Introduction: Festive Flashlights
Diane Brancazio, firstname.lastname@example.org, Edgerton Center staff
Justin Schmidt, email@example.com, Edgerton Center affiliate
For students and Makers age 8 and up.
Shine some light on a customizable cut-out figure with this festive electronics project. Make an LED flashlight, a reflector, and a holiday symbol out of easy-to-find materials. Your holiday symbol will come to life as the reflected light washes over it. Make lots and create a holiday atmosphere in your home or classroom. In our example, we are using a skull to celebrate Día de Muertos or Day of the Dead; a Mexican holiday observed at the end of October to remember family and friends who have died. The shape of your Festive Flashlight is up to you – celebrate whatever, however you choose!
Skills and Concepts:
- Circuit principles - insulators and conductors, series circuits, component functions
- Hand fabrication
- Graphic design
- Jumbo popsicle/craft sticks (6-inch long variety, 18mm x 150mm)
- Aluminum foil
- Clear tape or glue
- Cardstock (white or light-colored for the figure)
- Small binder clips
- Coin cell batteries (size 2032 works best)
- Color-changing LEDs (can be substituted with any single-color LED)
- Copper tape with conductive adhesive (¼ inch/6.35mm width tape works well)
- Black/dark fine-tip markers for decorating figures (optional)
- Vinyl/Craft cutter (such as Cricut or Silhouette)
- - OR -
- Xacto knife, cutting mat, straight edge
- Printer (optional, if cutting parts out by hand)
Step 1: Apply Copper Tape to the Flashlight Body
On one side of the popsicle stick, apply a strip of copper tape from end to end. This will be the POSITIVE (+) side of the circuit and will face down when the festive flashlight assembly is completed. Mark this side with a + on both ends.
On the other side, apply copper tape to the length of the popsicle stick, but leave about half an inch (or 12 mm) of space on one end with no copper tape. This is where the binder clip will be attached later. This will be the NEGATIVE (–) side of the circuit. Mark this side with a – on both ends.
Step 2: Connect the LED
If you don’t have a color-changing LED, use a single color LED. Test the LED on the coin cell battery to make sure you know which lead is positive (+) and which lead with negative (-). The positive (+) lead is usually a little bit longer than the negative lead.
Place the LED on the popsicle stick so that the leads of the LED are touching the copper tape on either side of the stick. Make sure to attach the longer LED lead to the positive (+) side of the popsicle stick (the side with the longer strip of copper tape).
Cover the leads of the LED with copper tape. Rub or “burnish” the copper tape with the edge of your fingernail or the back of a pen/etc. to ensure a solid connection to the LED!
The color-changing LED used in this project is actually three separate LEDs – red, blue, and green – in one component, along with an integrated circuit that controls the cycling and timing of the color changes. All of this circuitry is crammed into a single 5mm LED package! If you look closely, you can see the block inside that contains the integrated circuit, as well as the tiny wires connecting to each LED.
Step 3: Attach the Battery and Power Switch
On the opposite end of the popsicle stick from the LED, attach the battery with the binder clip. The positive side of the battery is marked with a + symbol. This side should touch the copper tape that is attached to the positive (+) leg of the LED.
The NEGATIVE side of the battery is connected to the other side of the popsicle stick through the binder clip, which serves as a switch. Flip the handle of the binder clip down to complete the circuit and light the LED.
You have just created an electronic circuit! Flip the binder clip handle to turn the LED on or off by closing and opening the circuit.
A short circuit is when part or all of the circuit is bypassed by an incorrect connection – like a stray wire – sometimes leading to very high current flowing through the circuit, potentially generating enough heat to cause damage to components. Short circuits can also cause fires if the current is high enough.
If the LED does not light, check for a short circuit. Start with the binder clip – is it creating a direct connection between the POSITIVE and NEGATIVE sides of the battery?
An open circuit is when current cannot flow because there is not a complete path between the POSITIVE and NEGATIVE sides of the power source. We want there to be open in this circuit when the binder clip handle on the negative side is flipped up – when the switch is in the OFF position.
If the LED does not light, and there is not a short circuit, look for an open. Make sure the battery is contacting the copper tape on the positive side and that the binder clip is positioned to contact the copper tape on the negative side. Check the connections between the copper tape and the leads of the LED – copper tape can be finicky and may require more pressure to ensure a good connection.
Step 4: Create the Reflector
To hand-cut a reflector, draw this shape onto a piece of cardstock.
If you are using a Cricut, Silhouette, or another computer-controlled vinyl/craft cutter to cut out the shape for the reflector base, import this .png image into your craft cutter software and trace to cut. Be sure to check your dimensions after importing – the overall dimensions of the .png should be 2.42in x 4.25in (61.47mm x 107.95mm).
Use clear tape or glue to attach a piece of aluminum foil to the reflector. Be sure to put the shiny side out. You can smooth out the foil before attaching it to the reflector, or leave it crinkly – experiment to see how the texture of the foil changes the way the light from the LED is reflected.
Fold the reflector as shown below. The green dotted lines in the diagram indicate valley folds - fold the reflector in towards you on these lines. The blue dotted line indicates a mountain fold - fold the reflector out away from you on this line.
Use glue or tape to complete the reflector assembly.
Step 5: Create the Figure
Your figure should be roughly 3 ½ inches (89 mm) tall and 2 ½ inches (64 mm) wide. Add a tab to the bottom of your figure, about an inch wide (25 mm) and ½ inch (13 mm) tall, to attach the shape to the reflector.
The skull used in this example, as well as others we have designed, are available to download at http://k12maker.mit.edu/electronics.html as .png images and .svg files which can be imported into a computer-controlled cutter program, or printed onto paper and cut out by hand.
The figure can be cut out of cardstock, but thinner material may be used for a backlit effect.
Attach your figure to the reflector with clear tape or glue, as shown.
Attach the reflector to the flashlight. Experiment with the distance between the aluminum foil and the LED to get the ideal projection on your figure. Once set, secure the reflector to the flashlight with clear tape or glue.
For best results, enjoy your Festive Flashlight in a darkened room!
Thanks for trying our Instructable!
We hope you had fun creating and lighting up your festive flashlight. What did you make? We want to see! If you did this in a K-12 classroom, what subject was it in? Send us an email or leave us a comment so we can see what you're making.
Visit our website k12maker.mit.edu to get resources for K-12 teachers:
- Maker skills workshops for K-12 educators - Spring, Summer, and Fall.
- Makerspace Design Guide for K-12 Makerspaces.
- Lists of Tools and Materials and illustrated charts to print and post.
- Supervision and safety guidelines for shop administrators.
- Training guides for common tools (including student checklists and refresher guides).
- Our Maker Methodology for designing Maker Projects for core curriculum, including sample projects.