Step 1: Gather All the Tools and Material
The key to success is proper material and tools. Here is what you gonna need.
- Narrow pliers – 2 kinds
- Round-nose pliers
- Side cutters
- Soldering station with 900M-T-2C soldering tip
- Double sided tape
- Piece of paper
- 1mm/0.8mm straight brass rod
- SMD 1206 LEDs
- coin cell battery (CR2016, CR2025, CR2032, ..)
- tin solder
- soldering paste
Step 2: Start With Template
I always start with a paper template. It will help you to make a precise shape. You can use some of mine own template attached or you can create your own.
Step 3: Bend Wire Into Outline
Bend the brass rod using pliers into the shape of the outline. Take your time, make it nice.
Step 4: Solder the Outline Ends Together
Use a tiny amount of the soldering paste and tin to solder the ends of outline wire together. Soldering paste will help the tin to nicely adhere to the brass.
Step 5: Place the LEDs
Another magic is to use a double-sided tape as a third hand to hold the shape and LEDs in place while soldering. Use double-sided tape to hold the outline in the place. Put all the LEDs into the proper positions while the outline wire is still on tape and solder them. Keep in mind that the LEDs have electrical polarity. They need to be placed in the correct position in order to lit. Take a look at my template there is a graphic explaining how you need to place them.
Tip: Do not use different colors of the LEDs on the same necklace. Different colors have different voltage properties so you would end up only with one color lit.
Tip: Double-sided tape will lose its stickiness when heated. So you most likely have only one try to solder the LED to the brass.
Step 6: Connecting LEDs
Now you need to interconnect all the other leads of the LEDs together to create a proper electrical circuit. Again bend the wire, place it on tape and solder to the other ends of LEDs.
Step 7: Create Battery Holder
Solder a wire on the back of the necklace to create a pocket for a battery.
Step 8: Done
Now place a battery into the necklace and see how nicely it lit up! There are different types of coin batteries with different diameters and thickness. The only requirement is to use 3V battery. The battery depending on the size and number of LEDs used will last around 24h.
You might be wondering why there is no current limiting resistor. Won’t the LED burn? My design uses an internal resistance of the battery. The battery itself won’t allow such high current to burn the LEDs. Nasty trick.
Step 9: Make More and Share!
Make whatever shape you like, the only requirement is to create a proper circuit for the battery to lit up the LEDs.