Topic of Research (Chiam Chuen) -- Wire Wilt: How light-emitting diodes fade as temperature increases

Topic Overview

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Wire Wilt: How Light-Emitting Diodes Fade As Temperature Increases

Time Required	Short (2-5 days)
Prerequisites	None
Material Availability	Readily available
Cost	Average ($50 - $100)
Safety	You should never look directly into an LED flashlight, as it can cause eye damage.

Abstract

What's your favorite thing to do on the hottest day of the year? Dip your toes in an icy river? Hang out by the pool? Retreat to a cool basement? Lie motionless in the shade? You're probably not too eager to move around and put out a lot of energy, like mowing the lawn in the mid-afternoon sun. Well, you're not the only one. In this electronics science fair project, you'll find out that some semiconductor devices, like light-emitting diodes (or LEDs), act the same way. As their internal temperature goes up, their light output goes down.

Objective

To determine how the output of an LED flashlight changes over time as its temperature increases.

Credits

Kristin Strong, Science Buddies

Edited by Steven Maranowski, PhD, Philips Lumileds Lighting Company.

Hypothesis and Variables

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Hypothesis:

If I increase the temperature around the LED light in a controlled environment, then the light output of the LED light will be lowered.

Variables:

Independent - Temperature

Dependent - Light output of LED light

Constant - Environment of testing and type of LED light

Research Questions

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What are they?

- LED is actually the short form for Light-Emitting Diodes, which are semiconductor light source, which are increasingly used for various purposes.

What are the current research?

- Most current researches focus on how the temperature affects its reliability, and not its light efficiency. An example would be an experiment conducted by the Department of Mechanical and Electronic Engineering, Jiangsu Vocational And Technical College of Finance and Economics, Huaian

223001, China. They were conducting various tests on LED lights to investigate how each variable affects the LED lights, and to what extend.

Why is it important?

- It is beneficial to places with great temperature changes, which requires enough light throughout the temperature change. Reliability is also needed for large scale application. LED lights are also used often as indicator lights, and if they were to fail, they could cause misinterpretation of data, causing more problems.

Equipment required:

- Similar type of LED lights

- A controlled environment with a thermostat, cooling and heating systems installed

- Light sensor

- Data collector