Electromagnetic Frequencies in the Prius.

ronhowell · 10-28-2007, 12:33 AM

Hi All,

Back in summer of 2005 there was considerable discussion on this website on the effects of the high voltages that exist in some of the electrical circuits of the Prius, and the potentially adverse electrical radiation associated with them. There appears to be some confusion over the nomenclature adopted, many people referring to the radiation as EMF, which to me stands for Electromotive Force, the force produced when current carrying wires cut through a magnetic field.

Nevertheless, one poster on the site claims to have measured a field of some 100mG (milliGauss?) in parts of the rear passenger compartment. That compared with a reading taken under electrical high tension lines in his state (I presume carrying power at least at 500,000 V) of some 50mG. As a result the the individual was planning to install additional shielding in his Prius, given that sources in Sweden claimed that any radiation above 2mG could be injurious to one's health.

Does anyone know whether this question was resolved, and if so how?

Cheers,
Ron Howell.

Rest · 10-28-2007, 02:40 AM

OMG not another threat about EMF's in a Hybrid vehicle causing harm to people. I remember reading a thread years about it in the Honda Insight forum. It was proved to be all talk and nothing to really worry about, yet the nut cases continued popping off about it.

For the record, EMF stands for Electro Magnetic Field.

narf · 10-28-2007, 03:02 AM

<div class='quotetop'>QUOTE(Ron Howell @ Oct 27 2007, 10:33 PM) [snapback]531455[/snapback]</div>

Quote:

Hi All,

Nevertheless, one poster on the site claims to have measured a field of some 100mG (milliGauss?) in parts of the rear passenger compartment. That compared with a reading taken under electrical high tension lines in his state (I presume carrying power at least at 500,000 V) of some 50mG.

Cheers,
Ron Howell.
[/b]

Somebody please correct me if I'm off base here, but aren't all the electrical components in the rear of the Prius DC, not AC? If so, DC components don't really radiate much in the way of EMF. That would require AC. (Magnetic field are generated by rapidly changing voltages, and you only get that in AC current.)
Most of the AC components are under the hood, like the buck-boost converters, DC- to DC converters, ETC. I'd expect more EMF coming off the speakers than the battery pack.

Anybody got any hard data on this?

fwellers · 10-28-2007, 06:30 AM

I have a mechanical watch, which would easily become magnetised and run poorly under such circumstances. I'll letchya know if it starts acting squirrely. So far, nothing. Runs like a top. :P

patsparks · 10-28-2007, 07:43 AM

<div class='quotetop'>QUOTE(fwellers @ Oct 28 2007, 08:00 PM) [snapback]531523[/snapback]</div>

Quote:

I have a mechanical watch, which would easily become magnetised and run poorly under such circumstances. I'll letchya know if it starts acting squirrely. So far, nothing. Runs like a top. :P
[/b]

One would hope it runs like a watch. (sorry, can't help it.)

qbee42 · 10-28-2007, 09:46 AM

<div class='quotetop'>QUOTE(narf @ Oct 28 2007, 03:02 AM) [snapback]531503[/snapback]</div>

Quote:

Somebody please correct me if I'm off base here, but aren't all the electrical components in the rear of the Prius DC, not AC? If so, DC components don't really radiate much in the way of EMF. That would require AC. (Magnetic field are generated by rapidly changing voltages, and you only get that in AC current.)
Most of the AC components are under the hood, like the buck-boost converters, DC- to DC converters, ETC. I'd expect more EMF coming off the speakers than the battery pack.

Anybody got any hard data on this?
[/b]

Okay, I'll correct you. The magnetic field around a DC carrying conductor is just a big as the one around an AC carrying conductor, as long as the currents are equivalent. Now that I have corrected you, let me also state that your general thoughts have some truth to them. AC currents will induce voltages in nearby conductors since the AC makes a time-varying magnetic field. DC currents will only induce voltages in nearby conductors when the DC current varies, which is a small effect compared to the continuously varying field of AC.

Induced voltages and currents are only one of the health risks associated with magnetic fields. The static effects of a strong field are worrisome because of ion migration and related effects, plus a person moving in a static field produces a time varying effect: turn you head and it will induce voltages and currents. In high field magnets you see flashes when you turn your head, from the voltages induced into your nerves. Tell me that's not scary!

Now that we have talked about all of the scary stuff, let me say categorically that I am not worried about the fields in the Prius even in the slightest. These are vary low voltages, as compared to transmission lines, and the amount of wire is minimal, plus you have shielding effects from the steel. I wouldn't worry about it.

As for an earlier poster who thought EMF was Electro Motive Force, that is correct. Engineers and physicists refer to a voltage source as a seat of EMF, which is why we use the symbol E for voltage when it is being supplied by a source, such as a battery. We use V for voltage when the voltage is induced by current flow or something similar. EMF can also be Electro Magnetic Field. There are too many acronyms and not enough letters, so even after borrowing from the Greeks, Romans, and Hebrews, many of the acronyms are over-loaded.

Tom

hobbit · 10-28-2007, 10:10 AM

Lemme ask the OP this: do you live somewhere that's wired for AC
power? If so, you've got way more to worry about there.
.
What amuses me no end is some people hollering about EMFs and
spending way too much gummint money on "studies", and then wearing
magnetic bracelets to "cure" arthritis or CTS. Our gullibility knows
no bounds, does it...
.
I'm even aware of some intelligent, scientific-thinking people who
have been taken in by this notion of magnets as an energy source,
from some misreading of old Tesla papers. Sorry, they're not
an energy source until you put work into moving them and keep it
up, and I'll believe otherwise when I see it in front of me.
.
_H*

fwellers · 10-28-2007, 10:20 AM

<div class='quotetop'>QUOTE(patsparks @ Oct 28 2007, 07:43 AM) [snapback]531526[/snapback]</div>

Quote:

One would hope it runs like a watch. (sorry, can't help it.) [/b]

Actually, we watch freaks pay some hefty $$ so they hopefully run as well as a $10 timex quartz.

Go figure.

<div class='quotetop'>QUOTE(qbee42 @ Oct 28 2007, 09:46 AM) [snapback]531534[/snapback]</div>

Quote:

Okay, I'll correct you. The magnetic field around a DC carrying conductor is just a big as the one around an AC carrying conductor, as long as the currents are equivalent. Now that I have corrected you, let me also state that your general thoughts have some truth to them. AC currents will induce voltages in nearby conductors since the AC makes a time-varying magnetic field. DC currents will only induce voltages in nearby conductors when the DC current varies, which is a small effect compared to the continuously varying field of AC.

Induced voltages and currents are only one of the health risks associated with magnetic fields. The static effects of a strong field are worrisome because of ion migration and related effects, plus a person moving in a static field produces a time varying effect: turn you head and it will induce voltages and currents. In high field magnets you see flashes when you turn your head, from the voltages induced into your nerves. Tell me that's not scary!

Now that we have talked about all of the scary stuff, let me say categorically that I am not worried about the fields in the Prius even in the slightest. These are vary low voltages, as compared to transmission lines, and the amount of wire is minimal, plus you have shielding effects from the steel. I wouldn't worry about it.

As for an earlier poster who thought EMF was Electro Motive Force, that is correct. Engineers and physicists refer to a voltage source as a seat of EMF, which is why we use the symbol E for voltage when it is being supplied by a source, such as a battery. We use V for voltage when the voltage is induced by current flow or something similar. EMF can also be Electro Magnetic Field. There are too many acronyms and not enough letters, so even after borrowing from the Greeks, Romans, and Hebrews, many of the acronyms are over-loaded.

Tom
[/b]

I think my Double-E detector is going off.

zenMachine · 10-28-2007, 10:28 AM

<div class='quotetop'>QUOTE(Ron Howell @ Oct 27 2007, 11:33 PM) [snapback]531455[/snapback]</div>

Quote:

Nevertheless, one poster on the site claims to have measured a field of some 100mG (milliGauss?) in parts of the rear passenger compartment. That compared with a reading taken under electrical high tension lines in his state (I presume carrying power at least at 500,000 V) of some 50mG. As a result the the individual was planning to install additional shielding in his Prius, given that sources in Sweden claimed that any radiation above 2mG could be injurious to one's health.

Does anyone know whether this question was resolved, and if so how?

Cheers,
Ron Howell.
[/b]

Here's the thread you're referring to, with some of the latest measurements.

http://priuschat.com/index.php?showtopic=39325&st=20

donee · 10-28-2007, 11:10 AM

Hi Ron,

Well, the higher the voltage the power transmission line, the less the magnetic field, for the same power transmitted. 500 KV is not a common power line. Around my town there is a 138 KV loop. You will only see the big 500 KV lines out between cities. And these are dramatically larger than what is commonly seen in an urban enviorment, like down the side of a road. And making the measurement requires knowing the power being tranmitted at the time too. So a deceptive practitioner would just wait till midnight and then say - "see how much lower the field is under the power line that the Prius!".

So, the point is, that finding a 500 KV line and measuring the magnetic field under it could be construed as deceptive or incompetent. As the whole purpose of going to such high voltages is to reduced the current in the conductors which just happens to reduce the magnetic fields around the conductors. And such a high tension wire, will be much more elevated above the ground as well. Again something that will reduce the ground level magnetic field.

The comparison of high tension line magnetic fields to those in the Prius smells of a stunt to me.

What should be measured in and around such high tension wires is the electrical field strength. And I would venture to say it would be off-the-chart in comparison to a Prius. One can hear the crackling on a damp day due to the electrical field under such high tension wires. A measured quantitiy of a high tension power transmission line being so much more than the Prius, is not nearly as impressive. And rightfully so, as the Prius is a 50 KW electrical system, and these transmission lines are capable of 100's of MegaWatts, or 2000 times as much power.

Oh, BTW, the Earth's magnetic field is on the order of 300 (equator) to 600 (magnetic pole) milli Gauss. Here is a link: http://en.wikipedia.org/wiki/Earth's_magnetic_field .

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10-28-2007, 12:33 AM	#1
ronhowell Senior Member Join Date: Oct 2007 Location: Cypress, CA. Posts: 122 My Car: 2008 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 1	Hi All, Back in summer of 2005 there was considerable discussion on this website on the effects of the high voltages that exist in some of the electrical circuits of the Prius, and the potentially adverse electrical radiation associated with them. There appears to be some confusion over the nomenclature adopted, many people referring to the radiation as EMF, which to me stands for Electromotive Force, the force produced when current carrying wires cut through a magnetic field. Nevertheless, one poster on the site claims to have measured a field of some 100mG (milliGauss?) in parts of the rear passenger compartment. That compared with a reading taken under electrical high tension lines in his state (I presume carrying power at least at 500,000 V) of some 50mG. As a result the the individual was planning to install additional shielding in his Prius, given that sources in Sweden claimed that any radiation above 2mG could be injurious to one's health. Does anyone know whether this question was resolved, and if so how? Cheers, Ron Howell.

10-28-2007, 02:40 AM	#2
Rest Senior Member Join Date: Aug 2005 Location: CA Posts: 741 My Car: 2007 Prius Package: N/A Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	OMG not another threat about EMF's in a Hybrid vehicle causing harm to people. I remember reading a thread years about it in the Honda Insight forum. It was proved to be all talk and nothing to really worry about, yet the nut cases continued popping off about it. For the record, EMF stands for Electro Magnetic Field.

10-28-2007, 06:30 AM	#4
fwellers Member Join Date: Oct 2007 Location: Northern Virginia Posts: 44 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I have a mechanical watch, which would easily become magnetised and run poorly under such circumstances. I'll letchya know if it starts acting squirrely. So far, nothing. Runs like a top. :P

10-28-2007, 10:10 AM	#7
hobbit Senior Member Join Date: Mar 2005 Location: Bahstahn Posts: 2,981 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Lemme ask the OP this: do you live somewhere that's wired for AC power? If so, you've got way more to worry about there. . What amuses me no end is some people hollering about EMFs and spending way too much gummint money on "studies", and then wearing magnetic bracelets to "cure" arthritis or CTS. Our gullibility knows no bounds, does it... . I'm even aware of some intelligent, scientific-thinking people who have been taken in by this notion of magnets as an energy source, from some misreading of old Tesla papers. Sorry, they're not an energy source until you put work into moving them and keep it up, and I'll believe otherwise when I see it in front of me. . _H*

10-28-2007, 11:10 AM	#10
donee Senior Member Join Date: Aug 2005 Location: Chicagoland Posts: 1,536 My Car: 2006 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Hi Ron, Well, the higher the voltage the power transmission line, the less the magnetic field, for the same power transmitted. 500 KV is not a common power line. Around my town there is a 138 KV loop. You will only see the big 500 KV lines out between cities. And these are dramatically larger than what is commonly seen in an urban enviorment, like down the side of a road. And making the measurement requires knowing the power being tranmitted at the time too. So a deceptive practitioner would just wait till midnight and then say - "see how much lower the field is under the power line that the Prius!". So, the point is, that finding a 500 KV line and measuring the magnetic field under it could be construed as deceptive or incompetent. As the whole purpose of going to such high voltages is to reduced the current in the conductors which just happens to reduce the magnetic fields around the conductors. And such a high tension wire, will be much more elevated above the ground as well. Again something that will reduce the ground level magnetic field. The comparison of high tension line magnetic fields to those in the Prius smells of a stunt to me. What should be measured in and around such high tension wires is the electrical field strength. And I would venture to say it would be off-the-chart in comparison to a Prius. One can hear the crackling on a damp day due to the electrical field under such high tension wires. A measured quantitiy of a high tension power transmission line being so much more than the Prius, is not nearly as impressive. And rightfully so, as the Prius is a 50 KW electrical system, and these transmission lines are capable of 100's of MegaWatts, or 2000 times as much power. Oh, BTW, the Earth's magnetic field is on the order of 300 (equator) to 600 (magnetic pole) milli Gauss. Here is a link: http://en.wikipedia.org/wiki/Earth's_magnetic_field .