Suresh electrical industries supplies continuously variable voltage auto transformers marketed under the tradename varipac. These are used in industries and technical institutes for smooth control of electric power, ac or dc, and deviation of power such as light, heat speed, etc. For heavy-duty industrial applications, sei has recently introduced high current varipacs, which are supplied in oil cooled construction. These are made in current ratings of 40 to 200 amps and suitable for 3-phase and 1-phase operations. They feature low losses, smooth and stepless variation and 12% excess output than the input voltage. These are available in hand operated construction, or motor drives suitable for remote control or automatic operation.