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Most of us need a UPS on every workstation in the home. The reason may not be clear to everyone, as was made obvious by this conversation. Click into the images to see Amazon reviews and product pages. (If you buy, it helps pay for this advice page.)

Q: My last computer shut down at the slightest drop in power--quicker than almost all my other electric items.  I thought it was just the computer.  But my Acer has the same problem.  Would the problem be solved if I had a better surge protector?  I don’t have a particularly expensive or high-tech one.  If so, which would you recommend?

TH: Yes, something better than a power strip with a surge protector is needed. Ideally, it's best to have a battery-capable Uninterruptible Power Supply (UPS).

Further discussion ensued.

Q: Actually, my main concern isn’t power outages.  My main concern is that my computer shuts down when there is the slightest momentary drop in power from lighting, a storm, etc. So do I really need a more expensive model of UPS?  On the other hand, the reviews for the models you mentioned seem to indicate that power outages can harm the computer where there has been no opportunity to power down.  What sorts of damage occur, and how often?  As far as I know, even though my computers have shut down many times as soon as there has been a drop in power, there has been no damage.

TH: The main risk in most areas to home computers is sags; some call these brownouts, but they can be only for a second or less. These damage the power supply, which, after the disk drives, is the most likely thing to fail in the computer. Some may wish to keep a spare power supply unit for this reason. The more expensive UPS model does a demonstrably better job of regulating the power. Not perfect, and you can spend more to get better. Still, either one would be a vast improvement over having nothing. Almost certainly, the sags and spikes have reduced the lifetime of the power supplies in your equipment. While we're on the subject, the same consideration applies for home theatre units and stereos. I'm pasting this explanation from this web post from Computer Power and Consulting: 
"A CRT or monitor for a personal computer uses a 120 volt AC power supply to convert the incoming voltage to specific DC voltages required to run the monitor, these voltages include 5 VDC for logic circuits and high voltage DC to operate the cathode ray tube (CRT). If the incoming voltage drops to 108 volts (-10%), the power supply is designed to draw more current or amps to maintain the proper internal voltages needed to operate the monitor. As a result of the higher current draw, the power supply runs hotter and internal components are stressed more. Although the operator of the monitor does not notice a problem, the long term effect of running on low voltage is reduced reliability and increased failures of the monitor. If the power drops below the operating range of the power supply, the monitor will shut down. If the voltage goes above 132 volts AC (+10%), the power supply will not be able to regulate the internal voltages and internal components will be damaged from high voltage; therefore, we conclude that the power quality requirements for the PC monitor are much higher than for a light bulb. Both high and low voltage can cause premature failures. The economic issues are much greater for the PC monitor in both replacement cost and utilization purposes."

Why You Need a UPS 

You need a battery backed power conditioner. There are many to choose from, so this is just a representative suggestion.

For instance, look at the Cyberpower models shown above. Depending the draw from what you connect to the UPS, these units may have enough juice to run a small LCD monitor through them, which is helpful should you happen to be around when the power goes out. You will be able to do a better job of closing down your system than the CyberPower software, though it will get the job done courtesy of one used USB port on your workstation. Be prepared for the hassle of feeding them a diet of relatively costly batteries around every 12-18 months.

Note The UPS makers are innovating. Be advised that new features coming, and already available on some units, will perform the task of the "green" power strips described below.

What About Unrelated Power Hogs If you have an appliance on the same circuit that uses a lot of power -- an AC or electric heater -- look for a different outlet completely that is not on the same circuit as the AC. Typically that is going to be either in a different side of the room, or even a different room. The reason is that the AC will introduce sags every time its compressor goes on. Putting it on a different outlet but on the same circuit won't change that. You'll probably have to run an extension cord (one of those 3 phase outdoor types) from the second circuit location. 

Put the new UPS on that extension cord, assuming you can't relocate the AC.

Cyberpower Manual Snip - Rear Panel 

UPS Outlet Types

The UPS will come with two types of outlets -- check the online manual (as shown above) to see how many of each. One set will provide protection + backup, the other just surge protection

A sample use for a protection-only outlet is an external hard drive that is used only occasionally for backup. More on the issue of backup later.

If you have an AC in the power chain, you can move the printer to the "outlet" that has the AC on it.

The protection-plus-backup outlets on the UPS would be for the computer, LCD, the modem/router adapter, and any USB devices that are attached to the computer, such as a USB hub with separate power -- i.e., anything that's hooked into the computer except the printer. Don't use a power strip for either application unless you run out of outlets on the UPS (but it's common to need more outlets).

If your existing power strip is in fact just a strip, you can continue to use it for the protection-only circuits if you need more outlets. But often these low cost units are sold with minimal circuit protection on them. E.g., look at this one. It's not just a power strip. So it can't be used in tandem with the UPS. Instead, if you need more Protection-only or Protection-plus-backup outlets, you need a simple extension device like this. As the description says, it provides "unfiltered pass-through." That means it will work in the power chain with the UPS.

If an AC in the power chain is the issue you're fighting, then after summer ends, you can dispense with the secondary circuit hassle and put everything back on the circuit that had the AC on it.

Other Handy Items

In dealing with these issues over the years, I've seen the need for some related gadget-ware that can be useful, and in some cases, save you money in the long run.

- An extender for the AC adapters which block the outlets either on the UPS or the power strip. Often the AC power adapters take up so much space that you can't use all the outlets you just purchased.

- 25' extension cord (18 AWG - if needed to extend the UPS to outlet; the UPS will come with a medium length, but not 25'.

- "Green" power strip; it automatically turns off power to the AC adapters when the computer is off.  I put one of these between the computer and the UPS. The reason is that most older power adapters continue to drain power even when you don't need them. They can also be used for items attached to the TV for the same reason; when the TV is off, it switches off power to associated devices. (For instance, the utility's router/modem power adapter goes into an always-on outlet.)

- If you don't want to bother with the green power strip (I prefer them as I forget to power down these auxiliary devices), you can use one of these Belkin power switches. Lately, there seem to be numerous devices that in a price-conscious world come without an on/off switch.

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