Nearly all of us turn a light on in the evening without giving a second thought to how it actually works. In fact, other than when it is time to change the bulb, few of us even know what it is that is providing the light we need.
We don’t all need to know the history of light bulbs in our day to day life, however, it is good to be aware of the different types of bulbs and when and where they are used for the next time you need to replace one.
Incandescent light bulbs
These were the first practical electric lamps invented in 1874 by American inventors Thomas Edison and Joseph Swan. They use a thin filament that is coiled up inside the bulb to make it more efficient when emitting light. The problem with this type of light is that they use around 90% of the energy used to generate heat rather than produce light, making them very inefficient. They also have a poor color rendering index (CRI) because they emit infrared radiation that makes objects appear warmer than they actually are when compared to daylight. Modern innovations in technology have replaced these traditional incandescent light bulbs with LED and compact fluorescent light bulbs.
These are similar to incandescent light bulbs but instead of a thin filament, they have an electrified quartz halogen tube. These were invented in 1939 by Wilhelm Haitz and sold under the brand name “Glow Lamp” or later on known as Glo-Ray. They can produce up to 105 lumens per watt compared with the standard 60 – 100 lumen/watt which is about 20% more efficient than incandescent lamps. They are only half the price of compact fluorescent lamps (CFLs). The downside is that they contain small amounts of mercury which, if disposed incorrectly of, can pollute the environment because of their hazardous material.
This stands for compact fluorescent lamps which replaced older types of light bulbs widely available in the 1980s and 1990s. They are more efficient, last longer while producing less heat and use a quarter of the energy of incandescent bulbs while lasting up to 15 times longer. The “CFL” is actually an umbrella term since there are many variations of this type including some with LED lighting built-in. A problem is that they contain mercury, a hazardous chemical element that can leak out if broken or not properly recycled. This has been reduced from 5 milligrams per CFL in 2007 to 2mg in 2014, but it’s still one of the main concerns associated with this type of bulb because mercury tends to be emitted into the environment when it’s broken.
LEDs (Light-emitting diodes)
These are a type of semiconductor light source that is solid state and emits light in a specific direction, making them very efficient because all of the energy goes into producing light rather than heat. LED technology has been around since the invention of the Light Emitting Diode by Oleg Losev in 1927 but was not commercialized until the 1960s. They use half as much energy as incandescent lamps and last 25 times longer, but they tend to cost more than CFLs per unit – about 20 times more expensive per lumen. Their initial costs were discouraging despite their superior functionality such as color rendering index(CRI) and longevity. Most of the “LED” bulbs you see in stores are actually LED-based CFLs, but newer types on the market have completely replaced incandescent light bulbs.
OLEDs (Organic LEDs)
This stands for organic light emitting diode which is a thin film made from organic semiconductive materials. This type of bulb uses a single layer of carbon atoms which emit light when it’s energized by an electric current. The problem with this type of bulb is that they’re still very expensive compared to traditional CFLs or even LEDs. They also have low efficiency, especially when lighting large areas, although there have been significant advances in this area that may one day make them more popular.
This is a high intensity discharge lamp that is often used for street lighting. They use an electrical arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. These are actually the type of lights found in most parking lots and stadiums since they can be placed very high without worrying about them breaking because not much heat is produced, allowing them to last longer. They emit more light per watt than incandescent lamps but also need larger reflectors, making them less efficient during the day. They require special power ballasts that produce flicker at 100Hz or 120Hz, depending on where they’re sold originally.
This is a combination of two or more types of lighting that tend to be combined because they’re already very efficient. For example, an LED-based CFL has good efficiency and runs for longer than regular CFLs and LEDs. This type will likely become more popular as time goes on since it should help expand the life span of the bulbs while also reducing energy consumption which in turn could save money over time.
These are some of the oldest types of light bulbs available. They work by running an electric current between electrodes through a gas-filled tube that emits ultraviolet light when energized, causing the tube to glow and create visible light we can see. There are many different types of fluorescent lamps, but in general, they have a poor energy efficiency level which is why they use so much more energy than other types – about six times more.
This type can come in either a straight or circular shape and contains argon and mercury vapour. The electrodes are made from coiled tungsten wires that vaporize when an electric current runs through it, causing the gas to emit ultraviolet light. This process requires two separate electrodes because the electrons flow down one coil (anode) and then return up another (cathode), making them run over 25% longer than incandescent bulbs with less heat produced. Fluorescent lamps require bulky external ballasts, making them difficult to install in some cases.
This group of light bulbs stands for high intensity discharge lamps. They often used in street lighting and to a lesser extent, car headlights. HIDs use an arc between tungsten electrodes inside a translucent or transparent fused quartz or alumina arc tube which is located within the lamp assembly. These types of lights also require very large reflectors to make them as efficient as possible when lighting large areas such as parking lots and stadiums.