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Fluorescents and migraines??

D

Dean Hoffman

Jan 1, 1970
0
http://tinyurl.com/296h8p

Is there any truth to this article?


I read another article claiming some of the old American house
wiring won't handle CFLs. How can that be if CFLs take less amperage
than incandescents?

Dean
 
B

bud--

Jan 1, 1970
0
CS said:
That's more a medical question than an electrical one, but adjustments
to how CFL's are manufactured could solve that problem.

Crossposted to sci.engr.lighting
Does the spectrum cause migranies and "skin eruptions"? I thought
migraines were flicker rate which should be a non-issue with CFLs.
That's just silly.
I agree
 
A

Andrew Gabriel

Jan 1, 1970
0
Crossposted to sci.engr.lighting
Does the spectrum cause migranies and "skin eruptions"? I thought
migraines were flicker rate which should be a non-issue with CFLs.

I think these might have started from a couple of BBC articles
last week accompanying short news features on radio/TV.

http://news.bbc.co.uk/1/hi/health/7167860.stm is an article
with an alarmist headline and nothing credible to back it up,
and an explanation near the bottom of how the misunderstanding
has come about. Basically an alarmist piece of crappy jornalism.

http://news.bbc.co.uk/1/hi/health/7167860.stm is the other
article. It's been discussed on the radio and the people
affected are affected by any bright light including sunlight.

These are remarkably poor articles, particularly for the BBC,
which are being picked up and propapated by other parts of the
media. It's been accompanied radio/TV coverage giving time to
those who just want to moan about filament lamps being phased
out.

There are actually real issues presented by the phasing out
of filament lamps, but those aren't getting any coverage at
all, of course.
 
B

bud--

Jan 1, 1970
0
Andrew said:
I think these might have started from a couple of BBC articles
last week accompanying short news features on radio/TV.

http://news.bbc.co.uk/1/hi/health/7167860.stm is an article
with an alarmist headline and nothing credible to back it up,
and an explanation near the bottom of how the misunderstanding
has come about. Basically an alarmist piece of crappy jornalism.
CFLs run at high frequency giving high frequency (probably totally
invisible) flicker. Is the high frequency flicker modulated at 50Hz
giving a visible flicker? (Just curious.)
http://news.bbc.co.uk/1/hi/health/7167860.stm is the other
article. It's been discussed on the radio and the people
affected are affected by any bright light including sunlight.
(This is the same link.)
CFLs shouldn't be brighter than incandescents???

So you can get migraines from "low intensity of the light" (1st article)
and other problems from the bright light. And both problems are caused
by CFLs.

Does the spectrum of fluorescents cause skin problems as the original
link claimed?
These are remarkably poor articles, particularly for the BBC,
which are being picked up and propapated by other parts of the
media. It's been accompanied radio/TV coverage giving time to
those who just want to moan about filament lamps being phased
out.
It is comforting to know that bad news reporting is not unique to the US.
There are actually real issues presented by the phasing out
of filament lamps, but those aren't getting any coverage at
all, of course.
Thanks for the further information.
 
A

Andrew Gabriel

Jan 1, 1970
0
CFLs run at high frequency giving high frequency (probably totally
invisible) flicker. Is the high frequency flicker modulated at 50Hz
giving a visible flicker? (Just curious.)

No. There could be 100Hz modulation. There is with some
filament lamps, but no one claims they give migranes.

You get 50Hz flicker from tubes on old magnetic control
gear if they are partially rectifying the discharge.
This can happen with badly manufactured tubes where one
of the electrodes isn't working well, and tubes in the
last couple of hours of life when the last bit of emissive
material is just wearing off one end immediately prior to
the tube going out. 50Hz flicker is certainly uncomfortable
to many people, resulting in stress and headaches, and
I suspect is a trigger for migraines in some people.

I think it's this effect which has got mixed up with the
issue of compact fluorescents, although it's impossible
with electronically ballasted fluorescents used in
compact fluorescent retrofit lamps.
(This is the same link.)

Oops, should have been http://news.bbc.co.uk/1/hi/health/7170246.stm
 
D

Don Klipstein

Jan 1, 1970
0
bud-- wrote:
[snip]
Does the spectrum of fluorescents cause skin problems as the original
link claimed?

If any, certainly not more severe than old style tubular fluorescents.
There was a discussion in s.e.l. long time ago, where it was mentioned
that the glass used on old style tubular fluorescents allows wavelengths
down to 370-380nm.

Mercury at low pressure emits a triplet at 365nm, but it is strongly
absorbed by the various phosphors used in fluorescent lamps, to the point
where its existence can barely be detected on high precision
spectroscopes.

There is no question for wavelengths below 365nm, because the soda lime glass
used on fluorescents strongly absorbs such radiation.

I've measured many CFLs with my spectroscopes, and I cannot detect any
appreciable radiation below 390-400nm.

The 365 nm triplet is actually a weak feature of the low pressure
mercury vapor discharge. It is related to the 577-579 nm yellow triplet,
which is also a strong feature of a high pressure mercery vapor discharge
but a weak feature of the low pressure one.

Most fluorescent lamp phosphors do not utilize 365 nm, though the
usual mid-blue component of triphosphors 3500K and higher does utilize it.

Also, soda lime glass is nearly enough transparent at least down to 340
nm. However, not much 310 nm gets through, and I think that is the next
shorter wavelength significant spectral feature of mercury vapor (another
triplet in the same series as the 577-579 and 365-366 nm ones).

Try exposing various fluorescents to a BLB blacklight. My experience is
that triphosphor ones 3500K and higher glow bright blue, meaning the glass
passes the UV. Most other fluorescents give little or no reaction,
indicating that the phosphor does not utilize that wavelength.

- Don Klipstein ([email protected])
 
D

Don Klipstein

Jan 1, 1970
0
Don Klipstein wrote:
[snip]
The 365 nm triplet is actually a weak feature of the low pressure
mercury vapor discharge. It is related to the 577-579 nm yellow
triplet, which is also a strong feature of a high pressure mercery
vapor discharge but a weak feature of the low pressure one.

Most fluorescent lamp phosphors do not utilize 365 nm, though the
usual mid-blue component of triphosphors 3500K and higher does
utilize it.

Also, soda lime glass is nearly enough transparent at least down to
340 nm.

My Optics reference (K.D. Alexopoulos, General Physics, Optics, Athens, 1966),
seems to agree with Don's 340nm for regular glass.

However, as much as I would hate to disagree with Don and with the above
reference, in my experience the above is a tad low. I have in front of me the
OSRAM catalog which gives the peak for UVA sun-tanning indium-amalgam
fluorescents, L40W/79 K In, as 350nm.

That sounds long to me for suntanning. Wavelengths longer than about
330-335 nm or so don't do that much.
If the 340nm lower bound for regular glass was correct, suntanning would be
possible behind regular glass windows. But it's not. Hence the 340nm
figure for soda lime glass cannot be correct.

I thik the effective cutoff wavelength is a little longer for windows
and a little shorter for fluorescent lamps, in part from window glass
being thicker, and in part from window glass having a slight tinting by
iron.

As for fluorescents made specifically for suntanning - I think they
would use a different glass to pass even shorter wavelengths.
Note however that the direction of radiation with respect to the glass envelope
and phosphor may be crucial to the transmissivity of UV. Whereas *outcoming*
365nm radiation may pass through the glass envelope and hit the phosphor and
excite it, this *DOES NOT* mean that there is *incoming* 365nm radiation which
manages to survive both the phosphor AND the CFL glass envelope and radiate
outwards.
As I said, spectroscopic analysis does not show any appreciable amounts of
radiation below 390nm, except traces in regular 2700K CFLs.

I will gladly stand corrected if anybody shows a specific spectrogram from a
calibrated spectroscope with non-trace amounts of UV below 390nm.

I don't expect there to be a whole lot because the 365-366 nm triplet is
a weak feature of the low pressure mercury vapor discharge.

Some spectral power distribution curves:

http://ledmuseum.home.att.net/spectra7.htm

Look for "Trisonic" 6500K (halophosphor) ones, all others noted as
"dollar store" ones, and compact fluorescents noted as 2700 K, Sylvania
"white" (halophosphor). The 365-366 nm feature is about half as strong as
the 404.7 nm one in all of these.

Two non-phosphor lamps that emit UVC are shown also: A "Water Purifier"
one and a "UVC" one (though with weak UVC output). The latter also has
365-366 about half as strong as 404.7, and the former has more 365 (I have
seen a similar lamp get hotter and have higher mercury vapor pressure -
that may be the explanation).

I tried getting the spectral power distribution of a Sylvania F40/350BL.
(Copying and pasting links is messy with Sylvania's website - I would try
searching their USA "business" lamp catalog for F40350BLECO 30/CS 1/SKU
or 24922.)

The spectral power distribution has the 365-366 nm spike smaller than
the 404.7 nm one, and there is a little one shown at 310 nm.

- Don Klipstein ([email protected])
 
| Does the spectrum cause migranies and "skin eruptions"? I thought
| migraines were flicker rate which should be a non-issue with CFLs.

I see CFLs that flicker. Probably very cheap ones. But they exist.

BTW, I bought an LED flashlight the other day that has a white spectrum
that does not bother me like other LEDs and all fluorescents and metal
halides do. And it's a rather bright and well built one. LEDs are now
looking more like they could be my future efficient lighting method.
 
| http://news.bbc.co.uk/1/hi/health/7167860.stm is the other
| article. It's been discussed on the radio and the people
| affected are affected by any bright light including sunlight.

I know I am affected by very bright light due to the brightness. But if
restricted enough, and that light is fine for me as a task or reading
light. Fluorescent lights, including CLFs, even when at low brightness,
can give me a headache within about 20-30 minutes


| There are actually real issues presented by the phasing out
| of filament lamps, but those aren't getting any coverage at
| all, of course.

Like how many CFLs does it take to keep my ophidian friends warm?
 
| CFLs run at high frequency giving high frequency (probably totally
| invisible) flicker. Is the high frequency flicker modulated at 50Hz
| giving a visible flicker? (Just curious.)

If they convert to DC and smooth it first, the answer would be no. Since
I see flicker from many CFLs, then it must be that not all of them do it.
FYI, this flicker is not what bothers me.


| Does the spectrum of fluorescents cause skin problems as the original
| link claimed?

What about unfiltered halogens?
 
B

bud--

Jan 1, 1970
0
Andrew said:
No. There could be 100Hz modulation. There is with some
filament lamps, but no one claims they give migranes.

I should have said 100Hz but comments about 50Hz are interesting.
My guess is the DC drops substantially twice a cycle which should
produce modulation. But the phosphor persistence would counteract that
depending on the value of persistence. I hadn't thought about filament
lamps...
 
V

Victor Roberts

Jan 1, 1970
0
Crossposted to sci.engr.lighting
Does the spectrum cause migranies and "skin eruptions"? I thought
migraines were flicker rate which should be a non-issue with CFLs.

Well, both CFLs and linear fluorescent lamps that use high
frequency electronic ballasts can and do have flicker if the
DC storage capacitor is nor large enough to prevent 100 Hz
or 120 Hz modulation of the internal DC link. I have
measured the flicker on a few CFLs using electronic ballasts
and plan to publish the data, but have yet not done so.

CFLs with integral electronic ballasts are much more likely
to have flicker than linear or compact fluorescent lamps
using separate ballasts due to the size and cost constraints
of the ballast in integral CFLs.

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.
 
V

Victor Roberts

Jan 1, 1970
0
I think these might have started from a couple of BBC articles
last week accompanying short news features on radio/TV.

http://news.bbc.co.uk/1/hi/health/7167860.stm is an article
with an alarmist headline and nothing credible to back it up,
and an explanation near the bottom of how the misunderstanding
has come about. Basically an alarmist piece of crappy jornalism.

Perhaps not so crappy, since integral CFLs can have flicker
even if they use high frequency electronic ballasts. See my
other note.
http://news.bbc.co.uk/1/hi/health/7167860.stm is the other
article. It's been discussed on the radio and the people
affected are affected by any bright light including sunlight.

This is the same link as the first.0
These are remarkably poor articles, particularly for the BBC,
which are being picked up and propapated by other parts of the
media. It's been accompanied radio/TV coverage giving time to
those who just want to moan about filament lamps being phased
out.

There are actually real issues presented by the phasing out
of filament lamps, but those aren't getting any coverage at
all, of course.

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.
 
V

Victor Roberts

Jan 1, 1970
0
| CFLs run at high frequency giving high frequency (probably totally
| invisible) flicker. Is the high frequency flicker modulated at 50Hz
| giving a visible flicker? (Just curious.)

If they convert to DC and smooth it first, the answer would be no. Since
I see flicker from many CFLs, then it must be that not all of them do it.
FYI, this flicker is not what bothers me.


They do smooth the DC - but not enough to remove all the
100/120 Hz flicker.

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.
 
V

Victor Roberts

Jan 1, 1970
0
| Does the spectrum cause migranies and "skin eruptions"? I thought
| migraines were flicker rate which should be a non-issue with CFLs.

I see CFLs that flicker. Probably very cheap ones. But they exist.

BTW, I bought an LED flashlight the other day that has a white spectrum
that does not bother me like other LEDs and all fluorescents and metal
halides do. And it's a rather bright and well built one. LEDs are now
looking more like they could be my future efficient lighting method.

Line-powered LEDs can also flicker if the DC link is not
properly filtered.

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.
 
T

TKM

Jan 1, 1970
0
I.N. Galidakis said:
Don Klipstein wrote:
[snip]
Two non-phosphor lamps that emit UVC are shown also: A "Water
Purifier" one and a "UVC" one (though with weak UVC output). The
latter also has 365-366 about half as strong as 404.7, and the former
has more 365 (I have seen a similar lamp get hotter and have higher
mercury vapor pressure - that may be the explanation).

I tried getting the spectral power distribution of a Sylvania
F40/350BL. (Copying and pasting links is messy with Sylvania's
website - I would try searching their USA "business" lamp catalog for
F40350BLECO 30/CS 1/SKU or 24922.)

The spectral power distribution has the 365-366 nm spike smaller
than the 404.7 nm one, and there is a little one shown at 310 nm.

I am not sure why you are bringing the above lamp kinds into the
discussion.

These are UVA/UVB/UVC CFLs/fluoros, and they are not used for commercial
lighting, so they are irrelevant to the question asked.

For the /third time/, and to return to one of the thread subjects: UV
content in
regular lighting CFLs is insignificant, so any claims of skin rashes
coming from
UV in CFLs are bogus, unless the test subject is skin-sensitive to the
390-440nm
area.

For a paper published some years ago on the UV output of "white" light
linear fluorescent lamps, we found that there was a substantial UV
differential between T8 lamps made in Europe and North American produced T8
lamps. An analysis indicated that the amount of iron in the glass was the
primary reason. Higher iron content reduces UV output.

Terry McGowan
 
D

Don Klipstein

Jan 1, 1970
0
Don Klipstein wrote:
[snip]
Two non-phosphor lamps that emit UVC are shown also: A "Water
Purifier" one and a "UVC" one (though with weak UVC output). The
latter also has 365-366 about half as strong as 404.7, and the former
has more 365 (I have seen a similar lamp get hotter and have higher
mercury vapor pressure - that may be the explanation).

I tried getting the spectral power distribution of a Sylvania
F40/350BL. (Copying and pasting links is messy with Sylvania's
website - I would try searching their USA "business" lamp catalog for
F40350BLECO 30/CS 1/SKU or 24922.)

The spectral power distribution has the 365-366 nm spike smaller
than the 404.7 nm one, and there is a little one shown at 310 nm.

I am not sure why you are bringing the above lamp kinds into the discussion.

These are UVA/UVB/UVC CFLs/fluoros, and they are not used for commercial
lighting, so they are irrelevant to the question asked.

For the /third time/, and to return to one of the thread subjects: UV
content in regular lighting CFLs is insignificant, so any claims of skin
rashes coming from UV in CFLs are bogus, unless the test subject is
skin-sensitive to the 390-440nm area.

I agree that the UV output below 390 nm of most general lighting
fluorescents is low. I was adding data to support my claim as to why it
is usually low - the low pressure mercury arc does not produce much
between the 253.7 and 404.7 nm features, and that mid-UVA (specifically
365-366 nm) passes through most glass and many to most fluorescent lamp
phosphors (so the glass is usually not the explanation for relative lack
of mid-UVA and often the phosphor is not).

- Don Klipstein ([email protected])
 
| On 9 Jan 2008 05:52:14 GMT, [email protected] wrote:
|
|>
|>| Does the spectrum cause migranies and "skin eruptions"? I thought
|>| migraines were flicker rate which should be a non-issue with CFLs.
|>
|>I see CFLs that flicker. Probably very cheap ones. But they exist.
|>
|>BTW, I bought an LED flashlight the other day that has a white spectrum
|>that does not bother me like other LEDs and all fluorescents and metal
|>halides do. And it's a rather bright and well built one. LEDs are now
|>looking more like they could be my future efficient lighting method.
|
| Line-powered LEDs can also flicker if the DC link is not
| properly filtered.

No doubt. Maybe one day the lighting industry will figure out how to
properly smooth out the DC? Hint: it can be done without those big
capacitors that power supplies of days gone by had. One idea that
comes to mind is to chop the current with a pulse width varied to
compensate for the lower frequency component(s) of the ripple.
 
V

Victor Roberts

Jan 1, 1970
0
| On 9 Jan 2008 05:52:14 GMT, [email protected] wrote:
|
|>
|>| Does the spectrum cause migranies and "skin eruptions"? I thought
|>| migraines were flicker rate which should be a non-issue with CFLs.
|>
|>I see CFLs that flicker. Probably very cheap ones. But they exist.
|>
|>BTW, I bought an LED flashlight the other day that has a white spectrum
|>that does not bother me like other LEDs and all fluorescents and metal
|>halides do. And it's a rather bright and well built one. LEDs are now
|>looking more like they could be my future efficient lighting method.
|
| Line-powered LEDs can also flicker if the DC link is not
| properly filtered.

No doubt. Maybe one day the lighting industry will figure out how to
properly smooth out the DC?

They already know, but it costs more money than most
consumers want to pay.
Hint: it can be done without those big
capacitors that power supplies of days gone by had. One idea that
comes to mind is to chop the current with a pulse width varied to
compensate for the lower frequency component(s) of the ripple.

I large number of circuits that have high input power
factor, low energy storage requirements and low DC ripple
have been published and/or patented. However, all cost
money and all dissipate energy.

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.
 
|>No doubt. Maybe one day the lighting industry will figure out how to
|>properly smooth out the DC?
|
| They already know, but it costs more money than most
| consumers want to pay.
|
|>Hint: it can be done without those big
|>capacitors that power supplies of days gone by had. One idea that
|>comes to mind is to chop the current with a pulse width varied to
|>compensate for the lower frequency component(s) of the ripple.
|
| I large number of circuits that have high input power
| factor, low energy storage requirements and low DC ripple
| have been published and/or patented. However, all cost
| money and all dissipate energy.

So just how much are we talking about to make a CFL that does not flicker?
I'm looking for two pricings. One considering that non-flicker CFLs might
be made mandatory and therefore would be forced to have economoy of scale
and thus a lower price, and one considering that flicker CFLs remain the
popular item and non-flicker CFLs remain high at least in part due to the
lack of economoy of scale. I want to use these figures during the coming
election to argue that our Congresspeople should dump the law they just
put in and start over with a better one (but I don't know just yet what
that should be). My dissatisfaction over the current one is, however, a
typical example of the junk we get from Congress. There are no standards
for forcing the market to have decent CFL devices. Of course for myself,
I would want not only the non-flicker devices, but also ones that have a
reasonably continuous spectrum (merely balancing 2 or 3 color peaks to get
an average white of the desired color temperature is not good enough).
 
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