’Tis the season … for tacky–holiday-sweater parties. Despite how funny it is that these crazy, off-the-wall sweaters are now in such high demand, it’s not funny to show up without one. So we’ve got some simple ideas that can help you turn any holiday sweater into the talk of the party.
Things You’ll Need from RadioShack:
– This is a great “plug-and-play” kit for any novice D.I.Y.ers. For this project, we’ll use wires to extend the LEDs so we can move them around the sweater.
– The kit requires some soldering, as does connecting your LEDs to the wire. This is a great chance to learn and practice proper soldering techniques.
– Try to get a small-gauge wire; we used 22-gauge for this project. Cut these in whatever size strands you need to extend the LEDs to your sweater. Use one color, or get red and black spools to specify the positive and negative polarity.
– You’ll need these to cut the wires and trim the pins of your components after soldering them onto your circuit board.
– Can’t light up without some power.
A festive holiday sweater
Where to Begin:
Start your project by clearing a workspace. When soldering, make sure there’s nothing lying around that could become a fire or burn hazard.
Open your Flashing LED Sweetheart Kit and make sure all components are included. Identify the resistors and each of their locations described in the instruction guide. Solder them onto the circuit board. Snip off the extra pin of each resistor after you solder it into place.
Continue by soldering the transistor and capacitors into place, per the instruction manual. Save the LEDs for last, because you will be extending them with wire.
Extending the LEDs
The next step can be done multiple ways. If you are inserting lights into a specific pattern on your sweater, you can lay the circuit board face-down on the sweater and measure two wires from the circuit board to the LED’s location. If you do this, leave at least an inch or so of wire on each side for connection and slack. If you want to place your LEDs in random places, or if you want to assemble without measuring, cut 56 strands of equal-length wire, one strand for each cathode and anode of each LED. If you are using wires of two colors, cut 28 of each.
Once you have your wires measured or cut, strip about half an inch off each side. Insert the wire into the circuit board. If you are using two colors, make sure the red (positive) wire is on the circular side of the LED insert and the black wire (negative) is on the flat side. Solder the wires onto the board and snip off the excess.
Connecting the LEDs
You can continue to solder all wires into place and then connect the LEDs at the end, or you can connect an LED with each pair of wires. To connect the LED, strip the ends of your positive and negative lead wires. Strip enough wire to wrap around the pegs of your LEDs—about half an inch. Connect the negative wire to the cathode (the shorter peg) by twisting the wire around the peg. You can use needle-nose pliers to help. Connect the positive wire to the anode (the longer peg) the same way. Once connected, solder the two together and trim any excess off the bottom of the peg.
If you want a clean look, cut small pieces of heat-shrink tubes (http://www.radioshack.com/product/index.jsp?productId=2104090) and insert them on the tube before connecting the LED. Once connected, slide the tube around the connections and use your soldering tool to apply heat close to the tube until it shrinks around the connection. You can also wrap each connection with a small piece of electrical tape (http://www.radioshack.com/product/index.jsp?productId=2103348).
Designing Your Sweater
Once all LEDs are connected, attach two longer wires to the battery connection on the circuit board. Solder these into place, and connect them to the negative and positive wires on the included battery holder. You may need to strip some of the wire on the battery holder connections.
Pop in your 9V battery and your lights should start blinking in an alternating pattern. Remove the battery before placing your lights. To position them in your sweater, bend the top of the LED so that it sticks through a small hole in the sweater and the wire is flush against the back of it. Secure the LED wires at the hole with electrical tape.
Your battery holder should be long enough to store in your pocket, or you can tape it to the inside of the sweater.
Tip: If You Want to Keep Your Sweater Washable
Instead of taping your LEDs to the inside of a sweater, attach them to the inside of a T-shirt first. Trim the shirt so that it fits inside the sweater and attach the new LED panel with Velcro to the inside of the sweater.
This kit and others available at RadioShack are great ways to learn the basics of building circuits— and with a little creativity, to customize into a cool new project. So, try it out, and if you do, let us know in the comments section!