As most people who've been using computers for a long time know only very well, a power failure could actually spell disaster, especially when you're working on something important, which can't be rebuilt in a matter of seconds (or simply with a few clicks). However, there's even a darker scenario possible, namely that of a power surge, which will literally “fry” most (if not all) of your computer's internal components.

Luckily, there's a special device out there that might mitigate both of these issues. That device is called an UPS (Uninterruptible power supply), and its internal circuits allow it to both protect the devices connected to it, as well as power them for a limited amount of time.

The field of UPS devices is a fairly large one, but, typically, they can be divided into two major categories: stand-by and continuous. Stand-by UPS devices feature a power inverter that transforms the DC current transmitted by the battery to AC current, which can be used by the equipment.

Normally, the power inverter and battery are not active, but they're only rapidly prompted to act whenever the power runs out (usually, it's a question of milliseconds). Unfortunately, the estimated functioning time for these batteries is quite low, which means that users will most likely have enough time just to save their current work and then shut down their computers properly.

Things are a bit different in the case of continuous UPS units. These devices also feature a battery and a power inverter, but all of the equipment connected to it runs off the battery, instead of the mains, with the battery being constantly recharged. In this way, there will be absolutely no delay between the power outage and the moment when the UPS kicks in, which is a critical issue in certain specific cases.

The first thing you have to do before starting searching for an UPS is to evaluate your needs. Thus, if you're planning to purchase such a peripheral for the one or two computers in your home, then getting a more expensive, continuous UPS is not exactly a very good idea. Of course, nobody's stopping you from doing so, but you'd be pretty much wasting your money, since a stand-by UPS will be able to take care of your needs quite well.

On the other hand, if you're the IT administrator of a datacenter or some sort of mission-critical area, then your best bet is a continuous UPS, which will make sure that absolutely no harm can come to the precious equipment found within the respective area.

Another thing you'll probably have to plan quite carefully is the number of devices you'll be connecting to your UPS. Most such products (at least the less-expensive ones) feature two to four outlets, but there are also certain models out there featuring 6 – 12 outlets. However, in general, the more devices you connect to an UPS, the faster it will get depleted, so it's probably a good idea to keep the respective number as low as possible (for example, just a PC and a monitor per a two-outlet UPS is quite a decent setup).

One of the main issues that must be considered regarding an UPS is the issue of the VA (volt-ampere) rating. For those of you who're not familiar with this term, you should know that the VA rating is actually the results of multiplying the voltage by the equipment's amperage. Typically, the amperage of an electronic device is clearly imprinted on a label found on the product itself or its box, but the location of the respective label generally varies quite a lot.

After you've obtained the VA ratings for all the devices you plan to connect to the UPS, sum them up and thus obtain the cumulative VA rating. Now, when you purchase an UPS, its VA rating should typically be around 15 to 20 percent higher than the cumulative VA rating of the devices you'll be connecting to it, just to be on the safe side. Generally, manufacturers point out this figures quite clearly on their websites, so be sure to check this data before making a final decision.

Another issue worth taking into account when purchasing an UPS is related to the various extra-features some of these things provide. For example, I'm pretty sure that very few people will be looking for who knows what extras in their devices, most of them settling for the basics. So, why spend a lot of extra cash on a product that, basically, will not significantly improve your consumer experience?

Last, but certainly not least, there's the issue of money. UPS devices are not exactly the most expensive things ever, an entry-level/mid-range unit selling for anywhere between 30 and 50 US dollars. Of course, more advanced products will also have higher price points, but that's pretty much the case with every/any device out there. This is the reason why you should be quite careful on what you settle, and, as in the case of any electronic product you purchase, check the web for user feedback before actually spending the money.

P.S. And be quite sure to get an extended warranty on these things, since some of them tend to break down pretty fast, even if not subjected to particularly serious stress.


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