Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A vector inversion generator (VIG) is an electric pulse compression and voltage multiplication device, allowing shaping a slower, lower voltage pulse to a narrower, higher-voltage one. VIGs are used in military technology, e.g. some directed-energy weapons, as a secondary stage of another pulsed power source, commonly an explosive-driven ferroelectric generator. A spiral VIG consists of four alternating conductor-insulator-conductor-insulator sheets, wound into a cylinder, forming a capacitor also acting as a single-ended transmission line, connected to a spark gap switch. The capacitor is charged from a power source, e.g. the EDFEG, then the spark gap fires after its breakdown voltage is reached.