How do Surge Suppressors work?
Surge suppressors usually do one of two things. Either they block the transient, or they short any voltages above a safe level to earth. Surge suppressors use various technologies to achieve this.
One of the most common designs is by the use of a MOV, or Metal Oxide Varistor. The MOV only works by conducting any excessive voltage to earth. In effect, the MOV is manufactured to breakdown at the pre-defined level, thus allowing the surge to pass through it. However, MOVs burn out after with repeated surges, so it is advisable to use the types of surge suppressor with indicator lights which show that the unit is still functioning. Because of this, it is not always advisable to use these types of surge suppressor, just in case you are using a failed unit.
Some of the more expensive surge suppressors feature a combination of both thyristors and filters. The filter is made up of both parallel capacitors and inductance coils. These block frequencies higher than 50 Hz, therefore cutting the energy.
Another method uses circuit breakers and fuses, which trip or burn out with a power surge, also with a battery to smooth out the transients to maintain a constant voltage level.
Summary
The final decision as to whether you should use a surge suppressor, and which type to use, is ultimately down to you and the size of your wallet. One thing is certain though, with us all becoming more and more reliant on our PCs and other sensitive equipment, can we really leave then unprotected and exposed to risk?