I used conductive spheres to shuttle electric charges between the poles of a high voltage (HV) DC source. This shuttle assembly was made from two, foil-covered spheres joined by a non-conducting, plastic tube. The assembly was sandwiched between two stationary, dumbbell shaped electrodes. When the upper dumbbell was grounded with respect to the negatively charged lower dumbbell, the shuttle began to bounce between the HV poles with a clacking noise as charges were transferred from the lower to the upper electrode. This rocking motion completed the HV circuit.
I powered the project with an electronic air ionizer purchased at a rummage sale; but other sources of HVDC, such as a Van de Graaff generator could be used to rock this clacker. For a video clip about the project, click here: http://www.youtube.com/watch?v=eQrXRCu066c .
If you choose a commercial air ionizer as the power source, use a model powered by a low voltage AC adapter. A line powered ionizer can be a serious shock hazard!!
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