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If you've ever wondered how surge protector strips are different from plug-in power conditioners, you're not alone. The enormous difference in price makes surge strips especially attractive to many people.
To make matters more confusing, manufacturers of these different devices often don't point out the performance differences, which are significant. If you buy any power protection device (including power strips) without knowing the facts, you may find you've purchased far less protection than you thought. The difference between a plug-in surge protector strip and plug-in power conditioner is more than just price. As you will see, surge strips are capable of providing only rudimentary protection.
Surge strips
The event commonly called a surge is more accurately defined as a high-voltage transient or impulse. Surge strips are designed to divert the impulse away from the sensitive electronic system. That's why the term diverter is more appropriate for this type of protective device.
Plug-in surge strips commonly use one or more of several electronic components, which may include metal oxide varistors (MOVs), silicon avalanche diodes (SADs), and gas tubes. There are differences in how each functions, but the intent is the same ( Fig. 1 ) - to divert a part of the harmful impulse energy away from the computer or system being protected.
All surge strips have a voltage threshold, called a "clamping voltage," at which they begin to conduct. Above that threshold, impulse energy is shunted across the diverter to another pathway - typically the safety ground. When the impulse voltage once again falls below the threshold, the surge strip stops conducting. Surge strips also have a "clamping response" time, which is the time required for the device to respond to an impulse. The amount of energy that a surge strip is capable of handling without being destroyed is also a consideration.
Due to these factors, each type of component typically used in surge strip has unique advantages and disadvantages.
MOV
This type of surge diverter component has a high clamping voltage (300V to 500V) but a slow response time. This means that, in best-case scenarios, voltage impulses of less than 500V usually enter the computer system unimpeded. In addition, higher voltage events with very fast rise times may pass by the MOV before...