 Pestarini also visited the United States in 1930, although there is no record of the system being used there.The General Electric engineers, led by Ernst Alexanderson, were interested, but modified the design by the addition of a compensating winding, which counteracted the effect of the flux produced by the load current.This turned the machine from a voltage-to-current amplifier into a voltage-to-voltage amplifier, and they called the new variant an Amplidyne.