A one inch corona discharge arc is generated with a low-voltage DC power supply and a rapidly switched induction coil.

Note: Demo is kinda janky and there's no real thing you're clearly demonstrating - at least for educational purposes. There appears to be no documentation, circuit diagram, etc. online, so it's mostly scrap… If you find a use for it, congrats.

J3, A4

PIRA DCS 5J10.20