[audioholic]

Originally Posted by Naveen_0181

I felt it multiple times while driving in the US when waiting at the signal, it is not specific to one brand, when ever I stop behind a car with LED tail lamps I feel the LED's are too bright to look into and most of the cars here being AT the drivers foot is always on the break when stopped at a signal.

Does anyone else share a similar experience?

As long as it's the brake light that causes glare, it is intended since it does a better job of grabbing the attention of the cars behind when the driver applies the brakes. Moreover, compared to the rear pilot lamps which are also red, there should be considerable difference in brightness for the brake lights to be recognizable. Hence they are pretty bright. If it is just the pilot lights or parking light that causes the glare, then we have a problem.

[Naveen_0181]

Originally Posted by audioholic

As long as it's the brake light that causes glare, it is intended since it does a better job of grabbing the attention of the cars behind when the driver applies the brakes.

brake lights should be brighter than pilot lights, however I never bothered by glare when staring at good old brake lights(the ones with normal filament bulb) and even with old bulb lights one could easily differentiate between pilot lights and brake lights!

I remember reading in one of the posts recently which says some premium brands are now having different brightness for LED brake lights based on ambient lighting(day/night) hopefully that could address this issue!

[ImmortalZ]

Further progress.

The Civic housing has been taken apart and 3D scanned. The RLX LED elements have also been 3D scanned. Now, all the finagling, required trimming and design of the mounting frame can be done in software.



Some more work and there should be a design available for plug and play - as much as such an extensive and invasive retrofit can be - design available for a Civic headlamp.

[arunphilip]

Originally Posted by Sankar

That said, I would like to experiment with LED headlights as the lower power draw attracts me

So here's the part that puzzles me a bit:

1. In household lighting, I see LEDs as roughly 10x as efficient as incandescent lighting, and 2x as efficient as fluorescent lighting (tubelights & CFL), which means there is a noticeable drop in power consumed and heat emitted. The reason I make this point is just to set a scale of power drawn by different lighting technologies.
2. However, in the automotive side, I see that halogens are rated 55/60W and LED 35W, let's call halogens as 2x that of LED. Yet I see that LED headlights come with cooling fans, while the good old legal halogens make do without any such forced cooling. What gives? Is it just the density of diode packaging and placement that results in higher thermals?

[venkyhere]

Originally Posted by arunphilip

So here's the part that puzzles me a bit:

1. In household lighting, I see LEDs as roughly 10x as efficient as incandescent lighting, and 2x as efficient as fluorescent lighting (tubelights & CFL), which means there is a noticeable drop in power consumed and heat emitted. The reason I make this point is just to set a scale of power drawn by different lighting technologies.
2. However, in the automotive side, I see that halogens are rated 55/60W and LED 35W, let's call halogens as 2x that of LED. Yet I see that LED headlights come with cooling fans, while the good old legal halogens make do without any such forced cooling. What gives? Is it just the density of diode packaging and placement that results in higher thermals?

2.
There is a big difference between LEDs used for household and LEDs used for headlamps - the former is sitting in an extremely 'airy' constant ambient while the latter is sitting in an airtight, hot (engine radiation) ambient. Where am I going with this ?

Lets take a step back and examine what happens when current is passing through a resistor (halogen lamp) and a semiconductor with special implants (LED lamp) :

Heat is generated primarily because an army of electrons are punching through a narrow alley, jam packed with atoms of the material - this causes these atoms to sway violently about their positions, increasing their amplitude of vibration, which we call heat and the effect of which we call temperature. These oscillating atoms (packets of charges vibrating violently) generate electrical and magnetic fields that are also oscillating - and voila, we have EM waves. Imagine a team of cheetahs running through a huge field of thick tall grass - the grass which is already swaying in the wind will sway violently along the edges of the path the moving animals make, and this sway will be transferred outwards, radially.
For a resistor, most of the generated EM waves fall in the infrared spectrum (the heat which we 'feel at a distance' from the lamp) and a little bit fall in the visible light spectrum (that is used to light up the road ahead).

LEDs on the other hand are actually PN junction diodes made with carefully chosen semiconductor material, such that when the same effect occurs (described above) when electrons are made to flow through it, there is more of visible light and less of infrared, making LEDs less heaty and more lighty.

However, there is a crucial difference.

Resistors have a positive temp coefficient of resistance, ie forging a path is more difficult for the electrons when the material is having a higher temperature (cheetahs find it harder to run through, when the grass is already violently swaying from the wind). The 'resistance' increases with temperature. If the heat generated by a resistor (proportional to the square of the current passing through it) is not taken away quickly, then the temp of the resistor rises, and increases the resistance, which will reduce the current, which in turn, generates less heat. This is a self regulating equilibrium where once a stable temp is reached (generated heat = removed heat + heat required to maintain the same temp of the resistor) , a constant, steady state current is consumed.

On the other hand, PN junctions have a negative temp coefficient of resistance, ie the electrons find it easy to forge a path when the material is hotter (here the grass is such that as the wind gets stronger, the grass uproots readily, making it easy for the cheetahs). If the heat generated is not taken away quickly, then there will be more current, leading to more heat, leading to more current, more heat...... a thermal runaway - something which can cause exponential rise in the current, burn the LED lamp from the heat and cause a short (there is no grass to sway if it all gets burnt in a fire).
Many of the good quality LEDs for headlamps come with a 'driver' or 'adapter' circuit (a box which dangles behind, as part of the wiring kit) - this primarily contains a DC-DC power supply adapter and a constant current regulator, the constant current drive is to prevent thermal runaway.

Hence, even though LEDs generate lesser heat than halogens, the removal of generated heat is extremely crucial to the working and lifespan of the LED lamp. Thats why they have these complicated fin designs, fans etc ; and halogen lamps dont bother with this, since there is auto regulation (as long as the max heat generated is within the melting point of the filament material)

1.
The extra power consumption for LED headlamps vis-a-vis home LED lamps for similar lumens output, is attributed to the more 'lossy' DC-DC power adapter support circuitry in the headlamps , compared to the AC-DC power adapter for home LED lamps. This is my guess, not very sure about it.

[Irish]

Hi Experts,

I am planning for headlight upgrade in my Safari 2.2 Dicor (2012). Please advise the best suitable upgrade for the same.

1. LED - Philips H4 Ultinon
2. HID - Make / Model (Morimoto / Philips / Osram)?
3. Halogen?

Will there be much damage to the existing headlight reflectors in case of HIDs / LEDs?

I have been driving with stock lamps / night breakers for the last 6 years but now wanted to explore other options also.

Cheers!
Irish

[Arsi]

Hello all, I had installed Bi-xenon HID setup in my global Fiesta back in '12 but now the lights have now given way. I want a complete revamp. I am looking forward for the following:

1- New Bi-xenon and projector setup for the low beam
2- LED for the high beam

So while on low beam, only HID will be working and while on high beam, both HIDs and LEDs will be working. Kindly suggest which brands/lights shall I look for. And is installing an LED a plug and play job?

[Mr. Nobody]

Originally Posted by Arsi

Hello all, I had installed Bi-xenon HID setup in my global Fiesta back in '12 but now the lights have now given way. I want a complete revamp. I am looking forward for the following:

1- New Bi-xenon and projector setup for the low beam
2- LED for the high beam

So while on low beam, only HID will be working and while on high beam, both HIDs and LEDs will be working. Kindly suggest which brands/lights shall I look for. And is installing an LED a plug and play job?

I would suggest a Halogen only for High beams. Led bulbs are a hit or miss in most reflectors and no way to predict that if it will work well in your housing.
Leds are plug and play in the sense that you do not need any modifications in wiring for the same as they consume less power, however there are always size issues as they have large heatsinks at back that require sufficient room to fix them in the headlight housing.

If you have a budget of 25-30k plus you can get a branded Morimoto projector kit which will give amazing lighting. Else there are other more value for money brands like Hylux for Ballasts and Cnlight for bulbs. Projectors you can easily get are the Mini H1/D2S or the Bigger G5 projectors.

There are LED projectors too like the Optima or iLens ones which should cost under 15k and work nearly as good as hid projectors. With a halogen High beam combo i would suggest a LED projector setup.

[Arsi]

Originally Posted by Mr. Nobody

I would suggest a Halogen only for High beams. Led bulbs are a hit or miss in most reflectors and no way to predict that if it will work well in your housing.
Leds are plug and play in the sense that you do not need any modifications in wiring for the same as they consume less power, however there are always size issues as they have large heatsinks at back that require sufficient room to fix them in the headlight housing.

If you have a budget of 25-30k plus you can get a branded Morimoto projector kit which will give amazing lighting. Else there are other more value for money brands like Hylux for Ballasts and Cnlight for bulbs. Projectors you can easily get are the Mini H1/D2S or the Bigger G5 projectors.

There are LED projectors too like the Optima or iLens ones which should cost under 15k and work nearly as good as hid projectors. With a halogen High beam combo i would suggest a LED projector setup.

If I use halogen for high beam, which brand/model of halogens is the best as of now? Osram or Philips? And what about Bi-LED projector setup for low beam? What brands are available in India?

[Mr. Nobody]

Originally Posted by Arsi

If I use halogen for high beam, which brand/model of halogens is the best as of now? Osram or Philips? And what about Bi-LED projector setup for low beam? What brands are available in India?

Philips Xtreme vision + has good reviews here on the forum, halogen bubs have pretty much reached a point of saturation point so theres hardly any difference actually. Bi-Led depends on your budget. You get Morimoto and many other brands in stock and one can anyway import any brand these days. Member drhoneycake has posted output shots from his Bi-Led setup, do check them out. I am also ordering Bi-Led soon.

[Arsi]

Originally Posted by Mr. Nobody

Philips Xtreme vision + has good reviews here on the forum, halogen bubs have pretty much reached a point of saturation point so theres hardly any difference actually. Bi-Led depends on your budget. You get Morimoto and many other brands in stock and one can anyway import any brand these days. Member drhoneycake has posted output shots from his Bi-Led setup, do check them out. I am also ordering Bi-Led soon.

Can you please help me with the link to the thread.

[a4anurag]

Originally Posted by Arsi

Can you please help me with the link to the thread.

Here you go: Bi-Beam LED projector output

[tsk1979]

Originally Posted by abhi7013

Going by this, fog lamps should ideally be yellow-ish to cut through the fog. But aesthetics seem to have taken over with people going for projectors even for the fog lamps!.

How will that help? Why would yellow cut through fog.

that said, I have LEDs in both high and low beam.
I recently switched brand of LEDs in high beam, and now its much better. Position of emitter and projector design influences beam quality quite a bit.
Same for HIDs. Its an arc source, so whether the projector is designed for it or not has quite an effect.

[abhi7013]

Originally Posted by tsk1979

How will that help? Why would yellow cut through fog.

There have been multiple discussions on the question raised in the quoted text above. Anyways to answer it: blue or even white light suck big time when it comes to visibility ln wet roads or in rains. Regular halogens may do well in such cases.
Pure yellow fog lamps help not in illumination but in penetrating fog and letting others know your position. Reason: wavelength.

[tsk1979]

Originally Posted by abhi7013

Pure yellow fog lamps help not in illumination but in penetrating fog and letting others know your position. Reason: wavelength.

?? Very strange! i have looked for the blue fog, but cannot find it
Don't you think if yellow and red penetrated more, fog color would be blue just like the sky which is blue due to Rayleigh scattering