History of Electric Light Bulb: Incandescent lamps, Gas discharge lamp (Fluorescent, CFL) and Led lamps

By -

Electric Light Bulb: Incandescent Lamps, Gas discharge Lamp (Fluorescent, CFL) and Led Lamps

        Electric light bulb is one of the greatest invention that truly illuminated human's life.  Though Thomas Edison is credited as the inventor of the electric light bulb as he could manage to develop and manipulate the entire requirements, other eminent researchers should be honoured for their contributions.

 Original carbon-filament bulb from Thomas Edison's shop in Menlo Park


Thomas Edison’s Signature

    The history of electric light bulb dates back to 1761 when Ebenezer Kinnersley demonstrated heating a wire to incandescence (means light producing). Next  breakthrough was in 1802, when Sir Humphry Davy could produce incandescent light by passing current through a strip of platinum (taking advantage of its high melting point and inertness for which it will not react with atmospheric gases), but the light was not bright enough nor did it last long enough. The high cost of platinum was indicating its replacement which triggered and helped in the invention of glowing carbon filament in vacuum. In 1878 joseph Swan used carbon filament in the vacuum (by pumping out the bulb by vacuum pump). Almost simultaneous, Thomas Edson also worked on carbon filament and vacuum and could succeed relatively better than Swan.

Evolution of  Thomas Edison's light and socket

    In 1904, the next generation electric light bulb could be prepared which used tungsten filament instead of carbon filament and used inert gas instead of vacuum which reduced the vaporisation of the filament and increased the life span of the filament, luminous efficacy (glowed better), and also reduced bulb blackening. 
    In this way the filament electric light bulb (or the incandescent light bulb) developed to modern day filament bulb made of tungsten coil and inert gas atmosphere inside the bulb.

1. Outline of glass bulb
2. Inert gas mixture (nitrogen, argon krypton xenon)
3. Tungsten filament
4,5,8. Contact wire
6. Support wire
7. glass mount or base
9. Cap
10. Insulation
11. Electric contact
    Next to Incandescent or filament bulb, comes the Gas discharge lamp. The popular category in this is the CFL (Compact Fluorescent Light).


    In gas discharge lamp, when electric field is applied across the electrodes, electron are produced from some of the the gaseous atoms/molecules (used as a gaseous mixture such as neon, argon, krypton, xenon, mercury, sodium, metal halides etc. inside the bulb) and are ionised. When these ionised species collide with neutral gaseous species they absorb electrons from the neutral species (and get discharged) and return to the lower energy state state by releasing energy in form of photons (light).


    The CFL comes under this gas discharge lamp category, where the tube containing gaseous materials is shaped into helical or folded shape to bring a compact size equivalent to filament bulb. This technology produces ultra violet light when excited mercury atoms come to lower energetic states. This UV light is absorbed by the fluorescent coating on the inner wall of the glass tube and thus visible light is produced.
The Compact fluorescent Light Bulb

    Next to fluorescent lamps comes the LED (light emitting diode) lamps or LED lights. In this technique, light emitting diodes are used. These light emitting diodes are  semiconductor light sources which produce light on passing current through them. The electron when combines with the holes (position where electron is absent) energy is emitted as light, hence called light emitting diodes. The main part of a  LED is a junction of p-type semiconductor with n -type semiconductor called the the p-n junction. The n-type semiconductor is the source of electrons while that of p-type semiconductor is the source of holes. On passing electric current the electros pass from n-type to p-type and combine at the holes to release light energy.

Household LED lamp with its internal LED elements and LED driver circuitry exposed.

Disclaimer:

Some of the images used in this post does not belong to my work hence their links and details are given below.

 1.       Original carbon-filament bulb from Thomas Edison's shop in Menlo Park

By Filip Mishevski from Skopje, Macedonia - edison's no. 1, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=56405099

https://creativecommons.org/licenses/by/2.0

2. Thomas Edison’s image

By Louis Bachrach, Bachrach Studios, restored by Michel Vuijlsteke - This image is available from the United States Library of Congress's Prints and Photographs divisionunder the digital ID cph.3c05139.This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information., Public Domain, https://commons.wikimedia.org/w/index.php?curid=6582301

3. Thomas Edison’s signature

By Thomas Alva Edison - Traced in Adobe Illustrator from http://www.fadedgiant.net/assets/images/edison-thomas-alva-signature-3.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=8860563

4. Evolution of Edison’s light bulb and Socket

 Richard Warren Lipack, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons

https://upload.wikimedia.org/wikipedia/commons/8/8a/1880EDISON1881LampsSOCKETSrwLIPACKowner.jpg

 https://commons.wikimedia.org/wiki/File:1880EDISON1881LampsSOCKETSrwLIPACKowner.jpg

https://creativecommons.org/licenses/by-sa/3.0

5. Filament Electric bulb

By Created by Fastfission in Inkscape. - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=763569

6. CFL Light

By http://en.wikipedia.org/wiki/User:PiccoloNamek - http://en.wikipedia.org/wiki/File:Compact-Flourescent-Bulb.jpg, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=8689967

https://commons.wikimedia.org/wiki/File:1880EDISON1881LampsSOCKETSrwLIPACKowner.jpg

https://creativecommons.org/licenses/by-sa/3.0

https://creativecommons.org/licenses/by/3.0

7.LED light

Household LED lamp with its internal LED elements and LED driver circuitry exposed.

By Loadmaster (David R. Tribble)This image was made by Loadmaster (David R. Tribble)Email the author: David R. TribbleAlso see my personal gallery at Google Photos - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=101149484

https://creativecommons.org/licenses/by-sa/4.0


Popular posts from this blog

Ethics and Values for Semester - I, Books, Syllabus, Important Questions and Answers

By -
Image
 Ethics and Values for Semester - I, Books,  Syllabus, Important Questions and Answers      Recently Odisha Universities have introduced a new course named "Ethics and Values" under AECC (Ability enhancement compulsory courses) for all streams (Arts/ Science/ Commerce). Being very new to the syllabus students are confused how to cover it and how to write the answers. Thus this post is for all of them who want to score well in this subject. This post will provide you all important question and answer related to this subject. Also this will provide you the best books to study and score good. Objectives and learning goals of the course: 1. To develop good human being and responsible citizensF, 2. To develop capability to choose between right and wrong which leads to correct behaviour. 3. To create a positive attitude and to develop healthy work culture. style="line-height: 35px; text-align: justify;">    ...
Read more

Previous Year M.Sc. Chemistry Entrance Examination Question Papers and Solutions

By -
Image
   Previous Year M.Sc. Chemistry Entrance Examination Previous year questions are very important tools to plan for the success in an entrance examination. We are providing here some previous year M.Sc. Chemistry Entrance questions papers and solutions, which will help you prepare for the same smoothly. You must practice the chapter wise previous year IIT JAM Chemistry questions.  Also you must test yourself by practicing online mock test for M.Sc chemistry.     The most common Syllabus for almost all universities and IIT and IISc for MSc Chemistry Entrance Examination are: 1 . Atomic Structure 2. Classification of Elements and Periodic Properties 3. Nuclear chemistry and Radioactivity 4. Chemical Bonding 5. Acids and Bases 6. Metallurgy 7. Hydrogen 8. s , p, d, and f block elements 9. Coordination chemistry and organometallic chemistry 10. Environmental Chemistry  11. general Organic Chemistry and Stereochemistry 12. hydrocarbons 13. Alkyl ...
Read more

Notes on Thermodynamics (Intermediate and BSc)

By -
Image
 Notes on Thermodynamics      A chapter in chemistry can be ranked according to its depth and complexity. Chemical thermodynamics can be ranked to the top most position in this concern. Hence it is almost essential to have either a very good book or very best notes to be able to get the concept and solve the problems and questions answers . You can also have notes on   Periodic table ,  Gaseous state  for BSc  ,  Phase rule ,  Industrial chemicals and environment , and  Solid state , Chemical equilibrium , .     This post is dedicated to all chemistry fans who enjoy reading wonderful explanations of chemistry. Bellow you will find best notes on Thermodynamics. Follow our YouTube Channel    Soul of Chemistry , to further strengthen your concept. The First Law of Thermodynamics      Thermodynamics is concerned with the heat motion (flow). In general, it deals with the relation between ...
Read more