Dynamos vs. LEDs (Re: Cyclist Explodes! (NW Cambridge Plans))

[Nick Maclaren]

In article <[email protected]>,
Simon Brooke <[email protected]> writes:
|>
|> > You almost certainly mean that individual LEDs can't use much current,
|> > but why the hell not use more than one LED? Most cyclists' lights
|> > (and even front lights for 90% of commuting) are primarily to be seen,
|> > and not to see by and you need the width anyway (as I said).
|>
|> You're an urban cyclist, aren't you? Some of us aren't. You may be right
|> that 90% of commuters ride only on lighted streets, but I wouldn't bet on
|> it.

My normal commuting route is actually suburban, though I used to ride
through Grantchester and Coton fairly regularly often, before the road
'improvements' increased the rat running through Grantchester so much.
I have also ridden at night in rural areas, recreationally.

But, I think that you will find that 90% of the commuters in Cambridge
is an underestimate. If I recall, the figure quoted for the number of
cycle trips less than 2 miles was getting on for 90%, and very few of
those are not on lighted roads.

But, even on the Grantchester and Coton route, it is FAR more important
not to be run over than to be able to ride at full speed at night.
You may disagree, but I doubt that you are typical of most people
(though you may be of cyclists posting to this group).


Regards,
Nick Maclaren.

 

[Nick Maclaren]

In article <[email protected]>,
Rob Morley <[email protected]> writes:
|> >
|> > They may be; they are insane to be. Most of those can't be seen except
|> > from almost dead ahead or dead behind, which is why they were banned
|> > for so long.
|>
|> They were never 'banned', they simply didn't comply with the relevant
|> standard which stated that an incandescent light source was required.

Sigh. For the last time, I looked at the actual regulations. It is
very clear that you did not.

It was forbidden for anyone to sell a bicycle with them attached
(whether or not there was an approved light as well), and it was
arguably forbidden for a cyclist to fit them, even as an adjunct.
As far as I know, it was never taken to a court entitled to establish
precedent.

The clue to this mess is that they were not permitted by the
Construction and Use Regulations, and there was a section in another
Act that forbade bring a vehicle onto the roads unless it complied
with those. And not just a motor vehicle.


Regards,
Nick Maclaren.

 

[Alan Braggins]

Simon Brooke wrote:
>in message <[email protected]>, Nick Maclaren
>('[email protected]') wrote:
>
>> You almost certainly mean that individual LEDs can't use much current,
>> but why the hell not use more than one LED? Most cyclists' lights
>> (and even front lights for 90% of commuting) are primarily to be seen,
>> and not to see by and you need the width anyway (as I said).
>
>You're an urban cyclist, aren't you? Some of us aren't. You may be right
>that 90% of commuters ride only on lighted streets, but I wouldn't bet on
>it.

Commuters riding longer distances are more likely to include unlit sections
so 90% of commuting by time or distance would be more than 90% of commuters.
It wouldn't surprise me at all if he is right though - on the occasions
when I do a long commute, I see _far_ more cyclists on the lit in-town part
of it. (Though on occasions when my wife has met me part way she has said
there were several other cyclists on the unlit part, but since they were
travelling at a similar speed in the same direction we hadn't seen each
other.)

 

[Alan Braggins]

In article <[email protected]>, Nick Maclaren wrote:
>It was forbidden for anyone to sell a bicycle with them attached
>(whether or not there was an approved light as well), and it was
>arguably forbidden for a cyclist to fit them, even as an adjunct.
>As far as I know, it was never taken to a court entitled to establish
>precedent.

Has there ever been a case taken to _any_ court of either a cyclist
with both approved lights and additional steady white front lights which
were not being used in a manner prohibited by
http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_4.htm#(Tiii)27restrictionuselampotherthanthosewhichregulation24refer
or of a cyclist whose lights were approved to BS6102/3 but not the 1986
edition (http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_7.htm#nsch2) ?

(Flashing lights were another matter. Possibly that is what you were
thinking off when you said "to evade them, you have to wear the lights
(which is why there was and still is a practice of doing so.)" which is
far more true of rear lights - relatively few commuters use helmet or
headband mounted lights, the only front lights I have seen worn.)
http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_3.htm#(Tii)i3lampshowsteadylight

 

[Nick Maclaren]

In article <[email protected]>,
[email protected] (Alan Braggins) writes:
|>
|> Commuters riding longer distances are more likely to include unlit sections
|> so 90% of commuting by time or distance would be more than 90% of commuters.
|> It wouldn't surprise me at all if he is right though - on the occasions
|> when I do a long commute, I see _far_ more cyclists on the lit in-town part
|> of it. (Though on occasions when my wife has met me part way she has said
|> there were several other cyclists on the unlit part, but since they were
|> travelling at a similar speed in the same direction we hadn't seen each
|> other.)

I am in complete agreement with that. Note that I was NOT saying that
a directed front light wasn't important, but that the front light have
a wide viewing angle was MORE important.

If I were designing a bicycle light system, there would be multiple
white LEDs for the wide angle, and a separate high-power LED/bulb for
the directed light. Indeed, if I recall, one light does precisely
that.


Regards,
Nick Maclaren.

 

[Nick Maclaren]

In article <[email protected]>,
[email protected] (Alan Braggins) writes:
|>
|> Has there ever been a case taken to _any_ court of either a cyclist
|> with both approved lights and additional steady white front lights which
|> were not being used in a manner prohibited by
|> http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_4.htm#(Tiii)27restrictionuselampotherthanthosewhichregulation24refer
|> or of a cyclist whose lights were approved to BS6102/3 but not the 1986
|> edition (http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_7.htm#nsch2) ?

I heard that did happen, but it was in the days when Raleigh's monopoly
was threatened by carbide lights, not LEDs. However, that is before
my time ....

|> (Flashing lights were another matter. Possibly that is what you were
|> thinking off when you said "to evade them, you have to wear the lights
|> (which is why there was and still is a practice of doing so.)" which is
|> far more true of rear lights - relatively few commuters use helmet or
|> headband mounted lights, the only front lights I have seen worn.)
|> http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_3.htm#(Tii)i3lampshowsteadylight

The law is the same for both, or at least was. Remember that I said
that they were banned and not that you would be prosecuted if you
used one.


Regards,
Nick Maclaren.

 

[Anthony Jones]

Nick Maclaren wrote:
> If I were designing a bicycle light system, there would be multiple
> white LEDs for the wide angle, and a separate high-power LED/bulb for
> the directed light. Indeed, if I recall, one light does precisely
> that.

I suspect that your design would be the bicycle light equivalent of
this:

http://en.wikipedia.org/wiki/List_of_vehicles_in_The_Simpsons#The_Homer

Anthony

 

[Alan Braggins]

In article <[email protected]>, Nick Maclaren wrote:
>I heard that did happen, but it was in the days when Raleigh's monopoly
>was threatened by carbide lights, not LEDs.

That's the third time I've seen you say "Raleigh" when "Ever Ready" might
possibly have made sense. Why? (And AIUI the incandescent bulb "monopoly"
was established to outlaw the existing use of carbide lamps.)


>|> (Flashing lights were another matter
>|> http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_3.htm#(Tii)i3lampshowsteadylight
>
>The law is the same for both, or at least was.

The link is to a section which says "no vehicle shall be fitted with a
lamp which automatically emits a flashing light" (followed by some exceptions,
such as "a direction indicator", none of which are for bicycle lights).
So, no, the law was not the same for both flashing and steady lights.

(http://www.opsi.gov.uk/si/si2005/20052559.htm
The Road Vehicles Lighting (Amendment) Regulations 2005
adds an exemption to the rule for cycle front position lights.)

[Additional non-approved lights]
> Remember that I said
>that they were banned and not that you would be prosecuted if you
>used one.

They were widely sold and used, you don't know of anyone prosecuted for
using them, and you haven't presented any evidence they were even
technically illegal. By what possible stretch of meaning is that "banned"?

 

[Tony Raven]

Alan Braggins wrote on 10/10/2006 10:07 +0100:
>
> The EL300 has a British Standard approval and was never banned.
> (And if you were a real pedant, you would realise that non-approved
> white lights weren't banned anyway, they merely weren't acceptable as
> the only front lights.)
>

Not strictly true. It does meet a British Standard, but unfortunately
not the one called up in the Road Vehicle Lighting Regulations 1989
which references a previous standard which only contains filament lamps.
Therefore in a strict legal sense it was BS marked but not legal.
--
Tony

"Anyone who conducts an argument by appealing to authority is not using
his intelligence; he is just using his memory."
- Leonardo da Vinci

 

[Alan Braggins]

In article <[email protected]>, Tony Raven wrote:
>Alan Braggins wrote on 10/10/2006 10:07 +0100:
>>
>> The EL300 has a British Standard approval and was never banned.
>> (And if you were a real pedant, you would realise that non-approved
>> white lights weren't banned anyway, they merely weren't acceptable as
>> the only front lights.)
>
>Not strictly true. It does meet a British Standard, but unfortunately
>not the one called up in the Road Vehicle Lighting Regulations 1989
>which references a previous standard which only contains filament lamps.

Yes, see elsewhere in the thread. Which actually makes what I said
strictly true, but incomplete. Had I said "has a British Standard approval
as required by RVLR 1989" that might not have been not strictly true.
There is the complication that what is required is "an approval mark
or a British Standard mark", and "an approval mark" is undefined for
bicycles there, but IIRC marks showing "equivalent" EU approvals are
allowed by other legistation, and that the required BS mark is:
"British Standard mark" means the mark indicated in the specification
for photometric and physical requirements for lighting equipment
published by the British Standards Institution under the reference
BS 6102: Part 3: 1986, namely "BS 6102/3".
Lights which are approved to later versions of BS 6102: Part 3 do still
carry the same mark indicated in the earlier version, namely "BS 6102/3",
so at least arguably do meet the requirements.

 

[Anthony Jones]

Nick Maclaren wrote:
> |> > If I were designing a bicycle light system, there would be multiple
> |> > white LEDs for the wide angle, and a separate high-power LED/bulb for
> |> > the directed light. Indeed, if I recall, one light does precisely
> |> > that.
> |>
> |> I suspect that your design would be the bicycle light equivalent of
> |> this:
> |>
> |> http://en.wikipedia.org/wiki/List_of_vehicles_in_The_Simpsons#The_Homer
>
> Try:
>
> http://www.planetbike.com/frontlights.html
>
> But I think that there was also a better known maker.

I assume that you are referring to this:

http://www.planetbike.com/pop/3023.html

Before high power LEDs were widely available, I can see that there was a
benefit to using both LEDs and a halogen bulb in the same light. This has
nothing to do with beam patterns though. There are single LED front lights
available that have perfectly adequate visibility from a wide range of
angles. Using multiple LEDs to achieve the desired beam pattern just adds
complexity without any benefit.

Anthony

PS - I've re-added uk.rec.cycling since this is more relevant there, I
didn't realise my newsreader was setting Followup-To to point to
cam.transport.

 

[Nick Maclaren]

In article <[email protected]>,
[email protected] (Alan Braggins) writes:
|>
|> Has there ever been a case taken to _any_ court of either a cyclist
|> with both approved lights and additional steady white front lights which
|> were not being used in a manner prohibited by
|> http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_4.htm#(Tiii)27restrictionuselampotherthanthosewhichregulation24refer
|> or of a cyclist whose lights were approved to BS6102/3 but not the 1986
|> edition (http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_7.htm#nsch2) ?

Oh, for heaven's sake! What on earth does that have to do with it?

A huge number of things are illegal but never get taken to court;
sometimes (like the ban on lipstick), they degrade and would get
thrown out; sometimes (like Blasphemous Libel), they are resuscitated
after decades or longer for a political persecution. I could give
dozens of other examples, but won't.

|> (Flashing lights were another matter. Possibly that is what you were
|> thinking off when you said "to evade them, you have to wear the lights
|> (which is why there was and still is a practice of doing so.)" which is
|> far more true of rear lights - relatively few commuters use helmet or
|> headband mounted lights, the only front lights I have seen worn.)
|> http://www.opsi.gov.uk/SI/si1989/Uksi_19891796_en_3.htm#(Tii)i3lampshowsteadylight

Please point out the legal differences between the two, except that they
are in different sections of the same Statutory Instrument.


Regards,
Nick Maclaren.

 

[Anthony Jones]

Nick Maclaren wrote:
> It is unclear whether disposable batteries are ecologically better or
> worse than rechargable ones, EVEN exclude NiCads (which are really nasty).

Do you have some evidence for that (I'm genuinely interested)?

> |> It would weigh a ton. The D size batteries are heavy by themselves, and
> |> then you'd need casing strong enough to support them in an environment
> |> with plenty of vibration. Why not just get a dynamo?
>
> Oh, come off it! They were the standard bicycle battery for years, and
> a lot of fittings still use them. And a decent dynamo isn't light,
> either. And, in any case, both are down in the noise level compared to
> even a very light rider.

Sorry, I should have clarified: I agree that for most utility cyclists the
extra weight on the bicycle is unimportant. Being able to fit the light in
a pocket often is though. Heavy and bulky lights make this difficult.

Anthony

(re-added uk.rec.cycling again, apologies for the unintentional yo-yo-ing
between groups)

 

[Nick Maclaren]

In article <[email protected]>,
Anthony Jones <[email protected]> writes:
|>
|> Before high power LEDs were widely available, I can see that there was a
|> benefit to using both LEDs and a halogen bulb in the same light. This has
|> nothing to do with beam patterns though. There are single LED front lights
|> available that have perfectly adequate visibility from a wide range of
|> angles. Using multiple LEDs to achieve the desired beam pattern just adds
|> complexity without any benefit.

No, the point actually applies to any technology! It is extremely
hard to design a light that gives a bright light directed 10 yards
ahead and one that provides a fairly uniform one for a wide angle.
Cars do it by overkill, and even then some headlights are not easily
visible from an angle.


Regards,
Nick Maclaren.

 

[Jonathan Amery]

In article <[email protected]>,
Nick Maclaren <[email protected]> wrote:
>
[some stuff]

On an entirely unrelated point your newsreader appears to be breaking
the References: line thusly:

References: <[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]> <eggict
^

--
Jonathan Amery. +---------+ ________________ _________________
##### |Cambridge| |# [] ## ## [] # | | # [] ## ## [] #|
#######__o +-+-----+-+ | [] [] | | [] [] |
#######'/ ----------+-----+--------- \-oo----------oo-/+\-oo----------oo-/

 

[Nick Maclaren]

In article <[email protected]>,
Anthony Jones <[email protected]> writes:
|> Nick Maclaren wrote:
|> > It is unclear whether disposable batteries are ecologically better or
|> > worse than rechargable ones, EVEN exclude NiCads (which are really nasty).
|>
|> Do you have some evidence for that (I'm genuinely interested)?

The evidence is that the lack of clear evidence to the contrary.
There. Now you have it!

Seriously. What metals are used in NiMH? I don't know. The ones
used for almost all disposables are significant and widespread
components of the biosphere, and so are not much of a hazard.
The onus is on anyone claiming that rechargeables are better to
provide evidence for THAT claim.


Regards,
Nick Maclaren.

 

[Tony Raven]

Nick Maclaren wrote on 11/10/2006 12:13 +0100:
>
> No, the point actually applies to any technology! It is extremely
> hard to design a light that gives a bright light directed 10 yards
> ahead and one that provides a fairly uniform one for a wide angle.
> Cars do it by overkill, and even then some headlights are not easily
> visible from an angle.
>

Rubbish. It's a trivial optical design exercise to mix the two unless
you have an extended source like a fluorescent tube which is difficult
to make directional in a reasonably sized package. The fact that it has
not generally been done does not mean its difficult to do. Designers
just seem to concentrate on either-or instead.


--
Tony

"Anyone who conducts an argument by appealing to authority is not using
his intelligence; he is just using his memory."
- Leonardo da Vinci

 

[Nick Maclaren]

In article <[email protected]>,
Tony Raven <[email protected]> writes:
|>
|> Rubbish. It's a trivial optical design exercise to mix the two unless
|> you have an extended source like a fluorescent tube which is difficult
|> to make directional in a reasonably sized package. The fact that it has
|> not generally been done does not mean its difficult to do. Designers
|> just seem to concentrate on either-or instead.

Some evidence of why you believe your claim might be amusing. You
may, of course, be right that all designers of such lights over the
past century have been incompetent, but it is possible that things
aren't that way round.


Regards,
Nick Maclaren.

 

[Anthony Jones]

Nick Maclaren wrote:
> No, the point actually applies to any technology! It is extremely
> hard to design a light that gives a bright light directed 10 yards
> ahead and one that provides a fairly uniform one for a wide angle.
> Cars do it by overkill, and even then some headlights are not easily
> visible from an angle.

Having not tried to design one, I can't really comment on how 'hard' it is.
However, I do know that my 1W LED front light has a bright central area
that is adequate for cycling at 20mph on unlit roads, and is also perfectly
visible from the sides. Someone once commented that they thought I was a
motorbike because of the headlight, even though the main part of the beam
was pointing entirely downwards at the road. Perhaps you are basing all of
your opinions on outdated LED technology and experience of typical
Cambridge cyclists (who seem to buy the cheapest Halfords LED lights they
can find, combine them with half-dead batteries, and then point them at the
sky).

Anthony

 

[sothach]

Nick Maclaren wrote:
> In article <[email protected]>,
> Anthony Jones <[email protected]> writes:
> |> Nick Maclaren wrote:
> |> > It is unclear whether disposable batteries are ecologically better or
> |> > worse than rechargable ones, EVEN exclude NiCads (which are really nasty).
> |>
> |> Do you have some evidence for that (I'm genuinely interested)?
>
> The evidence is that the lack of clear evidence to the contrary.
> There. Now you have it!
>
> Seriously. What metals are used in NiMH?

Rare-earth or nickel alloys with various metals ('metal' here seems to
used like 'meat' as in 'meat vindaloo'...), nickel oxyhydroxide,
potassium hydroxide - not stuff I'd want my drinking water to be
filtered through, and alkaline batteries, although not full of mercury
as once was the case, have: zinc, manganese dioxide and potassium
hydroxide, and are a useful source of dioxin when burnt.
'Skeptical environmentalists' are welcome to test the clarity of the
evidence by ingesting and breathing the results of indiscriminate
battery disposal.