Variable Transformers

These variable autotransformers are ideal for controlling AC voltage.
Single-phase enclosed versions can be placed upright or on their back for comfortable adjustment of the control knob, with carry handle(s) and most have an on/off switch. Single-phase open style versions are offered for incorporating into your own equipment/enclosures.
Three phase models are also available, open style and enclosed, starting from 5A. Very high current ratings are possible by assembling multiple units.
Other ratings from what you see here can be supplied, let us know your requirements.