We were inspired to make these ‘cards’ by the simplicity of using LEDs to add a spark of light to any project. This is a great “wiring 101” project because kids can see exactly how a circuit works, and they can assemble it themselves without stripping wires, adding switches or worrying about being shocked. Once they understand the connections, they can make card after card after card.
•LEDs (You can scavenge LED from a string of holiday lights or order a container for $4.95 from the Electronic Goldmine (http://www.goldmine-elec-products.com/prodinfo.asp?number=G17169)
•Wire (We use 26-gauge florist wire – from any craft store or florist. You just need 18”)
•Paper Fastener (from the office supply store)
•3V Battery (coin battery)
•A sheet of cardstock to fold into a card
•Other colored paper, markers, glue, scissors, etc, to design the card
Ages 6+ with grown-up help.
In this project, it is important to follow the steps and test your circuit as you go.
1. Plan out your design lightly in pencil before you get started. Fold the cardstock in half to make a card. You will cut away some portion of the front of the card so make sure to factor this into your design. We used cut paper to create the elements of our picture; we created these first so we could plane the layout, and then we set them to the side.
2. Plan out your circuit. The paper fastener will need to punch through the front of the card, and the battery must be affixed (negative side up) to the back of the card. When the card is closed, the button of the paper fastener should meet the (negative) face of the battery. The LED should show from the front, when the card is closed; the battery should be hidden.
3. Once you’ve sketched in the placement for your paper fastener, battery and LED, draw the path of the wires. One wire should connect the paper fastener to the cathode leg of the LED. Another wire should connect the anode leg of the LED with the positive side of the battery (the end of this wire will be sandwiched between the back of the card and the battery).To identify the Anode and Cathode legs, take a close look at your LED. The anode leg is slightly longer and the little flag at the top (inside the plastic ‘bulb’ section) is smaller. The cathode leg is shorter, and the little flag at the top is larger.
4. Now – start taping your circuit components into place. You can also use masking tape to make sure your wires don’t cross. Tips: Just tape the battery around the edges; don’t cover the whole thing because then you will lose the connection between the battery and the paper fastener. Also, you can bend the legs of the LED away from each other and this will make it easier to wrap the wire around them.
5. With everything taped down – test your circuit! Close the card; when you down on the paper fastener (so that it touches the battery) does the LED light up? If it doesn’t light up, trouble-shoot. Make sure your connections are secure at each point, that the wires are not touching, and that the positive side of the battery is pressing down firmly against the wire leading from the anode leg of the LED.
Then, finish your design! Draw or glue in the rest of your picture. You can cover the wires with another piece of paper if you don’t want them to show, but make sure to punch a small hole where the LED will stick through. Make sure to add a little note or circle on the front to let people know where to press to light up your card!