The world's simplest electronic train

An electro-train made of battery, magnets and copper wire
Author: supermagnete, Uster, Switzerland, [email protected]
A heart for a small train
A heart for a small train
We found this awesome magnet application in a forum: The world's simplest electro-engine! In order to share it with our customers we built it in our office. An exciting experiment for physics class and to copy at home.

Material needed

  • 2 neodymium disc magnets 15 x 8 mm
  • Batteries (our recommendation: several AA LR6 with 1,5 Volt)
  • Copper wire with 0,8 or 1,0 mm diameter
  • Rod with approx. 15 mm diameter
Since we couldn't find an uncoated copper wire at the hardware store next door, we had to make due with a silver-coated one. Please don't use a plasticised or lacquered copper wire; the experiment won't work.

Instruction

Wrap many metres of copper wire evenly around the rod until you reach the desired length of distance.
Place the magnets on the battery in a way that either both north poles or both south poles are connected with the battery. Otherwise the train won't run.
Now put the battery in the tunnel and... be amazed how the battery bolts through it!

For the advanced

Advanced builders can experiment with a longer tunnel. For this long distance, Reto wrapped 50 m wire and couldn't feel his arms afterwards...
The battery can even overcome little obstacles such as this jump. But don't be surprised if the battery is drained after a short period of time.

Explanation

And here an attempt to explain the phenomenon:
Via the magnets the battery shoots electricity through the coil, which creates a magnetic field within the coil. Something like this:
S - - - - - - - - - - - - - - - - - - - - - - - - - - N
With the battery ("= = =") and the magnets (S-N und N-S) it looks like this:
S - - - - S-N = = = = = = = = N-S - - - - N
On the left side the "S - - - - S" order causes repulsion. On the right side the "S - - - - N" order causes attraction. Hence, the battery is pushed to the right and shoots through the tunnel.

Similar applications

Batterie and magnets are a fascinating combination. We have many more applications with batteries - the distant favourite is The World's Simplest Electric Motor.

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