Autowound Transformers - Technical Notes

Using an auto-transformer is always an economical solution when you need to step down the voltage from 230V to 120V or vice versa, and the equipment already has a fully isolated transformer or when the components do not require an isolated transformer.

The toroidal construction of an auto-transformer offers important advantages in comparison with an E/I lamination core transformer, like smaller physical size and weight, 30-70% reduction (depending on secondary voltage) and very low magnetic stray fields. The auto-transformer can be mounted horizontally using a steel washer or an epoxy potted center with a mounting hole.

Step up/step down: Auto transformers
With its small size and weight, the auto-transformer can be installed easily in existing equipment or supplied in an enclosure, with or without cord, plug and receptacle.

Input 120V to 240V and
Input 240V to 120V

Input 110V to 415V and
Input 415V to 110V

Input 230V to 415V and
Input 415V to 415V