Summertime, and the living isn't easy -- for computers

Personal commputers

July 06, 1992|By Michael J. Himowitz | Michael J. Himowitz,Staff Writer

The lightning is flashing and the thunder is crashing, so it's time to think about keeping your computer safe and sound in this most dangerous time of year for all delicate electronic creatures.

Summer thunderstorms, brownouts, blackouts and just plain hot weather can turn your PC into an expensive doorstop or ruin your data and your day. But with the right precautions, you and your computer can survive intact.

The important thing is to avoid severe electric jolts. Your PC is composed of dozens of microchips containing millions of tiny electronic circuits. These tiny circuits are designed to handle low voltages, typically five or 12 volts.

Even normal house current carries 10 to 20 times more voltage than computer components are designed to handle, which is why your PC has what's known as a power supply somewhere in the back of the case.

Actually the term power supply is a misnomer, because your house or office supplies the power. The power supply is really a transformer that steps down house current to a voltage that's safe for the computer's circuits.

Power supplies and well-designed, well-grounded computer systems can handle most normal fluctuations in voltage. But a real surge of power can literally fry your electronic circuits.

The most obvious threat in this regard is summer lightning -- nature's version of Jolt Cola. Lightning is a huge bolt of static electricity that can send thousands of volts surging through any conductor in its path.

While most commercial buildings are well grounded and not prone to lightning damage, homes and small offices often are not so well protected. Most of you know someone who's had a television set or other electronic gadget blown away by a lightning strike on nearby power lines or a home TV antenna. The same thing can happen to your computer, even if it's turned off.

Ordinary surge suppressors aren't much help with lightning. They're just overmatched. The best protection against lightning is to unplug your home computer system (including the monitor and printer) if you're not going to be around and the forecast calls for thunderstorms.

If you're working with your computer and a thunderstorm approaches, unplug the system and take a break. Thunderstorms rarely hang around long, and you'll lose a lot more time and productivity if your PC gets knocked out for the count.

Less spectacular than lightning but probably more dangerous are summer blackouts and brownouts.

Blackouts can be the result of natural causes -- such as lightning that strikes a substation or a tree blown by over by high winds that takes out a power line on the way down.

But blackouts also can be the result of an overload on your utility company's generating capacity. This can take the form of a real power crash or a deliberate blackout that your utility company rolls through various sections of your community. Utilities euphemistically call this squalid little practice "load shedding."

Either way, you can be in big trouble if your PC is writing to your hard disk when the power goes out. The result may be scrambled data, or even damage that can make your hard drive unusable.

An even greater threat looms when the power comes back on -- often with a surge or voltage spike that can harm computer circuits.

Should the power go out while your computer is running, turn everything off and leave it off until the power returns -- and even then, wait a few minutes to make sure you don't get another sudden outage (power rarely comes back smoothly).

If you live in an area with frequent blackouts or your business can't afford computer down time, consider a gadget called an uninterruptible power supply, or UPS for short. This is a sophisticated battery backup unit that sits between your computer and your electric outlet.

Under normal circumstances, a UPS will filter the power from your outlet, protecting your computer against minor spikes as well as voltage drops caused by brownouts. If the power dies altogether, the UPS detects the drop in voltage instantaneously and switches to its battery.

UPS units cost anywhere between $200 and $1,000, depending on how many computers, printers and other devices you want to keep running and how long you want them to run before the battery runs out. They're good investments if your computers are performing critical tasks.

There's also an issue of summertime itself, which means heat. Generally speaking, if you can operate comfortably, your computer can operate comfortably.

But when the temperature goes above 90, many computers can suffer breakdowns. This means it's not a good idea to leave a computer running in a non-air conditioned environment when it's hot outside. Most computers come with an operating manual that specifies their operating temperature range. If you think you might exceed it, check the book or call your vendor to make sure.

Likewise, don't leave a laptop computer baking in the trunk of your car for a couple of hours and then turn it on without giving it a chance to cool down.

Be even more careful with floppy disks. If you're traveling with floppies, keep them with you. Don't leave them in the trunk or glove compartment. They're made of plastic, and they can melt or become so disfigured that they're unreadable.

The best protection against all these disasters is to make regular backups of critical data files. It's easy to replace a computer, and you can always re-install your software. It's almost impossible to replace accounts receivable, payroll records, or six months of work on a novel.

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