This is a project that uses an electronic magnetic pendulum drive similiar to instructables: https://www.instructables.com/id/The-Magbot-pendulum/
although the circuit I actually use is found here:  http://www.trainelectronics.com/Pendulum/article.htm   

I orginally built this pendulum circuit to work on a Foucault Pendulum which I have partially working but decided to use the pendulum drive to make this video of a double and an unbalanced pendulum.
The unbalanced pendulum is kind of interesting; there is only a certain amount of weight you can add to the top of the pendulum before it becomes disfunctional. Also you find that the heavier the little pendulum at the top, the less efficient the pendulum at the bottom. By adding a smaller pendulum to the top of the main pendulum you find the swing of the main pendulum getting reduced a bit. Not sure what is going on there.

Please watch the video to see how it works.

I haven't found any research so far that deals with double pendulums built the way this particular one has been built. I think this pendulum would be a great science fair project as it is somewhat unique. Also there seems to be no studies on this particular unbalanced pendulum as well.

I keep this pendulum in my living room and sometimes let it run for days as the batteries last forever and the pendulum makes a pleasant sound. It is also relaxing to just sit and watch it work.

Step 1: The Electronic Drive

The electronic drive is build according to this website:
Pendulum Animation http://http://www.trainelectronics.com/Pendulum/article.htm

It is a very simple circuit of only a few parts that can be gotten at a Radio Shack. I actually found some of the parts in my electronic junk box. The black box is an on/off push switch. The other components are two transistors, two resistors, a diode and an LED that ights up when the magnet is turned on. I used an IN4007 diode but I think any one will do. I built this circuit first on a breadboard and got it working before I soldered it up.
When I first plugged it all together it didn't work because my voltage was too high. Use 3 volts to 4.5 but no higher or lower.
One leadout goes to the batteries as shown, the other goes to the coil.

About This Instructable




Bio: I am an American teaching English at Shangluo University, Shaanxi. I like making machines that do interesting but fairly useless things - I call them Quixotic ... More »
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