Electromagnetic Swing

An automatic electromagnetic swing — it keeps swinging using the magnetic interaction between a coil and a permanent magnet. When the swing reaches the bottom of the arc it breaks an infrared beam that activates the coil which gives the swing a little kick upward.

Construction

The construction is fairly straight forward. The pieces can press fit together, but a tiny amount of glue wouldn't hurt. The coil should be around 8Ω which depending on the gauge wire could be a hundred or more turns.

Two versions can be made: A simple version that only needs a battery and momentary switch connected to the coil or an automated version. Two 3 mm holes are in the vertical slots can accommodate the infrared sensor and emitter.

Simple Operation

The simplest and most straight forward method is to use a battery and momentary push button connected to the coil. This is almost a test of human reaction ability as the button must be pressed exactly as the swing reaches the bottom of the arc.