 A metadyne can convert a constant-voltage input into a constant-current, variable-voltage output.The word "metadyne" is derived from the Greek words for conversion of power.While the name is believed to have been coined by Joseph Maximus Pestarini (Italian language Giuseppe Massimo Pestarini) in a paper which he submitted to the Montefiore International Contest at Liège, Belgium in 1928, the type of machine which it described had been known since the 1880s.