Tube Energy Varistor

Varistor (Metal Oxide Varistor, ZnO varistor) is an element that by its function protects electronic and other electrical assemblies from harmful voltage shocks generated by lightning, sparks, power outages and other similar events.

The current technology of manufacturing the basic body of the varistor is based on a disc shape, which is formed by compressing ZnO granules (small balls) according to the entire prescribed production process. The basic body of the varistor is ultimately installed in the appropriate circuits on the electrical circuit or is independently closed in plastic or. metal housing. The latter method is used mainly in the requirements for the protection of large and expensive devices and facilities (mining conditions, water pumping stations, etc.), wherever there could be major damage and disruption.

The disc variant of the varistor has one drawback, as the active surface of the varistor of suitable quality, made with compressed technology, is limited to approx. 80 cm2. Consequently, this means limiting the load on the active surface or changing the service life of adequate protection.

The tubular shape allows the production of the basic body of the varistor with an inappropriately large active surface. As a result, a higher stress surge is allowed, or a lower specific surface load, or the lifespan of adequate protection is affected. The technology of making a tubular varistor body is similar to the technology of making a disc varistor and differs mainly in the phase of “granulate compression” with an inventive design of the work tool, which allows making a varistor body with a homogeneous material structure throughout the volume.