The Tilt-Acitivated LED Candle project teaches kids about simple electric circuits and produces a cute decoration that students can take home!

This project is targeted towards 4-8 grade kids. I am a 4-H Teen Teacher and facilitated this project with 4th and 5th graders at my local Boys and Girls Club. All but two of the kids were able to successfully complete this project!

Before working on the project, I introduced:

What is an LED
Applications of LEDs
Basic electric circuits with batteries
How a tilt switch works

Happy making!

Supplies

Pre-wired 12V flickering LED

You can also make your own by wiring and taping together an LED and resistor.

A23 12V battery holder

Or any glass jar works too! I just thought the small jars look cuter.

Electric tape

Normal clear tape, painter's tape, or duct tape will also work.

Wire strippers

Scissors

Hot glue

Optional: decorating materials (glitter glue, ribbons, etc)

Step 1: Full Video Tutorial

This is a start to finish video tutorial for the project with voice instructions.

Step 2: Strip Wires on the Battery Holder and Pre-wired LED

Using wire strippers, put the wire in the hole, clamp down, and pull outwards. The plastic insulation should slip off, leaving only metal wires. Try to strip off a longer portion of the insulation to make it easier to tape. Strip the 2 wires attached to the LED and the 2 wires attached to the battery holder.

Tips:

Don't clamp down too hard with the strippers. Clamping down too hard might cut the wire, which we do not want.
If you don't have wire strippers, you could remove the insulation using scissors by gently cutting around the insulation without cutting through the metal wires.

Step 3: Tape the Ground Wires Together (black Wires)

Ground wires are the wires connected to the negative terminals of the battery and the LED. They are the black wires. Twist the ground wire of the battery together with the ground wire of the LED. Tape them together securely.

Tips:

Folding the twisted wires back and taping the them along the black wire will make it more stable.
Be generous with tape!

Step 4: Adding the Tilt Switch and Taping Together Positive Wires

The tilt switch has two ends: an end with a small nub and a completely flat end.

The positive wires are the wires connected to the positive terminals of the LED and battery. They are usually not black colored.

Twist the battery holder positive wire (red wire for me) around the wire from the flat end of the tilt switch. Tape them together.

Twist the LED's positive wire (yellow in my case) to the wire of the nub end of the tilt switch. Tape them together.

Fold the wires back so that the two wires and the tilt switch form one line. Tape this generously so that it forms one big mass.

Tips:

Bend the tilt switch's stiff wires slightly once you have taped them. This prevents the twisted-on wire from slipping off.

Step 5: Test the LED

Put the battery into the battery holder. The negative end (flat end) should be pressed against the spring.

Try moving and tilting the LED to different positions. You should observe that when the tilt switch is pointing one way the LED is on, and when the tilt switch is pointing the other way, the LED is off.

Take out the battery once you have made sure it works.

If it does not work:

Check that the battery is put in the battery holder correctly
Check that your wires are indeed well-connected and securely taped.
Check that the two ground (black) wires are connected and the positive wire of the battery is connected to the positive wire of the LED via the tilt switch.

Step 6: Cut Straw to Make the "candle"

Put the jar upside down. Using the jar as a reference, cut the bubble tea straw to be about one inch shorter than the jar's height.

Step 7: Tape Inside of Jar Lid

Use tape to cover the inside of the jar lid. Jar lids are usually treated to be nonstick, so hot glue will not hold on a bare lid. Covering it with tape will allow the hot glue to hold.

Step 8: Fold Wires and Thread Through Straw

Take the LED and battery unit. Make sure when you are holding it, the wires from the battery holder and the tilt switch are pointing up. Fold the LED wires down to the tilt switch, and then back up (as many times as you need to get the LED wire bundle to be about the same length as the straw piece from the previous step). Make sure that after folding, the LED itself is ultimately pointing upwards.

Take the piece of straw and thread the wire bundle through. Make sure that the LED is poking out of the straw at the end.

Tip:

Use a pencil/chopstick/skinny thing to poke the LED out of the straw if you're having trouble pulling it out.

Step 9: Glue Candle and Battery Holder Onto Lid and Put in Battery.

Using hot glue, glue the battery holder down onto the lid. Many jars will have a rubber ring around the perimeter of the lid which is meant to help the lid close. Make sure that you are not gluing any pieces on that ring, or else the jar will not close right.

Then, glue the straw LED bundle on the center of the lid. Make sure the LED is pointing up.

Add glue as needed to secure both pieces. Put the battery into the battery holder.