Strikesorb Surge Protective Devices – Technology

Strikesorb Surge Protective Devices – Technology


There are several manufacturers of Surge Protective Devices (SPD) worldwide, sharing a global market that is expected to exceed US$2.4 billion by 2020, driven by the global need to protect sensitive electronic equipment from power fluctuations. The overwhelming majority of the SPD manufacturers use the same technologies – developed some 30 years ago – to protect today’s sophisticated electronic equipment. Their approach to surge suppression relies on using a multitude of bulk produced, commercial quality, low surge current rated metal oxide varistors (MOV) or silicon avalanche diodes (SAD) originally developed for electronic printed circuit board (PCB) applications.

With the exception of Raycap’s Strikesorb surge protection modules which were introduced to the market in early 2000, no real advancements or major improvement regarding the SPD design principle, technology or performance in SPD technology, also known as Transient Voltage Surge Suppressors (TVSS), has been developed over the past several decades. Manufacturers have added more features to make them more attractive to the end user, but these features are irrelevant to the surge protection capabilities of the products. Strikesorb modules were designed to overcome all the shortcomings of existing SPD systems. They were specially designed to protect sensitive state-of-the-art electronic equipment against catastrophically intense transient surges.

Strikesorb surge protection modules provide the ultimate protection to sensitive equipment loads. They can be trusted to protect at all times and under the most severe service conditions. Strikesorb modules look different and perform differently than their conventional counterparts. They have been deployed worldwide and have been performing under the most extreme environmental conditions. They boast an excellent and proven track record and they have succeeded where every other SPD has failed. These successes have encouraged many customers to enter into strategic alliances with Raycap Corporation – the manufacturer of Strikesorb – to use the Strikesorb modules in their own applications. Numerous other equipment manufactures (OEMs) have integrated them into their own products as well. Raycap continuously strives to improve the product and increase its capabilities as industry needs intensify and standards organizations sharpen their performance and safety requirements. The Strikesorb technology is protected worldwide by several patents.


Each Strikesorb protector is constructed with a 30mm, 40mm or 80mm distribution grade zinc oxide varistor housed inside a robust, hermetically sealed metal casing. No potting or other flammable materials are utilized by the protector or contained within the casing. The zinc oxide varistor is placed between two electrodes that exhibit high thermal capacity and conductivity characteristics. The disk is not rigidly placed between the electrodes, but held under a high pressure to overcome the Piezoelectric and Lorentz forces that occur during surge events. The heat generated within the zinc oxide varistor disk efficiently dissipates into the environment via its electrodes and into the connected bus bars/metalwork via the device casing. The high thermal conductivity of the materials used ensures that any temperature rise within the varistor is minimal. Strikesorb modules are designed to remove 1000 times more thermal energy than products that deploy conventional surge protection designs. The lower temperature rise in the Strikesorb’s suppression component dramatically extends the product’s life expectancy and prevents the zinc oxide material’s ageing. Thermal runaway problems are precluded as the electrodes’ heat sinking effect smooths out any heat gradients across the minor surface imperfections of the amorphous crystalline MOV material.

Strikesorb mechanical design prevents fire, smoke, and explosions and allows efficient heat management and thermal energy removal from the varistor resulting in extended life time. The SPD design enables high energy handling capability and provides robustness and excellent performance under vibration conditions.


Strikesorb is designed to accommodate minimal inductance connections while at the same time maximizing the capacitance of the varistor disk. Its design is characterized by coaxial symmetry that results in a device that exhibits minimal impedance characteristics and minimal response time. Conventional varistors that utilize thin wire leads and even thinner electrodes are plagued by current ‘hogging” phenomena resulting from their uneven current paths. Their surge current capacity decreases and they are prone to developing hot spots that ultimately cause them to fail as they are stressed by surge events.

The thickness of the electrodes employed by Strikesorb on the other hand, ensure that the current conducted through the varistor is planar/parallel (uniform) and that no current ‘hogging’ occurs. In conventional MOV components, the lengths of the current paths that are employed by the individual current filaments vary considerably, leading to current flowing towards the outer edge of the varistor being restricted due to more resistive current paths in that region. The transit time of the current traveling through the longer paths is higher. The MOV’s surge current capacity is reduced below the levels it should be able to support. Current conducted through the component is more intense between the connection pins, as it is unable to take advantage of the total volume of the varistor. As a consequence, higher clamping voltages are realized as the MOV deteriorates and until it ultimately fails. Strikesorb overcomes this deficiency by essentially equalizing all current conduction path lengths to allow evenly distributed current flow throughout the entire conductive surface area of its zinc oxide varistor. For all practical purposes, the Strikesorb’s varistor conducts current evenly at all frequencies and utilizes the entire disk surface volume during current conduction conditions.