As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.
3. Because of the frequency (colour temperature?) the light does not
travel as far so streetlamps need to be placed closer together but.
Councils are not doing this for cost reasons, leaving blackspots in
illumination.

Is there any merit in these arguments?

"Scott" wrote in message
...
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.
3. Because of the frequency (colour temperature?) the light does not
travel as far so streetlamps need to be placed closer together but.
Councils are not doing this for cost reasons, leaving blackspots in
illumination.

Is there any merit in these arguments?

my eyes are very sensitive to light and I have trouble with the fault
finding flicker in cars but no problems at home......I find a nice white
blue light is much better tan that yellow flourescent rubbish we have had to
suffer to save energy in the past and my meigrane with aura is no worse with
LEDs ....however my kooncil is getting flack for bad led street lighting...

In article ,
Scott wrote:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.
3. Because of the frequency (colour temperature?) the light does not
travel as far so streetlamps need to be placed closer together but.
Councils are not doing this for cost reasons, leaving blackspots in
illumination.

Is there any merit in these arguments?

LED is unlikely to give continuous spectrum light as you'd get from
tungsten. It might be better or worse than CFL, though, which has the same
problem. All depends on how well they are made. Budget ones may be worse
than those from a high end maker.

I've never noticed any flicker from domestic LEDs. If high frequency
flicker you can't see can give you migraine, I dunno.

LEDs often appear brighter to look at. Sometimes uncomfortably so. But
seem to produce less light to the room than this suggests.

--
*Reality? Is that where the pizza delivery guy comes from?

Dave Plowman London SW
To e-mail, change noise into sound.

Here's a question for the group.

Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy bill?

--
*(on a baby-size shirt) "Party -- my crib -- two a.m

Dave Plowman London SW
To e-mail, change noise into sound.

On 03/12/2016 12:19, Dave Plowman (News) wrote:
Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy bill?

Too many variables to be accurate but as a rough guide I would say if
you have current 60w and move to say 12w LEDs then the lighting part of
leccy bill would approx a fifth of the cost (not including the cost of
the LED bulbs)

On Sat, 03 Dec 2016 12:19:14 +0000, Dave Plowman (News) wrote:

Here's a question for the group.

Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy bill?

Around 80-90% of their lighting costs. So, say, 4x 60w lamps on , thats
a quarter of a unit a hour, so what, around 4pence per hour.
Add on a few more for larger houses and multiple fittings in kitchens/
bathrooms, then you'll be up to 20 pence per hour.Average for 4 hours
throughout the year is reasonable, so 4 x 20p x 7 £5.60 a week (seems a
little high?) = £292/ a year.
With LEDS it'd be 2-3p per hour, 84p per week, £43 a year.

Of course, usage will change in every house, I'm at the lower end, other
houses I've been to rival Blackpool for internal illumination.

On Sat, 03 Dec 2016 06:37:15 -0600, Alan wrote:

On Sat, 03 Dec 2016 12:19:14 +0000, Dave Plowman (News) wrote:

Here's a question for the group.

Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy bill?

Around 80-90% of their lighting costs. So, say, 4x 60w lamps on , thats
a quarter of a unit a hour, so what, around 4pence per hour.
Add on a few more for larger houses and multiple fittings in kitchens/
bathrooms, then you'll be up to 20 pence per hour.Average for 4 hours
throughout the year is reasonable, so 4 x 20p x 7 £5.60 a week (seems a
little high?) = £292/ a year.
With LEDS it'd be 2-3p per hour, 84p per week, £43 a year.

Of course, usage will change in every house, I'm at the lower end, other
houses I've been to rival Blackpool for internal illumination.

Perhaps slightly offset by the temptation to leave them on for longer,
on the basis they don't really cost anything?

In article ,
Scott writes:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.
3. Because of the frequency (colour temperature?) the light does not
travel as far so streetlamps need to be placed closer together but.
Councils are not doing this for cost reasons, leaving blackspots in
illumination.

Is there any merit in these arguments?

No.

Lighting industry did lots of experiments with CFLs to try and
understand what people didn't like about them. However, it was
quickly shown that these people didn't like lights they thought
were CFLs and did like light they thought were filaments.
Since what they *thought* didn't match reality, it could only
be put down to physicological bias, not genuine physiological
issues.

Of course, there are poor quality CFLs and poor quality LEDs,
and if you buy those and don't like them, then don't be
surprised.

Some dimmable LEDs have no smoothing of the rectified mains,
so if you don't like 100Hz flicker of moving things, avoid
dimmable LEDs.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Sat, 03 Dec 2016 06:37:15 -0600, Alan wrote:

Around 80-90% of their lighting costs. So, say, 4x 60w lamps on , thats
a quarter of a unit a hour, so what, around 4pence per hour.
Add on a few more for larger houses and multiple fittings in kitchens/
bathrooms, then you'll be up to 20 pence per hour.Average for 4 hours
throughout the year is reasonable, so 4 x 20p x 7 £5.60 a week (seems a
little high?) = £292/ a year.

Complete mess up of figures.
That is a little high, as it should be 4p/hr x 4hrs =16p/day = £1.12/week
=£58/year
With LEDS it'd be between £5 and £10/year.

On 03/12/2016 12:44, Andrew Gabriel wrote:
In article ,
Scott writes:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.
3. Because of the frequency (colour temperature?) the light does not
travel as far so streetlamps need to be placed closer together but.
Councils are not doing this for cost reasons, leaving blackspots in
illumination.

Is there any merit in these arguments?

No.

Lighting industry did lots of experiments with CFLs to try and
understand what people didn't like about them. However, it was
quickly shown that these people didn't like lights they thought
were CFLs and did like light they thought were filaments.
Since what they *thought* didn't match reality, it could only
be put down to physicological bias, not genuine physiological
issues.

Couple of findings from peer reviewed sources:

"LED appears to support positive mood, extended wakefulness, and speeded
performance on both visual perceptual and cognitive tasks" in a work
context.

http://preview.tinyurl.com/gpymsdu (International Journal of Industrial
Ergonomics, 2012)

More general associations between LED light and well-being would need
somebody quite specialist, I'd think. Found this very odd sentence:

"Although highlighted in the scientific literature, concerns about the
potential impacts of increases in LED lights on cancer or other chronic
health outcomes were not raised by residents or key informants in any
settings in the fieldwork, public or private" (Reduced street lighting
at night and health, Health and Place 2015).

Overall, though, I think the evidence of a link between well-being and
LED lighting is weak. Trafford did a study using plain English which was
largely inconclusive: Trafford LED Street Lighting Programme Health
Impact Assessment (2013) - I've only skim read it though.

As for those physical/physiological relationships listed by the OP,
don't know - that literature is far too specialist for me.

I'd say anecdotally that I find the street lighting superficially bright
- it seems at first glance as though more is illuminated, but I can't
distinguish as much. Potholes for example - a big problem cycling at night.

At home (just about all LED now), I don't notice much difference between
tungsten and LED, once the problems of LED directionality and overly
bright source are removed. Decent bulbs and/or shades largely solve
these issues for me.

Never got on with CFL - glad to see(!) the back of them.

--
Cheers, Rob

On Saturday, December 3, 2016 at 11:11:01 AM UTC, Scott wrote:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

It`s a peaky spectrum and the effects are subject of investigation and controversy

http://darksky.org/ama-report-affirm...cts-from-leds/

2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.

Flicker should be well above perception level, as demonstrated by numerous crap car tailight designs this basic appears to have escaped some makers.


3. Because of the frequency (colour temperature?) the light does not
travel as far so streetlamps need to be placed closer together but.

Simply not as bright, just not as much light coming out the front.

Councils are not doing this for cost reasons, leaving blackspots in
illumination.

Because lighting is something that `just happens` and dosen`t need specialists with years of training and experience in their field.


Is there any merit in these arguments?

It`s not all wrong but a bit misunderstood in places.

On Saturday, December 3, 2016 at 12:45:30 PM UTC, Andrew Gabriel wrote:
In article ,
Scott writes:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.
3. Because of the frequency (colour temperature?) the light does not
travel as far so streetlamps need to be placed closer together but.
Councils are not doing this for cost reasons, leaving blackspots in
illumination.

Is there any merit in these arguments?


in on my own account, always remember to sign out of gmail on a guest machine....

No.

Lighting industry did lots of experiments with CFLs to try and
understand what people didn't like about them. However, it was
quickly shown that these people didn't like lights they thought
were CFLs and did like light they thought were filaments.
Since what they *thought* didn't match reality, it could only
be put down to physicological bias, not genuine physiological
issues.

C`mon Andrew, that is at best insincere, their are known physical issues with CFLs to photo sensitive people

"some energy
saving compact fluorescent lights may emit ultraviolet radiation at levels that,
under certain conditions of use, can result in exposures higher than guideline
levels. The HPAs view is that single envelope CFLs should not be used where
people are in close proximity - closer than 30 cm or 1 ft - to the bare light bulb
for over one hour a day. "

http://www.nhs.uk/ipgmedia/national/...ensitivity.pdf


Of course, there are poor quality CFLs and poor quality LEDs,
and if you buy those and don't like them, then don't be
surprised.

Some dimmable LEDs have no smoothing of the rectified mains,
so if you don't like 100Hz flicker of moving things, avoid
dimmable LEDs.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In the interests of balance ;-) heres industry response to AMA LED warning

http://ecmweb.com/lighting-control/industry-responds-ama-led-streetlight-warning

wrote:

Scott wrote:

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

It's a peaky spectrum

CFLs have a peaky spectrum, (some?/most?/all?) LEDs are broad like
incandescent

http://web.ncf.ca/jim/misc/cfl

Buy yourself a diffraction grating if you want to check any particular
LED ...

http://www.ebay.co.uk/itm/diffraction-grating/152316786639

On Saturday, December 3, 2016 at 1:39:03 PM UTC, Andy Burns wrote:
wrote:

Scott wrote:

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

It's a peaky spectrum

CFLs have a peaky spectrum, (some?/most?/all?) LEDs are broad like
incandescent

http://web.ncf.ca/jim/misc/cfl

You cannae change the laws of physics, blackbody radiator like tungsten has a continuous spectrum, sources that rely on phosphor conversion will always have peaks and troughs.

LEDs , of any current type, are many miles away from being broad band sources.

Work with LEDs come home to halogen in the main



Buy yourself a diffraction grating if you want to check any particular
LED ...

http://www.ebay.co.uk/itm/diffraction-grating/152316786639

Will let Mr Craig Johnson at the LED Museum show in more detail

http://www.ledmuseum.org

Adam Aglionby wrote:

Andy Burns wrote:

CFLs have a peaky spectrum, (some?/most?/all?) LEDs are broad like
incandescent

http://web.ncf.ca/jim/misc/cfl

You cannae change the laws of physics, blackbody radiator like
tungsten has a continuous spectrum, sources that rely on phosphor
conversion will always have peaks and troughs.

I said "broad" not "continuous"

LEDs , of any current type, are many miles away from being broad band sources.

You did look at the spectra on the page I linked to? It looks one hell
of a lot better than CFL to me.

In article ,
ss wrote:
On 03/12/2016 12:19, Dave Plowman (News) wrote:
Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy bill?

Too many variables to be accurate but as a rough guide I would say if
you have current 60w and move to say 12w LEDs then the lighting part of
leccy bill would approx a fifth of the cost (not including the cost of
the LED bulbs)

Snag with that is it's near impossible to know what proportion of your
leccy bill goes on lighting.

--
*It sounds like English, but I can't understand a word you're saying.

Dave Plowman London SW
To e-mail, change noise into sound.

On 03/12/16 13:27, wrote:
On Saturday, December 3, 2016 at 11:11:01 AM UTC, Scott wrote:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

It`s a peaky spectrum and the effects are subject of investigation and controversy

http://darksky.org/ama-report-affirm...cts-from-leds/

All that really is saying is that 'bluish light isn't great because your
body thinks its daytime'.

But LEDS do not come solely in bluish white. The spectrum can be
balanced - more so than mercury vapour lights.



--
New Socialism consists essentially in being seen to have your heart in
the right place whilst your head is in the clouds and your hand is in
someone else's pocket.

In article ,
wrote:
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.

Flicker should be well above perception level, as demonstrated by
numerous crap car tailight designs this basic appears to have escaped
some makers.

Some car LEDs are driven in a very different way from domestic mains LEDs.
Basically, you can't just transfer a problem with those to all.

--
*Toilet stolen from police station. Cops have nothing to go on.

Dave Plowman London SW
To e-mail, change noise into sound.

On Saturday, December 3, 2016 at 2:16:03 PM UTC, Andy Burns wrote:
Adam Aglionby wrote:

Andy Burns wrote:

CFLs have a peaky spectrum, (some?/most?/all?) LEDs are broad like
incandescent

http://web.ncf.ca/jim/misc/cfl

You cannae change the laws of physics, blackbody radiator like
tungsten has a continuous spectrum, sources that rely on phosphor
conversion will always have peaks and troughs.

I said "broad" not "continuous"

LEDs , of any current type, are many miles away from being broad band sources.

You did look at the spectra on the page I linked to? It looks one hell
of a lot better than CFL to me.

been looking at source spectra for 30 odd years, mebbe I read them differntly from yourself ;-)

On 03/12/16 13:39, Andy Burns wrote:
wrote:

Scott wrote:

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

It's a peaky spectrum

CFLs have a peaky spectrum, (some?/most?/all?) LEDs are broad like
incandescent

http://web.ncf.ca/jim/misc/cfl

Excellent find that page!
Confirms my gut feeling that CFLS have the worst spectrum, and LEDS were
immensely better.

I hated CFLs. I tried to love them, but I ended up hating them. They
were unutterable crap. I expected LEDS to be little better, but now I
won't buy anything else. There are issues with cooling, drivers and so
on, but when they work they are just perfect for me


Buy yourself a diffraction grating if you want to check any particular
LED ...

http://www.ebay.co.uk/itm/diffraction-grating/152316786639

Fun!

--
"In our post-modern world, climate science is not powerful because it is
true: it is true because it is powerful."

Lucas Bergkamp

On Saturday, December 3, 2016 at 2:21:12 PM UTC, The Natural Philosopher wrote:
On 03/12/16 13:27, wrote:
On Saturday, December 3, 2016 at 11:11:01 AM UTC, Scott wrote:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

It`s a peaky spectrum and the effects are subject of investigation and controversy

http://darksky.org/ama-report-affirm...cts-from-leds/

All that really is saying is that 'bluish light isn't great because your
body thinks its daytime'.

But LEDS do not come solely in bluish white. The spectrum can be
balanced - more so than mercury vapour lights.

Spectral Power Distribution, LEDs have a lot of near visble blue in them, whatever colour they are.

Metal halides and fluros have a blue peak much lower down.

Question is what effect does the high blue content have.




--
New Socialism consists essentially in being seen to have your heart in
the right place whilst your head is in the clouds and your hand is in
someone else's pocket.

In article ,
Andy Burns wrote:
wrote:

Scott wrote:

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

It's a peaky spectrum

CFLs have a peaky spectrum, (some?/most?/all?) LEDs are broad like
incandescent

With respect, bollox. ;-)

http://web.ncf.ca/jim/misc/cfl

Now try doing the same today using GLS and direct replacements for GLS.

Buy yourself a diffraction grating if you want to check any particular
LED ...

http://www.ebay.co.uk/itm/diffraction-grating/152316786639

You can do quite an easy test by looking at a paint colour chart under
both decent tungsten - ie halogen - and LED. It can be revealing.

--
*When you get a bladder infection urine trouble.*

Dave Plowman London SW
To e-mail, change noise into sound.

Adam Aglionby wrote:

LEDs have a lot of near visble blue in them

As spectacle wearing drivers will notice, it is noticeable that the blue
component is strong when looking at white LED daylight running lights of
a following car in your side-mirrors ...

On 03/12/16 14:26, Adam Aglionby wrote:
Spectral Power Distribution, LEDs have a lot of near visble blue in them, whatever colour they are.

Utter total ********

A red LED has almost NO emission in the blue part of the spectrum
whatsoever. Neither does an orange or yellow.

Greens have a little, but you need a BLUE LED to actually start to have
any appreciable 'whiteness' - let lone 'blueness' in the spectrum.

And LED emission is not, like fluorescents, single spectral lines that
excite phosphors, its broad spectral lines that excite phosphors.

So the option to use not only blue but also red and green LEDS in a
single light source together with a range of phosphors to spread te
energy around exists.

In short you can make an LED lamp have pretty much any spectrum you
want, although UV is rather hard


Metal halides and fluros have a blue peak much lower down.


No, they don't. LED spectra are tuneable.


Question is what effect does the high blue content have.

It seems to have driven you insane.


--
Future generations will wonder in bemused amazement that the early
twenty-first centurys developed world went into hysterical panic over a
globally average temperature increase of a few tenths of a degree, and,
on the basis of gross exaggerations of highly uncertain computer
projections combined into implausible chains of inference, proceeded to
contemplate a rollback of the industrial age.

Richard Lindzen

On Sat, 03 Dec 2016 14:18:00 +0000, Dave Plowman (News) wrote:

In article ,
ss wrote:
On 03/12/2016 12:19, Dave Plowman (News) wrote:
Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy
bill?

Too many variables to be accurate but as a rough guide I would say if
you have current 60w and move to say 12w LEDs then the lighting part of
leccy bill would approx a fifth of the cost (not including the cost of
the LED bulbs)

Snag with that is it's near impossible to know what proportion of your
leccy bill goes on lighting.

It's so swamped by other consumption here that I can't be arsed to work
it out! (current year is about 11,500 kWh).




--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

In article ,
Andy Burns wrote:
Adam Aglionby wrote:

Andy Burns wrote:

CFLs have a peaky spectrum, (some?/most?/all?) LEDs are broad like
incandescent

http://web.ncf.ca/jim/misc/cfl

You cannae change the laws of physics, blackbody radiator like
tungsten has a continuous spectrum, sources that rely on phosphor
conversion will always have peaks and troughs.

I said "broad" not "continuous"

LEDs , of any current type, are many miles away from being broad band
sources.

You did look at the spectra on the page I linked to? It looks one hell
of a lot better than CFL to me.

That's rather like saying a stroke is better than a heart attack. ;-)

You can make reasonably smooth continuous spectrum florries. But not down
to a price - and may also be less efficient.

The same happens with LEDs - the better the light quality the less
efficient they are. Although are improving.

--
*A woman drove me to drink and I didn't have the decency to thank her

Dave Plowman London SW
To e-mail, change noise into sound.

Andy Burns wrote in news:eag3e4Ffk7hU1
@mid.individual.net:

Adam Aglionby wrote:

LEDs have a lot of near visble blue in them

As spectacle wearing drivers will notice, it is noticeable that the blue
component is strong when looking at white LED daylight running lights of
a following car in your side-mirrors ...


I think that is "fringing" due to the lens being cheap and not colour
corrected (as a camera lens is) Different wavelengths refract differently
and give a rainbow fringe.

On Saturday, December 3, 2016 at 2:30:42 PM UTC, Dave Plowman (News) wrote:
In article ,
wrote:
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.

Flicker should be well above perception level, as demonstrated by
numerous crap car tailight designs this basic appears to have escaped
some makers.

Some car LEDs are driven in a very different way from domestic mains LEDs.
Basically, you can't just transfer a problem with those to all.

It is an example of how even well funded, well informed designers can get it wrong.

Guess that someone read something about getting more brightness out by pulsing and missed the rest of the article about average power.

Result being the strobe tail lights fitted to some early LED equipped cars, not got cheep Chinese knock offs to blame either ;-)


--
*Toilet stolen from police station. Cops have nothing to go on.

Dave Plowman London SW
To e-mail, change noise into sound.

DerbyBorn wrote:

Andy Burns wrote:

As spectacle wearing drivers will notice, it is noticeable that the blue
component is strong when looking at white LED daylight running lights of
a following car in your side-mirrors ...

I think that is "fringing" due to the lens being cheap and not colour
corrected (as a camera lens is) Different wavelengths refract differently
and give a rainbow fringe.

Maybe, but it's a lot stronger than the normal chromatic aberration you
get from spectacles, I thought it was the blue LED die combined with
yellow phosphor?

On Saturday, December 3, 2016 at 2:39:42 PM UTC, The Natural Philosopher wrote:
On 03/12/16 14:26, Adam Aglionby wrote:
Spectral Power Distribution, LEDs have a lot of near visble blue in them, whatever colour they are.

Utter total ********

A red LED has almost NO emission in the blue part of the spectrum
whatsoever. Neither does an orange or yellow.

Greens have a little, but you need a BLUE LED to actually start to have
any appreciable 'whiteness' - let lone 'blueness' in the spectrum.

For the purposes of the previous discussion was referring to blue with phosphor white LEDs....



And LED emission is not, like fluorescents, single spectral lines that
excite phosphors, its broad spectral lines that excite phosphors.

Regretably they certainly aren`t broad.

So the option to use not only blue but also red and green LEDS in a
single light source together with a range of phosphors to spread te
energy around exists.

Efficacy , its proven relatively easy to get more light out of 400nm+ LEDs, splash some phosphor on front, call 6000K white and wham, 100 lumens a Watt plus!

Lets ignore phosphor degradation , its not good for marketing.

Gets tougher lowering apparent colour temp with phosphor or adding higher wavelength primary emitters.

Amber and red LEDs efficiency isn`t anywhere near as good, need more of them to balance with lower wavelenghts.


In short you can make an LED lamp have pretty much any spectrum you
want, although UV is rather hard

You can , but its not a 1+1+1 combo of desired colours and its still a limited palette.



Metal halides and fluros have a blue peak much lower down.


No, they don't. LED spectra are tuneable.

Discharge sources are highly tuneable as well but they rely on the mercury line way down in UV to excite phosphor or metals in mix, LED uses vsible blue to excite phosphors.



Question is what effect does the high blue content have.

It seems to have driven you insane.

Back in day was demoed an expensive IIRC Sugden, audio amp, British built, notable feature was of 40W of output about 10W seemed to be permnanent broadband hiss, was told this was a `feature` of the amp.

White (phosphor) LED has a permanent 460nm ish peak, blue, in it.



--
Future generations will wonder in bemused amazement that the early
twenty-first centurys developed world went into hysterical panic over a
globally average temperature increase of a few tenths of a degree, and,
on the basis of gross exaggerations of highly uncertain computer
projections combined into implausible chains of inference, proceeded to
contemplate a rollback of the industrial age.

Richard Lindzen

RJH pretended :
Never got on with CFL - glad to see(!) the back of them.

Me too, but to a lesser extent. I found myself installing higher
wattage than needed CFL's, simply to overcome their initial dimness at
switch on. Not something LED suffers.

I have replaced all the lights which are in regular use with LED, but
left higher wattage CFL's as centre lights, where these are not
normally in use, just so we have brighter lighting available when
needed. LED's come on instantly at full brightness. Many of our lamps
are indistinguishable from ordinary lamps, though some are due to their
more limited colour spectrum.

I would compare LED v standard lamps are 1:7 to 1:9 in power saving,
but the savings only affect the lighting proportion of your
consumption. I have been logging consumption quite carefully over the
past year, from September - there was a very noticeable step change to
less consumption of around 1/3 less than was used in August. That
despite the heating pump running twice a day for HW, laptops running,
plus the usual kettle, microwave, TV's and etc.. Plus the darkening
evenings.

I have also implemented a trial policy of no larger wattage LED than is
needed for lighting an area. I found 3.5W LED's for hall, stairs and
landing adequate for normal use, but swapped them temporarily for 22w
CFL over the past couple of weeks whilst we were redecorating these
areas.

On Sat, 03 Dec 2016 14:18:00 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
ss wrote:
On 03/12/2016 12:19, Dave Plowman (News) wrote:
Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy bill?

Too many variables to be accurate but as a rough guide I would say if
you have current 60w and move to say 12w LEDs then the lighting part of
leccy bill would approx a fifth of the cost (not including the cost of
the LED bulbs)

Snag with that is it's near impossible to know what proportion of your
leccy bill goes on lighting.

Is there a need to know the proportion? If the question is, how much
money will be saved surely all you need to know is how much
electricity is consumed by the lighting?

On Sat, 3 Dec 2016 14:34:14 +0000, Andy Burns
wrote:

Adam Aglionby wrote:

LEDs have a lot of near visble blue in them

As spectacle wearing drivers will notice, it is noticeable that the blue
component is strong when looking at white LED daylight running lights of
a following car in your side-mirrors ...

I thought they were a design feature because some people seem to
believe it is trendy to have blue lights.

On 03/12/2016 11:10, Scott wrote:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

The LED colour rendering isn't quite right but 2700K tungsten lighting
is nothing like the natural light from the sun at 5000K. Colour film
sees the difference but the human eyes white balance auto adjusts.

Basically the body might need some UV exposure per day for vitamin D
synthesis but neither LED *nor* conventional incandescents provide it.

2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.

Persistence of vision and long phosphor glow time means that what little
flicker there is in LED lamps is negligible. They stay lit a suprisingly
long time after switching off. Incandescents also flicker slightly at 100Hz.

This isn't true of some brake lights on cars or pelican crossings which
give a really annoying brutal flashing effect in peripheral vision.

3. Because of the frequency (colour temperature?) the light does not
travel as far so streetlamps need to be placed closer together but.
Councils are not doing this for cost reasons, leaving blackspots in
illumination.

That is complete ********. The LED luminaires are more tightly
controlled than the old lamps which means if designed right there is a
lot less sideways glare and more light on the roadway. They do tend to
need to be closer together than some old types of street lamp.

The LEDs don't have to get much more efficient/cheaper before it becomes
possible to make them spaced the same as HPS/LPS fixtures.

The one criticism that you can make is that because of the very tight
control of sideways light spill it becomes more difficult to pick out
the future direction of a road lit by LED fixtures. You can really only
see them from a distance by the illumination of the supporting pole.

Is there any merit in these arguments?

Very little to none at all.

--
Regards,
Martin Brown

In article ,
Adam Aglionby wrote:
On Saturday, December 3, 2016 at 2:30:42 PM UTC, Dave Plowman (News) wrote:
In article ,
wrote:
2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.

Flicker should be well above perception level, as demonstrated by
numerous crap car tailight designs this basic appears to have escaped
some makers.

Some car LEDs are driven in a very different way from domestic mains
LEDs. Basically, you can't just transfer a problem with those to all.

It is an example of how even well funded, well informed designers can
get it wrong.

Guess that someone read something about getting more brightness out by
pulsing and missed the rest of the article about average power.

Result being the strobe tail lights fitted to some early LED equipped
cars, not got cheep Chinese knock offs to blame either ;-)

I'm not even shure why they strobe. Not something I've been particularly
aware of. Could it be an interaction with some street lighting?

--
*Dance like nobody's watching.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Scott wrote:
On Sat, 03 Dec 2016 14:18:00 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
ss wrote:
On 03/12/2016 12:19, Dave Plowman (News) wrote:
Average family living in an average 3 bedroom family house using
the average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy
bill?

Too many variables to be accurate but as a rough guide I would say if
you have current 60w and move to say 12w LEDs then the lighting part
of leccy bill would approx a fifth of the cost (not including the
cost of the LED bulbs)

Snag with that is it's near impossible to know what proportion of your
leccy bill goes on lighting.

Is there a need to know the proportion? If the question is, how much
money will be saved surely all you need to know is how much electricity
is consumed by the lighting?

I saw a figure quoted the other day.

It wouldn't be difficult to rig up a house with metering for light only
use. Or to calculate it, I suppose.

I was interested to see how much those on here thought they were saving by
changing to more efficient lighting. Especially as few have anything good
to say about CFL.

--
*A cartoonist was found dead in his home. Details are sketchy.*

Dave Plowman London SW
To e-mail, change noise into sound.

On 03/12/2016 12:19, Dave Plowman (News) wrote:
Here's a question for the group.

Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy bill?

I have managed to trim about 5kWh / day off my electrical usage in the
period where I phased in LED lighting. Not all of that will be just down
to lighting, but I expect most of it will be. However that's not an
average setup.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Scott wrote

As I mentioned elsewhere, I am experimenting with LED lighting.

Me too.

I was having a curry with a former colleague last
night, who mentioned his father hates LED lighting

Just another dinosaur IMO.

for the following reasons:

These are all bogus, just a rationalisation for being a dinosaur.

1. The spectrum is too narrow thus depriving
the body of the right kind of light.

Plenty of other stuff is MUCH worse in that regard.

And the same silly claim was made about fluoros too.

There is no 'right kind of light' that the body must have.

2. HIgh frequency flicker, higher than fluorescents

Just as true of CFLs.

possibly triggering migraine.

Not a shred of rigorous scientific evidence of that.

3. Because of the frequency (colour temperature?)
the light does not travel as far

Nothing to do with frequency or colour temperature,
this is due to the physical detail of the light source.

so streetlamps need to be placed closer together
but. Councils are not doing this for cost reasons,
leaving blackspots in illumination.

Irrelevant to what is viable in a house.

In fact it's the opposite with a house, because led
strips are possible with leds and not viable with
other light sources, you can get much more even
and shadow free illumination in places like kitchens
and with work surfaces. And its much easier to have
the most suitable colour temperature too and you
can in fact have completely programmable colour
temperature that can be set by the user for only
a little more than a fixed colour temperature.

Is there any merit in these arguments?

Nope.

In article ,
Martin Brown wrote:
On 03/12/2016 11:10, Scott wrote:
As I mentioned elsewhere, I am experimenting with LED lighting.

I was having a curry with a former colleague last night, who mentioned
his father hates LED lighting for the following reasons:

1. The spectrum is too narrow thus depriving the body of the right
kind of light.

The LED colour rendering isn't quite right but 2700K tungsten lighting
is nothing like the natural light from the sun at 5000K.

Care to say just how you're measuring that sun? The colour temperature of
daylight varies by the time of day and time of year. Even before clouds,
etc.

Colour film
sees the difference but the human eyes white balance auto adjusts.

Basically the body might need some UV exposure per day for vitamin D
synthesis but neither LED *nor* conventional incandescents provide it.

2. HIgh frequency flicker, higher than fluorescents possibly
triggering migraine.

Persistence of vision and long phosphor glow time means that what little
flicker there is in LED lamps is negligible. They stay lit a
suprisingly long time after switching off. Incandescents also flicker
slightly at 100Hz.

I'd say an LED 'stays lit' because of its power supply. Not intrinsically.

--
*Time is what keeps everything from happening at once.

Dave Plowman London SW
To e-mail, change noise into sound.

"Bob Eager" wrote in message ...

On Sat, 03 Dec 2016 14:18:00 +0000, Dave Plowman (News) wrote:

In article ,
ss wrote:
On 03/12/2016 12:19, Dave Plowman (News) wrote:
Average family living in an average 3 bedroom family house using the
average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy
bill?

Too many variables to be accurate but as a rough guide I would say if
you have current 60w and move to say 12w LEDs then the lighting part of
leccy bill would approx a fifth of the cost (not including the cost of
the LED bulbs)

Snag with that is it's near impossible to know what proportion of your
leccy bill goes on lighting.

It's so swamped by other consumption here that I can't be arsed to work
it out! (current year is about 11,500 kWh).

That makes my 4,508 kWh for the last 12 months seem quite frugal.