Picture of Asynchronous single-phase motor
Sorry, I'm French and my english is not very good.

This instructable shows a demonstration of a single-phase asynchronous motor (induction motor).
I made some pieces with a metal lathe, but you can customize the implementation using a simple drill and recycled materials (metal, plastic, wood, cardboard).
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Step 1: Materials and tools

Picture of materials and tools
Some Duplo bricks (like Lego but slightly larger)
2 or 3 x relays (I use only the 12V coils)
1 x capacitor 4.7µF
1 x used bicycle dynamo (I need only the magnet)
1 x transformer 110 or 230V / 12V
Some pieces of metal (aluminum tube, brass rod)
A few pieces of plastic
A few pieces of epoxy copper plates for printed circuit boards (PCB)

Tools :
Drill (preferably drill press)
Possibly a little lathe
Saw, file, soldering iron, glue

Step 2: AC generator

Picture of AC generator
A rotating magnet in front of a coil produces an induced current. This is the principle of the bicycle bike and alternators.

I mounted the magnet on an axis. It runs horizontally in front of a relay coil.
A LED is connected to the coil.
Turning the magnet, a current flows through the LED. The LED lights.

Step 3: Rotating magnetic field

Picture of rotating magnetic field
A rotating magnet induced an electric current in the cylinder. This current produces a magnetic field that opposes the magnetic field of the magnet. /

I made a rotor from an aluminum tube 30mm diameter. I glued a plastic disk on one side of the cylinder. In the middle of the disc, a piece of brass used as a pivot. It rests on a steel needle (a sharp nail). The rotor can rotate almost without friction.

The magnet is placed in front of the rotor, with a gap of about 1mm.
Note that the rotor is non-magnetic metal (aluminium). It's the induced current which bring rotation.

Step 4: AC power

Picture of AC power
In a transformer, the alternative current through the primary coil produces an alternating magnetic field.
This produces an alternative induced current in the secondary coil.
eblack83 days ago

Ok, first of all I want to thank you for this instructable. It was very informative and I intend to make a version of this. I have a question if you could kindly clear up for me. Why the need for two coils? Your using AC in the coils and this in turn should create a changing (oscillating) magnetic field. Thus, this should induce a current in the cylinder using just one coil, right? So wouldn't just one coil work? Please explain.

ivver7 months ago

Shaded pole motor :) you could do the same thing without capacitor and one coil and one aluminium plate between rotor and stator.

mski1 year ago
C'est très bien !
hhofkhan mski1 year ago

very good for teaching kids thanks a lot

Excellent, thanks!

And please don't ever apologise for your English — it's better than that of a LOT of English people!!

Very cool, thanks for sharing!