See the magbot pendulum in action (mpg, 3.3MB): Launch movie
The magbot demonstrates the ability to create motion without using a motor. Originally I wasn't very interested in building this as it didn't seem to offer much functionality, however, I am pleased that I did.
In the three pictures above you can see the motion of the pendulum, the magbot reaches these heights very quickly when sufficient light is available. The motion can be best seen in the video.
So what is the magbot pendulum? The magbot pendulum is a solar powered pendulum which does not require the use of a motor. The pendulum itself consists of a piece of string attached to a magnet, underneath the pendulum on the base is a coil.
The solar cell charges a main storage capacitor, the capacitor is linked into an circuit which will activate at a set voltage causing a pulse to be sent through the coil. The pulse in the coil creates an electromagnet which will replel the magnet.
The clever part about all of this is the timing, the discharge circuit is very sensitive and will be activated by the magnet moving, so a slight breeze will set the whole thing off. Each time the magnet swings over the coil, the coil is activated just as the magnet leaves
which causes it to be pushed further each time.