Surge protector

From ArticleWorld

A surge protector is a device used mainly in computing systems to prevent damage to sensitive parts due to power surges in the supplied electrical current. A surge protector, also known as a surge suppressor, is provided in various forms for the purpose of protection.

Several electronic components make up a surge protector. Some of them are described below. A surge protector, usually in the form of a power strip, may consist of one or more of such components.

• A circuit breaker or a fuse is provided to open the electrical circuit in the case of excessive power being input to a computer system or any other device. The fuse element may melt due to excess voltage in the supply or if the operating device is overloaded, posing the danger of damage due to the heating effect of electric current. A circuit breaker has a mechanism that causes its contacts to trip when such a situation occurs.

• Apart from the most obvious protection given by fuses and circuit breakers, surge protectors also involve constant voltage transformers (CVTs) to absorb power surges. These transformers, which are invariably 1:1 in their transformation ratios, do not transmit spike voltages or surges that cause saturation in the iron core.

• Metal oxide varistors (MOVs) are devices that allow surges to pass into the earth by shorting out when they encounter an excessively high voltage. MOVs are often referred to as one-shot devices since they are destroyed after every power surge.

• Uninterruptible power supplies (UPSs) are by far the most popular surge protection devices used, especially for computer systems. They are the most expensive of protectors and also the most effective. A UPS can be any of three types, namely, online, offline or line-interactive. An online UPS has a battery which is continuously charged by the supply voltage and at the same time discharged as the connected device draws power from it. An offline UPS allows the power from the mains to be used by the device, while providing the necessary surge protection, and switching on the battery only in cases of major discrepancies in the supply. A line-interactive UPS continuously monitors the supply and switches on the battery whenever there is an undervoltage problem or a surge in the mains.