Replacement Bulbs, LED conversions

Hi All

Happy New Year.

A while ago I tried a couple of LED replacement bulbs for the W5W bulbs in the third brake light. I wanted the instant light up of a LED as the theory is that this brings your brake light on a car length or so earlier at 70mph. None of the warm up time that filament bulbs take to light up. There are other advantages of low current draw and virtually no heat generated when bulbs are on. I was not happy at the very low light output of those first trial bulbs (only a single LED and much dimmer than the adjacent filament bulbs) so I did not install them permanently.
There now seems to be a second generation of high output multi LED bulbs on the market so I have ordered up a few to try in the dash/tail/sidelights.
Will let you know how I get on.

Regards

XMexc

The apparent low output of white LEDs behind a red lens seems to be down to the very low red content in the white LED output. You are advised to use red LEDs behind a red lens and white behind a white (e.g. Reversing light). It's all a new science to us motor people and we live and learn by our mistakes, and at our cost.

Hi XMexc

I find the multi LED lamps they use in a lot of the upmarket cars a trifle disconcerting, having had 50 years or so looking at tungsten lamps, this instant on/off action takes some getting used to, still, I got used to decimalisation! I like them in traffic lights though as they look very blue to me, as someone who is red/green blind, they are quite a safty feature!

There's no doubting that they are efficient, the light output for power consumed is excellent, and of course they dont get hot. LED headlights soon?

Peter.N.

Hi Peter and Techman

I first came across practical use of leds for lights nearly 10 years ago when we started to convert most railway shunting signals in this country to led. This enabled a single lens to show either red or white. So I will have to find out what lensing was used to show both red and white. I do not think leds will ever provide enough power for Headlights.
Techman thanks for mentioning the colour filtering effect. Looks like I need to get a few red/orange led bulbs and have a look in the junk pile for a few spare coloured lenses to try out the combinations.

Regards

XMexc

Hi all,

On the subject of LED lights thay strictly speaking don't use a lens as unlike tungsten lights only emit light at a particular frequency or a few discrete frequencies. The only way to get white light is by having multiple LEDs (red blue and yellow) in the same device and have them come on at the same time. Some (Cheap) white LEDs use a blue emitter and a phosphor which does the same thing as the phosphor in a flourescent tube. The output of these LEDs is very biased towards the blue end of the spectrum.

Regards and a Happy New Year to you all

John

Hi All

Just an update. While I was fitting HID's to the V6 I had the sidelights out to get at the headlamps so I tried the some white W5W LED bulbs that I had in the sidelights. These consisted of a single LED 10mm bulb, a triple LED and a Quad LED bulb. None of the gave enough light out put for me to leave in use. The large single LED was too dim and the others gave a too narrow beam in the forward direction only. I think that the 6 LED W5W's that are available have too large a head to fit into the XM sidelight.

As Techmanagain has said it is a new technology that can cost you to gain understanding of what works.

Regards

XMexc

Hi,

An interesting thread. Having looked around I found this US site:

http://www.superbrightleds.com/tail-brake-turn.html

The red 24-LED 15mm BC & 3 watt Luxeon 15mm BC look like good options for stop & stop/tail respectively (apart from the price).

However - there's a sting in the tail. I was in contact with the Dept for Transport today and when I was finished managed to have a word with their vehicle lighting expert (primarily to clarify the legality of after-market HID conversions). At the same time I asked about fitting LED bulbs as tail (they call them position) lights and stop lights.

Apparently it's legal to use LED's for both these functions but only if the lamp (i.e. the complete light unit - not just the bulb) is "E" marked - i.e approved. It's not legal to fit LED's into non-approved stop, tail or stop/tail light units.

Regulations are here for anyone who's interested (reg 7 for tail (position) and reg 6 for indicator:

http://www.unece.org/trans/main/wp29/wp29regs.html

As far as HID conversions are concerned it's also illegal to fit those (and to sell them for illegal fitting to vehicles) into a lamp unit designed for a filament bulb. This is because the beam pattern on the lamp is designed for a very specific position of filament and the HID arc will not be in the correct position (resulting in the potential for dazzle).

It won't necessarily stop them being used of course - but I thought I'd post the information here as it came from a definitive source and there's been quite a bit of discussion about it recently.

Roy