In this exercise you’ll be making a beautiful light-up necklace or patch with LEDs in a parallel series. We took a sheet of white felt and added flowers to it, but you can decorate your necklace however you want! You could easily turn this exercise into a light-up backpack patch.
- Multicolor Felt
- Sewing Needle
- Glue (preferably hot glue)
Creative Circuit Materials:
- 3 LEDs
- 2 Coin Cell Batteries
- 2 Coin Cell Battery holders
- Conductive Thread
Step 1: Bend the Legs!
Identify the negative (shorter) and positive (longer) legs of the LED. Bend the legs of the LEDs into loops that you will eventually sew around.
Trick: We usually make the positive leg of the LED into a square or angular loop, and the negative leg of the LED into more of a circle loop to tell them apart.
Step 2: Test the LED!
Double check that you know which leg is positive and which is negative with an LED before you move on. You can always add a sharper mark to the positive leg to make sure. You don’t want to have sewn your project and realize the legs of the LED are backwards - meaning it won’t light up :(
Step 3: Lay Out Your Circuit!
Identify the negative and positive sides of the battery holder. Typically the part of the battery holder that extends over and touches the top of the battery is the positive side. You can test this by putting a coin cell battery in the battery holder and then touching the legs of an LED to the two metallic sides of the battery holder. If it lights up, you know the
Lay your LEDs down on the backside of your decorated, or soon-to-be decorated piece of felt. We glued down the battery holders to keep them in place. Make sure the positive side of the battery holder and all the positive sides of the LEDs are all on the same path.
It doesn't hurt to stop here and do one last double check before you sew your LEDs and battery holders down. If one of the LEDs is turned around (meaning the negative leg aligns with the positive side of the battery holder) it will be an unfortunate waste of time.
Step 4: Let's Start Sewing!
You'll now be sewing two paths with two separate pieces of conductive thread.
This is the plan:
Path ONE: Path One will start with the negative-side of the sewable battery holder and connect all the negative legs of the LEDs and end at the second battery holder.
Path TWO: Path Two will start with the positive-side of the sewable battery holder and connect all the positive legs of the LEDs and end with a loop around the positive end of the second battery holder.
Make sure you loop around the sewable ends of the battery holders at least twice to secure the connection.
Step 5: Knot the Thread at the Negative End of the Battery Holder!
Knot the thread at the negative battery holder’s metal terminal, and cut the thread.
Step 6: Nail Polish!
TIP: Add clear nail polish to the knot on the negative side of the battery holders for extra circuit security.
Step 7: Repeat...Sew Path 2
Thread your needle with another length of conductive thread.
Repeat the Path ONE sewing process, but this time connect the positive sides of the battery holder to the three positive looped legs of the LEDs until you get to the second battery holder. Loop the thread through the other battery holder's positive side. Make a knot and cut the thread.
Step 8: Get Your Batteries Out!
Once you’ve completed sewing, test your circuit with one coin cell battery. It should work, meaning your LEDs should light up. To add brightness, add another coin cell battery to the other side of the circuit.
Step 9: Decorate!
Decorate your necklace or patch with felt cut-outs however you may wish! Add ribbon, or a chain, and show your friends your new blink blink creative circuit necklace (with parallel circuit!).