N- 126 Ring Terminal:
This is a 70mm-diameter suction cup with a stainless steel eye bolt. When mounted on the dome of a Van de Graaff generator, it provides a convenient place to connect a wire for the purpose of carrying charge to some other device.
N-128 Banana Jack Terminal
This is a 70mm-diameter suction cup similar to the N-126 except that, instead of a ring, it provides a jack for the insertion of a banana plug. It can be used with the grounding wire that is furnished with the standard N-122 discharge electrode.
N-127 Point Terminal
This device shows one particular aspect of static charge behavior. With the suction cup adhered to the generator dome, the sharp point provides an easy discharge path into the air. Several things will be apparent. The dome’s voltage level will be lower, producing only very small arc discharges. And there will be a noticeable wind blowing away from the point, caused by the ionization of air and subsequent repulsion of charged ions.
See video tab for demonstration.