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Car headlight brightness regulations?
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Phil
Nov 7, 2012, 10:15:02 AM11/7/12
to
Is there a minimum acceptable brightness for car headlights? Last night while driving along a pitch black single carriageway I passed a car whose headlights looked like they were dipped, with a very visible yellow hue. Given that there were portions of the road where I had to use double beams, I can't imagine driving with such low illumination is safe.
Also, is there a maximum acceptable brightness for car headlights? I have passed cars which I thought were on full beam, but were not. Some of the newer cars, or those with xenon lamps, appear to have on standard headlight the luminosity of older ones on double beam.
Also, is there a maximum acceptable brightness for car headlights? I have passed cars which I thought were on full beam, but were not. Some of the newer cars, or those with xenon lamps, appear to have on standard headlight the luminosity of older ones on double beam.
Jethro_uk
Nov 7, 2012, 12:00:04 PM11/7/12
to
specify lumens/area ... I know they mandate the wavelength of "red" for
rear and stop lights !
GB
Nov 7, 2012, 12:50:02 PM11/7/12
to
On 07/11/2012 15:15, Phil wrote:
> Is there a minimum acceptable brightness for car headlights? Last night while driving along a pitch black single carriageway I passed a car whose headlights looked like they were dipped, with a very visible yellow hue. Given that there were portions of the road where I had to use double beams, I can't imagine driving with such low illumination is safe.
>
> Also, is there a maximum acceptable brightness for car headlights? I have passed cars which I thought were on full beam, but were not. Some of the newer cars, or those with xenon lamps, appear to have on standard headlight the luminosity of older ones on double beam.
>
Curiously, dim headlights may actually help. My experience is that I
> Is there a minimum acceptable brightness for car headlights? Last night while driving along a pitch black single carriageway I passed a car whose headlights looked like they were dipped, with a very visible yellow hue. Given that there were portions of the road where I had to use double beams, I can't imagine driving with such low illumination is safe.
>
> Also, is there a maximum acceptable brightness for car headlights? I have passed cars which I thought were on full beam, but were not. Some of the newer cars, or those with xenon lamps, appear to have on standard headlight the luminosity of older ones on double beam.
>
upgraded my dipped beam bulbs to xenon. The result is that the near
stuff is now much brighter, reducing my pupil size, so more distant
stuff is harder to see than before.
Nightjar
Nov 7, 2012, 1:00:04 PM11/7/12
to
On 07/11/2012 15:15, Phil wrote:
> Is there a minimum acceptable brightness for car headlights? Last night while driving along a pitch black single carriageway I passed a car whose headlights looked like they were dipped, with a very visible yellow hue. Given that there were portions of the road where I had to use double beams, I can't imagine driving with such low illumination is safe.
>
> Also, is there a maximum acceptable brightness for car headlights? I have passed cars which I thought were on full beam, but were not. Some of the newer cars, or those with xenon lamps, appear to have on standard headlight the luminosity of older ones on double beam.
>
Vehicle lights are covered by the The Road Vehicles Lighting Regulations
>
> Also, is there a maximum acceptable brightness for car headlights? I have passed cars which I thought were on full beam, but were not. Some of the newer cars, or those with xenon lamps, appear to have on standard headlight the luminosity of older ones on double beam.
>
1989. Vehicles first used on or after 1st April 1986 must have their
lights marked to show that they comply with a relevant EU or British
Standard. Finding out what they specify would involve wading through a
lot of EU Directives, or getting hold of a British Standard and the
latter are not published online.
If the lights looked yellowish, they were probably pre-halogen lights,
which would make them older than that. Then there was a minimum wattage
per lamp for dipped headlamps, varying from 10w for a motor cycle with
an engine of under 250cc and a maximum speed of not more than 25mph to
30w for a motor vehicle with four or more wheels and a maximum wattage
of 55w per lamp.
Colin Bignell
Lordgnome
Nov 7, 2012, 1:25:01 PM11/7/12
to
On 07/11/2012 18:00, Nightjar wrote:
>
> If the lights looked yellowish, they were probably pre-halogen lights,
> which would make them older than that. Then there was a minimum
> wattage per lamp for dipped headlamps, varying from 10w for a motor
> cycle with an engine of under 250cc and a maximum speed of not more
> than 25mph to 30w for a motor vehicle with four or more wheels and a
> maximum wattage of 55w per lamp.
>
> Colin Bignell
>
>
Reminds me of my old Ford Pilot. 6 volt system with enormous headlights
>
> If the lights looked yellowish, they were probably pre-halogen lights,
> which would make them older than that. Then there was a minimum
> wattage per lamp for dipped headlamps, varying from 10w for a motor
> cycle with an engine of under 250cc and a maximum speed of not more
> than 25mph to 30w for a motor vehicle with four or more wheels and a
> maximum wattage of 55w per lamp.
>
> Colin Bignell
>
>
which were sadly so dim, you had to strike a match to see if they were on!
Les.
Andy Champ
Nov 7, 2012, 6:40:03 PM11/7/12
to
On 07/11/2012 17:50, GB wrote:
> Curiously, dim headlights may actually help. My experience is that I
> upgraded my dipped beam bulbs to xenon. The result is that the near
> stuff is now much brighter, reducing my pupil size, so more distant
> stuff is harder to see than before.
That's not the brightness, that's the sharp cutoff. I used to have
> Curiously, dim headlights may actually help. My experience is that I
> upgraded my dipped beam bulbs to xenon. The result is that the near
> stuff is now much brighter, reducing my pupil size, so more distant
> stuff is harder to see than before.
some, and really didn't like them.
Andy
GB
Nov 8, 2012, 2:55:02 AM11/8/12
to
Ian Jackson
Nov 8, 2012, 6:50:02 AM11/8/12
to
In message <cHxms.190082$lz1....@fx28.am4>, Lordgnome
<l...@nospam.null> writes
I had a 1953 Ford Prefect (essentially a baby brother to the Pilot). My
6V headlights lights were actually pretty good (as were the rod brakes).
--
Ian
<l...@nospam.null> writes
6V headlights lights were actually pretty good (as were the rod brakes).
--
Ian
R. Mark Clayton
Nov 8, 2012, 10:15:09 AM11/8/12
to
"Ian Jackson" <ianREMOVET...@g3ohx.demon.co.uk> wrote in message
news:ctVPvfM8...@g3ohx.demon.co.uk...
In modern cars with hydraulically operated disk brakes the braking distance
is close to the physical limit and approaching half that given in the
highway code, which are based on the cars of over half a century ago which
had cable / rod operated drum brakes.
Andy Champ
Nov 8, 2012, 2:40:16 PM11/8/12
to
On 08/11/2012 15:15, R. Mark Clayton wrote:
> I had 1 1963 Honda motorcycle with 6Velectrics. The headlight was rubbish.
>
> In modern cars with hydraulically operated disk brakes the braking distance
> is close to the physical limit and approaching half that given in the
> highway code, which are based on the cars of over half a century ago which
> had cable / rod operated drum brakes.
Apparently (I haven't tried it) Land Rover Discoveries are similar to
> I had 1 1963 Honda motorcycle with 6Velectrics. The headlight was rubbish.
>
> In modern cars with hydraulically operated disk brakes the braking distance
> is close to the physical limit and approaching half that given in the
> highway code, which are based on the cars of over half a century ago which
> had cable / rod operated drum brakes.
the book figures.
Remember this next time one is tailgating you!
Andy
Lordgnome
Nov 8, 2012, 3:50:02 PM11/8/12
to
On 08/11/2012 15:15, R. Mark Clayton wrote:
pilot - it was a heavy beast, yet could stop rather smartly. You had to
put rather more weight on the pedal than you do these days though!
Les.
Nightjar
Nov 8, 2012, 5:30:04 PM11/8/12
to
On 08/11/2012 15:15, R. Mark Clayton wrote:
....
> In modern cars with hydraulically operated disk brakes the braking distance
> is close to the physical limit and approaching half that given in the
> highway code, which are based on the cars of over half a century ago which
> had cable / rod operated drum brakes.
I can't recall any car I was driving that recently having anything but
> is close to the physical limit and approaching half that given in the
> highway code, which are based on the cars of over half a century ago which
> had cable / rod operated drum brakes.
hydraulic brakes, although some did have drum brakes on the rear.
The Highway Code distances are based upon a reaction time of 0.7 seconds
and a braking efficiency of 77%, as compared to the 50% that will get an
MOT pass.
Colin Bignell
Andy Champ
Nov 9, 2012, 5:00:06 PM11/9/12
to
MOT pass was 5m/s/s - I don't know what "efficiency" means. I'd expect
a good car to exceed a G - which would give braking distances 2/3 of the
ones in the code.
(Note - having written that I googled. 10m/s would seem to be a good
average, and I couldn't find anything worse than 7.5m/s, which was a
yank tank - but the people who publish these are all sports car reviewers)
The problem is that if people are half a second behind the guy in front,
and he brakes, the one behind will be 0.2 seconds past the point where
the first one braked when he brakes. The next one will be another 0.2
seconds. The fourth car will hit the third one. Not hard. The fifth one
will be a bit harder...
Andy
philmc...@gmail.com
Nov 10, 2012, 6:10:02 PM11/10/12
to
If I knew there was oncoming traffic because of reflected light from their headlights I would have taken them much more slowly in case they were taking the corner fast & wide (every other driver is an idiot rule).
Roland Perry
Nov 11, 2012, 3:50:01 AM11/11/12
to
In message <45c14009-4c62-40e2...@googlegroups.com>, at
23:10:02 on Sat, 10 Nov 2012, philmc...@gmail.com remarked:
the corner is a broken down or parked vehicle with no lights at all?
--
Roland Perry
23:10:02 on Sat, 10 Nov 2012, philmc...@gmail.com remarked:
>I have taken some narrow blind corners and been surprised by oncoming traffic that I did not expect because they had very dim headlights.
>
>If I knew there was oncoming traffic because of reflected light from their headlights I would have taken them much more slowly in case they
>were taking the corner fast & wide (every other driver is an idiot rule).
How does that driving style accommodate the possibility that just round
>
>If I knew there was oncoming traffic because of reflected light from their headlights I would have taken them much more slowly in case they
>were taking the corner fast & wide (every other driver is an idiot rule).
the corner is a broken down or parked vehicle with no lights at all?
--
Roland Perry
Percy Picacity
Nov 11, 2012, 5:50:03 AM11/11/12
to
--
Percy Picacity
R. Mark Clayton
Nov 12, 2012, 8:30:04 PM11/12/12
to
"Andy Champ" <no....@nospam.invalid> wrote in message
news:6KqdncgpjLfJ4QDN...@eclipse.net.uk...
> On 08/11/2012 22:30, Nightjar wrote:
>> On 08/11/2012 15:15, R. Mark Clayton wrote:
>> ....
>>> In modern cars with hydraulically operated disk brakes the braking
>>> distance
>>> is close to the physical limit and approaching half that given in the
>>> highway code, which are based on the cars of over half a century ago
>>> which
>>> had cable / rod operated drum brakes.
>>
>> I can't recall any car I was driving that recently having anything but
>> hydraulic brakes, although some did have drum brakes on the rear.
>>
>> The Highway Code distances are based upon a reaction time of 0.7 seconds
>> and a braking efficiency of 77%, as compared to the 50% that will get an
>> MOT pass.
>>
>
> AFAICS the highway code figures are on about 6.5m/s/s. I understood an
> MOT pass was 5m/s/s - I don't know what "efficiency" means. I'd expect a
> good car to exceed a G - which would give braking distances 2/3 of the
> ones in the code.
Well the brakes won't pull more than a G on road cars, altough you might
>> On 08/11/2012 15:15, R. Mark Clayton wrote:
>> ....
>>> In modern cars with hydraulically operated disk brakes the braking
>>> distance
>>> is close to the physical limit and approaching half that given in the
>>> highway code, which are based on the cars of over half a century ago
>>> which
>>> had cable / rod operated drum brakes.
>>
>> I can't recall any car I was driving that recently having anything but
>> hydraulic brakes, although some did have drum brakes on the rear.
>>
>> The Highway Code distances are based upon a reaction time of 0.7 seconds
>> and a braking efficiency of 77%, as compared to the 50% that will get an
>> MOT pass.
>>
>
> AFAICS the highway code figures are on about 6.5m/s/s. I understood an
> MOT pass was 5m/s/s - I don't know what "efficiency" means. I'd expect a
> good car to exceed a G - which would give braking distances 2/3 of the
> ones in the code.
just get slightly more decelleration at very high speed due to air
resistance.
A modern car with disk brakes, especially with ABS, should pull nearly a G
on a reasonable road.
As you point out the MOT requirement is only 50%, however 50 years ago it
was only 40% and most cars did not have servos, so you needed consderable
strength to get that out of cable operated drum brakes, especially for a
fast stop when the brakes would warm up and fade*.
>
> (Note - having written that I googled. 10m/s would seem to be a good
> average, and I couldn't find anything worse than 7.5m/s, which was a yank
> tank - but the people who publish these are all sports car reviewers)
>
> The problem is that if people are half a second behind the guy in front,
> and he brakes, the one behind will be 0.2 seconds past the point where the
> first one braked when he brakes. The next one will be another 0.2
> seconds. The fourth car will hit the third one. Not hard. The fifth one
> will be a bit harder...
normally only happen in poor visibility.
>
> Andy
>
* this only happened to me once about thirty years ago in a Rover 3500SD1 on
long descent in the Pennines. At nearly 2 tonne with unventilated disks at
the front and drums at the back this was an alarming moment.
Roland Perry
Nov 13, 2012, 3:55:02 AM11/13/12
to
In message <YZedne39YaGLPzzN...@bt.com>, at 01:30:04 on
Tue, 13 Nov 2012, R. Mark Clayton <nospam...@btinternet.com>
remarked:
>cable operated drum brakes, especially for a
>fast stop when the brakes would warm up and fade*.
...
production cars in the 50's giving a talk at University, and he said it
was that sort of long decent (but the Alps rather than the Pennines)
which convinced them that better brakes were needed.
--
Roland Perry
Tue, 13 Nov 2012, R. Mark Clayton <nospam...@btinternet.com>
remarked:
>cable operated drum brakes, especially for a
>fast stop when the brakes would warm up and fade*.
>* this only happened to me once about thirty years ago in a Rover 3500SD1 on
>long descent in the Pennines. At nearly 2 tonne with unventilated disks at
>the front and drums at the back this was an alarming moment.
I recall one of the designers involved in the roll-out of disc brakes to
>long descent in the Pennines. At nearly 2 tonne with unventilated disks at
>the front and drums at the back this was an alarming moment.
production cars in the 50's giving a talk at University, and he said it
was that sort of long decent (but the Alps rather than the Pennines)
which convinced them that better brakes were needed.
--
Roland Perry
Phil Mcbride
Nov 14, 2012, 5:20:02 AM11/14/12
to
1) Doing an emergency stop is easier than an emergency swerve from the
worst case speed of 60mph on a single carriageway. With an emergency
swerve you run a real risk of hitting the kerb, entering the grass/
dirt/mud by the side of the road at speed and losing control.
2) Two cars coming in opposite directions close the distance in half
the time and twice the relative speed around a blind corner
3) The severity of a 60mph (worst case) rear collision vs. a
stationary parked car is not as bad as a 60mph head-on vs. another
60mph car.
Percy Picacity
Nov 14, 2012, 3:20:02 PM11/14/12
to
unprotected by machinery. Your analysis seems unremittingly
motorist-centric.
--
Percy Picacity
Jethro_uk
Nov 15, 2012, 7:55:02 AM11/15/12
to
experts. It seems to be becoming more prevalent too. I think it's a side-
effect of the low esteem we hold politicians in - we now distrust
*anyone* of authority.
Robin Bignall
Nov 15, 2012, 4:55:02 PM11/15/12
to
On Thu, 15 Nov 2012 12:55:02 +0000, Jethro_uk <jeth...@hotmailbin.com>
wrote:
When paying for your kids to have football or piano lessons is good,
while paying for them to go to good schools is elitist, one wonders if
the (western) world has gone mad.
--
Robin Bignall
Herts, England
wrote:
while paying for them to go to good schools is elitist, one wonders if
the (western) world has gone mad.
--
Robin Bignall
Herts, England
Roland Perry
Nov 16, 2012, 2:30:02 AM11/16/12
to
In message <vsoaa8lh681bm4a28...@4ax.com>, at 21:55:02 on
Thu, 15 Nov 2012, Robin Bignall <docr...@ntlworld.com> remarked:
at football or music, but not for being very good at maths or running an
organisation (unless that organisation is a football club, at which
point it seems some of the ladder-kicking premium rubs off on the
manager).
--
Roland Perry
Thu, 15 Nov 2012, Robin Bignall <docr...@ntlworld.com> remarked:
>When paying for your kids to have football or piano lessons is good,
>while paying for them to go to good schools is elitist, one wonders if
>the (western) world has gone mad.
It goes deeper than that. OK to pay someone loads-a-money for being good
>while paying for them to go to good schools is elitist, one wonders if
>the (western) world has gone mad.
at football or music, but not for being very good at maths or running an
organisation (unless that organisation is a football club, at which
point it seems some of the ladder-kicking premium rubs off on the
manager).
--
Roland Perry
Nightjar
Nov 16, 2012, 5:10:03 AM11/16/12
to
On 09/11/2012 22:00, Andy Champ wrote:
> On 08/11/2012 22:30, Nightjar wrote:
>> On 08/11/2012 15:15, R. Mark Clayton wrote:
>> ....
>>> In modern cars with hydraulically operated disk brakes the braking
>>> distance
>>> is close to the physical limit and approaching half that given in the
>>> highway code, which are based on the cars of over half a century ago
>>> which
>>> had cable / rod operated drum brakes.
>>
>> I can't recall any car I was driving that recently having anything but
>> hydraulic brakes, although some did have drum brakes on the rear.
>>
>> The Highway Code distances are based upon a reaction time of 0.7 seconds
>> and a braking efficiency of 77%, as compared to the 50% that will get an
>> MOT pass.
>>
>
> AFAICS the highway code figures are on about 6.5m/s/s. I understood an
> MOT pass was 5m/s/s - I don't know what "efficiency" means.
It is defined in the MOT testing documents as the maximum braking force,
> On 08/11/2012 22:30, Nightjar wrote:
>> On 08/11/2012 15:15, R. Mark Clayton wrote:
>> ....
>>> In modern cars with hydraulically operated disk brakes the braking
>>> distance
>>> is close to the physical limit and approaching half that given in the
>>> highway code, which are based on the cars of over half a century ago
>>> which
>>> had cable / rod operated drum brakes.
>>
>> I can't recall any car I was driving that recently having anything but
>> hydraulic brakes, although some did have drum brakes on the rear.
>>
>> The Highway Code distances are based upon a reaction time of 0.7 seconds
>> and a braking efficiency of 77%, as compared to the 50% that will get an
>> MOT pass.
>>
>
> AFAICS the highway code figures are on about 6.5m/s/s. I understood an
> MOT pass was 5m/s/s - I don't know what "efficiency" means.
as measured by a rolling road, expressed as a percentage of the weight
of the car.
> I'd expect
> a good car to exceed a G - which would give braking distances 2/3 of the
> ones in the code.
Some cars will, in practice, perform better, some will perform worse.
> (Note - having written that I googled. 10m/s would seem to be a good
> average, and I couldn't find anything worse than 7.5m/s, which was a
> yank tank - but the people who publish these are all sports car reviewers)
>
> The problem is that if people are half a second behind the guy in front,
> and he brakes, the one behind will be 0.2 seconds past the point where
> the first one braked when he brakes.
typical for a person to see a stimulus, recognise the meaning of the
stimulus, react to the stimulus (that is your 0.2 seconds) and take
action following the stimulus. Of course, at 70mph, the first vehicle
will be over 20m further down the road in that 0.7 seconds.
> The next one will be another 0.2
> seconds. The fourth car will hit the third one. Not hard. The fifth one
> will be a bit harder...
least two seconds and you should be looking further ahead than just the
car in front.
Colin Bignell
Message has been deleted
Percy Picacity
Nov 16, 2012, 6:30:03 PM11/16/12
to
On 2012-11-16 22:40:02 +0000, Phil W Lee said:
>
>
> [2] Nobody stays as alert in normal driving as a person who is a
> voluntary subject on this kind of test. They may be that alert for
> limited portions of their driving, but that level of alertness is not
> sustainable on a continuous basis for more than a few minutes.
Hence the great importance of recognising potential hazards in good
time, so you can be alert when negotiating them. Rather more valuable
in practice than a quick response time. Probably why us old people are
such good drivers.
--
Percy Picacity
>
>
> [2] Nobody stays as alert in normal driving as a person who is a
> voluntary subject on this kind of test. They may be that alert for
> limited portions of their driving, but that level of alertness is not
> sustainable on a continuous basis for more than a few minutes.
Hence the great importance of recognising potential hazards in good
time, so you can be alert when negotiating them. Rather more valuable
in practice than a quick response time. Probably why us old people are
such good drivers.
--
Percy Picacity
Andy Champ
Nov 16, 2012, 6:25:02 PM11/16/12
to
On 16/11/2012 10:10, Nightjar wrote:
> On 09/11/2012 22:00, Andy Champ wrote:
>>
>> AFAICS the highway code figures are on about 6.5m/s/s. I understood an
>> MOT pass was 5m/s/s - I don't know what "efficiency" means.
>
> It is defined in the MOT testing documents as the maximum braking force,
> as measured by a rolling road, expressed as a percentage of the weight
> of the car.
>
OK, thanks.
> On 09/11/2012 22:00, Andy Champ wrote:
>>
>> AFAICS the highway code figures are on about 6.5m/s/s. I understood an
>> MOT pass was 5m/s/s - I don't know what "efficiency" means.
>
> It is defined in the MOT testing documents as the maximum braking force,
> as measured by a rolling road, expressed as a percentage of the weight
> of the car.
>
>> I'd expect
>> a good car to exceed a G - which would give braking distances 2/3 of the
>> ones in the code.
>
> The Highway Code braking distances are only intended as a general guide.
> Some cars will, in practice, perform better, some will perform worse.
>
gaps than most people.
>> (Note - having written that I googled. 10m/s would seem to be a good
>> average, and I couldn't find anything worse than 7.5m/s, which was a
>> yank tank - but the people who publish these are all sports car
>> reviewers)
>>
>> The problem is that if people are half a second behind the guy in front,
>> and he brakes, the one behind will be 0.2 seconds past the point where
>> the first one braked when he brakes.
>
> The 0.7 seconds used for the Highway Code thinking distance is more
> typical for a person to see a stimulus, recognise the meaning of the
> stimulus, react to the stimulus (that is your 0.2 seconds) and take
> action following the stimulus. Of course, at 70mph, the first vehicle
> will be over 20m further down the road in that 0.7 seconds.
>
the one behind. If the gap is only 0.5 seconds...
>> The next one will be another 0.2
>> seconds. The fourth car will hit the third one. Not hard. The fifth one
>> will be a bit harder...
>
> You shouldn't be half a second behind the car in front. You should be at
> least two seconds and you should be looking further ahead than just the
> car in front.
>
don't.
On the other hand I do wonder what effect it would have on the M25 (or
the Birmingham ring, or around Edinburgh etc) if people increased their
distances. The whole thing might grind to a halt!
Andy
Nick Odell
Nov 16, 2012, 6:35:09 PM11/16/12
to
Nick
Message has been deleted
jami...@gmail.com
Sep 22, 2017, 2:51:59 AM9/22/17
to
On Wednesday, November 7, 2012 at 7:15:02 AM UTC-8, Phil wrote:
> Is there a minimum acceptable brightness for car headlights? Last night while driving along a pitch black single carriageway I passed a car whose headlights looked like they were dipped, with a very visible yellow hue. Given that there were portions of the road where I had to use double beams, I can't imagine driving with such low illumination is safe.
>
> Also, is there a maximum acceptable brightness for car headlights? I have passed cars which I thought were on full beam, but were not. Some of the newer cars, or those with xenon lamps, appear to have on standard headlight the luminosity of older ones on double beam.
I swear some of the cars on the road now are equipped with laser beam headlights. We need to ban the fuck out of those annoying dangerous lights!
> Is there a minimum acceptable brightness for car headlights? Last night while driving along a pitch black single carriageway I passed a car whose headlights looked like they were dipped, with a very visible yellow hue. Given that there were portions of the road where I had to use double beams, I can't imagine driving with such low illumination is safe.
>
> Also, is there a maximum acceptable brightness for car headlights? I have passed cars which I thought were on full beam, but were not. Some of the newer cars, or those with xenon lamps, appear to have on standard headlight the luminosity of older ones on double beam.
Andy Burns
Sep 22, 2017, 4:46:21 AM9/22/17
to
jami...@gmail.com wrote:
> I swear some of the cars on the road now are equipped with laser beam headlights.
Close enough
> I swear some of the cars on the road now are equipped with laser beam headlights.
<http://jalopnik.com/bmw-laser-headlights-1521586271>
lordgnome
Sep 22, 2017, 6:53:56 AM9/22/17
to
a ton of bricks. I would have thought that excessive headlights could
also be dangerous, but the complaints about modern headlights seem to
get shrugged off.
Mike Scott
Sep 22, 2017, 9:43:10 AM9/22/17
to
could spread the stuff around rather more than one might desire.
Especially as white/yellow would seem the most toxic and flammable, as I
recall. (Add some fuel - napalm in a car accident?)
And as for "BMW says that in situations like accidents where the laser
emitters may end up pointed past the mirrors and lens, the system would
automatically shut down." I can only admire their trust. "If something
can go wrong, it will" is a motto that springs to mind.
--
Mike Scott (unet2 <at> [deletethis] scottsonline.org.uk)
Harlow Essex
"The only way is Brexit" -- anon.
R. Mark Clayton
Sep 22, 2017, 9:43:29 AM9/22/17
to
This is more common with discharge lights, where there is a chromatic effect which makes the top fringe appear blue (because it is) when first seen. Easily noticed when such cars go over speed bumps.
More recent LED ones are the most accurate and on top range cars adjust dynamically to keep the beam down: -
http://www.audi.com/en/innovation/design/Matrix_LED.html
Caecilius
Sep 22, 2017, 9:43:35 AM9/22/17
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output level. I think the limit is 60w, which is why most standard
headlight bulbs are 55w.
Harry Bloomfield
Sep 22, 2017, 10:09:35 AM9/22/17
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R. Mark Clayton explained :
adjust their height, is this something new?
My xenon adjust themselves for level each time they are switched on,
based upon sensors measuring the load on each axle.
> More recent LED ones are the most accurate and on top range cars adjust
> dynamically to keep the beam down: -
>
> http://www.audi.com/en/innovation/design/Matrix_LED.html
There has always been a C&U regulation requiring xenon lights to self
> dynamically to keep the beam down: -
>
> http://www.audi.com/en/innovation/design/Matrix_LED.html
adjust their height, is this something new?
My xenon adjust themselves for level each time they are switched on,
based upon sensors measuring the load on each axle.
Harry Bloomfield
Sep 22, 2017, 10:11:26 AM9/22/17
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Caecilius was thinking very hard :
produces much more light output. My xenon lamps are 35w.
> I beleive the limit is the wattage of the bulbs rather than the light
> output level. I think the limit is 60w, which is why most standard
> headlight bulbs are 55w.
Which was fine in the days of filament lamps, but not now when 55w
> output level. I think the limit is 60w, which is why most standard
> headlight bulbs are 55w.
produces much more light output. My xenon lamps are 35w.
Brian Reay
Sep 22, 2017, 11:38:47 AM9/22/17
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in my youth, a friend had a motobike (probably a moped from the style)
and the headlight was like the proverbial 'fag end', it passed the MOT
with no problem. The filament just glowed, there was no real 'beam'.
It was a the same on other examples of the same model- one of those
pressed metal frame things from Europe.
The check they do during the MOT is for 'direction' of the dipped beam,
not intensity.
R. Mark Clayton
Sep 22, 2017, 11:39:11 AM9/22/17
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On Friday, 22 September 2017 15:09:35 UTC+1, Harry Bloomfield wrote:
> R. Mark Clayton explained :
> > More recent LED ones are the most accurate and on top range cars adjust
> > dynamically to keep the beam down: -
> >
> > http://www.audi.com/en/innovation/design/Matrix_LED.html
>
> There has always been a C&U regulation requiring xenon lights to self
> adjust their height, is this something new?
Dunno - my BMW does this and it and its predecessor had a manual adjust as well.
> R. Mark Clayton explained :
> > More recent LED ones are the most accurate and on top range cars adjust
> > dynamically to keep the beam down: -
> >
> > http://www.audi.com/en/innovation/design/Matrix_LED.html
>
> There has always been a C&U regulation requiring xenon lights to self
> adjust their height, is this something new?
>
> My xenon adjust themselves for level each time they are switched on,
Clive Arthur
Sep 29, 2017, 5:14:21 AM9/29/17
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On 22/09/2017 14:21, Mike Scott wrote:
<snip>
> I'm not sure about phosphorus in headlights - presumably an accident
> could spread the stuff around rather more than one might desire.
> Especially as white/yellow would seem the most toxic and flammable, as I
> recall. (Add some fuel - napalm in a car accident?)
I imagine that 'Phosphorous' is journalistic non-science for 'a phosphor'.
Cheers
--
Clive
<snip>
> I'm not sure about phosphorus in headlights - presumably an accident
> could spread the stuff around rather more than one might desire.
> Especially as white/yellow would seem the most toxic and flammable, as I
> recall. (Add some fuel - napalm in a car accident?)
Cheers
--
Clive
R. Mark Clayton
Sep 29, 2017, 6:24:31 AM9/29/17
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newshound
Sep 29, 2017, 6:35:51 AM9/29/17
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On 29/09/2017 11:23, R. Mark Clayton wrote:
>
> Pressed metal things from Japan. I had one for a while (Honda C100 - 90cc) - only 6V electrics, so pretty poor headlight.
>
IIRC they were at least as good as the lights on my 6 volt 500 and 650cc
>
> Pressed metal things from Japan. I had one for a while (Honda C100 - 90cc) - only 6V electrics, so pretty poor headlight.
>
British "classics".
Mike Scott
Sep 29, 2017, 10:18:34 AM9/29/17
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But that article is very clear about "yellow phosphorus" - as is for
example
http://auto.howstuffworks.com/laser-powered-headlight1.htm
newshound
Sep 29, 2017, 10:46:26 AM9/29/17
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On 29/09/2017 12:39, Jeff wrote:
> Which led to the expression Joe Lucas Prince of Darkness.
>
> Jeff
My Velocettes had Miller dynamos which were no more powerful, though
some considered them more reliable. And the cognoscenti preferred BTH
magnetos to Lucas. Those great names from the past, where are they now?
>
> Jeff
My Velocettes had Miller dynamos which were no more powerful, though
some considered them more reliable. And the cognoscenti preferred BTH
magnetos to Lucas. Those great names from the past, where are they now?
Clive Arthur
Sep 29, 2017, 11:52:55 AM9/29/17
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On 29/09/2017 15:16, Mike Scott wrote:
> On 29/09/17 10:14, Clive Arthur wrote:
>> On 22/09/2017 14:21, Mike Scott wrote:
>>
>> <snip>
>>
>>> I'm not sure about phosphorus in headlights - presumably an accident
>>> could spread the stuff around rather more than one might desire.
>>> Especially as white/yellow would seem the most toxic and flammable,
>>> as I recall. (Add some fuel - napalm in a car accident?)
>>
>> I imagine that 'Phosphorous' is journalistic non-science for 'a
>> phosphor'.
>>
>> Cheers
>
> Maybe.
>
> But that article is very clear about "yellow phosphorus" - as is for
> example
> http://auto.howstuffworks.com/laser-powered-headlight1.htm
Nah, it's a yellow phosphor which likely has no Phosphorous content at
> On 29/09/17 10:14, Clive Arthur wrote:
>> On 22/09/2017 14:21, Mike Scott wrote:
>>
>> <snip>
>>
>>> I'm not sure about phosphorus in headlights - presumably an accident
>>> could spread the stuff around rather more than one might desire.
>>> Especially as white/yellow would seem the most toxic and flammable,
>>> as I recall. (Add some fuel - napalm in a car accident?)
>>
>> I imagine that 'Phosphorous' is journalistic non-science for 'a
>> phosphor'.
>>
>> Cheers
>
> Maybe.
>
> But that article is very clear about "yellow phosphorus" - as is for
> example
> http://auto.howstuffworks.com/laser-powered-headlight1.htm
all. Google it if you're interested.
In this case, the phosphor essentially converts some of the blue light
to yellow light, giving an approximation to white. Nearly all white LED
lamps do the same, they contain blue LEDs with a yellow phosphor.
Cheers
--
Clive
Mike Scott
Oct 1, 2017, 5:48:27 AM10/1/17
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http://www.laserfocusworld.com/articles/2013/09/ucsb-laser-plus-phosphor-white-lighting-is-efficient-and-stable.html
which mentions "yellow YAG phosphor" - YAG being yttrium aluminium
garnet. So nothing nastily flammable, just badly confusable to a non-techy.
But I'd still be concerned about use of lasers, especially invisible and
powerful near-UV ones.
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