Each of us relies upon them whenever we drive during the evening. We depend on them to illuminate the road as well as the objects in front of our vehicles. Yet few of us give headlights more than a moment's notice, or consider how far they've evolved since they debuted generations ago. They are a critical part of our driving experience, and play a key role in our safety.
This article will provide a brief tour though the history of the automotive head light. You'll discover the evolution of Thomas Edison's groundbreaking invention (i.e. the light bulb) seemed destined to dovetail with that of the automobile.
In The Beginning: A Bumpy Start
When Edison first revealed his invention to the world, it was fragile. It could not be shaken aggressively without risking its breakage. For this reason, it was a poor fit for an automobile. At the time, the roads were rough, and tires were not designed to absorb road impact. Had Edison's bulbs been installed as headlights, they would have quickly shattered.
This issue was resolved when bulbs began to be produced with filaments. These were springs that were flexible, and thus could absorb impact. Electrical current traveled through the filaments, generating heat to the point that it produced light. Filament-based designs underwent many years of evolution, but even during the early years, the new bulbs began showing up in automobiles.
From Incandescent Bulbs To Halogen Bulbs
As filament bulbs evolved, a particular type emerged to become the standard for the automotive industry. This was the incandescent bulb. It worked based on the same process described above: electricity traveled through a filament (tungsten in this case), and heated it to produce light. The tungsten filaments were thin, yet durable, making them a reliable light source for cars. Hence, they were used as headlights, turn signals, instrument panel lights, and brake lights. This continued until the halogen bulb debuted.
Halogen lights use the same tungsten filament as their incandescent predecessors. The difference is that they rely upon halogen gas to heat the filament. This gas is capable of producing much higher temperatures than was possible with the previous design. The problem was that such intense heat could melt a conventional glass bulb. This is the reason halogen lamps are enclosed within quartz bulbs.
Halogen gas offered two important advantages. First, the hotter filament produced more light. Second, the gas extended the life of the filament, which meant the lamps lasted longer. Within a few decades, they had become the automotive industry standard.
Introduction Of Light-Emitting Diode (LED) Bulbs
LED bulbs represented a radical departure from filament-based lamps. They do not use a filament to produce light. Nor do they generate the same intense heat. Instead, electricity courses through a semiconductor chip to provide illumination.
Because light-emitting diodes run so much cooler than their filament-based counterparts, they can be housed in plastic rather than glass or quartz. Plastic tends to be much more durable, as well as resistant to vibrations. These bulbs are also designed to last for the life of your vehicle.
High-Intensity Discharge (HID) Bulbs: A Growing Trend
HID bulbs have actually been around for many years. Similar to light-emitting diodes, they do not use a filament. Instead, xenon gas is pressurized and heated with electricity Autel Maxidas DS808. The result is a bluish-white light that is brighter than a typical headlight.
Once they are in operation, high-intensity discharge bulbs only require a small amount of electricity. This is one of the reasons they are common on hybrids and similar vehicles. The advantage to using HIDs is that they produce more powerful light than other headlamps, and can potentially last the life of the vehicle. The downside is that they cost more.
Even now, more advanced versions of automotive headlights are being developed. LEDs and HIDs, both groundbreaking in their own ways Autel MaxiSys, will one day cede ground to the new generation of headlamps.