There are many ways to make electricity; one of the most common ways is to move magnets and wire coils relative to each other. In this project, you will make an electric generator that lights up some LEDs as you shake magnets past wire coils, no batteries required!
This project introduces wire winding, a key technique of the motor winding trade, an integral process in making motors and generators. Note: it is easiest to wind the wire directly from the spool onto your project by placing a pencil through the spool and resting it over the rim of a mug. 300 wraps (about 100’ of 28AWG wire) should be enough to light up a 3mm red LED. If you have 150’ of wire (enough for 500 wraps), your LEDs will light up even more brightly.
Make sure to keep the strong magnets used in this project away from pets and small children, as they can cause complications if swallowed. Be sure to also keep them away from your electronics and any bank cards.
Teachers: this project offers strong links to the BC curriculum, including making “energy shakes” with your science grade 4s as examples of devices that transform energy, or with your science 7s as a way to illustrate the different methods of generating electricity (and associated environmental impacts).
This project introduces wire winding, a key technique of the motor winding trade, an integral process in making motors and generators. Note: it is easiest to wind the wire directly from the spool onto your project by placing a pencil through the spool and resting it over the rim of a mug. 300 wraps (about 100’ of 28AWG wire) should be enough to light up a 3mm red LED. If you have 150’ of wire (enough for 500 wraps), your LEDs will light up even more brightly.
Make sure to keep the strong magnets used in this project away from pets and small children, as they can cause complications if swallowed. Be sure to also keep them away from your electronics and any bank cards.
Teachers: this project offers strong links to the BC curriculum, including making “energy shakes” with your science grade 4s as examples of devices that transform energy, or with your science 7s as a way to illustrate the different methods of generating electricity (and associated environmental impacts).
Tools & Materials
Material List
- ~2 1/2" x 6" cardstock
- minimum 100' ~28 AWG enameled magnet wire (enough for 300-500 wraps)
- two 3mm red LED bulbs
- three 3/4" neodymium disc magnets
- scrap paper
- tape (any type)
- pencil
Tool list
- wire cutters
- measuring tape
- sandpaper, any grit
- ~7/8” diameter x ~8” long cylindrical found object (eg. a candle or dowel)
- soldering iron and electronics solder
Optional
Procedure
-
Combine your two LEDs in “parallel”. Splay their wires apart slightly, and put the bulbs side by side. Twist one LED’s short wire and the other LED’s long wire together. Next, twist the remaining two wires together. Splay the twisted legs apart so that no parts of the two “legs” are touching the other, or you will create a short circuit and the LEDs won’t light up. -
Wrap the cardboard around the found round object to make a long tube. Use tape to hold the cardboard tube together, but be careful not to tape the cardboard onto the object below. Leave the tube on the object for now. -
Halfway down the tube, tape the free end of the wire on as shown, leaving a 2” tail. Thread your wire spool onto a pencil and place it over a mug (or ask a friend to hold onto the pencil ends for you) while you wrap the wire onto your project. -
Wrap the wire around your tube, keeping within about 1” of the middle of the tube. -
Make between 300 and 500 wraps, depending on how much wire you have. Lay a strip of tape over the last wrap, and clip the wire, leaving a 2” tail. -
Use the sandpaper to scrape off the enamel coating from the last 1” of each wire end.
-
Twist one bare wire end to one of the LED twisted legs. Attach the other wire end to the other LED twisted leg. To prevent a short circuit, make sure none of the bare wires or LED legs from one side/end are touching bare wires or LED legs from the other side/end. -
Wrap these connections with tape. (Note: if you have access to solder and a soldering iron, soldering these connections would make them even stronger). -
Tape the LED assembly securely to the tube, leaving the bulbs uncovered.
-
Pull the tube off the object. Crumple up some scrap paper into a small ball then tape it to one end of the tube to close it. -
Stack your magnets and slide them into the tube. -
Optional: if your magnets are a lot smaller in diameter than your tube, create a cylindrical cuff of cardstock to tape them into tightly so that they remain aligned inside the tube instead of tumbling around randomly. This will help make your energy shake more efficient and your LEDs glow brighter. See the photo for how to line the batteries up in the cardstock cuff. -
Close up the other end of the tube with another crumpled piece of paper, then tape into place. -
Shake your generator back and forth so the magnets whizz past the wire wraps and watch what happens!
-
Try shaking faster
-
Observe your generator in a darker room; sometimes the LEDs light up only faintly.
-
Check for a short circuit: pull the LED bulbs apart slightly so that there is no unintended crossing of wires (the twisted ends should be the only wires touching each other)
-
Try starting again with a new piece of wire, adding another 100 or 200 wraps than you did on your previous design.
-
Add another magnet (or more!) to your stack.
TROUBLESHOOTING if your LEDs won't light up:
Extension Challenges
- Figure out how slowly you can shake the generator and still have the lights go on. Calculate the “shakes per minute” by counting how many shakes you do in 15 seconds, then multiply that number by 4. Is it faster than your heart rate?
- Replace your red LEDs with different colours. Do they light up with the same shake rate as the red ones? Why do you think this might be?
- Design a shake generator that has more LEDs on it.
- Decorate your generator with stickers or paints, or papier mache the whole thing!
- Attach a multimeter to your shake generator to see how much voltage you produce with each shake (connect one probe to each wire end using connector wires with alligator clip ends). Look up “active buzzers” to see if you make enough voltage to make one work. If so, try wiring one up (connect one buzzer lead to each wire end).