Auto transformers Step down Step up can be designed with suitable turns &taps in 1 phase and 3 phase at any frequency and voltages.
The size and weight for the required rating is much smaller than isolation transformers, besides higher efficiency, good regulation & coupling or impedance.
The continuously variable voltage auto transformers fall on the same category.
Can reduce size weight, Cost of step up or step down at higher efficiencies & good regulations.
This is employed where Isolation input output is not required.
Range: 1 VA to 1000 KVA Open dry type
Frequency: 20 to 1000 HZ.
Phase: 1 Phase, 3 Phase
Termination: Flying leads to shrouded Terminal Blocks, Ring Lungs on bolts, Bus Bars.
Enclosure: Open type IP 00 or enclosure with required IP protection
Applications
Buck & Booster of voltages, Motor starting purpose Line voltage regulators,Testing systems, lighting systems Energy savers,