Ever wonder how Light Bulbs came to its present state of usage? We know that Thomas Alva Edison invented the first practical incandescent bulb in the 19th century, but there have been innumerable modifications producing the present variation of light bulbs.

Various Kinds Of Light Bulbs Seen Over Time

To talk about the basics, lamps are primarily energy converters. Although they might have secondary functions, their major function is transforming electrical energy into electromagnetic radiations are visible to the naked human eye.

The main factors influencing the manufacturing of light bulbs have been external forces of marketing. It was, in fact, the large-scale production as well as the distribution of electrical energy, that was needed for meeting the demand for lighting that determined its growth. 

There are various kinds of light bulbs which evolved over time, to give the sort of lighting used in modern days, we could categorise them as the following:

  1. Edison Bulbs
  2. Incandescent Lamps
  3. Compact Fluorescent Lamps(CFL)
  4. Halogen Lamps
  5. Metal Halide Lamps
  6. Light Emitting Diode (LED)
  7. High-Intensity Discharge Lamps
  8. Low-Pressure Sodium Lamps

We’ve already discussed the advent of electricity and how did the incandescent light reach its modern form. Let’s talk about it in detail:

 

Edison Bulbs

Edison Bulbs

The Edison light bulbs also called Antique filament light bulbs, as well as vintage light bulbs, refer to either the carbon or early tungsten filament lamps. Most of those bulbs were reproductions of wound filament bulbs, which were made popular by the  Edison Electric Light Company at the turn of the 19th century. They can easily be identified by their long winding internal filaments. They can be recognized by their warm-yellow light that they generate (these bulbs emit light at the colour temperature of 2200-2400K).

The first commercially viable light bulbs were used in lamps to light the inventors’ laboratories, but this model went on to be used in businesses and homes, mainly in lamps until socket wiring gained popularity.

 

Incandescent Bulbs

Incandescent Lamp

When a solid and a liquid are heated simultaneously, an emission of visible radiation with temperatures more than 1,000 Kelvin is observed, this phenomenon is known as incandescence.

This very heat is the basis of light generation in filament lamps, as an electrical current passes through a thin tungsten wire. The wire’s temperature rises to about 2,500 to 3,200 Kelvin, concerning the type of lamp as well as its application.

Incandescent bulbs could be used for most household applications.

 

Compact Fluorescent Lamps (CFL)

(CFL)Compact Fluorescent Lamps

A compact fluorescent lamp is an energy saving bulb, it was designed to replace incandescent bulbs. These fit into light fixtures designed for incandescent bulbs. The lights employ a tube which is folded in a way that it fits in the place of the incandescent bulb.

The operating principle is the same as in another fluorescent lighting. Electrons which are supposed to carry mercury atoms are excited to a state where they start radiating ultraviolet rays as they return to a lower energy level. The emitted ultraviolet rays change into visible light as it strikes the fluorescent coating.

CFLs are four times more energy efficient than incandescent bulbs. A 100-Watt incandescent bulb could be replaced by a 22-Watt CFL bulb and get the same of amount light.

 

Halogen Lamp

Halogen Bulbs

A halogen lamp is an incandescent lamp consisting of a tungsten filament sealed into a compact transparent pocket that has a mixture of inert gases, either Iodine or Bromine.

The combination of the halogen gas and the tungsten filament produces a halogen cycle chemical reaction which redeposits evaporated tungsten to the filament, this increases its life, maintaining the clarity of the pocket.

A halogen lamp needs to be operated at a higher temperature than the gas-filled lamp of similar power to produce light of a higher luminance as well as colour temperature. Halogen lamps are of smaller sizes that helps in their usage with projectors and illumination. Halogen reflectors are often preferred for directed lighting such as spotlights and floodlights.

 

Metal Halide Lamps

Metal Halide Lamps

The lamps are made of small fused quartz or ceramic arc tube which contains the gases and the arc.

Enclosed inside is a larger glass bulb which is coated to filter ultraviolet radiations. A pressure between 4 to 20 atmospheres, is used to operate them. They need special fixtures to operate safely and an electrical ballast.

Most of the light output is produced by metal atoms. A warm-up period of several minutes is needed to reach the full light output.

The smaller bulbs are used in handheld flashlights, they were used in Europe for automobile headlights for some time. The light was brighter and had created controversy as it could make the road more dangerous by blinding other drivers.

The most important usage of this light is in stadiums and sports fields as well as at parking lots and street lighting in cities.

 

Light Emitting Diode(LED)

Light Emitting Diode (LED)

Unlike most fluorescent lamps, and similar to incandescent lamps, these LED lights come to full brightness without the need for a warm-up time. The life of fluorescent lighting is also reduced by frequent switching on and off. LED lights at its initial buying come to a higher cost. LED dye degrade over time due to which there is a reduction in the light output to some extent.

LED bulbs, as the name suggests, operate on diodes. It works on the concept of direct current, while, its alternating current is usually at much higher voltage than the LED can accept. Low voltage LED lamps are available as well in form of LED lamps and they can contain a circuit for converting the alternating current into direct current at the correct voltage. Its circuits consist of rectifiers as well as capacitors. They may have other electronic components, which may or may not permit the lamp to be dimmed.

LED Lights can be used for entertainment, events, signage, home applications, business applications, boat and automobile applications, and even artwork as well as the enhancement of it.

 

High-intensity Discharge Lamps

HID lamps

High-intensity discharge lamps (HID lamps) are a kind of electrical gas-discharge lamps that give light with the help of an electric arc between tungsten electrodes stored inside a translucent or transparent fused quartz or fused aluminium arc tube.

HID lights are used as replacements for halogen lights, they are clearer and come with much intensity.

 

Low-Pressure Sodium Lamps

Low Pressure Sodium Lamp

Low-pressure sodium lamps are known to be very efficient electrical light sources, however, their yellow light restricts their usage to outdoor lighting like street lamps. The sodium-vapour lamp is a gas-discharge lamp which employs sodium in an excited state to generate light at a wavelength near 589 nm.

These lamps are mostly used for street lighting as well as industrial uses.

Underneath is a comparison for 60-Watt incandescent and equivalent light bulbs.

Incandescent Halogen CFL LED (Cree)
Watts 60 43 14 9.5
Lumens (mean) 860 750 775 815
lumens/watt 14.3 17.4 55.4 85.8
Color temperature kelvin 2700 2920 2700 2700
CRI 100 100 82 85
Lifespan (hours) 1,000 1,000 10,000 25,000
Lamp lifetime in years @ 6 hours/day 0.46 0.46 4.6 11.4

 

Different types of lights have vastly differing efficiencies and colour of light.

Name Optical spectrum Nominal efficacy

(lm/W)

Lifetime (MTTF)

(hours)

Color temperature

(kelvin)

Color Color

rendering

index

Incandescent light bulb Continuous 4–17 2-20,000 2,400–3,400 Warm white (yellowish) 100
Halogen lamp Continuous 16–23 3,000–6,000 3,200 Warm white (yellowish) 100
Fluorescent lamp Mercury line + Phosphor 52–100 (white) 8,000-20,000 2,700–5,000* White (various color temperatures), as well as saturated colors available 15–85
Metal halide lamp Quasi-continuous 50–115 6,000-20,000 3,000–4,500 Cold white 65–93
High pressure sodium Broadband 55–140 10,000-40,000 1,800–2,200* Pinkish orange 0–70
Low pressure sodium Narrow line 100–200 18,000-20,000 1,800* Yellow, no color rendering 0
LED lamp Line plus phosphor 10–110 (white) 50,000–100,000 Various white from 2,700 to 6,000* Various color temperatures, as well as saturated colors 70–85 (white)

*Color temperature is defined as the temperature of a black body emitting a similar spectrum; these spectra are quite different from those of black bodies.

One of the most useful inventions are these light bulbs. Light is crucial for sight. Without light bulbs, people would be unable to see and perhaps would have to rely on their other senses to do tasks alone. Of course, they would have candles, but wouldn’t that be such a strain!

It is innate to understand the lighting categories or the sort of bulbs one uses in their homes and their workplaces in form of essencial as well as decorative lighting. This  understanding should help us make a well-informed decision, where lighting is concerned. the bulbs we opt for influence the brightness of a household. Therefore, a clear picture of which bulbs are present in the market is needed.

This article intends to present a deeper understanding of what light bulbs are, concerning their technical aspects as well as their application!