One of the most demanded types of pulse switching devices is the triggered vacuum switch (TVS). A TVS consists of an electrode system containing two main and one triggering electrode. The electrode system is placed in a ceramic vacuum chamber. The triggering electrode is placed on one of the main electrodes but separated from it by means of a dielectric insert (the triggering gap). The distance between the main electrodes remains constant and defined by the required dielectric strength. Also the TVS contains a shield system which protects the internal walls of the chamber from metallization through byproducts from main electrodes erosion.

For the first time the rod electrode system was proposed by I. A. Rich for high-currents at industrial frequency. Different studies were provided in order to improve TVS’s characteristics and nowadays TVS is applied in different fields of electrical engineering.

The TVS possesses important properties for practical use, such as the ability to work with a wide range of operating voltage and current, a high stability to emergency influences and rather low cost in comparison with semi-conductor devices. During the last decade new types of switches were developed. The most powerful of them are capable to switch pulse currents up to 500 кА with transferred charge of up to hundreds Coulombs repeatedly.

• Switching on of power-intensive capacitor energy storages in electrophysical plants;
• Electroimpulse technologies: magnetoimpulse and hydropulse processing of materials, electrodynamic welding, electrohydraulic processing of oil wells and concrete piles, etc.:
• Equipment for protection power equipments in electric power systems from overvoltages and overcurrents;
• DC vacuum contactors and DC vacuum circuit-breakers