The best dollar you can spend on a child’s STEAM education is to take them to the dollar store, buy an electronic item, and then take it apart. Learning how a handheld fan, LED light, remote control, or headphones work will help show how wind turbines, traffic lights, speakers, keyboards, and other modern devices function.
The next step is to take apart a dollar store item and make it better — combine two items, replace a switch, create something new and unique. Scrappy Circuits is the perfect way to get started.
I first developed Scrappy Circuits with Chris Connors and Eva Luna while working at Xraise, an education outreach program at Cornell University. What began as an exploration of DIY switches ended later as a self-made invention system sourced from a fifty-cent LED tea light. Educators can build it with their class for about $20. Anyone with access to office supplies and a dollar store can make the five Core Bricks for about $1. Here’s how to create each one.
Take Apart a Tea Light
Open the battery compartment, remove the 3V coin cell battery, and pry the base/LED holder apart from the outer cylinder body. You’ll use three parts: the LED, battery, and cylinder body. For a simple demonstration of how electricity travels, make the LED legs straddle the battery, with the long leg touching the positive (+) side.
The power source for your Scrappy Circuits.
- Clip a binder clip to one side of a rectangle of cardboard (a “brick”).
- Flip one binder clip arm down.
- Trim the opposite side of the cardboard slightly longer than the extended arm.
- Place the battery on top of the clip arm with the smooth, positive (+) side down.
- Clip a second binder clip over the battery.
- Label each clip positive (+) or negative (–) based on which side of the battery it touches. This makes lighting the LED easier later.
Of the Core Bricks, this is the only load, or item that consumes electricity.
- Stretch the legs of the LED apart.
- Clip a binder clip around the longer LED leg and the cardboard. Label this side (+).
- Clip the opposite leg and label it (–).
Binder Clip Switch
It operates just like a toggle light switch.
- Clip two binder clips to opposite sides of a brick.
- Flip one arm flat against the brick. It should not touch the other binder clip. If it does, cut a larger brick.
- When you flip the opposite arm down, it completes the circuit (turns on). When you lift the arm, it turns the circuit off.
Momentary switches turn on when pushed down. When released, they turn off again.
- Clip one binder clip to a cardboard brick.
- Lower the upper arm.
- Lay a paper clip perpendicular over the binder clip arm.
- Use a second binder clip to hold the paper clip in place.
- After it is clipped, bend the paper clip up slightly so it’s not touching the other arm.
- Push the paper clip down to close the switch and turn your LED on.
A creative use of the tea light cylinder body.
- Use glue stick to attach aluminum foil to each side of a cardboard brick. Be sure the two pieces do not touch in the center.
- Add binder clips to each end.
- Glue foil to 50%–75% of the inside and outside of the lower edge of the cylinder.
- Poke a hole through the cardboard.
- Insert a straightened paper clip through the cylinder and the hole.
- Bend the paper clip to capture the cylinder. Tape it down or cut off excess.
- Spin to turn on or off. When the foil on the cylinder touches both pieces on the cardboard, the circuit will turn on. When it touches just one side, it will be off.
Your bricks can be connected with alligator clips or with Scrappy Clips. To make a Scrappy Clip, cut 6″–10″ of aluminum foil. Fold it in half a few times and then roll it tight. Hook each end through the one-hoop end of a small paper clip. Squeeze the connection tight with pliers.
Make a Circuit!
Gather two Scrappy Clips, the Battery Brick, and the LED Brick. Slide a Scrappy Clip onto the binder clip to connect your bricks. Connect the positive (+) side of the battery brick to the (+) side of your LED brick. Next connect the two remaining sides to illuminate your LED. (If it doesn’t light, try sanding the mouth of your binder clips and squeezing each connection.) Take a moment to appreciate how cool this is. You just created an electrical circuit!
Now get one of your switch bricks to learn how you can control your circuit. Disconnect any clip and reconnect it to your switch. Use another Scrappy Clip to connect the remaining sides. The switch now controls the LED light.
Make a Buzzer, Magic Wand, Light Sensor, and more at www.scrappycircuits.com. And please consider supporting our Kickstarter campaign to bring Scrappy Circuits to more inventors-in-training around the world.