Step 1: Gather Parts and Tools
• 5mm LED light (3.6 volts, 25 mA)
• Resistor (68 ohms)
• 5mm LED holder
• USB 2.0 cable
• Electric Tape
• Wire Coat Hanger (Pipe cleaners will also work)
• Heat Shrink tube (optional, but preferred)
• Soldering Iron
• Rosin Core Solder
• Wire cutters
• Wire strippers (razor blade may be needed if wires are too small for strippers)
• Hairdryer or Heat gun
Warning: Do not have your USB cable inserted into any USB port while constructing your USB light (you might get shocked).
Warning: Place your soldering iron tip on its stand so it does not burn you or your workstation.
Step 2: Prepping the USB Cable
a.) With your wire cutters, cut your cable to 12 inches in length, measured from the "A" end (see picture 2)
b.) Peel back the outer insulation around one or two inches to reveal the inner USB cable wires (see picture 3).
c.) Locate the red (positive) wire and the black (negative) wire; and use your wire strippers to strip about one inch off of each wire.
TIP: If your wire is too small to be stripped by your wire strippers, place the wire on a sturdy surface and make an incision down the wire with a razor blade (see picture 4 ).
NOTE: If your USB cable has other wires (green and white) securely wrap each end with electric tape. These wires are data cables, which will not be needed (see pictures 3 and 5).
Warning: Use care if using razor blades, they can cause serious lacerations.
Step 3: Attaching LED's and Resistors
Tip: If you are using heat shrink tube slip it over your USB cable now. This will make it easier to set later.
a.) Insert your LED light into the LED holder (see picture 1).
b.) Take the stripped portion of the red (positive) wire and twist it around the long (positive) end of the LED light (see picture 1).
Note: A tightly bound twist is desirable because it ensures a good connection.
c.) Attach the short (negative) end of the LED light (see picture 1) to one end of the resistor using the same method in step 3b.
d.) Attach the other end of the resistor to the black (negative) wire, using the same method in step 3b.
Note: After completing step 3c your red wire, LED, resistor, and black wire should make a single loop, in other words they should be in series with one another.
Step 4: Soldering Connections
a.) Plug in your Soldering Iron and wait the manufacturer's specified time for it to heat up. While you wait use your wire cutters to cut a three or four inch section of solder from the soldering spool.
b.) Once the iron is heated touch the end of the iron to the LED-red wire connection for about 10 seconds. This heats up the wires so they accept the solder better (see picture 1)
c.) Immediately upon heating up the connection, take the solder and touch it to the heated twisted connection and touch the end of the soldering iron to the solder to help it melt. Once melted, remove solder and soldering iron and allow the connection to cool for a few seconds (see picture 2).
d.) When the solder has cooled, repeat step 5b and 5c for the LED-resistor connection and the resistor-black wire connection.
When completed your USB light should look like picture 3 above.
Step 5: Testing the Connections
a.) Plug your USB cable into a USB port. Be sure to not touch a bare wire while performing this check, because you might get shocked! If the LED lights up your connections are good and you can proceed to step 5b (see picture 1). If the LED does not light up, unplug the USB cable and ensure the proper connections have been made (See step 3).
b.) When you have verified your connections are good, unplug the USB cable. Once the cable is unplugged wrap the bare wires with electric tape (see picture 2).
Warning: Do not touch or modify exposed components while performing your test due to electric shock risks.
Step 6: Add Structural Support and Seal Up
a.) Cut your wire coat hanger with your wire cutters so that the wire starts at the "A" end of the cable and ends right before the LED holder; this gives you the option of moving the tip of the light around (see picture 1).
b.) Once the wire is cut to length insert it into the heat shrink tubing, along with the USB cable (see picture 2).
c.) After inserting the wire, heat up the heat shrink tube with the hairdryer until it conforms to the shape of your wire and cable. If there are any parts (such as wire or cable) exposed, use electrical tape to seal them together (see picture 3).