We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byPaulina Flowers
Modified over 4 years ago
IP2.22.3 Introduction © Oxford University Press 2011 Introduction
IP2.22.3 Introduction © Oxford University Press 2011 Filament lamps and LEDs are both devices that transform electrical energy into light. The way they do it is very different and technological advancements have changed how they are used in everyday applications.
IP2.22.3 Introduction © Oxford University Press 2011 A filament lamp is a thin coil of wire which is usually made of a metal with a high melting point such as tungsten. When a current flows through the wire, it glows brightly and becomes hot. The glowing filament gives off useful light but it also generates a lot of wasted heat. These bulbs are very inefficient. Efficiency of a filament bulb is about 7.5%.
IP2.22.3 Introduction © Oxford University Press 2011 An LED, or Light Emitting Diode, uses special substances called semiconductors. When these semiconductors are arranged in a particular way they allow a current to pass through them in one direction but not in the other. However, when the current flows light energy is emitted from the semiconductor. Very little heat is produced so this type of lighting is very efficient. Efficiency of an LED is about 75%.
IP2.22.3 Introduction © Oxford University Press 2011 Semiconductors only emit light of one frequency (i.e. one colour). For many years LEDs have been mainly red, green or blue. However, with advances in techniques manufacturers now add phosphors inside blue LEDs which absorb and re-emit light of different colours. These LEDs create a mixture of light which looks nearly white. This advancement and cheaper manufacturing costs has meant that they are now beginning to replace filament lamps with more efficient LEDs. LED lights use less energy, are smaller and also last longer.
How LEDs Work.
Review for SENV7700 Independent Study Project A Review of LED lighting of Building on Energy Efficient ZHANG XI
How Architectural Engineers Impact Building Energy Use Lighting, Controls and Energy Savings.
Light & APPLICATIONS OF Optics
What is Light?.
USING LIGHT EMITTING DIODES FOR LIGHTING BY: GRANT GORMAN AND ALEC PAHL 5/6/2013 ABSTRACT: LIGHT EMITTING DIODES ARE SEMICONDUCTOR DEVICES THAT EMIT LIGHT.
Types of Light Bulbs and Their Uses
Incandescent bulbs are the original form of electric lighting and have been in use for over 100 years. While Thomas Edison is widely considered to be the.
What Affects the Flow of Electricity? Some materials are good conductors. Electricity flows best through conductors. The base and the wires of a light.
Man Made Sources of Light AKA Mr. Abe’s “Light Show”
Producing Visible Light EQ: How is visible light produced?
12.3 Essential Questions What are the advantages and disadvantages of different lighting devices? How does a laser produce coherent light? What are some.
Lesson 3. Producing Visible Light The most important natural source of light on Earth is the Sun. There are, however, other natural sources of light,
Light. What you see depends on the amount of light in the room and the color of the objects. For you to see an object, it must reflect some light back.
Sun- nuclear fusion Process: H + H He + Energy All elements are made like this… we are all star dust! Qualities and Applications: All colours.
Inside an Incandescent Light Bulb. You are will be using an incandescent light bulb to build circuits in class.
Mr. Fleming. D. 5 Explain how electricity is used to produce heat and light in incandescent bulbs and heating elements.
“We now know a thousand ways not to build a light bulb”
© 2019 SlidePlayer.com Inc. All rights reserved.