Not that I know of Ron.  The AC power coming into your house is in the form of whats called a sine wave.  You could take an oscilloscope and look at the sine wave and see if the wave has perfectly rounded on the edges.  A lot of AC that needs conditioning comes in as a partial square wave sometimes.  Also a power conditioner will stop four nasty power conditions: surges, sags (also know as brownouts),and spikes, but will not stop blackouts or outages.  The only thing that helps with the blackouts would be a UPS.  A surge is a lengthy (2.5 second or longer) increase in the supply voltage. A sag or brownout is a  decrease in the main AC power.  Spikes are the real nastiest. A spike is a brief increase in the supply voltage - less than 2.5 seconds, often a lot less. For a fraction of a second, a spike can easily subject your equipment to several hundred volts. 

            There are a lot of inexpensive good power conditioners or whats also known as Power strips, that will stop or decrease the chance of spikes and surges for about 50 bucks or so.  A surge-clamping component in a basic filter-board is a Metal-Oxide Varistor (MOV). MOVs pass current only when the voltage across them is above a pre-set value, and they react very quickly, like in a matter of microseconds. That’s the good news. The bad news is that MOVs wear out and they are only good for a few uses, and the bigger the spike, the more damage is done and the sooner they wear out. 

    If you live in a decent size city, I highly doubt that you will need a line conditioner to take care of the sine wave, as larger power companies are good at taking care of this problem.  The only time you would probably need an expensive power conditioner would be if you were running your equipment off of an inexpensive generator.  I make it a point to change my power strips or surge suppressors every 18 months or so.  If the light goes out on your power strip, that's a hint that you are no longer protected.  If you really think you need a power conditioner, in my opinion, a an inexpensive SPS(Standby Power Supply) is good to use.  A lot of SPS are sold as UPS's (Uninterruptible Power Supply).

    SPS's act as a surge suppressor or line filter , but they also contain a backup battery  and an inverter.   An inverter is a circuit device that makes AC power from the battery.  The inverter only kicks in when there’s a power outage  Small models have enough battery power for only a few minutes of operation, but that’s long enough to save your files and shut down unless your really brave and want to try and ride out the blackout.  Bigger models have multiple battery banks that can keep important equipment running for much longer.

    If you wish to spend a little more cash,  buy a true UPS.  It's inverter runs all the time, so there’s no switchover time if the incoming power drops out.  Good UPS's have to have high quality inverters, which produce an output waveform as close as possible to an AC sine wave. Cheap "square wave" inverters are unsuitable for many applications and can, over time, damage  power supplies, and the "modified square wave" versions that have become popular recently aren’t a whole lot better, for continuous use.

     The bottom line, If you live out from larger cities, I would highly recommend a true UPS not SPS.  Be careful when you buy a UPS, as like I said before, more then half of the stores I went to wanted to sell me a SPS and said it was a UPS.  A UPS is exactly what it says it is, an Uninterruptible Power Supply.  If you live in a larger city, a good power surge strip will usually handle nasty surges and spikes.  Some even off er a warranty if it does not work and your equipment blows out.

MusicmanIA said: How important are surge protectors, and do they work? I installed an expensive home theater system in a customer's house. His satellite dish was out in the yard. He bought the $200 Monster Power Center. Two months later lightning hits the dish. The Power Center was melted down to half its height. The surge did not touch one piece of his system. We sent it to Monster, they replaced it of course. They are necessary and they work!

That's an incredible story! I can't say this is all that common though. Typically, proper surge protection will indeed supress major surges from the power lines, but I wouldn't say any surge protector will commonly stop something like a lightning strike. Serioulsy, it's a little box... and it's tough to handle that much current in a little box. That's why surge protectors come with insurance policies to cover your gear if it's taken out by catastrophic events like lightning.

Cool though that this managed to keep the gear safe from the strike. Again, not particularly common in my experience, but pretty darn cool to hear these stories. Now if you only had a pic of the melted power center! That would be neat to see. 

Mind Over Matt'er - Technology musings, opinion, and more straight from TechLore's head geek.