackpot theories are FACTUAL *until* "disproven" -- a *classic* Logical Fallacy that would bring every debate coach in the land to his knees in paroxisms of laughter.)

I swear, if this was Usenet, several of you would by now be well along your way to a successful KoTM nomination.

You persist in spouting off the most outlandish crackpot "theories" as fact -- and then crow in victory because -- by rejecting out of hand all evidence to the contrary, that your "theories" have been "proven."

This is SO far removed from the boundaries of rational discourse and BASIC LOGIC as to merit nothing greater than ridicule.

And then, the peanut gallery weighs in, judging the merits of the various parties on the basis of who maintains the fattest mellow. Lose your mellow, lose the debate, and mere things like FACTS don't even matter in the least. The Peanutters have declared that you've lost your mellow, and thus, they declare that your points are invalid.

This is the saddest commentary on the future of western civilization that I have ever seen. It is an indictment of the public education system, and an indicator of really, really, really BAD times for "the west."

If you think that by insulting ME, you will bait me into seriously debating your pathological fear of technology, then I have a large (EMF-free!) bridge to sell you.

One last time -- EMF hysteria is pure bunkum. A few starting points, for free (if you want more, find it yourself. It's not exactly "hidden knowledge" after all):

http://www.acsh.org/factsfears/newsID.254/news_detail.asp

http://junkfoodscience.blogspot.com/2007/04/tragedy-of-overwhelming-fear.html

http://www.lib.niu.edu/1993/im930425.html

http://www.wave-guide.org/archives/emf-l/Aug1999/TGIF-----Snake-oil----.html

That's all, folks. You can screech your nonsense as loud as you like, and I hope you enjoy the echo chamber, because I will NOT be back in this sandbox. (I do hope though that you realize that you DO provide a valuable service to the numerous lurkers who sit there spewing coffee on their keyboards as they read your cockamamie decrees -- on a *technology* site!)


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## Marduke (Jan 25, 2009)

r-s,
If you will give a simple and direct answer to this one basic question, I'll let all your above nonsensical babbling go without pointing and laughing my *** off.

Question:
EXACTLY what level of EMF exposure is safe?


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## traplight (Jan 25, 2009)

Wow, that's amazing. I believe it because i saw it on TV and read it on the internet.

http://www.acsh.org/factsfears/newsID.254/news_detail.asp - subsitute OJ simpson for EMF and you get the idea... An ignorant jury and a good lawyer will always win.. even if 'evident'. Let's be good americans and lobby... woohoo! We'll petition the ACSH. Write a letter to our senator!

http://junkfoodscience.blogspot.com/2007/04/tragedy-of-overwhelming-fear.html - Yes, another case of limited intelligence in this corner of the universe. I'm sick because i believe it will make me sick. Let's not even get into placebos and the FDA... looking at the side-effects of the plethora of drugs which are passed by the government makes you wonder a little doesn't it? Hey, a little EMF never hurt anybody right?

http://www.lib.niu.edu/1993/im930425.html - "no level of EMF has been determined to be safe or unsafe". Why?... we'll get more blah blah blah... This time we can write a letter to our military asking them if they have any particular uses for large directional microwave ovens. The kind we can use for that one-mile roasted chicken recipe we've been saving for the neighbors.

http://www.lib.niu.edu/1993/im930425.html - Archives from 1999? Weren't we still using x486 computers back then and smacking Mac's around? That's a little outdated as far as the technology sector is concerned.

I can say this. Your verbal disposition will not allow a debate on any subject due to your beliefs. It can be compared to having a Christian try to convert a Muslim or visa-versa. Religeous context analogies aside, your POV on EMF's is STILL as valid as anyone's here.

Tesla was a major proponent to EM work. He lived a very long life, albeit poor and misunderstood toward the end, within EM fields that would have made the hair pop off of any tree loving technophite of today. His work undermined Edisons projects so much that Edison decided to shock stray animals on the street to show the public just how dangerous AC power was.

We are all using AC power today... and still using the same damn lightbulbs that edison patented! Light bulbs are inefficient and how long did it take for scientists to question this? How long before there is a better way. A safer way?

- If we only use 10% of our brains then 90% of the time we are 100% WRONG!

Now, Assuming you are subscribed to this thread, you are still going to be chomping your jaws like Clint Eastwood with a 'Gran Torino' style racial hatred towards all of those who don't see it your way.

See you soon


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## hopkins (Jan 25, 2009)

Light On - Your points were all refuted in earlier posts that cited studies
funded by the US govt. I read them. Take a look. They tackled the special case of RF sources in direct contact with living tissue.

r-s recently posted (and cited info) all refer to distant RF sources but do not address the special case
of an RF source in contact with living tissue. The purpose of this thread. 

I'm not worried about distant Rf sources nor should anyone be. One that's on your forehead is what we'd like to know more about.
---Which way are the radiation lobes going for instance.


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## Guy's Dropper (Jan 25, 2009)

r-s said:


> I told you people I was done trying to reason with your looney nonsense. You're not interested in debate, you're not interested in facts... the craziest part of all is that you're HERE, on a TECHNOLOGY venue, railing against... technology.
> 
> You're like rabid vegetarians camping out at a BBQ forum raving endless screeds against the deadly effects of meat-eating.
> 
> ...


So... We ask for some proof that RF radiation is safe at all levels and you give us this list of crackpot websites.... How mature of you... This really supports your claims. If I had not read some of your earlier posts, I would have thought that you are some type of troll who is posting stuff like this just to annoy us and waste our time.


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## Marduke (Jan 25, 2009)

Guy's Dropper said:


> If I had not read some of your earlier posts, I would have thought that you are some type of troll who is posting stuff like this just to annoy us and waste our time.



He's not??


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## hopkins (Jan 25, 2009)

yellow - here's a test anyone can do to test the shielding effect of aluminum
on a RF noisy headlamp. 
First choose a headlamp that makes an AM radio squeal when held close.
Then wrap the turned on headlamp in aluminum foil carefully, making sure its sealed. Then hold the AM radio close again.

I was surprised to still hear lots of noise even through the aluminum. A bit less noise but still a lot. So an aluminum box with a hole in it for the LED to shine out of won't do the trick to quiet regulated headlamps. 

(used a 1AA Rayovac Sportsman Extreme headlamp)


I did this same thing to a cellphone and could not call it anymore when it was wrapped in aluminum foil. Interesting.


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## LLCoolBeans (Jan 25, 2009)

r-s said:


> I told you people I was done trying to reason with your looney nonsense. You're not interested in debate, you're not interested in facts... the craziest part of all is that you're HERE, on a TECHNOLOGY venue, railing against... technology.



I'm not sure who this comment is aimed at, but I think I speak for most, if not all, of us when I say, that we *are* interested in debate and the facts. So, if you are such a fountain of knowledge, why not drop some here? Sorry, but "you are a crackpot" is not an argument. Grow up.




r-s said:


> One last time, and then I am DONE with you crazies.



You keep saying that, yet you keep coming back. If your only intention is to flame and troll, I suggest you re-read the CPF rules or find another message board to troll on.


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## TITAN1833 (Jan 25, 2009)

@r-s this thread has been around 3 months I doubt you will make three more days the rate you are going, chill out!!


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## madcat108 (Jan 25, 2009)

HarryN said:


> You know, its really not that hard to design an LED light that only uses nominal resistance as the driver / current limiter. The efficiency and output consistency is actually not that bad over a substantial portion of the run time.
> 
> ........
> 
> ...




I've never dealt with flashlight DIY but you have a point !
Discharge curves of NiMH and Li-Ion cells are relatively flat. 







So it looks like a regulation gives a bigger advantage with Alkaline cells.... but they are being used less frequently i guess.

So if you build an unregulated 80% (your data) efficient flashlight it will be 15% at most below the best regulated one in terms of efficiency and very close in terms of the curves. 

Very interesting perspective......
At first glance regulation seems to have a larger advantage.....

Or do i miss something ?


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## uk_caver (Jan 25, 2009)

One major advantage of using a linear regulator rather than a resistor to drive LEDs is that LEDs vary in the voltage required to drive a given current through them.
One way of looking at it is that the 'resistance' of an LED is highly dependent on the current flowing through it.
Not only that, but variation exists even between LEDs of exactly the same type, for a single LED the characteristics change when it heats up (the resistance drops with temperature), and can also change over the life of a single LED, with the LED tending to drop in.

Using linear regulation means that (within limits), the designer doesn't have to try and match a circuit to an individual LED, or worry about device characteristics changing over time.
In any case, a linear regulator is effectively just a smart resistor, with no likely EMF implications, and regulators are often low cost.


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## madcat108 (Jan 25, 2009)

-LightOn- said:


> I'm a RF engineer so I think I know what I am talking about. And while I understand the concern of the people here, I'm afraid I have to agree with r-s about the dangers of low frequency EMR. (Though not his flaming)
> 
> Take for example microwave ovens. They operate at around 2.4GHz and use hundreds of watts to warm the food by getting the water molecules to vibrate. Now cell phones operate at frequencies of roughly 1, 2 and 2.4GHz. The GSM power amplifiers put out about 2W maximum (33dBm) and these things are designed to radiate that energy out of the antenna. As was stated previously, the phone is held to the ear which is the weakest part of the skull and still no one has been able to prove that prologned use would actually cause tissue alteration or anything else.
> 
> ...




I understand what you are saying. But you have many assumptions. The most basic one that is not in plain text but possibly you mean it (sorry if i'm wrong) that only heating of the tissue cause damage. There are a lot of scientific and medical evidence that not only heating cause damage. (a kind of sensitive topic for many so i'd better stop here).

I've showed pictures of open Apex to my friend (also engineer) and he thinks that the coils have pretty closed design (although we don't see them from the bottom) and looks like the EMF shouldn't be too strong. Of course this is an assumption as well. 

I knew pretty much about ionizing radiation and high frequency RF. But at the time i've discovered the dangers of ELF i've been more than surprised. So i've bought the ELF meter just to check everything myself. Before checking i had some assumptions also. Many of them turned to be completely wrong. The above small fan has few times stronger ELF field than my 3.5 Horse Power A/C compressor, Large fans, Fridge, and more. And that an old 220v powered shaving machine has about the same ELF and this Fan !
It looks like the emission depends not only on the currents involved but on the magnetic design on the system. That fan has a simple single pole induction engine. While larger fans has multiple poles. I've tested a few single poles motors and they all had a very strong ELF. Probaby thanks to an excessive magnetic leaks due to asymmetric design.

My point is that without measuring and comparing to official standards we can get very wrong.

Just as an example : from the same TCO'03



> *Emissions*
> Alternating electrical fields must be a maximum of:
> - Band I: 5 Hz to 2 kHz, <= 10 V/m, measured at 30 cm and 50 cm in front of the display.
> - Band II: 2 kHz to 400 kHz, <= 1.0 V/m, measured at 50 cm around and 30 cm in front of the display.
> ...


http://www.tcodevelopment.com/pls/nvp/Document.Show?CID=4146&MID=262

looking at the magnetic field as an example you can see that Band II limit is 8 times less than Band I. Possibly it wont be too wrong to assume that the regulator used in Apex works at around 1 MHz. And by extrapolation (which also may be wrong) we get that the safety level at that frequency is around 2nT which is 100 times less than at lower frequencies. (probably because a higher frequency wave caries more energy).... Are you getting my point ? Things get smaller but not nescesary safier....

Anyway I would "slept better at night" if regulated headlights would have to pass EMF emission tests... like any other electronic equipment while considering the zero distance from our head.


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## gsegelk (Jan 25, 2009)

So what exactly would you need to measure the EMF from something like this? You mentioned that yours was not capable of doing it so could you link to one that might be capable? There's a chance that a different project within the company I work for might have one. Just a disclaimer for the people who need it: I'm just interested at this point...I'm not thinking this is the end of the world!


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## rushnrockt (Jan 26, 2009)

hopkins said:


> Light On - Your points were all refuted in earlier posts that cited studies funded by the US govt. I read them. Take a look. They tackled the special case of RF sources in direct contact with living tissue.



Are you referring to the paper written by John Michael Williams in regards to UWB transmissions? Although he brings up some valid points, his response is meant for a considerably higher frequency applications with actual antennas (as UWB transmissions have them). The general ideas can still be transferred over to lower frequencies and powers, but if you are claiming it "refutes" things, then I will have to disagree. There'd be quite a few more pages of text and more of an actual study to claim that it refutes anything. It does provide solid reasoning for changing approach to measuring EM impact on cells. I did not see any other links that pertained to what -LightOn- was saying. 

Sighting WashingtonPost story on RFID implants really doesn't get us anywhere in this particular discussion. There is a world of difference between an implant and something that's close your body. Just like alpha radiation can be absolutely deadly to a body or merely annoying  The article did not even mention if the RFID tags were passive/active or low/high frequency. There wasn't a single mention of control groups with just the glass capsules without the tags themselves, did I miss that? Again, viable concerns, but in this case the information presented is lacking; it's like neither side has good proof for their beliefs, so they go with half truths and omission of facts.



hopkins said:


> yellow - here's a test anyone can do to test the shielding effect of aluminum on a RF noisy headlamp.
> First choose a headlamp that makes an AM radio squeal when held close.
> Then wrap the turned on headlamp in aluminum foil carefully, making sure its sealed. Then hold the AM radio close again.
> 
> ...



Are you really surprised? The headlamp is probably using a cheapo regulator in 500-750 kHz range or probably 1MHz if they splurged. That's quite different from 800/900/1800/1900/2100 MHz range of the phones. This is a good reason to remember than tin foil headgear might not stop *them* from reading your mind!


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## hopkins (Jan 26, 2009)

gsegelk - none of this EMF jazz is the end of the world unless it helps induce
a personal end of the world. 

During this past year how many multi-day power failures affected 1,000,000's
of people and how many of those wore regulated headlamps to continue their activities? How many children with brains still developing? 

A proposed guideline is to keep all EMF generating devices away from the head. At least the distance that it will overpower the band on an AM radio making it squeal/buzz.... 8-to-12inches approx.
Something any nontechnical person can do.

Rushnrockt - you're right I take back 'refute'. Too strong. Lighton made good points that for distant EMF sources are likely true. 

Hypothetically speaking lets say there is an evil James Bond type villain out there, could he design a nefarious regulated headlamp that directed all its EMF into the skull with frequency and power level carefully chosen to induce a tumor.
If such a thing were possible (not saying it is) then we would all want headlamps with specs as far removed from this as possible.


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## -LightOn- (Jan 26, 2009)

madcat108 said:


> I understand what you are saying. But you have many assumptions. The most basic one that is not in plain text but possibly you mean it (sorry if i'm wrong) that only heating of the tissue cause damage. There are a lot of scientific and medical evidence that not only heating cause damage. (a kind of sensitive topic for many so i'd better stop here).


Actually, I did not assume this and I'm sorry if you got the impression that I did so. But I agree on the fact that damage can occur in other ways also - like ionizing with x-rays.



> I've showed pictures of open Apex to my friend (also engineer) and he thinks that the coils have pretty closed design (although we don't see them from the bottom) and looks like the EMF shouldn't be too strong. Of course this is an assumption as well.



Having a closed metal case (faradays cage) around the device to shield off radiation is still a good idea. 



> I knew pretty much about ionizing radiation and high frequency RF. But at the time i've discovered the dangers of ELF i've been more than surprised. So i've bought the ELF meter just to check everything myself.


I have to confess that my knowledge is not complete as I also know more about the high frequency stuff. How exactly does that meter measure the field? I guess I have to go down to our measurement lab to do some measurements with my buck-driver.



> looking at the magnetic field as an example you can see that Band II limit is 8 times less than Band I. Possibly it wont be too wrong to assume that the regulator used in Apex works at around 1 MHz. And by extrapolation (which also may be wrong) we get that the safety level at that frequency is around 2nT which is 100 times less than at lower frequencies. (probably because a higher frequency wave caries more energy).... Are you getting my point ? Things get smaller but not nescesary safier....


And also remember that attenuation goes by 1/f. One has to also consider what kind of antenna does the human body form. It is another thing to measure electric field with a meter than what is actually coupled to the body.



> Anyway I would "slept better at night" if regulated headlights would have to pass EMF emission tests... like any other electronic equipment while considering the zero distance from our head.


This I agree on completely :thumbsup: But the distance is not zero like it is with implants.


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## hopkins (Jan 26, 2009)

Good points Light-on. I should not have said 'refute' in the earlier post.
The study implied there was an effect and needed more investigation.
Maybe fishing for more grant money.

My bluetooth earpiece seems to radiate more out of the side away from the head. If true thats a hopeful sign that the designers are trying to avoid any 
problems as well increase performance. Or maybe its unintentional...hmmm.


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## -LightOn- (Jan 26, 2009)

I did some measurements, not very scientific but still... to get some idea. I used an Agilent 2GSps oscilloscope with 2 different wire lengths (20cm and 80cm) at a 1MOhm input.
High impedance input is likely to catch any electric fields going around.

First, a regular 60W incandecent lamp. Frequency 50Hz and amplitude 10 mV which gives 0.1 nW. My buck driver which is cased in a metal body gives the strongest field directly in front of the led. At the sides there is very little or no field. Frequency is 800kHz and amplitude 8 mV which gives 0.064 nW. When compared to e.g. GSM receiver sensitivity (0.1 pW), the measured figure is really low. Bearing in mind that the GSM receiver is designed to pick up a signal many kilometers away from the basestation.


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## DM51 (Jan 26, 2009)

r-s… you jumped into this thread with a series of abusive and sneering posts which, far from advancing whatever points you may have had to make, have only succeeded in doing the opposite. Others have made restrained responses to your insulting input, and you have just made yourself sound unpleasant and arrogant, laying yourself wide open to ridicule in the process. 

Take some time off to rethink your attitude. When you return, we will expect to see a change in your style.


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## yellow (Jan 26, 2009)

*[Rule violation - content deleted by moderator]*


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## DM51 (Jan 26, 2009)

yellow, I have sent you a PM. You need to pay careful attention to it.


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## yellow (Jan 27, 2009)

understand,
somehow missed 2nd part of rule #4
sorry


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## HarryN (Jan 28, 2009)

madcat108 said:


> I've never dealt with flashlight DIY but you have a point !
> Discharge curves of NiMH and Li-Ion cells are relatively flat.
> 
> 
> ...



Hi - sorry for taking a long time to answer your reply. 

First let me say that I am in no way claiming that an LED with a resistor is going to give the equivalent regulated performance (efficiency or light output consistency) of a well designed driver circuit combined with the correct battery pack and LED arrangement. The real questions are: 
a) What are you gaining ? 
b) What are you giving up ? 
c) Are you satisfied with the trade off ?

These are not as simple to answer as they seem, but let me make some examples so you can come to your own conclusions. I will use mostly Lumileds parts as I am more familiar with them.

1 x CR123 driving a single Lux III or K2 Red / orange LED.

- If the LED is Red / Orange, the Vf is under the V bat, but only by about 0.5 - 1 volt
- Many drivers cannot regulate under such a small voltage difference, but a few higher end ones can. 
- A 1 – 2 ohm resistor will bring the current down to 1 ish amps and work just fine over the life of the cell
- Even when the cell is very low, the LED will still turn on – just on lower
- Since the LED Vf drops with current flow (as a curve), as the battery starts to loose voltage, the actual “change” in current flow is less than you might expect
- Assume 1 ohm resistor and about 1 amp, then resistance loss is

V bat – Vf = 1 ish volts. Worst case Power lost in 1 ohm resistor = 1 V x 1 A = 1 watt for a 3 ish watt LED setup, so 25 % loss in conversion. 

The few drivers that can actually regulate like go to zero output long before the cell is dead, but might hit 85% efficiency for this setup while running.

Light output effect
- So, how much can current change before you really can observe light output change ? - Most indications are that 25% is not very substantial in normal use conditions.
- How much will light output chance due to thermal effects – more than 25 %, even in a decent flashlight.
- Tradeoff – for this particular setup, a driver circuit might not make sense.


1 x CR123 driving a single white K2 or Lux III
- This is a bit tricky for any setup
- The depending on the LED, the Vbat might start higher than the Vf, then swing lower than the Vf during the run in a driver setup. This means you need a complex buck / boost circuit, or make sure your LEDs have a high Vf (reduced efficiency)
- If you want to also use R 123, then the problem is actually larger
- Selecting a very low Vf LED bin solves this for the DIY / custom market, but high volume light makers cannot survive trying to specialty bin LEDs for Vf.
- The normal answer for them is 2 x 123 and a simple buck driver.
- A similar problem exists for 2 x CR123 and a 2S2P LED (Lux V, 4 die Cree and 4 die SS)


My Project “breeze” example
- 2 ohm resistor + 2 x CR2 or 2 x RCR2 + Lux V WWOS
- This is a very special example and not something that is easy to obtain parts for anymore
- WWOS Lux V has a Vf of around 6 – 6.5 volts at 700ma (don’t remember anymore, but it is the S at the end)
- With 2 ohm resistor, 700ma burns off 1 ish watts from a nominal 5 watt LED
- This low Vf allows me to use it with R CR2 or CR2
- The main problems are of course, Lux V is not easy to obtain, CR2 primaries are expensive, and protected RCR2 are not available (anymore).
- Still, I EDC the light, mostly for fun / show and tell.

- So – why didn’t I use a driver circuit – it would not fit – not even close. I even had to have special 1206 size resistors made that could handle 1 watt +, and that was much more costly than any driver circuit.

The key is really to design the LED / battery combo so that the average voltage of the pack is in the range of 1 - 2 volts more than the LED Vf. This is a tight requirement but can be done.

How much EMI comes from 1 ish amp DC going through a resistor, 1 in of wire, and an LED ? – I don’t know, but I am pretty sure that any current flow through a wire produces a magnetic field – and that is the hard part to shield. Still, this seems like it would be less than any other regulation method as there is not transistor or coil switching of any kind.

Was I satisfied with the trade off – yes, and so were a number of people that saw the light once they held it in their hands and tried it. Is it better than a commercially available headlight for banging around in a cave – that is not so clear.


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