This is another project that has no practical use (or I didn't find any yet), but
is very cool :). It is a three-phase arc - arc that burns between three electrodes powered
by three-phase high voltage supply. The electrodes are arranged in a horizontal equilateral triangle. Its side
during experiments was about 5-15 cm. Arcs reached the height of 80cm (32''). Later I put salt on the electrodes to make
the arcs orange.
As a source of three-phase high voltage, 9 MOTs (transformers from microwave ovens) were used, 3 in parallel in each phase. The cold end of the secondary has been connected to line to insrease the voltage The current was limited at the secondary side using resonant capacitors - 5pcs of microwave oven capacitors for each phase, about 5uF total, rated 2100V~ (Test voltage of these capacitors is supposed to 7100V AC and 9000V DC). It draws about 30A on each phase. 16A circuit breaker at this current trips after about 20s. To avoid tripping breakers when switching on, each phase is connected first through the 35mH coil and then directly. instead of coil resistance can be used.