Lantern

Materials used for this project:

Metal can (originally used to store coffee)

LED lamp 3.6 v

9 v battery (lab)

270 or 470 resistor (lab)

Twist ties (originally used to bind leafy greens)

A piece of 1” X 2” corrugated carton

A 1” x 1” chicken wire

Aluminum foil

Since the first day we were given the assignment, I started to look for anything around me that could be used for this project. Checking the recycled bin, I had a few options but decided to go with a metal can which was originally used as a storage for ground coffee. My selection was influenced by the Poor People Energy Outlook 2014 reading. My main point was to use a material that will be reflective and add some source of heat. This coffee can includes a reflective lining. Additionally, being metal, the can may provide a little heat when the light is on. I also added a small empty anchovies can that would serve as a tray to hold the battery—I ended up not using that can.

I did some calculations to select the right resistor:

I first did a basic calculation without deducting the 3.6 v from the 9 v. and was looking for a 450 Ohms resistor. Since there was no 450 I settled on 470 Ohms.  The resistor was not in the right drawer, therefor I ended up using a resistor color code to calculate various resistors until I found the 470 Ohms resistor.   Later, I did the original calculation but subtracted the 3.6 V from the 9 V and divided by 20 mA. This gave me a resistor size of 270 Ohms. Trying both, I realized there was no much difference in the intensity of the lights. Therefore, I decided to build the circuit with the 470 resistor, figuring that my battery will last longer if less current goes through it.

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 Next, I draw the circuit diagram and the idea.   I envisioned the on/off switch on the side of the container. See below

 Creating the circuit, I first checked that the 9 V battery and my LED were working properly. I created a circuit by attaching the resistor to the plus sign; then I attached to the free side of the resistor the long leg of the LED, and attached the short leg of the LED to the negative side of the battery. All looked good. The light was bright enough. I decided to stay with that resistor. However I needed a longer circuit so that I could position the LED properly and have room for the on/off switch. I first pulled the plastic off of the edges of a used twist tie. Next, I attached the resistor to the plus side by creating a loop around the plus of the battery. I attached the end of one wire to the resistor and then the long leg of the LED lamp to the other end of the wire, on the plus side.  I then extended the short leg of the LED with another piece of twist tie and checked the circuit. 

All looked good. Next, I created the switch. I used scraps of chicken wire for this purpose. I attached one end to the plus side of the circuit and one side to the minus. I wrapped the part that would extend through the slit with electric tape so that it would not come in contact with the metal. I used a piece of corrugated carton as the external part of the on/off switch. The lantern worked properly. I envisioned it as a handy flashlight that can be assembled everywhere when needed.