Omega Owners Forum
Omega Help Area => Omega Electrical and Audio Help => Topic started by: Dave DND on 18 July 2011, 09:24:00
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Not strictly an Omega question, but I`m having a play with LED`s and rear lights on my Beach Buggy at the moment, and this may even have some relevance.
Ok, tin of worms time I know, but just wondering what the official / unofficial line is from the MOT guys amongst you regarding LED rear lights -
I know the rules / regs regarding placement of lights and correct wattage bulbs of 21W flasher and 21W/5W for stop and tail, but many of the modern cars nowadays have LED rear lights instead that do not actually conform to these wattages. Although LED lights look bright, due to their efficiancy they run way under the power figures qouted for recommended wattages and I have never seen an MOT station measure the brightness output, so I just wondered if there were any guidelines as to what you would recommend for someone like me who is looking to build / convert a new rear set.
Does the number of led`s make a difference ? I know that there needs to be a brightness variation between tail ones and brake ones, or does it go on a percentage of bulbs showing between stop and tail ?
Roughly speaking, my plan is to go for around 30 medium intensity leds for tail with an additional 100 high intensity leds for brake, 50 high intensity for indicators, and 30 high intensity for reverse, (each side) within the original lenses.
Before you ask why not use the off the shelf LED conversion bulbs, well, its a fair question, but if you have ever tried some of those bulbs behind Classic Car lenses, you would have answered your own question.
They are pityfull - and in my mind bloody dangerous as they are often so dim.
The replacement stop / tail bulbs generally have a maximum of 24 or 36 leds, 30% of which don`t even point outwards, and the variation between tail and brake is not that good. On tail, there are usually only 9 bulbs running at 75% intensity, and when used behind a smoked lens can hardly be seen at all. From research I have done so far, Motorcycle plastics and modern plastics of lights lens`s seem to be a little thinner and allow light to pass through much more readily, wheras some of the older classic car lens are so thick, that even a filament bulb can often appear dim.
I tried fitting an LED replacement on one side and a 10 Watt bulb on the other and there was no difference - (I have tried both red and white LED bulbs for comparison) and surprisingly, the red bulb gave a slightly better light behind a red lens than the white one, but still wasn`t great.
If I am going to brake, then beleive me, people will see my brake lights !!
But it was this variation that got me wondering as to how they were "perceived" by the guys who make the decisions on the front line, ie: MOT testers. There must be a point where they think that it either isn`t bright enough, or the variation of intensity between tail and brake is insufficient?
So how would this be challenged or proven ? Or is it such an obscure problem that there is no real definative answer, and simply, "common sense rules"?
Any thoughts ?
:-?
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http://www.motuk.co.uk/manual/contents.htm
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Without reading the MOT handbook, I guess the MOTers current just care if they work. Apparently next year, the rules are stricter on many aspects.
What I have no idea about is what angle from the side do you need to see the lights, if any.
I suspect, like HIDs, there are no real laws, just a grey area because the EU allow them, the UK has to, without making proper, clear guidelines...
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Good question. :y
How are you planning on fitting your leds behind the lenses? :-/
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I have a feeling the SVA/IVA manual (failing that the core construction and use specs) would be the place to look for the definitive information. From memory SVA/IVA certainly specifies the filament lamps of 21w or 5w but adds a get-out that they can be other types of "equivalent brightness".
At MOT, the tester will probably only consider if the lights are working and, subjectively, if the brightness is adequate. Having an MOT doesn't mean you are compliant with the C&U regs, though. ;)
FWIW, a group of kit car owners to which I belong have made up a PCB with LED stop and tail lights which fits into a standard Caterham style light cluster. I will post some pictures if you're interested. IIRC, they had 30-40 red high intensity LEDs each, and a subset of these came on as tail lights, the whole lot with the brakes.
These have been in use on a dozen or so cars for a couple of years with no MOT issues that I'm aware of.
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Good question. :y
How are you planning on fitting your leds behind the lenses? :-/
I have cut a sheet of acrylic to the same shape of the whole of the rear lens and the LEDS will mount to this. The sheet will then sit abot 2cm from the inside edge of the lens, so that the LEDS are very close to the plastic. This also enable me to retain the original bulb mounts so that I can revert back to filaments within minutes as the connections are made using old modified bulbs and simply plugged into the respective positions.
I`ll get some pictures up once I am happy with it.
;)
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I have a feeling the SVA/IVA manual (failing that the core construction and use specs) would be the place to look for the definitive information. From memory SVA/IVA certainly specifies the filament lamps of 21w or 5w but adds a get-out that they can be other types of "equivalent brightness".
At MOT, the tester will probably only consider if the lights are working and, subjectively, if the brightness is adequate. Having an MOT doesn't mean you are compliant with the C&U regs, though. ;)
FWIW, a group of kit car owners to which I belong have made up a PCB with LED stop and tail lights which fits into a standard Caterham style light cluster. I will post some pictures if you're interested. IIRC, they had 30-40 red high intensity LEDs each, and a subset of these came on as tail lights, the whole lot with the brakes.
These have been in use on a dozen or so cars for a couple of years with no MOT issues that I'm aware of.
Thats the bit I`m thinking of - and to my knowledge, the testing centres do not have, nor use any light intensity measuring equipment - so is it really down to what the tester had for breakfast ?
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Should have added, the SVA/IVA manuals also specify viewing angles and position of all lights. :y
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http://www.motuk.co.uk/manual/contents.htm
Nothing is stated here about intensity of lights, nor how to measure brightness
:-?
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Should have added, the SVA/IVA manuals also specify viewing angles and position of all lights. :y
Placement of lights, (although a valid point) is not really an issue here, and as far as I can tell, the only guidelines are regarding the percentage of bulbs that must work before a unit is deemed to have failed and requires replacement.
Still not found anything relavent with regards to illumination intensity and LEDs
:-/
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FWIW, a group of kit car owners to which I belong have made up a PCB with LED stop and tail lights which fits into a standard Caterham style light cluster. I will post some pictures if you're interested. IIRC, they had 30-40 red high intensity LEDs each, and a subset of these came on as tail lights, the whole lot with the brakes.
Interesting, I was planning on doing the same thing for Lucas housings when I get to that point with the kit car (though I still need to order a chassis & body, first ;D)
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At MOT, the tester will probably only consider if the lights are working and, subjectively, if the brightness is adequate. Having an MOT doesn't mean you are compliant with the C&U regs, though.
True, but if challenged by the Feds, its usually an MOT centre that they will direct you to for a check. I suspect it would take considerably more before VOSA got involved for a tail light
:-/
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http://www.motuk.co.uk/manual/contents.htm
Nothing is stated here about intensity of lights, nor how to measure brightness
:-?
I suppose the "inoperative, excessively damaged, deteriorated or obscured so that they are not visible from a reasonable distance" clause would cover if the light was considered to be dangerously dim by the tester, but they certainly wouldn't measure it.
IVA manual states that "All lamps must emit light of an equivalent brightness and colour when compared to an "e" approved lamp of the same type". Since that's how a kit car gets onto the road, I take it to mean that it doesn't have to be incandescent or a recognised type of fitting but the inspector could compare it with an e marked fitting (and probably would, the pedantic b'stards ;)) and decide if it was too bright, too dim or equivalent.
True, but if challenged by the Feds, its usually an MOT centre that they will direct you to for a check. I suspect it would take considerably more before VOSA got involved for a tail light
Indeed. However, I'm always conscious that, whilst you can get away with all sorts of things, especially with a kit car, if a really serious incident happened, you could find yourself before the beak justifying your actions before an expert witness. :-/ OK, unlikely in the case of a light cluster, I agree.
Interesting, I was planning on doing the same thing for Lucas housings when I get to that point with the kit car (though I still need to order a chassis & body, first Grin)
I'll take some pictures of one when I get a chance. :y
Kevin
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Indeed. However, I'm always conscious that, whilst you can get away with all sorts of things, especially with a kit car, if a really serious incident happened, you could find yourself before the beak justifying your actions before an expert witness. :-/ OK, unlikely in the case of a light cluster, I agree.
All it would take is a "I couldn't see his brake lights, Officer", I suppose :(
Still, as you say, probably unlikely.
I'll take some pictures of one when I get a chance. :y
Cheers Kevin :) LED lights, digital dash.. the folks on the Cobra Club will be apoplectic at my creation ;D ;D
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All it would take is a "I couldn't see his brake lights, Officer", I suppose
Somebody on another forum posted an interesting observation.
If you are unlucky enough to have suffered a rear end accident (Oo-er missus) the police can often determine if you were braking at the time by looking at any burnt out bulb filaments that have been subject to the atmosphere when the glass breaks -
Not something you could determine with LED`s
Food for thought I suppose ?
:-/
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As a more tech tip, when putting together LED clusters for such use, ensure you have a series rectifier diode with a good reverse voltage figure (e.g.a 1N4004 or better) as LED's dont like reverse voltage (and as we know, car power supplies are 'orrible' with lots of transients). :y
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All it would take is a "I couldn't see his brake lights, Officer", I suppose
Somebody on another forum posted an interesting observation.
If you are unlucky enough to have suffered a rear end accident (Oo-er missus) the police can often determine if you were braking at the time by looking at any burnt out bulb filaments that have been subject to the atmosphere when the glass breaks -
Not something you could determine with LED`s
Food for thought I suppose ?
:-/
An interesting point, that, Dave! Although it won't help with kit cars, I imagine with the very latest cars they can just plug into the onboard computer and ask it if the brakes were on at the time of impact..
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As a more tech tip, when putting together LED clusters for such use, ensure you have a series rectifier diode with a good reverse voltage figure (e.g.a 1N4004 or better) as LED's dont like reverse voltage (and as we know, car power supplies are 'orrible' with lots of transients). :y
Good tip !! Must admit, I hadn`t considered that !
:-[
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Hi Dave. From a mot point of view as long as they function as they're supposed to and they don't interfere with each other then its a pass. We don't measure brightness or angle so that's not an issue.
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Hi Dave. From a mot point of view as long as they function as they're supposed to and they don't interfere with each other then its a pass. We don't measure brightness or angle so that's not an issue.
Do I take it that you are an MOT tester ?
If so, imagine this scenario -
You are testing a tail light that is incredibly dim and dark to the point that your eyebrows are raised and you think about failing it as it could be dangerous - I am not questioning your decision, nor powers to do this, if you think this is a safety fail, then rightly so -
However, if the owner of the car disagrees and says, "Oh no it isn`t" - where do you go from there ?
what guidelines / information / powers that be, have the final definative say on this, as I`m really struggling to satisfy my curiosity on this now.
:-?
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Hi Dave. From a mot point of view as long as they function as they're supposed to and they don't interfere with each other then its a pass. We don't measure brightness or angle so that's not an issue.
Do I take it that you are an MOT tester ?
If so, imagine this scenario -
You are testing a tail light that is incredibly dim and dark to the point that your eyebrows are raised and you think about failing it as it could be dangerous - I am not questioning your decision, nor powers to do this, if you think this is a safety fail, then rightly so -
However, if the owner of the car disagrees and says, "Oh no it isn`t" - where do you go from there ?
what guidelines / information / powers that be, have the final definative say on this, as I`m really struggling to satisfy my curiosity on this now.
:-?
Yes I am a tester. At the end of the day it is down to the tester but if it was that dim you were struggling to see it then its a fail (it must be visible from a reasonable distance ). If in any doubt then then we should pass and advise. I tend to go about 20 meters away and see if I can see them.
As a tester we have to follow the manual http://www.transportoffice.gov.uk/crt/doitonline/bl/mottestingmanualsandguides/mottestingmanualsandguides.htm .
As for who makes the final decision that would be the tester if the owner disagrees then they can put in an appeal to vosa and see the outcome(either win or lose if they win the appeal the tester gets sent for retraining and or a bollicking. If they lose then they're £50 odd down and still have to fix it
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lee4206 ,
Thank you for confirming my suspicions - That was exactly the reply I was hoping for from an MOT tester, and its refreshing to know that you guys have an element of discretion -
I have read the MOT "Bible" and couldn`t find anything in there either, and as yet, I do not feel that VOSA have any definative rules and regulations regarding this.
So as long as common sense is used when converting the lights, and the MOT tester is happy, then all should be well (for the time being anyway)
:y
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Having an MOT doesn't mean you are compliant with the C&U regs, though. ;)
Spot on :y
The number plate on my bike is not even close to road legal due to it's size, but it passes every year as the tester claims to have "above average eyesight" and says he can read it from the required distance ;)
@ Dave,
Why not just go for the LED lamps that are "standard" replacements for the filament jobbies?
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@ Dave,
Why not just go for the LED lamps that are "standard" replacements for the filament jobbies?
I think Dave covered that in the opening post ;)
Before you ask why not use the off the shelf LED conversion bulbs, well, its a fair question, but if you have ever tried some of those bulbs behind Classic Car lenses, you would have answered your own question.
They are pityfull - and in my mind bloody dangerous as they are often so dim.
The replacement stop / tail bulbs generally have a maximum of 24 or 36 leds, 30% of which don`t even point outwards, and the variation between tail and brake is not that good. On tail, there are usually only 9 bulbs running at 75% intensity, and when used behind a smoked lens can hardly be seen at all. From research I have done so far, Motorcycle plastics and modern plastics of lights lens`s seem to be a little thinner and allow light to pass through much more readily, wheras some of the older classic car lens are so thick, that even a filament bulb can often appear dim.
I tried fitting an LED replacement on one side and a 10 Watt bulb on the other and there was no difference - (I have tried both red and white LED bulbs for comparison) and surprisingly, the red bulb gave a slightly better light behind a red lens than the white one, but still wasn`t great.
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I think Dave covered that in the opening post ;)
Doh!
Speed reading and chemo/radio just don't go together ;D
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:-X :P
I keep getting into trouble by speed reading as well
:-X :P
:y
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the only guidelines are regarding the percentage of bulbs that must work before a unit is deemed to have failed and requires replacement.
I wrote that bit - under a contract placed by the MoD DfT representative. To quote "At least 50% of the individual LEDs in the cluster must remain working"
Yes, it's almost exactly like the HiD scenario.....
In the UK, there's the lighting Regs, which as you say don't have a requirement for either wattage or intensity. ( Schedule 10, items 8 & 9 ) These are all you need as the owner of the vehicle to be allowed on the road - they do also include viewing angles.
Going one step further, as the manufacturer of the vehicle or the first registerer of the vehicle you must meet either type approval or IVA/SVA, which would require you to have an approved lamp. BUT you're not in that position, 'cos your just an owner making a change to his vehicle.
You're right - the lighting regs haven't caught up with LEDs yet.
I am sure of one thing though - if you ask VOSA, they'll tell you that the lamps must be "approved", just like they've erroneously done in the HiD case.
call me if you need any other advice
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the only guidelines are regarding the percentage of bulbs that must work before a unit is deemed to have failed and requires replacement.
I wrote that bit - under a contract placed by the MoD DfT representative. To quote "At least 50% of the individual LEDs in the cluster must remain working"
Yes, it's almost exactly like the HiD scenario.....
In the UK, there's the lighting Regs, which as you say don't have a requirement for either wattage or intensity. ( Schedule 10, items 8 & 9 ) These are all you need as the owner of the vehicle to be allowed on the road - they do also include viewing angles.
Going one step further, as the manufacturer of the vehicle or the first registerer of the vehicle you must meet either type approval or IVA/SVA, which would require you to have an approved lamp. BUT you're not in that position, 'cos your just an owner making a change to his vehicle.
You're right - the lighting regs haven't caught up with LEDs yet.
I am sure of one thing though - if you ask VOSA, they'll tell you that the lamps must be "approved", just like they've erroneously done in the HiD case.
call me if you need any other advice
Brilliant ! (No pun intended!) ;D
Thanks for the extra clarification.
:y
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nee bother :y
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A lot of manufactures are using leds for rear lights well side and brake anyway due to the points raised here leds are brighter and cost less and last longer and you can have better styled lights also a few years back a company called ultra brought out led rear lights for the chavs favorite the saxo and I think its audi who have bright white running lights just my ideas on the subject leds are the best though imo
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All it would take is a "I couldn't see his brake lights, Officer", I suppose
Somebody on another forum posted an interesting observation.
If you are unlucky enough to have suffered a rear end accident (Oo-er missus) the police can often determine if you were braking at the time by looking at any burnt out bulb filaments that have been subject to the atmosphere when the glass breaks -
Not something you could determine with LED`s
Food for thought I suppose ?
:-/
I would've thought there would have to be serious death for them to go that far, 90% of claims are probably solved by the most convincing insurance bullsh*t form.
I would imagine as noticed elsewhere that if the regs are modded, then LED's would be quite a large consideration after the LED cat's eyes vs. epileptic argument.
As many will know, passing an LED cat's eye can appear as a "strobing" effect due (i believe) to their directionality. An epileptic passing those, or anyone passing an idiot with some k4's in his lights can be rather dangerous.
Is a shame because the LED eyes are very effective on an unlit road. I don't for a second mean we should ignore those with epilepsy, but if a way could be found round it then so much the better- as with tail lights
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Don`t start me on epilepsy and lights . . . .
Have you seen what some idiot has deemed acceptable and has now introduced in the form of "Flashing" rear brake lights? The have started to appear on new cars in Europe (Only seen it myself on a Merc) and basically when the brake lights come on, they flash very fast instead of the "in yer face" red tail light that we have come to understand as STOP.
>:(
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Strobing of LED lights is down to how they are driven, most likely. I think the cat's eyes PWM the LED to achieve the correct drive current in the face of a variable battery voltage. Same as many cars strobe the rear LED lights to dim them for tail light use, then light them up full-on for brake lights.
Why they don't use a decent switching frequency beats me (probably to keep the drive electronics cheap) because I find the strobing of some LED tail lights very distracting (VW/Audi/Merc seem to be the worst).
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Strobing of LED lights is down to how they are driven, most likely. I think the cat's eyes PWM the LED to achieve the correct drive current in the face of a variable battery voltage. Same as many cars strobe the rear LED lights to dim them for tail light use, then light them up full-on for brake lights.
Why they don't use a decent switching frequency beats me (probably to keep the drive electronics cheap) because I find the strobing of some LED tail lights very distracting (VW/Audi/Merc seem to be the worst).
The worst is a Peugeot skip with slash styled lights.
I would class them as - dangerous
I would class the Audi and Merc gaytime running lights the same - dangerous
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Why do I have the feeling that you lot are going to dissapprove of what I am doing to my Beach Buggy ?
:P
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Don`t start me on epilepsy and lights . . . .
Have you seen what some idiot has deemed acceptable and has now introduced in the form of "Flashing" rear brake lights? The have started to appear on new cars in Europe (Only seen it myself on a Merc) and basically when the brake lights come on, they flash very fast instead of the "in yer face" red tail light that we have come to understand as STOP.
>:(
As a time-served lampy, believe me I'm with you!
At least one of the makes (can't remember which) has a system whereby they only strobe if you've not used the brakes in 10 seconds or so, and if they're on for more than about 3 seconds- theory being hard braking on a motorway- the ex-doris had similar with the hazzards on a new ford fester.
I can kinda see the point if it's done properly, but now there's kits on fleabay for that, 'cept they seem to do it every time, and obviously for chavs with stripes
Why do I have the feeling that you lot are going to dissapprove of what I am doing to my Beach Buggy ?
:P
If you use it on a beach, you'll not offend anyone ::)
Pics to follow I assume?