Transformer for arc and plasma setups having broad current adjustment range

A variable-ratio transformer for arc and plasma setups, comprising:

• a magnetic core made up of a main part and a first additional part;
• said main part of said magnetic core, composed of a first yoke and a second yoke and a group of legs in accordance with the number of phases of said variable-ratio transformer;
• said first additional part of said magnetic core, disposed on the side of said first yoke of said main part thereof and composed of a yoke and a group of legs whose number is equal to that of said legs of said main part and at least one of which is placed with a gap in respect of said first yoke;
• a primary winding in accordance with the number of said phases made up of at least two series-connected parts, the first of said parts being disposed on said main part of said magnetic core and the second of said parts being disposed on said first additional part thereof;
• a secondary winding in accordance with the number of said phases, disposed on said main part of said magnetic core;
• a controlled electronic switch, which regulates the load current flowing through said secondary winding of each said phase, connected in parallel to one of said parts of said primary winding of each said phase.