The Difference between HID, LED, and Incandescent Lamps
Every since the mass production of the modern automobile, lighting has been an essential component of vehicles. While the first mass produced automobiles did not use electricity to create light, using instead carbide lights which create light by mixing Calcium Carbide and Water together. However, by the 1920s, electrical lights were common usage on automobiles. Lights provide a number of uses such as illumination to see better when visibility is limited, for others to see you, to indicate your driving intent such as turning and reversing, and to see the license plate number for law enforcement. With technology constantly improving, the methods of lighting up an automobile are also changing. There are three primary types of light being used in modern automobiles; they include incandescent tungsten-halogen bulbs, high-intensity discharge lights (HIDs), and light emitting diodes (LEDs). Each light source has its advantages and disadvantages to their uses, but as time progresses, innovative solutions and improving technology are creating more feasible versions of the lights.
Incandescent tungsten-halogen is the most common type of light used in automotive applications. It is also the simplest form of light produced as well that has its origins back in the early 1800s. Incandescent tungsten-halogen bulbs produce light by running an electric current through a metal tungsten filament which super heats it till it glows. The filament does eventually evaporate due to the heat, but thanks to a adding a small amount of halogen such as iodine or bromine, the evaporated material is redeposit back onto the filament. This is known as the halogen cycle. Due to the simplistic design of the lights, they are very cheap to produce and are easily replaced due to their integrated nature in the automotive world. However, since these are very basic, they are not very efficient. Approximately 90% of the electricity consumed by these bulbs is turned into heat rather than visible light; these are highly inefficient at turning power into light.
High-intensity discharge lamps are a common feature on many higher end vehicle models. This is a commonly accepted upgrade for incandescent lamps as they are much brighter; incandescent bulbs produce roughly 800-1000 lm (lumen) while a factory installed HID system produces roughly 2900-3200 lm. A HID lamp produces light by creating an arc of electricity between two electrodes in a quartz-glass tube. Between the two electrodes are metallic salts and gas that ignites when the arc is produced. The gas facilitates the electrical arc and once the metallic salts are evaporated, this creates “plasma” which is the light that is created. HID lamps are much more energy efficient compared to regular incandescent lamps, while they require a substantial amount of power during start-up to create the light, the amount of power required to sustain the light is considerably less compared to regular incandescent lamps. HID lamps are also much more durable with an average working life of 2000 hours compared to the 500-800 working hours of an incandescent halogen bulb.
Mercedes-Benz Active LED Headlights
The newest form of vehicle lighting that has recently begun to pick up pace are light-emitting diodes or LEDs. LEDs are semi-conductors that produce light when electricity is passed through it. These lights are very efficient at turning electricity into visible light; they also produce very little heat (when compared to other alternatives), are very durable, and have a very long working life of over 25,000 to 100,000 hours (the life varies depending on the heat and amount of current being passed through it). LED bulbs produce more light (lumen) per watt than incandescent bulbs allowing them to be much more efficient at doing their intended purpose. These lights are also resistant to damage from external vibrations and shock since they are a solid-state component. LED lights are slowly becoming standard feature on many cars thanks to their smaller size, improved lifespan, and the speed of lighting up (beneficial for stop lights to indicate other drivers you are slowing quicker). The only disadvantage to LED lights at the moment is their cost, since they are relatively new in the time span of modern vehicles; the cost of production is still quite high compared to incandescent halogen bulbs.
Audi A7 Lighting Sequence
Technology innovations are constantly changing the design of automobiles. While incandescent halogen bulbs are still common on most automobiles, they are slowly becoming obsolete as the technology for other alternative light sources such as LEDs are becoming more wide spread. Incandescent halogen bulbs, HID lights, and LED lights are the common lights used on automobiles, but as we proceed into the future, there are possibilities that other forms of light can be discovered and the current forms being innovated to perform better and more efficiently.