Monday, March 12, 2018

Everything you need to know about car's headlamp.

Audible 
https://amzn.to/2YzVNqM
Lights have come a long way since the original tungsten filament light was introduced and subsequently replaced by the Halogen lightbulb in the early 60’s. It remained the standard with little in the way of innovation until the early 90s when the HID headlamp was unveiled by BMW and then 13 years later the LED Headlight by Audi.
These days the most common head lamp to be found on cars is still the halogen headlight, but this is eventually going to become antiquated in favour of newer technologies such as HID, LED and as futuristic as it sounds LASER.
Before we get into the details of each of the above there are a few things to become acquainted with if you intend on buying a replacement or upgrading your existing headlights.
Alignment: A lot of people may be unaware of this but your headlights are actually aimed specifically to suit countries that drive on the right side or the left side. Headlights for use in left lane traffic countries have low-beam headlamps that dip to the left, the light is distributed with a downward/lefthand bias to show the driver the road and signs ahead without blinding oncoming traffic and vice versa for countries that drive on the right side with most of their light directed downward/righthand. So you could not buy a Headlight in Ireland if you intend to drive in France unless you plan on having the car lights properly calibrated for the change in the road. However, some cars have headlights that can adjust themselves with the flick of a button that will set it to either RHD or LHD.
Auto Levelling/Load adjustment: Used very effectively in trucks load adjustment means that the headlights will adjust themselves and dip the beam downwards to not blind other road users if the car becomes higher or lower depending on the weight fluctuation or when the car accelerates or decelerates.
Lumens: This is the standard measurement of light output.
Reflector and Projector Headlights:
reflector headlamp is just what it sounds like, the actual light comes from a bulb in the center of the headlamp housing and reflects off of the sides of the housing. This allows the light being emitted from the small bulb to be spread out on the road in front of the vehicle.

Projector headlights also do exactly what they sound like-they project the light rather than reflecting it. This type of housing calls for a different type of light bulb to accommodate the housing. Projector headlights allow for more control of the light beams as they are emitted from the housing. One should not confuse projector headlights with HID headlights. While all HID’s come in a type of projector housing, not all projector headlight housings use HID bulbs which is why you will see projector headlights come with H1/7/15 bulbs etc.
Halogen Headlights
 Halogen: Halogen lights contain a gas, usually a combination of nitrogen and argon, and a tungsten filament, that are encased in a glass tube. The glass is made to resist extremely high temperatures. When the light bulb receives the electrical current from the car, this heats the tungsten filament creating light. The most common headlight bulb you will find in the automotive world, it is estimated to be installed in as much as 80% of all cars. Since the 60’s it has become the standard due to the cheapness and the ease of replacement mixed with a relative good lifecycle. They also turn on extremely quick in comparison to a Xenon bulb



However, there are reasons why newer technologies are being developed to replace this type of Light.
  • It is inefficient and dim in comparisons to other available light options. A standard Halogen bulb will produce 1300 Lumen. While this is good there are far better options if the better light is what you seek.
  • Another downside is that they are extremely sensitive to substances, using your bare hands will leave an oily residue on the glass which will alter the heat distribution and lower the lifespan emphatically.
  • Energy wise it is inefficient as it creates a lot of heat which is then wasted.
  • There is also the problem with light not being focused so any illumination of the road isn’t what it could be.
HID (High intensity Discharge):
 HID: Sometimes referred to as Xenon made their debut in the early 90s by BMW for the BMW 7 series and since then it has gradually been adopted by increasing numbers of manufacturers for various Premium and non-premium level cars.
High intensity discharge headlights contain a mixture of gases and rare metals that are heated to generate a bright white (or blue) glow which legislators have stipulated all new cars must illuminate. Not only do they produce white light this white light has a blue hue to it which adds to the aesthetic beauty of your car.
HID’s are roughly two to three times brighter than the standard halogen bulbs about 3000 Lumen compared to 1400 produced from Halogen bulbs and as a result, has led to complaints about the level of glare these lamps produce.
This increases vision which increases reaction time to unforeseen obstacles making driving safer at night.
HID lamps actually require more power to start up but once they are on they operate at a much lower power usage than Halogen. Drawing only about 35 watts of power, they generally are good for about 2000 hours of life. This makes HID lights more efficient than halogen.
This also means there will be less taxing demands on the alternator which won’t require more engine torque to sustain the electricity demand. However, any fuel efficiency gains will be minimum at best but if your environmentally aware it does mean slightly fewer emissions.
Like most things it is not all plain sailing for Xenon lights or everybody would install them.
  • Firstly, the cost alone is most of the reason these haven’t completely taken over as the industry standard. They are not cheap to replace due to the rare metals they use.
  • They are also notorious for being a failing component of car inspection tests(NCT) if someone manages to jerry rig these bulbs into a halogen bulb housing.
  • The uncontrolled brightness will cause huge amounts of glare compromising road safety. These Xenon bulbs require a projector style headlamp to house them.
  • They require a short period of time to attain full brightness.
  • Some countries require a Xenon equipped headlight to have an automatic washer installed.
Bi-Xenon: On most car models, HID lighting is only used for the low beams while the high beam light is provided by an entirely separate set of halogen lights primarily because high beams need to be turned on and off instantly which HID is not great at. For vehicles with bi-xenon headlights, the HIDs provide both the low and the high beam from the same enclosure of xenon lights via a shutter that moves up and down when prompted meaning since the bulb is already operating there is no delay when turning it on.
Also, a Bi-Xenon lamp uses two bulbs whilst normal Xenon lamp uses 4 which means more cost attached for replacements in the long run.
However, whilst not overly common the shutter is susceptible to wear and tear and could malfunction given time. However, this is not a problem for standard Xenon lights which don’t use shutters.
LED
LED (short for light emitting diodes) car lights have surprisingly been around since 2004 but have only begun to gain popularity recently with more and more people looking for better alternatives to the standard Halogen bulbs.
One of the biggest draws for the LED bulb is that it is by far the most energy efficient option on the market. LED Bulbs draw 15 to 18 watts of power whereas Halogen bulbs draw 55 to 65 watts and HID draws around 42.
They also have an incredibly long lifespan 30000-40000 hours which could potentially see out the entire lifetime of the car which is pretty unprecedented in itself.
LEDs do not contain mercury and a push is being made to replace lead-containing solders with material devoid of any lead, keeping them in line with European directives further decreasing their environmental footprint.
Their small size also enables them to be arranged into virtually any design which makes them ideal for customization fanatics. In terms of illumination, they fall in-between HID and Halogen for brightness.
However, LED’s like most things have their own drawbacks.
Although LEDs do not produce heat like halogen headlights would they do however create a small amount of heat at the emitter when electricity passes through since this location is close to a number of sensitive cables and other electrical components this creates the possibility that other parts (assemblies and connectivity cables) become damaged.
This is why LED headlights require cooling in the form of fans and heat sinks to keep from melting. However, LED cooling systems are generally positioned in the engine bay. This limits manufacturers ability to make lights for certain makes and models, this also explains why they are more expensive than other types of headlights.
Something to be very wary of when buying LED kits and if the price is a consideration…A lot of the cheap LED kits use poor quality aluminium heat sinks, and these sometimes significantly shorten lifespans.
Luckily LED daytime running lights and tail lights don’t use heat-sinks because DRL’s and rear lights/indicators aren’t used to see at night so less power is diverted to the running of these lights/ less power = less heat when it comes to LED’s. The current running through the chips is not enough to create any sort of problem.
They also have the shortest rise time (the time it takes to turn on) at 1 millisecond, this makes it over 250 times faster than Halogen making it extremely useful as a brake or indicator light.
Unfortunately, at the moment LED large scale manufacturing isn’t cost effective as there are so many components human hands have to do the majority of the assembly. This leads to high production costs that are pushed onto the end user, so far now LED lights are going to be pricey.
LED Matrix:
It’s a sign of Audi’s confidence in LED lights that despite their poor adoption rates by large scale manufacturers so far, they have kept on innovating and recently they unveiled the Matrix LED headlights sort of the headlights version of the smartphone, they allow drivers to leave the high beams left permanently on as they have the capability to detect other vehicles and pedestrians and divert light away so that they don’t blind other drivers while at the same time continue to cast their full light in the areas where there isn’t another vehicle(probably why they are sometimes referred to as smart lights). This is made possible because the light path is created using numerous LEDs roughly 25 per headlight unit spread over a grid (or matrix), and these are controlled by a central control unit that is being fed information on road conditions through a camera mounted on the front of the vehicle.


It is interesting that this technology is currently banned in the US due to an outdated law made back in the late 60s requiring vehicles to have a driver controlled High and Low beam, it also took nearly a decade for the US to approve of Halogen lights so it might be a while before the US sees smart headlights!
LASER:
The word laser probably conjures up images of Star Wars and other Sci fi type scenarios where lasers are used as deadly weapons. But in the real world, it is not quite as dangerous, or at least the laser headlights produced by BMW and Audi. Laser headlights are touted as being the next big thing in headlights technologies being brighter and more energy efficient than existing lights.
How new are they you ask? Very new is the answer. So new in-fact that only a couple of cars currently have them (and not the cheap types of cars either) BMW’s i8 which costs upwards of 100k and BMW’s 7 series range also currently supports laser light.


Laser headlights also boast at being much brighter than LED or HID lights, so bright in-fact that LASER headlights only kick in when you drive in speeds excess of 60km, anything below then the LED lights take over so it will be tricky showing these lights off in any urban setting.
And if you were worried that an abundance of these lights on roads posed the risk of blinding you then don’t worry as the dangerous part of the lasers are buried deep in the assembly and have reflectors and all sorts of safety systems built in to prevent any danger to the public.
Earlier we discussed the LED Matrix smart-light system, BMW have also come up with their own laser version called the ‘M4 Concept Iconic Lights’. Not only do these lights prevent other drivers being blinded but they also project messages onto the road warning of a dangerous over take etc.
Lasers have many advantages over the conventional LED lights:
Pros:
  • They use energy more efficiently, even though the actual lasers are 1,000 times brighter than LEDs, the system uses only about half the power.
  • Because laser-powered headlights can put out more brightness for their size, the headlamp units themselves can be much smaller. As a result, designers can have a lot more flexibility to make more aerodynamic designs.
  • The laser lights can be much smaller than conventional lighting systems, they can use less energy to operate and well, they look pretty darn cool.
  • Lasers lights as we know are much more focused so do not get scattered easily thus they illuminate longer distances than conventional lights.
Cons:
  • At the moment they are only available for an extremely small range of cars.
  • They are going to be insanely expensive for the foreseeable future since last Gen innovations such as LED and HID are still on the pricey side of things.
Which should I buy?
It goes without saying that unless you’re driving a BMW i8 or M7 then you should forget about laser headlights for the time being until they become more widely available. If the price isn’t too big of an obstacle, then HID for better illumination but if you’re looking for something almost as good but way better for efficiency and the environment then LED is the way to go.
If you liked this post follow my blog for more technology reviews and share it on your favorite social media.
If you have any inputs/queries post it in the comments, thank you.     
                                                
                                                                             
                                                         

No comments:

Post a Comment

HOW TO CHOOSE A BADMINTON RACKET

  HOW TO CHOOSE A BADMINTON RACKET This guide is intended for beginners who are new to badminton or for anyone that needs some help with cho...