Let's talk about power. Not the kind of power that we usually think of when we think of computers and power. I don't mean processor power measured in gigahertz or anything like that. Let's talk about the power that your computer needs to run, good, old-fashioned AC power. All computers need it to function, but not many people understand just how critical "clean" power is for the proper operation of a machine.

The power we get raw out of the wall can fluctuate, sometimes wildly, due to any number of environmental issues, from thousands of users suddenly kicking on their air conditioning all at the same time to solar flares causing glitches in the power grid.

In order to "clean up" power, it's recommended to plug a surge suppressor into your wall outlet and then plug your computer equipment into that. But what does that do? How does that help ensure your machine is getting the squeaky clean power that it needs?

Well, surge suppressors are devices that are designed to clean out the normal fluctuations in power that are common on all power grids by keeping the voltage at a constant cycle. The surge suppressor will clip off any spikes in the voltage that could cause damage to sensitive hardware in your computer. But there are some things your average surge suppressor can't do anything about.

For instance, if the voltage drops due to a brown out, your surge suppressor can't really do anything about that (it's an "under-voltage" situation, not an "over-voltage" or "surge") and if you take a direct hit from a lightning strike, forget about it; all bets are off.

A lightning strike has so much power behind it (think hotter than the sun) that it usually flows right through your average surge suppressor, toasting everything in its path, including the surge suppressor itself.

Many are really surprised to learn after suffering from a lightning strike, that their surge suppressor did nothing to protect their equipment.

The mistake here is that people think of lightning as just another surge in power, and the surge suppressor is there to handle surges.

Unfortunately, that's not entirely the case. With a direct lightning strike, there is not much available to protect equipment, save unplugging all of it during a storm. And with the frequency of storms that we get around here, that's not always practical.

OK, so that covers lightning, but what about brown outs? A brown out is a phenomenon that is just the opposite of the surge. When everyone suddenly kicks on their AC and all the lights go dim for a few seconds or even minutes, that lower voltage can often cause machines to act squirrelly. But since it's a low-voltage situation instead of a surge in voltage, most of your basic surge suppressors are unable to supply the extra power to keep it at the proper levels for your computer.

And then there are the outright power outages that can last for seconds, minutes and even hours. For these kinds of power conditions, the best thing you can add to your system is an uninterruptible power supply (also known as a UPS or battery backup.)

Most battery backup systems come equipped with surge suppressor circuitry so you get the best of both worlds; you get the benefit of clipping over voltage spikes from your system and you get a constant flow of balanced electricity regardless of whether the power coming from the wall drops due to a brown out or cuts out altogether.

The thing to keep in mind about UPS systems is that they are not designed to allow you to keep working through a power outage; they are there to allow you just enough time to save your work and do a controlled and proper shutdown of your system rather than having the system just drop out on you.

In a nutshell, the least desirable way to set up your computer equipment is to just plug everything right into the wall. The next best thing is to plug your equipment into a surge suppressor of some type; that way you at least have a way to clean any normal spikes from your power.

The best solution is to get a UPS and plug your monitor and tower alone into it. That protects you from spikes and brownouts and full-blown power outages.

Sean McCarthy fixes computers. He can be reached at (888) 752-9049 or help@ComputeThisOnline.com (no hyphens).