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LED lights - Good or bad?
Posted: 17 Jul 2008, 13:43
by HarryMann
To avoid polluting CovKid's nice article on rear number plate LED conversion, thought I'd dump any safety or ergonomic comments here...
*
The second problem is with regard to the safety of such devices and the potential long term effects of using LED products. It is now widely accepted that traditional 10,000 Lux bright white light is safe. However questions have been raised about blue light safety and the use of white and blue LEDs, both of which emit light with peaks in the blue end of spectrum (470nM)
Light-induced photochemical damage to the eyes is particularly related to light at the blue wavelength. This type of damage to the retina is known as "blue-light hazard". Older people are particularly susceptible to such light induced retinal damage.
Some manufacturers of LED products state* that their devices have been approved by leading medical physicists, and that they have been certified as not exceeding the threshold levels for damage from blue light exposure set by international safety guidelines. The difficulty with this assertion however, is that individual susceptibility to blue light damage is so variable that these standards may not be able to presume to eliminate the risk to every individual, of acute damage from a blue light or LED device. In addition, the percentage of blue light entering the eye that reaches the retina may be highly variable from one individual to another. For these reasons, it may be difficult to calibrate a level of blue light that is both effective and safe for a wide range of individuals.
* state/declare - but don't give genuine references or evidence of...
Posted: 17 Jul 2008, 13:45
by HarryMann
Titus A Duxuss says:
Light-induced photochemical damage to the eyes is particularly related to light at the blue wavelength. This type of damage to the retina is known as "blue-light hazard".
- This is quite shocking when you consider that nearly everything comes with Blue LEDs to make it look cool (even my new TV has one on the front).
HarryMann says:
There used to be very strict guidelines about what could be used as a headlight and a rear lights on automobiles, but the situation now is that manufacturers are leading and coercing govt bodies and regulatory authorities and experts to their own way of thinking, ~ a bit like the pharmaceutical companies go about their campaigns for new drugs!
Posted: 17 Jul 2008, 14:11
by Titus A Duxass
I think the rear bicycle lamps/lights are neat, the batteries last for ages (greener) and you can get them to pulse (not legal but effective).
I also so have a LED front lamp/light, still undecided about it.
It has the capability of strobing which is a great attention getter.
But as for lighting your way it's pants.
Replacing the external signal/warning/lights on an old vehicle is questionable.
Sure it's cool and probably will work out to be greener in the long run,
but it would take a bit of analysis to work out the break even point.
Posted: 17 Jul 2008, 14:41
by High Peaker
To put energy consumption into perspective:
A 1.9 engine develops 78hp, which is 57kW. That's 57,000W.
A tail lamp consumes 5W, which is one 11400th of your engine's output!
LEDs only realy have an energy consumption argument for internal lighting in campers, or parking lights.
An LED high level brake lamp is always a good idea - their illumination time is visibly quicker than an incandescent bulb so improves reaction times. Everything else is just "coolness", which is entirely a matter of personal taste.
Personally, I think the whole point of an old vehicle is to look old!
Parafin lamps anyone?
Posted: 17 Jul 2008, 15:04
by Titus A Duxass
Parafin! - bit too modern mate, Calcium Carbide for me.
Posted: 17 Jul 2008, 16:29
by Snakes Alive
Titus,
Flashing LEDs
used to be illegal, but this changed about 3 years ago, provided the lights met the requirements.
I know this isn't a bike forum or thread but I didn't start going on about bikes, just helping to keep the info accurate!
Info here:
http://www.aukweb.net/lights/legal.htm
Posted: 17 Jul 2008, 16:52
by CovKid
I'm totally against all those blue running lights that seem prevalent and I agree, some common sense is needed in terms of brightness of LEDs used but they are more reliable than bulbs and definately come on quicker. A recent report suggests that LED brake lights can mean a diffenence of 19 ft in terms of stopping space for a vehicle behind so there are definately adavantages.
If i bought everything off the shelf it would work out ridiculously expensive but I'm making my own as far as possible. There are also so many areas in which LEDs can be used very economically without running your battery down, particularly if you use them in conjunction with solar panels. Certainly for most homes, unless you need a strong light at night, LEDS can save a fortune on your annual electricity bills. Take a look at:
http://dmcleish.com/MauiHome/
Posted: 17 Jul 2008, 22:31
by AngeloEvs
Supabright LED'd have a very narrow beam angle and if placed behind the light lens will diffuse the light, and given all the advantages over filament bulbs, are most definitley worth upgrading to. You cannot use them in place of the indicator bulbs unless you ditch the flasher unit and fit a an electronic pulsing circuit. As for cyclists using them, damned sensible in terms of their safety and no where near as annoying as drivers who don't dip their headlights and fit 100W+ halogen bulbs.
Posted: 18 Jul 2008, 05:30
by Titus A Duxass
Flashing LEDs used to be illegal, but this changed about 3 years ago,..
- Typical, I leave the country for 10 years and everything changes.
Posted: 18 Jul 2008, 06:57
by VWlewis
AngeloEvs wrote:... You cannot use them in place of the indicator bulbs unless you ditch the flasher unit and fit a an electronic pulsing circuit.
Actually you can buy a replacement electronic relay that is a direct exchange for the original flasher unit. It sorts out the problem of quick flashing when LED bulbs are fitted... about £12 from eBAY and an easy job.... Trust me I have done it and they are zoooper!
The SMD LEDs are the best - high light output as you can see below!
[img:640:480]
http://www.wardenjp.com/7443_30led3.jpg[/img]
You need to fit LED bulbs all round at the same time as changing the relay - what about when an LED bulb stops working - you can temporarily run with one normal bulb which I carry as a spare.
Posted: 18 Jul 2008, 10:59
by HarryMann
It has the capability of strobing which is a great attention getter.
But as for lighting your way it's pants.
The ones I meant are about £100? (I was told) and definitely don't fit that description - they are more like landing lights for a Boeing 747 and having had three come towards me the other day in the middle of the road (didn't have a clue there were 3, just a searchlight in my eyes from 100 yards) - my first instinct was to floor the accelerator so whatever it was would reveal itself as friend or foe
(as I didn't know what, where and how many there were, assumed they were evil aliens landing from another planet).
These things scatter light everywhere, so wouldn't call them directional, but imagine cyclists who can afford them just love the effect - until they get mowed down under a car or truck whose driver is totally blinded by them - a lot of new car headlights should also be banned - they break all sensible standards and conventions (sod the law that
seems to allow them, lets use common senese) when anything but on a flat road and dipped, and as we know, the country is filled with bad roads and humps, making their sharp beam cutoff totally meaningless... my view is they are dangerous and total overkill on anything other than empty fast and smooth A roads. 'Nice to drive behind' someone said. I say bwuddy selfish or a poor driver to think you need them....
... very much in the same ridiculous way that OTT vehicle sounds systems impinge on MY auditory space. ONE person's selfish sounds affecting hundreds of others people - if that isn't selfish, tell me what is? They also don't exactly enhance road saftey in a +ve way, always thought a driver should be focused on driving, and sounds around them are a key part of that.
So... I reserve the right to be equally selfish and stick a sharp pointy steel straight through the side of their car to disable their 'woofer', if their reverberations interfere with my eardrums.
Er! No,
not making apology for rant, as well reasoned and unobjectionable, so if you are going to counter, then please do likewise

Posted: 18 Jul 2008, 11:47
by Titus A Duxass
I'm 100% with you on the noise business, pity we can find some electronic magnetic drive by way of disabling the systems.
I never come across the lights that you describe, I paid 5 euro for mine (front and back) so I think they are not the same.
You are also correct about the new car lights, bloody bright but also a very harsh light.
(Beginning to sound (read) like the grumpy old barsteward that my wife says I am).
I feel a signature change is in order.
Posted: 18 Jul 2008, 12:25
by HarryMann
pity we can find some electronic magnetic drive by way of disabling the systems.
Let's start a research project on that one
Ah yes, Grumpy Midget's been taken (by a 6 foot sixer)
Maybe Grumpy Giant then for me...
Grumpy Old Man? Who cares, let's grump away

Posted: 18 Jul 2008, 12:36
by Titus A Duxass
A quick google of electromagnetic pulse generator resulted in some very interesting reading, for example
"..just a huge capacitor bank charged up to lots of volts, then discharge it through a huge coil of a couple turns of huge wire. If you're lucky, the electricity will resonate through the coil and cause enough EM interference to fry sensitive components"
There are also some good link for extra reading.
Big capacitors, etc. I can often find in our electronic scrap area at work.
Bike LEDS
Posted: 18 Jul 2008, 12:37
by silverstripe
Yes I know that it's not a bike forum, but have any of you grumpies ever ridden a push-bike on an un-lit road? LED headlights do scatter light about a bit (maybe just need better lenses?) but at least you can see more than 6 feet in front of you. They also don't fade from white thru yellow to brown every half an hour.
Personally I'd rather avoid dry stone walls, potholes etc.....
No more from me on the bike subject.
