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TERM 2 SCIENCE ACE DONE BY: HOON TIAN JUN, TERRENCE LEDs VS Energy-saving Light Bulbs.

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Presentation on theme: "TERM 2 SCIENCE ACE DONE BY: HOON TIAN JUN, TERRENCE LEDs VS Energy-saving Light Bulbs."— Presentation transcript:

1 TERM 2 SCIENCE ACE DONE BY: HOON TIAN JUN, TERRENCE LEDs VS Energy-saving Light Bulbs

2 What are LEDs? a.k.a. light emitting diode a semiconductor light source demonstrates the phenomenon of electroluminescence

3 Practical Usage of LEDs replacements for neon and incandescent indicator lamps seven-segment displays (in telephones, calculators, watches etc.) Illumination (advertising, automotive lighting etc.)

4 How do LEDs Work? LEDs are made up of semiconductors, materials with varying abilities of electrical conductivity consists of a section of N-type (cathode) material bonded to a section of P-type (anode) material with extra holes when electrical current is applied to the diode, electrons from the N-type side travel to the P-type side, falling into one of the holes the energy from the electron falling into a hole is released in the form of a photon, which is a particle of light, giving off light as a result

5 Pros Cons Efficient energy use Long lasting Radiate little heat in the form of infrared Quick on/off response Small sized High initial price Dependence on surrounding temperature Pros & Cons of LEDs

6 Energy-saving Light Bulbs? a.k.a compact fluorescent lamp (CFL) a fluorescent lamp designed to replace incandescent lamps

7 How do CFLs Work? CFLs contain argon and mercury vapor also have an ballast, which produces an electric current to pass through the vaporous mixture, colliding with the gas molecules when the gas gets excited, it produces ultraviolet light the ultraviolet light in turn stimulates a phosphor coating on the inside of the tube as this coating absorbs energy, it emits visible light

8 Pros Cons Low initial cost Versatile Energy efficient (compared to incandescent bulbs) Dependence on surrounding temperatures Sensitive to on/off cycling Pros & Cons of CFLs

9 Comparison Compared to incandescent bulbs, both are superior CFLs are the best choices for people who are not looking for anything more than illumination LEDs are more cost efficient due to their longer lifetimes and durability, although the initial cost is higher Conclusion: LEDs are better than Energy saving Light Bulbs

10 References bulb bulb reen-tech/sustainable/cfl-bulb.htm reen-tech/sustainable/cfl-bulb.htm Compact-Fluorescent-Bulbs-Work%3F.html Compact-Fluorescent-Bulbs-Work%3F.html


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