Light Bulbs

About Light Bulbs

As electrical technology has advanced throughout the twentieth and twenty-first centuries, numerous types of light bulbs have been developed. From the oldest commercially-produced incandescent lamps to new "smart" LEDs, there are hundreds of variations of type, size, lighting technology, and power.

LED (Light Emitting Diodes)

LED lighting utilizes semiconductor diodes to emit light when an electrical current passes through them. Known for their high energy efficiency, long lifespan, and durability, LEDs are widely used in residential, commercial, and industrial applications. They produce less heat that other light sources, come in various colors and color temperatures, and are highly versatile. This makes them suitable for almost every application, from ambient lighting to task and accent lighting. Advances in LED technology have also enabled smart lighting features, including app-controlled features, dimming, and color-changing capabilities. These lamps require a driver, which regulates power between the line voltage and the LED.

Linear Fluorescent

Linear fluorescent lighting consists of long glass tubes filled with mercury vapor, with a phosphor coating. These lamps emit light when an electrical current excites the gas. A fluorescent ballast is used to regulate the power between the building line voltage and the fluorescent tube. These lights are more energy-efficient than incandescent bulbs and are commonly used in offices, schools, and retail spaces. However, they contain small amounts of mercury, requiring proper disposal. Fluorescent tubes provide bright, diffused lighting but can flicker or hum over time, especially with a failing ballast or older magnetic ballast. They are gradually being replaced by LED alternatives due to higher efficiency and better light quality, although fluorescent lamps are still hard to beat in terms of longevity and price.

Compact Fluorescent (CFL)

Compact fluorescent lamps (CFLs) are a smaller, coiled version of linear fluorescent bulbs designed to replace incandescent and halogen bulbs in standard fixtures. They use less energy and last longer than incandescents but take time to warm up to full brightness. They also usually have a lower color rendering index than incandescent, which is part of the reason CFLs gained a poor reputation. CFLs contain trace amounts of mercury, raising environmental concerns. While once popular for home lighting, they have declined in use due to competition from more efficient and instant-on LED bulbs. However, they can still compete with LEDs in hotter environments which can shorten the life of LED bulbs.

Ultraviolet (UV)

Ultraviolet lamps emit light in the UV spectrum, which is invisible to the human eye but has applications in sterilization, medical therapy, counterfeit detection, and many more specialized applications. UV lamps are used in water purification, HVAC systems, and forensic analysis. Prolonged exposure can be harmful, requiring protective measures. UV LEDs are becoming more common due to their precision and energy efficiency in specialized applications like ultraviolet curing and disinfecting surfaces. While ultraviolet LEDs and excimer lamps are more available and cost effective than a few years ago, fluorescent type ultraviolet lamps are still the industry standard.

High Intensity Discharge (HID)

HID lamps produce light by creating an electric arc between tungsten electrodes inside a gas-filled tube, generating intense brightness. Common types include metal halide, high pressure sodium, and mercury vapor lamps, used in streetlights, stadiums, industrial settings, medical equipment, and projectors. HID lamps are highly efficient for large-area lighting but require warm-up time and can emit harsh light. They are increasingly being replaced by LEDs in many commercial applications, which offer instant-on capability and better color rendering.

Halogen

Halogen bulbs are an advanced type of incandescent lighting that uses a tungsten filament enclosed in a small quartz capsule filled with a halogen, such as iodine or bomine. This extends the bulb's lifespan compared to incandescent. Halogen lamps produce bright, white light with excellent color rendering, making them ideal for task lighting, automotive headlights, medical equipment, some older projectors, and other color-critical applications. However, they are less energy-efficient than LEDs and CFLs and can become extremely hot during operation, posing burn and fire risks if not used properly.

Incandescent

Incandescent lighting works by heating a tungsten filament until it glows, producing warm, familiar light. These bulbs are inexpensive but highly inefficient, converting most energy into heat rather than light. Due to their short lifespan and high energy consumption, many countries have phased them out in favor of more efficient alternatives like LEDs. However, incandescent bulbs remain popular for decorative and vintage-style lighting due to their pleasing light quality. They are also still used in traffic signals and for photographic applications like photoflood lighting and enlarger equipment.

Xenon Miniature

Xenon miniature lamps are small, high-intensity bulbs filled with xenon gas, which produces bright, white light when an electric current passes through a filament or creates an arc. Commonly used in flashlights, medical devices, and automotive applications, these lamps offer excellent color accuracy and instant brightness. While more efficient than standard incandescent bulbs, xenon miniatures are being increasingly replaced by high-power LEDs, which provide similar performance with greater energy efficiency and longevity.