Radiotone Open Construction Variable Autotransformers (colloquially known as Variac) manufactured by us use a special technology which minimizes the heating of coils on No Load (270v). In these high current rated coils, the voltage per turn is quite high leading to excessive heating even on No Load due to shorting of 2 turns. Further, heat gets generated due to paralleling of carbons on the same turn.
Hence using our special technology, the coils do not get heated up excessively on No Load, even if kept on 24/7 (in Oil) which allows us to use 4 brushes per coil. They are useful for oil cooled applications
Models : 200A /250A /300A