1. 9EE605A.3to4 1 Department of Technical Education Andhra Pradesh Name Designation Branch Institute Year/Semester Subject Subject Code Topic Duration Sub Topic Teaching Aids : P. Balanarsimlu : Lecturer : Electrical Engineering : Govt. Polytechnic Nizamabad : VI Semester : Electrical Utilisation and Traction : EE605 A : Electric Lighting : 100 Mins : Types of Lamps, Glare, Requirements of Good Lighting : PPT, Diagrams. Animation Revised By : K. Chandra Sekhar, L/EEE, GPT, HYD

2. 9EE605A.3to42 Recap In the last class you have learnt about Units of Wave Length Definitions of Plane angle and Solid angle

3. 9EE605A.3to43 Objectives On completion of this topic you would be able to know about Applications of lamps for different situations Domestic, Industrial, Decorative, Advertisement, Street lighting and Flood lighting Phenomenon of glare Requirements of good lighting

4. 9EE605A.3to44 Types of Lamps Lamps are classified into Incandescent lamps Arc lamps Discharge lamps  Sodium vapour lamps  Mercury vapour lamps  Fluorescent lamps  Neon lamps

5. 9EE605A.3to45 Lamps For Different Situations 1)Domestic Lighting The requirements of illumination varies from place to place, such as study room, drawing room, bedroom, verandah and toilets etc Incandescent lamps,fluorescent lamps, compact fluorescent (CFL) lamps are well suited for domestic lighting

6. Lamps For Different Situations 2) Industrial Lighting Sufficient light in Industries increases the production, quality of work and reduces the accidents An illumination of about 200 lux is required to obtain day light 9EE605A.3to46

7. Lamps For Different Situations Incandescent, fluorescent,CFL and mercury vapour lamps are suitable for industrial lighting The lamps should be mounted at sufficient height to provide uniform illumination without any glare In case of Traveling crane, side lights with deep reflectors should be provided Machine shops are usually provided with general and local lighting 9EE605A.3to47

8. Lamps For Different Situations 3)Decoration Lighting Decorative lighting is provided in functions and tourist places, such as Lord Venkateshwara temple, Taj mahal, Golden temple, Brindavan gardens, etc MV lamps, SV lamps,incandescent, fluorescent, halogen, series and neon lamps are used for decoration purpose MV lamps play an important role in decorative lighting 9EE605A.3to48

9. Lamps For Different Situations 4) Advertisement Lighting This type of lighting is used to attract the public and to increase the sales Dress materials, signboards, cosmetics, automobiles, road junctions, public places and domestic appliances etc. comes under this category Almost all types of lamps with reflectors are used for advertising lighting 9EE605A.3to49

10. Lamps For Different Situations 5) Street Lighting The purpose of street lighting is to promote safety and convenience to pedestrians, vehicles, police supervision and other purposes The high illumination is required on traffic roads and shopping centers 9EE605A.3to410

11. Lamps For Different Situations 5) Street Lighting The light should be directed downwards from the lamp by suitably designed reflectors MV,SV, Fluorescent and Incandescent lamps are used for street lighting 9EE605A.3to411

12. Lamps For Different Situations 6) Flood Lighting It is the night time lighting of exterior areas such as open area of an industry, railway yards, sports stadiums, quarries and temples Flood lighting to parks, gardens,lakes,flower beds, buildings and ancient monuments should enhance the beauty and attract the public M.V.lamps,S.V.lamps and Halogen lamps with water tight reflectors are used for flood lighting 9EE605A.3to412

13. 9EE605A.3to413 Illumination of Different Practical Sources summer mid day, in open cloudless sky = 1,00,000 lux summer mid day under a balcony = 2000-3000 lux summer behind a window = 1000-3000 lux winter mid day, in open cloudless sky = 10,000 lux Sunrise and sunset = 500 lux Full moon and bright sky = 0-25 lux

14. Glare Glare is defined as unwanted light It is also defined as the light over and above that required for the performance of a visual task under most comfortable viewing conditions If the human eye is exposed to a very bright light, the pupil (dark circular opening in the center of the iris of the eye ) contracts in order to reduce the amount of light admitted and prevent damage to the retina. This phenomenon is known as glare 9EE605A.3to414

15. 9EE605A.3to415 Glare It is well familiar in connection with vehicle headlights If a lamp with out reflector is mounted at a very less height from the floor, causes glare Glare is also caused when high power lamp or high shining objects are seen

16. 9EE605A.3to416 Need of Good Lighting Good lighting makes seeing easy and comfortable. Visual comfort increases the efficiency of a workman When light is too dim,we can’t observe the objects properly. On the other hand, if light is too bright, we feel strain to open the eye lids If the eyes are opened by force, the water comes out and it makes seeing uneasy and discomfort

17. 9EE605A.3to417 Requirements of Good Lighting 1) Illumination Level The visibility of the object depends on the level of illumination, which in turn depends on the State of object Size of object Period of observation Colour of object Background contrast

18. Requirements of Good Lighting ii) Uniformity of Illumination The human eye adjusts itself automatically to the brightness within the field of vision If there is a lack of uniformity,the iris of eye has to adjust more frequently and causes fatigue to the eye For uniform illumination general and local lighting with brightness ratio not greater than 3:1 is to be provided 9EE605A.3to418

19. Requirements of Good Lighting iii) Absence of Glare The glare should be avoided Light sources should be mounted above the normal line of sight By using diffusers and reflectors glare can be reduced 9EE605A.3to419

20. Requirements of Good Lighting iv) Colour of Light The Colour of the incident light effects the appearance of the object Colour The composition of the light should be such that the Colour appears is natural and makes no difference from that under light S.V. and M.V. lamps produce Colour distortion, can be used in street lighting 9EE605A.3to420

21. Requirements of Good Lighting V) Shadows Long and hard shadows should be eliminated because they cause fatigue on eyes complete absence of shadows is not an ideal lighting, dull shadows are necessary to give the three dimensional view of any object 9EE605A.3to421

22. Requirements of Good Lighting vi) Contrast The local lighting should be supported by general lighting, otherwise it causes strain on the eyes 9EE605A.3to422

23. 9EE605A.3to423 Summary So far we have discussed about Applications of lamps for different situations Domestic, Industrial, Decorative, Advertisement, Street lighting and Flood lighting Phenomenon of glare Requirements of good lighting

24. 9EE605A.3to424 Quiz 1.A poor man for his kitchen lamp _____ is used a) S.V. lamp b) M.V. lamp c) Incandescent lamp d) Fluorescent lamp

25. 9EE605A.3to425 Quiz 2) Glare is reduced by a) increasing the mounting height of the lamp b) using diffusers c) using reflectors d) all of the above

26. 9EE605A.3to426 3) An illumination of about ----- lux is required to obtain day light a) 20 b) 300 c) 200 d) 100 Quiz

27. 9EE605A.3to427 4) when ___________ light enters in to the iris closes to protect the retina of the eyes a) dim -light b) bright light c) medium light d) none Quiz

28. 9EE605A.3to428 Frequently Asked Questions 1.State the requirements of good lighting 2.What is glare? how it can be minimized? 3.Explain domestic and industrial lighting

29. 29 THANK YOU 9EE605A.3to4