I see I can now buy a 60W equivalent LED light bulb Philips myAmbiance
872790091840300 at a price which will take the best part of £40.00!

Are they any good?

I have also seen LED car stop & tail bulbs. Should I get one the next
time a bulb fails?

--
Michael Chare

In article ,
Michael Chare mUNDERSCOREnews@chareDOTorgDOTuk wrote:
I have also seen LED car stop & tail bulbs. Should I get one the next
time a bulb fails?

Check if they carry the E mark - as all suitable replacements must do to
meet the regs. You'll likely find they don't.

--
*Any connection between your reality and mine is purely coincidental

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

In article ,
Michael Chare mUNDERSCOREnews@chareDOTorgDOTuk writes:
I see I can now buy a 60W equivalent LED light bulb Philips myAmbiance
872790091840300 at a price which will take the best part of £40.00!

Are they any good?

I would start with a very large dose of scepticism, based on past
experience of Philips (and others) claims for performance of new
lamp technologies.

I wouldn't spend £40 to find out, but if someone gave me one,
I'd certainly kick the tyres. The datasheet shows how much better
it is than a 60W filament lamp, but it's got to be very significantly
better than a £2 15W CFL before it's viable in my eyes, and it
isn't. When it costs a quarter of the current price, I would buy
one to try.

Being dimmable is interesting, but most light dimmers won't work
with such a low load, so that's probably not useful unless you have
lots of them.

I have also seen LED car stop & tail bulbs. Should I get one the next
time a bulb fails?

Only if the car manufacturer states they still meet the regs, which
they almost certainly will not unless they're original equipment.

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

On 13/04/2012 20:15, Andrew Gabriel wrote:
In articleRpidnTRYB6M28xXSnZ2dnUVZ8tadnZ2d@brightvie w.co.uk,
Michael CharemUNDERSCOREnews@chareDOTorgDOTuk writes:
I see I can now buy a 60W equivalent LED light bulb Philips myAmbiance
872790091840300 at a price which will take the best part of £40.00!

Are they any good?

I would start with a very large dose of scepticism, based on past
experience of Philips (and others) claims for performance of new
lamp technologies.

I wouldn't spend £40 to find out, but if someone gave me one,
I'd certainly kick the tyres. The datasheet shows how much better
it is than a 60W filament lamp, but it's got to be very significantly
better than a £2 15W CFL before it's viable in my eyes, and it
isn't. When it costs a quarter of the current price, I would buy
one to try.

Being dimmable is interesting, but most light dimmers won't work
with such a low load, so that's probably not useful unless you have
lots of them.

I have also seen LED car stop& tail bulbs. Should I get one the next
time a bulb fails?

Only if the car manufacturer states they still meet the regs, which
they almost certainly will not unless they're original equipment.

I read recently that LEDs in cars are not as efficient as touted, it
seems they need cooling to work efficiently, so that may apply to the
home as well.

--
Residing on low ground in North Staffordshire

Moonraker wrote:
I read recently that LEDs in cars are not as efficient as touted, it
seems they need cooling to work efficiently, so that may apply to the
home as well.

The benefits of LEDs on vehicles are the long life and resistance to
vibration. They also normally fail in a manner that leaves at least some
light being generated by the unit, which is safer than the all or
nothing when a filament lamp fails.

The efficiency savings for mobile use aren't worth bothering about
except for applications like battery powered cycle lights or torches, as
the power used by the lighting on a car is a small percentage of the
total power used to move it. At 30mph on a flat road, the absolute
maximum total lighting load on most cars, including headlamps and
foglamps, is less than 400 watts, as against ten kilowatts or more being
used to overcome rolling and air resistance.

LEDS in fixed installations are noticeably more efficient than filament
bulbs, as they use a switched mode supply, with a total comsumption of
about 10% or 15% that of the filament bulbs for the same light output.

--
Tciao for Now!

John.

In article ,
John Williamson writes:
Moonraker wrote:
I read recently that LEDs in cars are not as efficient as touted, it
seems they need cooling to work efficiently, so that may apply to the
home as well.

Indeed it does. The lighting industry got a very bad reputation
with the dishonest claims for CFLs, and LEDs started off even worse,
e.g. quoting efficiencies with the LED chip at 25C, which is only
going to apply if you run the thing in your freezer.

The benefits of LEDs on vehicles are the long life and resistance to
vibration.

Also, faster 'ON' time, particularly for brake lights.

However, the lamp cluster needs to have been designed for LEDs.
Retrofitting them into a cluster designed for a filament light
source isn't going to conform to regs.

They also normally fail in a manner that leaves at least some
light being generated by the unit, which is safer than the all or
nothing when a filament lamp fails.

The efficiency savings for mobile use aren't worth bothering about
except for applications like battery powered cycle lights or torches, as
the power used by the lighting on a car is a small percentage of the
total power used to move it. At 30mph on a flat road, the absolute
maximum total lighting load on most cars, including headlamps and
foglamps, is less than 400 watts, as against ten kilowatts or more being
used to overcome rolling and air resistance.

LEDS in fixed installations are noticeably more efficient than filament
bulbs, as they use a switched mode supply, with a total comsumption of
about 10% or 15% that of the filament bulbs for the same light output.

LEDs at that efficiency do exist, but are pricy. Most of the LEDs
you'll see at halfway affordable prices are around the same efficieny
as CFLs, and the cheaper ones are nearer the efficiency of LV halogens.

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

In article ,
John Williamson wrote:
LEDS in fixed installations are noticeably more efficient than filament
bulbs, as they use a switched mode supply, with a total comsumption of
about 10% or 15% that of the filament bulbs for the same light output.

Cars use SMPS too for LEDs.

A difference is that 12v tungsten are already more efficient than mains
ones.

I'd love to see *any* LED with the same light output as halogen mains. And
by that I mean a near 360 degree output of the same colour spectrum. Not
just measured by pointing some crude light meter at it. And using the very
worst possible tungsten as the comparison.

--
*What are the pink bits in my tyres? Cyclists & Joggers*

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

In article ,
Andrew Gabriel wrote:
In article ,
John Williamson writes:
Moonraker wrote:
I read recently that LEDs in cars are not as efficient as touted, it
seems they need cooling to work efficiently, so that may apply to the
home as well.

Indeed it does. The lighting industry got a very bad reputation
with the dishonest claims for CFLs, and LEDs started off even worse,
e.g. quoting efficiencies with the LED chip at 25C, which is only
going to apply if you run the thing in your freezer.

Sorry, but while you might get 25°F in your freezer, 25°C is a slightly
warm ambient temperature.

--
From KT24

Using a RISC OS computer running v5.18

John Williamson wrote:

The efficiency savings for mobile use aren't worth bothering about
except for applications like battery powered cycle lights or torches, as
the power used by the lighting on a car is a small percentage of the
total power used to move it. At 30mph on a flat road, the absolute
maximum total lighting load on most cars, including headlamps and
foglamps, is less than 400 watts, as against ten kilowatts or more being
used to overcome rolling and air resistance.

If that 400W could be reduced to 100W there would be worthwhile fuel
savings.

Bill

Bill Wright wrote:
John Williamson wrote:

The efficiency savings for mobile use aren't worth bothering about
except for applications like battery powered cycle lights or torches,
as the power used by the lighting on a car is a small percentage of
the total power used to move it. At 30mph on a flat road, the absolute
maximum total lighting load on most cars, including headlamps and
foglamps, is less than 400 watts, as against ten kilowatts or more
being used to overcome rolling and air resistance.

If that 400W could be reduced to 100W there would be worthwhile fuel
savings.

Less than 3% at constant speed in town, less at higher speeds or when
accelerating. Stopping at one red traffic light in a five mile journey
would make more difference. Correcting the tyre pressures every time the
load changes can make more difference. Removing the toolbox or shopping
from the boot makes almost as much difference. The absolute maximum on
my car is 210W, and that's using high beam headights and rear fog lights
while I'm signalling a turn.

To get the maximum lighting load down to 100W, you'd need to replace the
headlights with ultra efficient lights, which at the moment isn't
practical. In town, using dipped beams, the load is more like 150W,
anyway. You'll only use 400W in a situation where you are driving in
foggy conditions or using four high power halogen main beam lights.

--
Tciao for Now!

John.

"Bill Wright" wrote in message
...
John Williamson wrote:

The efficiency savings for mobile use aren't worth bothering about except
for applications like battery powered cycle lights or torches, as the
power used by the lighting on a car is a small percentage of the total
power used to move it. At 30mph on a flat road, the absolute maximum
total lighting load on most cars, including headlamps and foglamps, is
less than 400 watts, as against ten kilowatts or more being used to
overcome rolling and air resistance.

If that 400W could be reduced to 100W there would be worthwhile fuel
savings.

Bill

Depends what you mean by worthwhile.
Back of a fag packet calcs. (assuming the vehicle does 35mpg and speed
averages 32mph) that 300W saving is 0.7% of your energy budget.
At £1.40 litre current petrol price that is about 1p per litre.
When you factor in the conversion cost I think it is a non starter.

Andy

On Apr 14, 12:48*pm, charles wrote:
In article ,
* *Andrew Gabriel wrote:

In article ,
* *John Williamson writes:
Moonraker wrote:
I read recently that LEDs in cars are not as efficient as touted, it
seems they need cooling to work efficiently, so that may apply to the
home as well.
Indeed it does. The lighting industry got a very bad reputation
with the dishonest claims for CFLs, and LEDs started off even worse,
e.g. quoting efficiencies with the LED chip at 25C, which is only
going to apply if you run the thing in your freezer.

Sorry, but while you might get 25°F in your freezer, 25°C is a slightly
warm ambient temperature.

Thats the Temperature Junction, Tj, in the data sheets, which is
actually a tiny area less than 1mm ^2 heating rapidly as soon as
energised.

Astounding effiency can be demonstrated by a couple of difficult to
replicate outside of the lab ,er, strategies.

Measure the output in first few miliseconds of start up with a boosted
current.

Actively chill the heatsink, to get Tj to 25C means heatsink is going
to have to start colder.

Run the device at a tiny current lowering self heating effects then
supply the numbers for massage to marketing department....

Cheers
Adam

--
From KT24

Using a RISC OS computer running v5.18

On Sat, 14 Apr 2012 13:18:50 +0100
John Williamson wrote:

In town, using dipped beams, the load is more like 150W,
anyway. You'll only use 400W in a situation where you are driving in
foggy conditions or using four high power halogen main beam lights.

How can foggy conditions result in so much more load? A pair of front
foglamps will be the same power as a pair of dipped headlamps and the
rear foglamps will only add 21w each which will only push it up to
about 200w total

--
Mike Clarke

Mike Clarke wrote:
On Sat, 14 Apr 2012 13:18:50 +0100
John Williamson wrote:

In town, using dipped beams, the load is more like 150W,
anyway. You'll only use 400W in a situation where you are driving in
foggy conditions or using four high power halogen main beam lights.

How can foggy conditions result in so much more load? A pair of front
foglamps will be the same power as a pair of dipped headlamps and the
rear foglamps will only add 21w each which will only push it up to
about 200w total

You've got 200W minimum at the front, due to the dipped headlamps *and*
foglamps being on, then add the 42W drawn by the high intensity rear
lamps, plus at least 42W for brake lights and the same for indicators,
when they're being used. Plus, of course, at least 24W for side and tail
lights, not forgetting the side marker lights fitted to some cars. I was
giving maximum loads, not average ones.

Four bright halogen main beam lights are 350W just on their own.

--
Tciao for Now!

John.

In article ,
Bill Wright wrote:
The efficiency savings for mobile use aren't worth bothering about
except for applications like battery powered cycle lights or torches,
as the power used by the lighting on a car is a small percentage of
the total power used to move it. At 30mph on a flat road, the
absolute maximum total lighting load on most cars, including
headlamps and foglamps, is less than 400 watts, as against ten
kilowatts or more being used to overcome rolling and air resistance.

If that 400W could be reduced to 100W there would be worthwhile fuel
savings.

It would, but that 400w includes headlights. And very few cars have LED
ones. HID are more common - and vastly more efficient than tungsten. My 35
watt units produce much more light than 55w halogen. I'm not sure how LED
compares to that.

--
*There are two kinds of pedestrians... the quick and the dead.

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

In article ,
John Williamson wrote:
To get the maximum lighting load down to 100W, you'd need to replace the
headlights with ultra efficient lights, which at the moment isn't
practical.

It already is. HID are commonly 35 watts per lamp. And produce far more
light than 55w halogen.

--
*Corduroy pillows are making headlines.

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

Dave Plowman (News) wrote:

that 400w includes headlights. And very few cars have LED
ones. HID are more common - and vastly more efficient than tungsten. My 35
watt units produce much more light than 55w halogen. I'm not sure how LED
compares to that.

The top-end Audis have optional LED headlights, it mentions 40W per unit
for the dipped beam, but doesn't state the wattage for high-beam.

In article ,
John Williamson wrote:
You've got 200W minimum at the front, due to the dipped headlamps *and*
foglamps being on,

There is absolutely no point in using both in fog. The idea of low mounted
fog lights is they cut beneath the fog and light the road. Headlights as
well will just produce scatter and blind you.

--
*We waste time, so you don't have to *

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

In article ,
Andy Burns wrote:
that 400w includes headlights. And very few cars have LED ones. HID
are more common - and vastly more efficient than tungsten. My 35 watt
units produce much more light than 55w halogen. I'm not sure how LED
compares to that.

The top-end Audis have optional LED headlights, it mentions 40W per unit
for the dipped beam, but doesn't state the wattage for high-beam.

That's more or less the same as HID. Be interesting to do a comparison.
I'm very happy with my HID units.

The only snags with HID is the time they take to reach full brightness,
and not being a good idea to flash them, like all such types. Not a
problem in practice, but means you can't switch them on and off like
'normal' units. So you either use mirrors for dip/main beam or add
conventional mains. And some other lamps for flashing.

I suspect LED will prove cheaper, rather than better, in the scheme of
things.

--
*Indian Driver - Smoke signals only*

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

In article ,
"Dave Plowman (News)" writes:
In article ,
John Williamson wrote:
You've got 200W minimum at the front, due to the dipped headlamps *and*
foglamps being on,

There is absolutely no point in using both in fog. The idea of low mounted
fog lights is they cut beneath the fog and light the road.

The original "aim" was to pick out the kerb with the left one, and
the lane marking with the right one, nearer to the car than the
dip beam headlamps will effectively light. Nowadays, they're rather
more cosmetic than functional, and often can't even be adjusted to
aim/cutoff correctly.

Headlights as well will just produce scatter and blind you.

Can do, depending on conditions, but not always.

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

In article ,
Andrew Gabriel wrote:
There is absolutely no point in using both in fog. The idea of low mounted
fog lights is they cut beneath the fog and light the road.

The original "aim" was to pick out the kerb with the left one, and
the lane marking with the right one, nearer to the car than the
dip beam headlamps will effectively light.

All proper fog lights have a wide beam with a sharp cutoff. So can't
really be aimed as you suggest.

Nowadays, they're rather
more cosmetic than functional, and often can't even be adjusted to
aim/cutoff correctly.

Some cars have extra driving lights rather than true fogs. As you say more
to differentiate the head of paper clips car from his mere salesmen.

Headlights as well will just produce scatter and blind you.

Can do, depending on conditions, but not always.

Always. That's why foglights are low mounted and illegal in good
visibility. If the headlights were good in fog - why have specialised
lighting just for it?

But I'm talking about proper fog where you're reduced to walking pace.

--
*On the seventh day He brewed beer *

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

In article ,
Mike Clarke wrote:
On Sat, 14 Apr 2012 13:18:50 +0100
John Williamson wrote:

In town, using dipped beams, the load is more like 150W,
anyway. You'll only use 400W in a situation where you are driving in
foggy conditions or using four high power halogen main beam lights.

How can foggy conditions result in so much more load? A pair of front
foglamps will be the same power as a pair of dipped headlamps and the
rear foglamps will only add 21w each which will only push it up to
about 200w total

'cos most cars, idiotically, only allow you to use the fog lights when the
headlamps are switched on.

--
From KT24

Using a RISC OS computer running v5.18

In article ,
Dave Plowman (News) wrote:
In article ,
John Williamson wrote:
To get the maximum lighting load down to 100W, you'd need to replace
the headlights with ultra efficient lights, which at the moment isn't
practical.

It already is. HID are commonly 35 watts per lamp. And produce far more
light than 55w halogen.

and even they give out a lot more light than the tungsten as supplied with
my Anglia.

--
From KT24

Using a RISC OS computer running v5.18

Dave Plowman (News) wrote:

That's more or less the same as HID. Be interesting to do a comparison.

Test drive an R8 about 5pm in winter then!

I'm very happy with my HID units.

Ditto.

The only snags with HID is the time they take to reach full brightness,

I think by the time they've struck and been waggled to level them,
they're at full rightness

and not being a good idea to flash them

I don't know if that applies or not, I think mine has some normal bulbs
used for flashing and during the warm-up, you see the colour change when
these switch off, not examined them in detail though.

like all such types. Not a
problem in practice, but means you can't switch them on and off like
'normal' units. So you either use mirrors for dip/main beam or add
conventional mains.

Dunno if mine is mirrors or some sort of shade that is raised to unmask
for high beam, again I've not looked.

In article ,
"Dave Plowman (News)" writes:
In article ,
Andy Burns wrote:
that 400w includes headlights. And very few cars have LED ones. HID
are more common - and vastly more efficient than tungsten. My 35 watt
units produce much more light than 55w halogen. I'm not sure how LED
compares to that.

The top-end Audis have optional LED headlights, it mentions 40W per unit
for the dipped beam, but doesn't state the wattage for high-beam.

That's more or less the same as HID. Be interesting to do a comparison.
I'm very happy with my HID units.

The only snags with HID is the time they take to reach full brightness,
and not being a good idea to flash them, like all such types. Not a
problem in practice, but means you can't switch them on and off like
'normal' units. So you either use mirrors for dip/main beam or add
conventional mains. And some other lamps for flashing.

I suspect LED will prove cheaper, rather than better, in the scheme of
things.

HIDs are cheap to make and factory fit and increase the perceived
value of the car, which makes for a good manufacturer profit margin.
Also good profit on spare parts.

LEDs are still expensive to design and manufacture for the required
performance, and don't add much (if any) perceived value over HID,
so not yet so compelling for manufacturers. It will probably come
in time though, particularly as efficiency isn't a significant
factor in this application (high efficiency jacks up LED price).

LED would perhaps allow for some clever stuff with dynamic cut-off
adjustments, such as automatic left/right side dipping based on
GPS (country, and even road-specific, e.g. where there can't be
any oncoming traffic). If the French still required yellow
headlamps, I could imagine some adjustable colour versions
too (again, derived from the GPS location).

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

On Sat, 14 Apr 2012 17:21:48 +0100
charles wrote:

'cos most cars, idiotically, only allow you to use the fog lights
when the headlamps are switched on.

Glad mine doesn't fall into the "most cars" category then. The scatter
from the headlights would defeat the benefit of the sharp cut-off beam
from the fog lights.

--
Mike Clarke

On Sat, 14 Apr 2012 14:41:33 +0100, Mike Clarke wrote:

How can foggy conditions result in so much more load? A pair of front
foglamps will be the same power as a pair of dipped headlamps and the
rear foglamps will only add 21w each which will only push it up to
about 200w total

Full lighting load, as standard, on my car is something over 400W.

6 x 55W (dip, main, fog), front side lights, rear lights, rear fogs.
Braking (+42W) indicating (+50W, 2 x 21W plus side marker) 500W+ ...

Admittedly if one needs the front fogs on at all then the main and
dip are off as you get too much glare back from them.

--
Cheers
Dave.

On Sat, 14 Apr 2012 17:19:21 +0100, Dave Plowman (News) wrote:

Headlights as well will just produce scatter and blind you.

Can do, depending on conditions, but not always.

Always. That's why foglights are low mounted and illegal in good
visibility. If the headlights were good in fog - why have specialised
lighting just for it?

Quite agree.

But I'm talking about proper fog where you're reduced to walking pace.

Proper fog that most people never ever see.

I think I've had to drop to front fogs just a handful of times up
here on the North Pennines where we almost live in the hill fog. When
the snow poles are too far apart to see from one to the next, there
is thick fog visibilty about 15' max and everything is also smoothly
covered in snow with no tracks to follow it makes for an
"interesting" drive. Fast walking pace, concentration, and "if it
gets bumpy I'm probably no longer on the road". B-)

--
Cheers
Dave.

"Dave Plowman (News)" wrote in message
...
In article ,
John Williamson wrote:
LEDS in fixed installations are noticeably more efficient than filament
bulbs, as they use a switched mode supply, with a total comsumption of
about 10% or 15% that of the filament bulbs for the same light output.

Cars use SMPS too for LEDs.

A difference is that 12v tungsten are already more efficient than mains
ones.

I'd love to see *any* LED with the same light output as halogen mains. And
by that I mean a near 360 degree output of the same colour spectrum. Not
just measured by pointing some crude light meter at it. And using the very
worst possible tungsten as the comparison.

Let us know when you can get halogen lights that can do this
http://www.youtube.com/watch?v=znivDtjl1N4

"charles" wrote in message
...
In article ,
Mike Clarke wrote:
On Sat, 14 Apr 2012 13:18:50 +0100
John Williamson wrote:

In town, using dipped beams, the load is more like 150W,
anyway. You'll only use 400W in a situation where you are driving in
foggy conditions or using four high power halogen main beam lights.

How can foggy conditions result in so much more load? A pair of front
foglamps will be the same power as a pair of dipped headlamps and the
rear foglamps will only add 21w each which will only push it up to
about 200w total

'cos most cars, idiotically, only allow you to use the fog lights when the
headlamps are switched on.

Do you mean the rear fogs, I know of none that have front fogs where you
have to have the headlamps on as well.

On Sat, 14 Apr 2012 21:58:55 +0100, "dennis@home"
wrote:

Let us know when you can get halogen lights that can do this
http://www.youtube.com/watch?v=znivDtjl1N4

Oh, I do like that; especially the selective illumination in the face
of oncoming traffic.
Otoh, it's just another gadget/gizmo to go expensively wrong.

In article ,
dennis@home wrote:
I'd love to see *any* LED with the same light output as halogen mains.
And by that I mean a near 360 degree output of the same colour
spectrum. Not just measured by pointing some crude light meter at it.
And using the very worst possible tungsten as the comparison.

Let us know when you can get halogen lights that can do this
http://www.youtube.com/watch?v=znivDtjl1N4

I realise you're not technical, Dennis, but multiple lamp halogens could
do exactly the same thing. Although just why you'd want to escapes me.

But it's nice to see you're impressed by computer animation.

--
*I like cats, too. Let's exchange recipes.

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

On 14 Apr,
"Dave Plowman (News)" wrote:

Always. That's why foglights are low mounted and illegal in good
visibility.

Can you quote evidence of that? I'm sure that was the case in the 60s and
have trawled the net to find the rules for how high lights must be to be used
in good visibility and failed miserably in finding any evidence of the
illegality of the current spate of foglights in good visibility.

If the headlights were good in fog - why have specialised lighting just for
it?

Exactly! It's fairly rare for any fog lights to be needed. Rear foglights
should only be used when visbility is below 100 metres, so speed needs to be
restricted too. Most peeps switch on rear fog lights as soon as there's a
hint of mist, and don't slow down, being unaware that the fog lights mask
their brake lights and signals, being much brighter.

The regulations state that only one rear fog light is allowed, and that must
be on the offside, to reduce the likelyhood of them being mistaken for brake
lights.

--
B Thumbs
Change lycos to yahoo to reply

"Dave Plowman (News)" wrote in message
...
In article ,
dennis@home wrote:
I'd love to see *any* LED with the same light output as halogen mains.
And by that I mean a near 360 degree output of the same colour
spectrum. Not just measured by pointing some crude light meter at it.
And using the very worst possible tungsten as the comparison.

Let us know when you can get halogen lights that can do this
http://www.youtube.com/watch?v=znivDtjl1N4

I realise you're not technical, Dennis, but multiple lamp halogens could
do exactly the same thing. Although just why you'd want to escapes me.

I realise you don't know as much as you think but the optics to do that with
halogen lamps would be rather difficult.
The filament would have to be too long to actually make the sharp cut off
required.
But I guess you don't know much about the differences between LED lamps and
filament lamps.


But it's nice to see you're impressed by computer animation.

Its not all animation, but I realise that you can't tell the difference.
Even Mickey mouse cartoons are more impressive than you these days.

On Sat, 14 Apr 2012 21:46:08 +0100 (BST), Dave Liquorice wrote:

But I'm talking about proper fog where you're reduced to walking pace.

Proper fog that most people never ever see.

I think I've had to drop to front fogs just a handful of times up
here on the North Pennines where we almost live in the hill fog. When
the snow poles are too far apart to see from one to the next, there
is thick fog visibilty about 15' max and everything is also smoothly
covered in snow with no tracks to follow it makes for an
"interesting" drive. Fast walking pace, concentration, and "if it
gets bumpy I'm probably no longer on the road". B-)

Last had that coming home from walking on Kinder Scout. Brilliant day on the
tops but cloud below 1500'.
On the last roundabout on the southern edge of Derby I lost the kerb and had
to go round again; I could just see the signs fron about 5 yards away.

A bit further on we turned L into a pub's car-park (we often used that pub)
and were followed by another car. The other car realised that we'd parked
and swung L. It got to an exit (visibility there was about 10 yards), turned
L onto a minor road, reached the A-road from which it had come and turned R!
It had Channel Island plates, so it might just have been a tad lost - only
180 deg. though.
--
Peter.
The gods will stay away
whilst religions hold sway

In article ,
Mike Clarke wrote:
On Sat, 14 Apr 2012 17:21:48 +0100
charles wrote:

'cos most cars, idiotically, only allow you to use the fog lights
when the headlamps are switched on.

Glad mine doesn't fall into the "most cars" category then. The scatter
from the headlights would defeat the benefit of the sharp cut-off beam
from the fog lights.

agreed

--
From KT24

Using a RISC OS computer running v5.18

In article ,
wrote:
On 14 Apr,
"Dave Plowman (News)" wrote:

Always. That's why foglights are low mounted and illegal in good
visibility.

Can you quote evidence of that? I'm sure that was the case in the 60s
and have trawled the net to find the rules for how high lights must be
to be used in good visibility and failed miserably in finding any
evidence of the illegality of the current spate of foglights in good
visibility.

You can't have tried very hard. It's in the highway code.

http://www.direct.gov.uk/en/TravelAn...code/DG_069859

although that seems to suggest they must be used with headlights. Which
completely defeats the purpose of them.

If the headlights were good in fog - why have specialised lighting
just for it?

Exactly! It's fairly rare for any fog lights to be needed. Rear
foglights should only be used when visbility is below 100 metres, so
speed needs to be restricted too. Most peeps switch on rear fog lights
as soon as there's a hint of mist, and don't slow down, being unaware
that the fog lights mask their brake lights and signals, being much
brighter.

They are normally the same brightness as stop lamps or indictors. They are
also very useful in heavy rain in daylight. They allow you to see there is
a car in front before you can actually see the car itself.

The regulations state that only one rear fog light is allowed, and that
must be on the offside, to reduce the likelyhood of them being mistaken
for brake lights.

Both my cars have twin rear fog lights.

--
*What do little birdies see when they get knocked unconscious? *

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

In article ,
dennis@home wrote:
I realise you're not technical, Dennis, but multiple lamp halogens
could do exactly the same thing. Although just why you'd want to
escapes me.

I realise you don't know as much as you think but the optics to do that
with halogen lamps would be rather difficult. The filament would have
to be too long to actually make the sharp cut off required.

A sharp cutoff is achieved with a french flag. Many many cars with halogen
and HID units do this. LEDs will be no different. It's down to the optics,
not light source.

But I guess you don't know much about the differences between LED lamps
and filament lamps.

Obviously a lot more than you.

But it's nice to see you're impressed by computer animation.

Its not all animation, but I realise that you can't tell the difference.
Even Mickey mouse cartoons are more impressive than you these days.

If they have to resort to animation, it means real world conditions don't
show the effects they're conning the likes of you into believing. Are you
actually dribble? He's another who believes everything he sees in adverts.

--
*Why doesn't Tarzan have a beard? *

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

Dave Plowman (News) wrote
wrote
Dave Plowman (News) wrote

Always. That's why foglights are low mounted and illegal in good
visibility.

Can you quote evidence of that? I'm sure that was the case in the 60s
and have trawled the net to find the rules for how high lights must be
to be used in good visibility and failed miserably in finding any
evidence
of the illegality of the current spate of foglights in good visibility.

You can't have tried very hard. It's in the highway code.
http://www.direct.gov.uk/en/TravelAn...code/DG_069859

although that seems to suggest they must be used with headlights.

No it does not.

Which completely defeats the purpose of them.

Which is presumably why it doesn't say that.

If the headlights were good in fog - why have specialised lighting just
for it?

Exactly! It's fairly rare for any fog lights to be needed. Rear
foglights should only be used when visbility is below 100 metres, so
speed needs to be restricted too. Most peeps switch on rear fog lights
as soon as there's a hint of mist, and don't slow down, being unaware
that the fog lights mask their brake lights and signals, being much
brighter.

They are normally the same brightness as stop lamps or indictors.
They are also very useful in heavy rain in daylight. They allow you
to see there is a car in front before you can actually see the car itself.

The regulations state that only one rear fog light is allowed, and that
must be on the offside, to reduce the likelyhood of them being mistaken
for brake lights.

Both my cars have twin rear fog lights.

Dave Liquorice wrote:

Fast walking pace, concentration, and "if it
gets bumpy I'm probably no longer on the road". B-)

vbg


--
Adam