Posted by Doug Root on 18th Jun 2020

Incandescent to LED Light Bulbs: A Primer on Some Common Bulbs

You can turn to us here at Atlanta Light Bulbs to outfit you with many different types of specialty bulbs, including medical lighting, UV bulbs for a number of different uses, airfield lighting, spectral lamps, and more. We are without a doubt your source for light bulbs, lighting fixtures, and accessories of all sorts, and we’re proud to be one of the places to which you can turn when you have a need for specialty lighting that you just can’t solve elsewhere.

With that in mind, specialty bulbs are only one part of the picture. Throughout most of the day, most people come in contact with many different types of light bulbs and light fixtures, and a large number of them fall into one of the categories that we are going to discuss in this article. With no further ado, here are some of the more common types of light bulbs that you will find in most homes and businesses, along with a little background information, how they work, and their purposes. 

Incandescent Bulbs

Incandescent bulbs were, for a long time, the most common form of lighting in most internal residential settings, and they may still be. Certainly, for all their widespread use, they represent one of the most immediately recognizable forms of lighting in the world.

Incandescent bulbs are the oldest form of electric lighting technology, with forms of incandescent bulbs dating all the way back to the late 1800s. Many of Thomas Edison’s experiments took on incandescent lighting, and some modern incandescent bulbs are iterations of his earlier designs, although he was not the first to create an incandescent bulb. In fact, there were successful experiments producing light through incandescent processes contained within glass bulbs as early as 1838. Earlier forms of incandescent technology involved heating wires until they glowed; this is the same technology that is employed in modern lighting, though modern bulbs are created to sustainably and safely produce light.

The basic principle behind the operation of an incandescent bulb is fairly simple. Incandescence is the process by which light is produced through a current of electricity to heat up a filament until it glows. Early light bulbs used carbon fiber filaments or metals such as osmium or molybdenum. Today most incandescent filaments are made from tungsten. When electricity passes through the metal filament, it heats the filament up and it glows. This production of light is known as incandescence. It is a reliable way to sustainably produce light, however, in the presence of oxygen many suitable filaments would oxidize and thus would burn out.

To combat this problem, incandescent bulbs typically contain a noble gas or a relatively unreactive gas like nitrogen or argon, although some are produced in the form of a vacuum. This helps to shield the filament from the process of oxidation that would destroy the filament and render the process useless.

Because the technology behind an incandescent bulb is relatively simple - it is just a wire within a vacuum or an unreactive atmosphere that is heated by an electric current until it glows - they are relatively cheap to manufacture. They are also compatible with AC and DC systems and thus have been very popular for many years.

Unfortunately, although they are affordable to produce and easy to operate, they produce a lot of heat and draw a large amount of energy to operate. Therefore, many other forms of lighting are preferable to them in certain situations. One of these widespread and energy-efficient alternatives is fluorescent lighting. 

Fluorescent Lighting

Fluorescent lighting requires an electric current to produce luminescence, although by a slightly different process than incandescence. Unsurprisingly, fluorescent bulbs produce light through fluorescence, which is the process by which certain materials produce light when exposed to ultraviolet radiation. Here’s how it works.

The way in which a fluorescent light bulb works is somewhat more involved than with an incandescent light bulb. A fluorescent bulb contains a tube that is coated in phosphor powder with electrodes, typically tungsten electrodes, at either end. Within the phosphor-coated tube, there is also an inert gas, typically argon, and a little bit of mercury.

When you switch the light on and feed current to the assembly, a portion of the system or of the lamp itself called the ballast allows a certain amount of current to reach the first electrode. That electricity arcs through the tube to the electrode on the other end.

As the electricity passes through the tube that contains the gas and mercury, it excites the mercury which vaporizes. When the mercury vaporizes, its electrons become excited and jump to higher electron shells. At this point, the mercury vapor begins to emit ultraviolet radiation. This is the critical step behind the operation of fluorescent bulbs.

Fluorescence itself is a term used to describe materials that glow when exposed to UV radiation. For example, fluorite, a mineral high in fluorine and for which fluorescence is named, glows when exposed to ultraviolet light.

When the mercury emits this UV light, it strikes the phosphor powder that coats the inside of the tube. The phosphor powders contain fluorine, typically in the form of fluorine oxide, and thus glow brightly when irradiated by UV light.

Fluorescent lights are widely used, particularly in commercial and industrial settings, because they can offer a very bright white light suitable for illuminating large, typically indoor spaces, and offer a number of benefits over traditional incandescent lighting.

Although they are more expensive upfront than incandescent bulbs and contain mercury, which requires careful handling and disposal, fluorescent lights are significantly more energy-efficient than incandescent bulbs and they are rated to last much longer as well. In addition, they do not produce as much energy in the form of heat which makes them suitable for helping to keep down HVAC costs, especially in the summer.

A type of fluorescent bulb that has been gaining in popularity is the CFL or compact fluorescent lamp. These small fluorescent lamps were designed to be suitable alternatives to many incandescent lights that are so common in residential settings. For the most part, they contain their own ballasts and so they are perfect for ‘plug and play’ replacement. Some of them have bases that are compatible with medium base sockets that are typically used by incandescent bulbs. However, like other fluorescent lights, they are much more energy-efficient than incandescents and also last a lot longer.

High-Intensity Discharge (HID) Lamps

High-intensity discharge lamps, like fluorescent light bulbs, constitute a class of arc lamps. There are several different types of HID lamps, including high-pressure and low-pressure sodium lamps and metal halide lamps. They are fairly efficient, last a long time, and can produce a great output of light, typically of a warm color temperature.

As opposed to incandescent bulbs which glow when the filament within them is heated, HID lamps are made up of a bulb that contains another glass tube that is filled with metal salts and a gas that releases energy in the form of light when electricity passes through it. Like fluorescent lamps, HID lamps contain an inner bulb with two electrodes between which a current passes and is responsible for exciting the gases within. Also like fluorescent lamps, they last a fairly long time.

The way they work follows. When power is fed to the lamp as regulated by the lamp’s ballast, the metal salts within the inner tube are vaporized and the gas within the tube is excited. As the gas becomes excited by the energy flowing through it, its electrons are excited to higher shells; when they release the energy that they have absorbed to fall back into their regular allotted orbits, that energy is emitted in the form of light. In the case of an HID lamp, that light is very bright.

Because HID lamps are so energy efficient and equally capable of producing exceptionally bright light, you will commonly see them lighting large indoor and more commonly outdoor spaces. For example, stadium and arena lights, parking lights, warehouses, and street lights are commonly HID lamps such as metal halide lamps. In addition, they are sometimes encountered in the form of grow lights for their remarkable output. However, because some lamps present some delay in reaching their full brightness because they need time to warm up, they may not be suitable in situations wherein the lights need to be regularly switched on or off. For the most part, this makes them more than ideal for the situations described above.

Halogen Lamps

Halogen lamps are somewhat similar to incandescent lamps in their operation, although they are also rated to last a long time. In fact, because the principles of operation are similar, halogen bulbs can even be classified as a subcategory of incandescent lighting.

Halogen bulbs, like incandescents, contain a filament which is typically made of tungsten. The filament is contained within a bulb that contains halogen gas, which is made up of a combination of iodine and bromine. When a current is fed to and through the filament, it begins to glow. There is a key difference in operation here, however.

As stated, incandescent bulbs are created to present the filament within a vacuum or surrounded by an inert or relatively unreactive gas like nitrogen to protect it from the influence of oxidation. However, even in the absence of oxygen, over time the filament will deteriorate.

The same could be said of halogen bulbs, except that as the filament within the halogen filled bulb deteriorates, the halogen gas redeposits the particles that “burn off” of the filament right back onto it. This process is known as the halogen cycle and enables the filament to last much longer in a halogen bulb - typically two to three times longer than it would in an incandescent.

As such, halogen bulbs are preferred by some because of their relatively longer lifespans as well as the fact that they are somewhat more affordable than some other forms of lighting. They are also preferred by some for the rich quality of their light output. In addition, as incandescent lights are phased out of certain locations, some turn to halogen as a suitable alternative.

LED Light Bulbs

In addition to the styles of lighting we have explored so far we also offer a wealth of LED light bulbs and solutions here at Atlanta Light Bulbs. LED light bulbs are a great light source for many different situations given some of their unique strengths, although the method by which they work is somewhat different from everything we have explored so far.

To keep things simple, LEDs, or light-emitting diodes, contain a semiconductor across which a current passes; as the current passes across the semiconductor it produces light. LED light bulbs, unlike the previous options we have explored, contain no gases and no filaments. The capsule that covers the semiconductor is there to protect it and is often a solid, hard epoxy lens.

LED lights are capable of producing a range of colors from warm white to cool white and many colors in between. LED lights are also extremely energy-efficient lights as well as very long-lived ones. LED lights draw very little power and some are rated to last almost 100,000 hours; far longer than any other alternatives explored herein.

In addition, there are many styles of LED bulbs that are designed to be compatible with bases for fluorescent tube lights and even bulbs that are designed to look and operate like incandescent bulbs while offering the same benefits of LEDs. The bulb pictured at the top of this article is actually an LED bulb that is designed to look like an incandescent bulb, for those who appreciate the look and light of older incandescent models. As you can see, LEDs offer a lot of flexibility with a number of benefits.

Whereas the cost of semiconductors used to make LED lights cost-prohibitive, in the last two decades the costs have dropped significantly. This has caused many homeowners and businesses to investigate LED lights as an energy-saving measure. For the sake of brevity, know that there are many advantages of LED light bulbs; you can read about some more of them in detail in the link above.

We offer many different types of light bulbs, fixtures, and accessories, including examples from the categories we explored herein along with the specialty bulbs we mentioned earlier in this article. Please don’t hesitate to reach out to our team, whether you are interested in bulk pricing on fluorescent lamps for your business or for dimmable LED or decorative LED solutions for your home. You can reach us at 1-888-988-2852; our team would be more than happy to help you answer any questions you might have.