This project is pretty technical mechanically, but not much computing is involved. This is a good project for people who are interested in learning about soldering, how circuits work, or wiring. This project can be used to create an exit sign above a doorway or window to help evacuate people in an emergency.
Step 1: Materials
- 100 pack of red 5mm LED Lights (color can be changed depending on preference)
- 7"x9" piece of thin wood
- ruler with centimeters and inches
- soldering iron
- DC Power supply
- Alligator clips
Step 2: Setting Up the Board
To set up the board, a thin piece of wood is recommended. The wood I used was about 1/16" thick. Measure a 7"x9" section of the wood and use a saw, particularly a band saw, to cut the piece of wood. Use your ruler to measure a 1/2" section from the perimeter of the board to create a boundary. This is the farthest to the edge that the LED's will be placed. Next, holes for the LED's need to be drawn. With the exception of the X, all of the LED"s will be placed 2 cm from each other. For the E, 3 LED's will be drawn on the top and the bottom of the edge when the board is running horizontally(when talking about the project, it is horizontal). Vertically, use 8 LED's, including the LED's from the horizontal lines along the left boundary. Next to the middle LED, place another LED 2 cm apart from the LED. On the horizontal boundary, place another LED 2cm after the third LED. These will be the basis of the X. @ inches away on the other horizontal boundary, place another LED. Draw a vertical on from opposing LED's to create the lines where you will be placing the LED's. In the place that the lines meet, put an LED. Put three LED;s, 2 cm apart on both sides of the horizontal line starting from the horizontal boundary. 2" away from the furthest LED to the right on the horizontal axis, create a vertical line from one horizontal boundary to the other. This will create an I. Place the LED's 2cm apart from each other. 2 inches away from the Top LED on the horizontal perimeter, line 3 LED"s 2cm apart; the last LED should reach the vertical boundary. Coming down from the middle LED of the three sbould be a vertical line from the horizontal boundary to the other that have LED's lined up 2cm apart from each other. Your board should be similar to this one.
Step 3: Drilling Holes and Putting in LED's
Using a drill bit that is 1/16", drill holes in the previously marked spots. You can use sandpaper to sand off the lines you drew in the previous step. Once this is completed, place an LED in each hole. It is helpful for the wiring to keep all of the positive anode(the longer leg of the LED) on the right while the negative cathode(the short one) on the left. The LED bulb should be showing on the side of the wood that you plan to show. Mark a positive or negative symbol next to the corresponding legs(do this on the back of the board).
Step 4: Wiring and Soldering
This is the most complicated part of the project. In order to wire, make sure that all of the correct legs of the LED is lined up with similar polarity. Split the LED legs apart far enough that the wire will not touch. Using long, thin strands of copper wire(I used telephone wire), wrap the wire around the LED one time and then wrap the wire around the next LED similarly. Do this for all of the vertical letters separately from the horizontal parts, and connect later. When connecting, make sure that NO WIRES OF OPPOSITE POLARITY COME IN CONTACT!!!!! On the X, only one diagonal can be totally strung while the other diagonal has to be split and come in contact with other from different letters.
For soldering, solder each wire to the leg of the LED with a STRONG connection. Make sure the connection is strong is strong before soldering, this was my mistake. My LED's are either not as strong or not showing up because the soldering connection is not strong. Make sure that the solder does not come in contact with the other polarity as it will create a nonfunctioning circuit. Soldering is the most meticulous part of this project.
Step 5: Power
Without the power, this doesn't work. For a power source, you need a DC power supply at around 2.9 or 3 volts. Use alligator clips to connect the positive wire to the positive knob on the power supply as well as the negative. Make sure the clips do not touch opposing wires or clips. One clip should be sufficient because you have created a complete circuit. Your board should light up, but if it doesn't, check the connections between LED's and wires, as well as any wires that could possibly be touching. Hopefully more LED's light up than mine, but this is what it should generally look like.