Lantern Reflection

When the class was first told that we had to build a lantern using a resistor, a nine volt battery, and an LED bulb, I was nervous. How could I build anything so complicated that it required a familiarity with basic electrical engineering? I thought that there was no way that I could handle the monumental task of actually creating something (that worked) from scratch.

I was wrong. I ended up building a flashlight. I used a juice bottle that I had lying around (which I drank for science, of course) as my body. I took off the plastic wrapping, washed it out, and let it air-dry. While that was going on, I did a few calculations. Using Ohm's Law, I determined that I would need a resistor of at least 450 ohms so that the bulb didn't burn out. I would also need to fashion some makeshift wires out of metal so if the battery was at the bottom of the bottle, the bulb could stick out of the top. I used aluminum foil for those - it turned out to be highly malleable and easy to work with, and once I had wrapped my "wires" with electrical tape to secure them, they proved to function effectively.

The circuit itself was not very difficult to build because it had only three main components: the bulb, the battery, and the resistor (which ended up being 470 ohms because there was no resistor in the lab that was exactly 450 ohms). However, incorporating a switch turned out to be an interesting challenge. I decided to use a brad fastener as mine because it is sturdy and long. To turn on my lantern, one must wrap the exposed aluminum foil around the brad and the LED will shine brightly. I also faced a challenge in trying to intensify the bulb's light, but then I noticed that the aluminum foil I was using had a particularly reflective and shiny side. I exploited this by wrapping it around the mouth of my flashlight so it surrounded my bulb. In doing so, the light reflects off of the foil's surface and focuses in a singe direction (ahead of the bulb). In this sense, it is a true flashlight. I imagine that it could be used to light one's way in a very dark night. The benefit of this flashlight versus a regular one is that this one is much lighter and if need be, one can shake it around to make noise and scare away any animals or other predators. The bottle can also be crinkled to make a loud noise without damaging the quality of the light itself. Going outside in the middle of the night is easy because the light stays on if the aluminum foil is wrapped around the fastening brad.

This is my flashlight! I spiced its body up with some sharpies, but other than that, the design is purely functional. I am very proud of how I was able to pull it together, especially since I would not have imagined that I would have been able to as little as two weeks ago. After five very productive hours, here is my work:

Until next time, 

Ananya