I'm working on a school project where we're creating a maze, and players will use an electromagnet behind cardboard to control a small metal object on the other side. Despite the electromagnet being strong enough to lift heavy bolts, it can't attract even a paper clip through 2-3 mm of cardboard. I'm looking for advice on how to enhance the electromagnet's ability to work through the cardboard and attract items like light metal nuts. For context, we're using 28 gauge enameled wire with a 9V alkaline battery and have made many turns concentrated in a small area on the core. Any suggestions would be greatly appreciated!
2 Answers
First off, make sure your battery is in good shape—if it’s weak, that could impact performance. You could also try using materials that have a higher iron content or lightly scuffing the surface of the metal with sandpaper to improve contact. Just a couple of tweaks can sometimes make a big difference!
I know you can’t see it directly, but the strength of your field will drop significantly with just a few millimeters of distance. Field lines tend to spread out and lose strength quickly, so it makes sense that it can't attract objects through the cardboard. You might want to try a stronger or wider electromagnet or increase the number of turns, or even try a better core material to amplify the magnetic field.
That’s interesting! Does the wire gauge affect the strength of the electromagnet at all? Also, would a single 18650 lithium ion cell produce more current than the 9V battery?
Thanks for the tips! The battery works well, but do you have any other ideas for boosting the magnetic field?