Secrets of Surge Protection!
(Or: How To Increase The Life Of Your Electronics)
Electronics Reviews & Guides
You've seen those power strips that are supposed to be "surge protectors".
Internally, they're not much different from the $100 ones. They all rely on a metal oxide varistor (MOV), which is about a 25-cent part. The MOV is supposed to become conductive during a surge or spike. That forms a shunt to ground.
When it works, the surge is supposed to go out of your building and
into the ground.
Often that's not what happens.
Spikes and surges do not behave like 60 Hz AC. If they find even a little bit of impedance in the ground wire, they'll gladly take a detour through your electronics. Sometimes they'll do it anyway.
MOV's go bad, too. And you won't know it, usually.
Maybe lightning is not a problem in your area? Your electronics can get spikes or surges from refrigerators, air conditioners, even downed trees
hitting the lines a few miles away.
No thunderstorm required.
That $100 "home theater power center" could be quietly failing to protect against surges. And it may be polluting your building's
ground wire with voltages that should not be there. Start messing with the GND reference, and weird stuff happens. An old power strip almost ruined the motor on my refrigerator. Stray voltages can pop capacitors (which often can't take reverse polarity) and wreck lots of other things.
Put your open hand slowly into water, and it's easy.
At high speeds, that changes. Fast enough, and it's like hitting pavement.
That's a great way to think of reactance. The faster a surge tries to rise, the more impedance it encounters.
That is how a series-mode surge eliminator works.
It's transparent to mains voltage at 60 Hz, but as soon as it gets hit with a
surge or spike, it acts like a wall.
I'd seen enough fried electronics to know there had to be something better, and here it was! When I switched
over, these units surpassed my expectations.
If you're already wondering where you can get your hot little hands on
one of these gems, they're made by SurgeX and you can get them here. (I also put a few more links at the bottom of this page.) '
Still going strong, nearly a decade later!
I can't even begin to describe how great these things are. The
inductor is completely unaffected by surge voltage. Unlike with
MOV-based units, you don't have to replace the unit every time there's
A SurgeX lasts indefinitely. They use their products in Carnegie Hall, Yankee Stadium, and other places that take
their equipment seriously. There's no cheesy little 25-cent part to fail.
And by the way. Another danger of MOV-based "surge protectors" is
that even when they work as designed, MOV's can easily fry other stuff in your
Remember I said that MOV's only redirect the surge! That power strip where you
plug in your microwave could be slowly destroying your computer, your
stereo, your TV... and you won't even know it, until the day they quit
I have a feeling that a lot of hard drive
failures and data losses are due to this fact, also.
In all likelihood, a lot of "wall wart" power supplies fail
because of small surges that otherwise go undetected. As you probably know, those "wall-warts"
are responsible for a lot of fires. Getting a SurgeX
can give you an extra line of protection in those cases where it's not
practical to unplug the wall warts when you're not home.
6,000 Volts at 3,000 Amps?!
These protectors can stop a surge of 6,000 volts at 3,000
amps without any difficulty.
"That's silly," you point out. "If it stopped the surge, then 3,000 amps wouldn't flow."
You're right. Years ago, I saw the equipment that was used to test these devices. It could generate 6,000 volts with enough "juice" that 3,000 amps would flow, if the test item could handle it.
They used to blow up metal-oxide varistors with it. Often it took a lot less than 3,000 amps to do that.
That same type of MOV is what's in most "surge protectors".
Now, get this. When they applied the same power to the series-mode surge neutralizers... NOTHING. No smoke, no explosion; everything was the same as it had been. The surge ran into the massive reactance of the device, which canceled it out.
So, you're right: 3,000 amps didn't actually flow. But without the series-mode surge neutralizer, it would have.
These surge neutralizers are probably the safest place you can plug anything.
Power Supplies No Longer Toasted
I used to see a lot of computer power supplies with a particular type
of failure. A low-ohm resistor would go bad with scorch marks around it. Once that resistor went, it would take out other stuff, too.
I lost track of how many power supplies I've seen with that problem.
Almost all of them were plugged into "surge protectors". And all those were built around that same 25-cent MOV that fails.
Since I began using series-mode surge protection, I don't think I've had so much as one power supply go bad. (Hard drives still
fail, because they have moving parts. And of course capacitors can go bad, on their own.)
Anyone who values their electronics needs one of these things.
If you really want to do it up right, throw out all the MOV-based power
strips and replace them with these. Then, you won't have to worry about MOV's polluting your
The SurgeX SA-82 Flatpak
has 2 outlets and is rated for a draw of 8 amps. That's sufficient for an average computer workstation, or any other combination of things
that draws less than about 760 watts.
The larger SA-1810
has 10 outlets and allows a draw of up to 15 amps, which is the maximum
current provided by a standard North American household circuit
breaker. That means you can run just about any piece of equipment
through this unit, as long as it can be plugged into a standard
Get your SA-1810 through this link and it helps to keep my website on-line.
Both units filter EMI/RFI noise,
making them great for protecting your vital electronic equipment.
This technology is the best thing I've seen in surge protection, ever. I would highly recommend it if you care about your electronics.
I hope you've found this article helpful. Please help me out by
purchasing your gear through any of these links. Thanks for reading!
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