Math and Science Report

Cris Belfer
Systems Engineering II
1/10/08

Math and Science Report

Introduction

When making an LED lighting fixture, math and science are a key element of the process, shaping the design aspects as well as functionality and performance. Designing a lighting fixture requires quite specific calculations and measurements. These along with precise scientific information, specifically heat and light properties, tie into the overall success of the fixture. But, none of this would be possible without the fast-growing and advanced technologies that aid in material manufacturing as well as product marketing.

Science

The science aspect of my design revolves around light-emitting diodes. And, one of the biggest factors when dealing with LED’s is their heat. If an LED gets too hot, its efficiency starts failing rapidly which would basically render the LED useless and the fixture a failure. So to compensate for the temperature, it has become common practice to give the heat a place to escape, away from the LED’s. For my design, I integrated the cylinder, in which the two LED strips reside, with ridges on the outside so that the surface area is greatly increased and allows the heat to run off.

Math

Artificial light sources are usually evaluated in terms of a related quantity, the overall luminous efficacy. This is the ratio between the total luminous flux emitted by a device and the total amount of input power (electrical, etc.) it consumes. This is often simply called “luminous efficacy”, which can be confusing as it also has units of lm(lumens)/W(watt). The range of a white LED is 26-70 lm/W with a 3.8%-10.2% efficiency. This compares to a 100 W incandescent (220 V) which has 13 lm/W and a 1.9% efficiency. This all compares to the theoretical maximum of 682.002 lm/W (100% efficiency).

Technology

Many technologies are used in the making of my design. In this case, LED’s are the prominent technology. Very small (figure 2.1) and very efficient, LED’s are widely popular for their longevity and applicability. From remote controls to streetlights, they are used in every capacity available and will have even more use as technology progresses (doubling every eight months).

Conclusion

In conclusion, making an LED lighting fixture requires all three categories (math, science, and technology) to be perfectly in tune. Without the science of how LED’s give off heat would we be able to compensate properly. Or without the math of lm/W could we see what the LED’s overall luminous efficiency is. And without the help of newer and better technologies it can get done faster and safer.