2035-09-A

Gas Discharge Tube arresters (GDTs) are a type of surge arrestor designed to protect electrical systems from damaging over voltages. They are most often used to protect electronic and semiconductor components from excessive electrical transients caused by lightning, power utility switching, and external sources. GDTs are designed to have a breakdown voltage that is much higher than the normal working voltage of the protected device(s). When an over voltage condition occurs, the GDT conducts the damaging surge current and prevents it from reaching the sensitive components.

GDTs work differently than other types of surge protectors. Their design relies on a gas discharge tube, which acts as a spark-gap to control the discharge of a voltage surge. When the voltage across the tube exceeds a certain level, the gas inside the tube ionizes and breaks down, allowing the surge current to flow. The breakdown of the gas causes an arc across the tube which dissipates the energy of the surge before it can reach sensitive components.

The operating principle of a GDT is based on the physics of ionized gas. When an electric field is applied to a gas, it causes the molecules of the gas to become ionized and form a space-charge plasma. The electric field increases with the voltage and eventually reaches a point at which the gas will become ionized, allowing current to flow. This process, known as “avalanche breakdown”, is what causes a surge arrester to activate. The breakdown voltage is determined by the gap between the electrodes of the GDT.

GDTs are used in many applications, such as telecom systems, power distribution systems, and other electronic equipment. In telecom systems, for example, GDTs are used to protect components from high-voltage pulses generated from nearby lightning strikes or power outages. GDTs are also used in high-voltage power distribution systems to protect equipment from the harmful effects of power surges. Lastly, GDTs are commonly used in the manufacturing of electronic components to protect them from voltage transients.

GDTs offer many benefits as surge protection devices. They are relatively inexpensive, small, and lightweight. They can respond quickly to voltage surges and can sustain multiple surges before failing. Furthermore, GDTs allow greater control over the current that they can handle, as the gap between the electrodes can be adjusted to regulate the breakdown voltage.

GDTs are an effective and low-cost solution to surge protection. Their design allows them to respond quickly to voltage surges, protecting the components they are defending from damage. They are used in a wide variety of applications, from telecom systems to manufactured electronic components, making them a versatile choice for many industries.