I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.
[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

-- Richard

"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when you
mention it, most people don't know what you're on about.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?


--

Graham.

%Profound_observation%

On 30/05/2015 16:32, Graham. wrote:

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

Sure that's not just to keep the LEDs from cooking themselves? Probably
easier (read cheaper) to strobe than use effective heatsinking...

In article ,
Lee wrote:

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

Sure that's not just to keep the LEDs from cooking themselves? Probably
easier (read cheaper) to strobe than use effective heatsinking...

That would only apply if they were more efficient when run from a
pulsed high current than a constant lower one. It that true?

-- Richard

"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.


I have just fitted 84 of the 10W Integral LEDs (equivalent to 60W).

The beam angle is low IMHO

--
Adam

"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when you
mention it, most people don't know what you're on about.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?


Graham.

%Profound_observation%

....and why use stupid LEDs in cars ayway ?

Jim GM4DHJ/m ... wrote:
"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when you
mention it, most people don't know what you're on about.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?


Graham.

%Profound_observation%

....and why use stupid LEDs in cars ayway ?

LEDs are smart in brake lights because they give a slightly earlier warning.

--
Mike Barnes
Cheshire, England

On 30/05/2015 16:32, Graham. wrote:

snip

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

For a given current, 'strobing' reduces the average light output - the
LED is only on for some fraction of the time. Pulse Width Modulation
(PWM) and mark-space ration are words to Google.

The same LEDs are used for tail and brake lights. They're 'strobed' for
tail (dimmer) and continuous for brake (brightest) to get the necessary
brightness difference.

Cheers
--
Syd

"Mike Barnes" wrote in message
...
Jim GM4DHJ/m ... wrote:
"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when you
mention it, most people don't know what you're on about.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?


Graham.

%Profound_observation%

....and why use stupid LEDs in cars ayway ?

LEDs are smart in brake lights because they give a slightly earlier
warning.

will that help stop wummin drivers crashing in to you ? ....

"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when
you mention it, most people don't know what you're on about.

Yeah, I certainly don't get any effect like that with traffic lights.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

Because they need to be brighter because they need to work in full
sunlight with the traffic lights particularly but also the indicator and
stop lights with cars.

I assume the reason bike lights flash is because that
sees them get more time out of a charge of the battery.

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?

"Richard Tobin" wrote in message
...
In article ,
Lee wrote:

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

Sure that's not just to keep the LEDs from cooking themselves? Probably
easier (read cheaper) to strobe than use effective heatsinking...

That would only apply if they were more efficient when
run from a pulsed high current than a constant lower one.

It's also true if you need the LED bright
enough to be very visible in full sunlight.

It that true?

"Jim GM4DHJ/m ..." wrote in message
...

"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when you
mention it, most people don't know what you're on about.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?

...and why use stupid LEDs in cars ayway ?

Because they last a lot longer than incandescents when done right.

On 30/05/2015 12:54, Richard Tobin wrote:
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

A few months ago I got a few 13W from Ryness supposed to be a
replacement for 75W incandescents (1060 Lumens), but they seem to us to
be adequate replacements for old 100W bulbs, especially as you say the
light is directed downwards a bit more than with an incandescent. Price
not quite as ridiculous at £12 - might be good value if the claimed life
is really reached:

https://www.ryness.co.uk/integral-13...amp-1060-lumen

I assume that other retailers have something similar.

--
Clive Page

On 30/05/2015 12:54, Richard Tobin wrote:
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

-- Richard


At that price you may as well buy the Philips 18W MASTER LED Bulb (100W
Replacement) Warm White bulbs which have a better colour (IMHO) and
light distribution.


--
Michael Chare

Rod Speed wrote:


"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when
you mention it, most people don't know what you're on about.

Yeah, I certainly don't get any effect like that with traffic lights.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

Because they need to be brighter because they need to work in full
sunlight with the traffic lights particularly but also the indicator and
stop lights with cars.

I assume the reason bike lights flash is because that
sees them get more time out of a charge of the battery.

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?


I think they flash just to annoy me

"F Murtz" wrote in message
web.com...
Rod Speed wrote:


"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when
you mention it, most people don't know what you're on about.

Yeah, I certainly don't get any effect like that with traffic lights.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

Because they need to be brighter because they need to work in full
sunlight with the traffic lights particularly but also the indicator and
stop lights with cars.

I assume the reason bike lights flash is because that
sees them get more time out of a charge of the battery.

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?


I think they flash just to annoy me

Then you should run over every bike rider you come across,
even those who don't have any lights at all on during the day.

"Clive Page" wrote in message
...
On 30/05/2015 12:54, Richard Tobin wrote:
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

A few months ago I got a few 13W from Ryness supposed to be a replacement
for 75W incandescents (1060 Lumens), but they seem to us to be adequate
replacements for old 100W bulbs, especially as you say the light is
directed downwards a bit more than with an incandescent. Price not quite
as ridiculous at £12 - might be good value if the claimed life is really
reached:

https://www.ryness.co.uk/integral-13...amp-1060-lumen

I assume that other retailers have something similar.

£9 in B&Q

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ/m ...
wrote:

"Mike Barnes" wrote in message
...
Jim GM4DHJ/m ... wrote:

....and why use stupid LEDs in cars ayway ?

LEDs are smart in brake lights because they give a slightly earlier
warning.

will that help stop wummin drivers crashing in to you ? ....

Does that happen to you a lot? Perhaps you should learn which gears are
forward and which are reverse.

would that help ? ...

On Saturday, 30 May 2015 21:45:56 UTC+1, Rod Speed wrote:

I assume the reason bike lights flash is because that
sees them get more time out of a charge of the battery.

Partly, but also partly because it is believed to attract driver's
attention. Personally, I dislike flashing bike lights in the dark
because I find it hard to identify exactly where they are. (At
dusk they are fine - the flashing draws my attention, and then I can
see the cyclist's body).

(Aside: I am a cyclist far more often than a driver).

That is all down to the range of frequencies they give out though. They try
to fool the eye into thinking its white, but its got big holes in the
spectrum apparently.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Jim GM4DHJ/m ..." wrote in message
...

"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

Is it not something to do with duty cycle? Which reminds me, the new lower
wattage versions of those bulbs may well be more efficient so they
dissipate less heat, resulting in the lower wattage. The cheaper prices may
well have been to clear the old stock.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when you
mention it, most people don't know what you're on about.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?


--

Graham.

%Profound_observation%

"Tim Streater" wrote in message
.. .

will that help stop wummin drivers crashing in to you ? ....

Does that happen to you a lot? Perhaps you should learn which gears are
forward and which are reverse.


Not often. But the last one to do so came out with a brilliant excuse after
reversing out of her drive across the road and into my van.

"Its not my fault, you were not parked there when I put my car on the drive"

--
Adam

On 31/05/2015 06:10, Graham. wrote:
Syd Rumpo Wrote in message:
On 30/05/2015 16:32, Graham. wrote:

snip

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

For a given current, 'strobing' reduces the average light output - the
LED is only on for some fraction of the time. Pulse Width Modulation
(PWM) and mark-space ration are words to Google.

The same LEDs are used for tail and brake lights. They're 'strobed' for
tail (dimmer) and continuous for brake (brightest) to get the necessary
brightness difference.

Cheers
--
Syd


I agree with your first paragraph but not the second.

The human eye does not average out perceived brightness like
that, and the light will look pretty much the same brightness as
if it was on continuously, but with a valuable reduction in power
dissipation.

That's incorrect, as is easily demonstrated - 100% on is vastly
different to 1% on. In any case, LED drivers do use PWM for brightness
control.

(There were largely unsubstantiated claims about this years ago, but if
an effect exists at all, it's very small.)

As for my tail/brake light claim, this is easy to prove in traffic by
sweeping your eyes across an LED tail light. Retinal persistence shows
dots on tail and continuous on brake.

(bad form to answer ones own question, sorry).

Perhaps the answer is to run them continuously at night, and
strobe them in the daylight with higher instantaneous
power.


Cheers
--
Syd

On 31/05/2015 12:42, Tim Streater wrote:
In article , Syd Rumpo
wrote:

As for my tail/brake light claim, this is easy to prove in traffic by
sweeping your eyes across an LED tail light. Retinal persistence
shows dots on tail and continuous on brake.

Presumably retinal non-persistence. At what frequency are they strobed?
(someone may have said, but if so then I missed it) Cranking the rate
up ought to fix it but any sort of strobing is gonna be distracting.



I think persistence, as you sweep you eyes across the light the image
persists on your retina for a short time giving a string of red dashes
for tail and a solid red streak for brake.

As for frequency, I'd guess 100Hz or so as it looks similar to but
quicker than the effect you see with mains mercury vapour lamps. That's
fast enough to appear continuous if you don't mess about looking like a
loony as you flick your eyes around.

'Strobing' is the wrong term really, it's PWM.

Cheers
--
Syd

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when you
mention it, most people don't know what you're on about.

Phew ! .....I thought it was just me .........

On Sun, 31 May 2015 12:42:38 +0100, Tim Streater wrote:

In article , Syd Rumpo
wrote:

As for my tail/brake light claim, this is easy to prove in traffic by
sweeping your eyes across an LED tail light. Retinal persistence shows
dots on tail and continuous on brake.

Presumably retinal non-persistence. At what frequency are they strobed?
(someone may have said, but if so then I missed it) Cranking the rate up
ought to fix it but any sort of strobing is gonna be distracting.

There's a zebra crossing round here with illuminated poles (well, the
white bits are). It strobes like crazy, very disorienting.

On 31/05/2015 13:53, Tim Streater wrote:
In article , Syd Rumpo
wrote:

I think persistence, as you sweep you eyes across the light the image
persists on your retina for a short time giving a string of red dashes
for tail and a solid red streak for brake.

Ah, now I'm with you.

As for frequency, I'd guess 100Hz or so as it looks similar to but
quicker than the effect you see with mains mercury vapour lamps.
That's fast enough to appear continuous if you don't mess about
looking like a loony as you flick your eyes around.

:-)

Well of course when you're driving then at times when someone's brake
lights may be important to you, there's a good chance you *are*
flicking your eyes around.

Any reason they couldn't crank the frequency up to a few hundred Hz?

I just Googled 'Automotive LED PWM' and the first hit is a Maxim app
note for a MAX16804 driver showing a 20% duty cycle for tail and 100%
for brake. It also shows that the switching is at 200Hz, so my guess
wasn't that terrible.

I don't see any compelling reason why it couldn't be higher - there'd be
more switching losses, so a little more heat to lose, so maybe a small
extra cost.

http://www.maximintegrated.com/en/ap...ex.mvp/id/4316

Cheers
--
Syd

Rod Speed wrote:


"Jim GM4DHJ/m ..." wrote in message
...

"Graham." wrote in message
...
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when you
mention it, most people don't know what you're on about.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?

...and why use stupid LEDs in cars ayway ?

Because they last a lot longer than incandescents when done right.

& presumably they can save a few pennies because they will make no
provision for user lamp replacement - "sealed for life" - & greater
flexibility in placement.

Assume it will be a ££££ job if they do fail of course...

Chris K

"Tim Streater" wrote in message
.. .
In article , Syd Rumpo
wrote:

As for my tail/brake light claim, this is easy to prove in traffic by
sweeping your eyes across an LED tail light. Retinal persistence shows
dots on tail and continuous on brake.

Presumably retinal non-persistence. At what frequency are they strobed?
(someone may have said, but if so then I missed it) Cranking the rate
up ought to fix it but any sort of strobing is gonna be distracting.

Can't be that distracting if some of us haven't noticed any difference
with LED tail lights until their attention is drawn to that in discussion.

On Sat, 30 May 2015 16:32:30 +0100, Graham. wrote:

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

They use less energy that way.

On 30/05/2015 16:32, Graham. wrote:
And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?

I've always wondered that.

Next time I buy a car I'll make a point of carefully checking. I don't
want to be using strobing headlights

Andy

On 31/05/2015 14:10, Syd Rumpo wrote:
It also shows that the switching is at 200Hz, so my guess wasn't that
terrible.

Hmm. It never seems that high. I'd have guessed 50... I can't see
flicker on a 75Hz CRT(1), but I can see these.

Andy
--
OK, couldn't. Haven't seen one for a while...

On 31/05/15 21:59, Vir Campestris wrote:
On 31/05/2015 14:10, Syd Rumpo wrote:
It also shows that the switching is at 200Hz, so my guess wasn't that
terrible.

Hmm. It never seems that high. I'd have guessed 50... I can't see
flicker on a 75Hz CRT(1), but I can see these.


Persistence dear boy, persistence


LEDS have none. They can pulse up to GHz.

Phosphors have lots and lots


Andy


--
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.

"Vir Campestris" wrote in message
o.uk...
On 30/05/2015 16:32, Graham. wrote:
And how fast does a car tail light need to strobe, so as not to be
considered flashing by the construction & use rules, or whatever
legislation governs these things?

I've always wondered that.

Next time I buy a car I'll make a point of carefully checking. I don't
want to be using strobing headlights

Andy


me too ......

On Sun, 31 May 2015 06:45:39 +1000, "Rod Speed"
wrote:



"Graham." wrote in message
.. .
On Sat, 30 May 2015 14:52:33 +0100, "Jim GM4DHJ/m ..."
wrote:


"Richard Tobin" wrote in message
...
I recently bought a couple of these Integral 16W[*] LED bulbs:

http://www.amazon.co.uk/gp/product/B00OLPNZ0C

They really do seem to be as bright as a 100W bulb, and similar to a
Philips "110W equivalent" 23W compact fluorescent. The light is
directed downwards more than with an incandescent (they claim a 140
degree angle) but they seem to light up the useful areas of the room
perfectly well (I'm using spherical paper shades).

Of course they are ridiculously expensive, and have even gone up
on the Amazon website since I bought them.

[*] The Integral web site has two pages for bulbs with the same
part number, one described as 16W and discontinued, the other
described as 13.5W. So I'm not certain which I have.

- Richard

led lights on cars make my eyes go funny ...hate them

+1
And LED traffic lights too.
They strobe and leave a dotted trail across my field of vision. It
surprises me that more people aren't affected, but in general when
you mention it, most people don't know what you're on about.

Yeah, I certainly don't get any effect like that with traffic lights.

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

Because they need to be brighter because they need to work in full
sunlight with the traffic lights particularly but also the indicator and
stop lights with cars.

I assume the reason bike lights flash is because that
sees them get more time out of a charge of the battery.

Yes, and no doubt it was argued that it makes them stand out from cars
and street furniture.

I understand they were technically illegal for some time.

--

Graham.

%Profound_observation%

Syd Rumpo Wrote in message:
On 30/05/2015 16:32, Graham. wrote:

snip

Domestic LED lights use DC and are more than bright enough for vehicle
lamps, so why does the automotive industry need to strobe theirs?

For a given current, 'strobing' reduces the average light output - the
LED is only on for some fraction of the time. Pulse Width Modulation
(PWM) and mark-space ration are words to Google.

The same LEDs are used for tail and brake lights. They're 'strobed' for
tail (dimmer) and continuous for brake (brightest) to get the necessary
brightness difference.

Cheers
--
Syd


I agree with your first paragraph but not the second.

The human eye does not average out perceived brightness like
that, and the light will look pretty much the same brightness as
if it was on continuously, but with a valuable reduction in power
dissipation.

(bad form to answer ones own question, sorry).

Perhaps the answer is to run them continuously at night, and
strobe them in the daylight with higher instantaneous
power.
--

Graham.
%Profound_observation%


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