Van de Graaff generator generates :

A Van de Graaff generator is a classic electrostatic device designed to produce extremely high electric potentials. It functions by accumulating electric charge on a hollow metal globe using a moving belt, which transfers charge from a source to the terminal. This process generates high voltage, often reaching several million volts, while maintaining a very low current. Crucially, the electricity produced is direct current (DC) because the charges are accumulated and flow in a single direction rather than alternating. While it is an electrostatic generator that builds up static charge, its primary functional output in a circuit or discharge context is characterized as high voltage low direct current. This makes it distinct from electromagnetic generators that typically produce alternating current unless rectified.