Electricity is a wonderful thing that we depend upon every day. Electricity also can be a dangerous enemy if not given proper respect. Around 1,000 people are killed in the U.S. every year from accidental electrocution. Countless more computers are shocked to death, as well.

Electronic equipment requires very specific amounts of electricity to function properly. The electricity in our homes and businesses fluctuates in intensity all of the time. Too much electricity, in the form of a voltage surge or "spike," can kill a computer faster than you can say, "How much do you charge per hour?" Other, smaller power surges, while not causing immediate termination, can repeatedly chip away at a computer's inner components until they eventually fail. I have seen many computers that have been fried by power surges.

The most visible and well-known source of power surges is lightning. Lightning hits a power line, telephone line or cable TV line, travels down the line into your home and bam -- suddenly, your computer doesn't work right. This can happen even if the lightning strike is many miles away. There are more than 20 million cloud-to-ground lightning strikes reported is the U.S. every year.

Lightning, however, is only a minor source of power surges. I was doing computer work in a home not long ago when the power shut off three different times in the space of about 10 minutes, and there was not a cloud in the sky. Each time the power came back on, every piece of electronic equipment in the house received a power surge. The homeowner said such power failures had happened many times in the past. They also had me look at a fairly new computer that had simply stopped working. I concluded that the computer's main circuit board was faulty, due probably to a power surge.

Animals (most notoriously, squirrels), birds and trees can also mess with power lines, causing surges. Damage from construction and other accidents also can lead to power surges, as well as electrical equipment cycling on and off. Crummy wiring can have the same effect. The average home experiences hundreds of power surges every year.

Fortunately, there are some inexpensive devices called "surge protectors" that can prevent major disaster. Forget those cheap, $5-10 surge-protected power strips, though. Spend a little extra money and get far better protection by buying what is called an uninterruptible power supply (UPS).

Also know as a battery backup system, a UPS contains circuitry to protect your computer against damaging power surges, usually better than what you'll find in those cheap power strips. A UPS also contains a battery capable of running your computer during a power failure. The battery allows you to shut down your computer in an orderly fashion, rather than subjecting it to a jarring "pull the plug" power outage. This makes a UPS superior to simple surge-protected "power strips." I have five UPS devices protecting equipment in my house and they have saved my gear more than once. I've even used a UPS to power small table lamps to light my home during power blackouts.

Every computer that you own, including printers, scanners, powered speakers, cable/DSL modems and routers should be plugged into a UPS. Telephone and cable/satellite TV lines also should be protected. Starting at around $60, a UPS is cheap insurance. Get one today.

Dave Moore has been repairing computers in Norman since 1984, when he borrowed $1,200 to buy a Commodore 64 system. He can be reached at 919-9901 or www.davemoorecomputers.com.