Mostly it is a case of devices imported from abroad, or some special devices, which don´t have a voltage selection switch 110/230V. Most of electronically skilled designers will probably get an idea to use a transformer or autotransformer with a primary/ secondary ratio approx. 2:1. However, to make such a transformer as homemade, with a sufficient power and conforming all safety rules, is not a trivial thing and in most cases it even isn´t economically rewarding. We offer to you more types of these converters from 45 to 300W.