On Sun, 30 Jan 2011 10:37:59 -0500, mm
wrote:

Question at ==== line:

http://www.squidoo.com/small-led-light-surge-protector

Small LED Light As Indicator In A Surge Protector

Cute. Too bad the article doesn't say what the LED actually does.
Offhand, I would say that the cute form factor of the electrical
octopus is the major selling point.

However, the most beneficial advancement of late is that small LED
bulbs are now utilized as indicator lights in the device that protects
equipment from power surges, the surge protector.

Really? Surge protectors work by absorbing energy (Joules) that would
normally do some damage if that energy arrived at the protected
electronics. A good MOV protector will absorb about 1000 Joules. An
LED can hardly absorb perhaps 1 Joule. If you decode the muddled
intent of the article, the LED light probably just lights when there
has been a surge.
http://en.wikipedia.org/wiki/Varistor

Surges, otherwise
called voltage spikes or transient surges, are abrupt increases in
household voltage what happen when high-energy appliances or computers
are powered on.

Ok, they got that right.

Such surges can take place in excess of 2,000 times
per year in homes, slowly destroying the components of a home.

I have a power line monitor and recorder at several mountain top radio
sites. It monitors surges, glitches, sags, over voltage, and other
power line impairments. On a typical day, it records about 10 alarms,
most of which are surges. During a storm, I'll see hundreds each day.
Most of them are harmless and will never go through a transformer or
get past even the most crude protection circuits. However, about once
a week, I see an event that has the potential for doing real damage.
http://www.enetics.com/app-PQM.html
(It's not this one but something similar).

===== Is this sentence true. Many times a year? And more
importantly, *slowly* destroying. Not ruined or "no damage"?

Nope, it's not true. Glitches do not erode or promote progressive
deterioration in electronic devices. Glitches break down
semiconductor junctions, which kills the transistor(s). It's the same
as getting hit by a static blast or lightning bolt. Once zapped, it's
totally ruined.

There are some obscure failure modes where static and power line
glitches cause a form of progressive deterioration by increasing
device leakage current, but that's rare and unusual.

computer, a cell phone, and other fragile electronic equipment. Other
home appliances, furnaces, air conditioners, washers, dryers, and the
like, are also know to create surges which travel back through the
main breaker panel and out again through the home wiring.

Amazing. Yes, back EMF glitches are theoretically possible from these
devices. However, all of the appliances already contain surge
protectors that protect in both directions (going in, and coming out).
With AC motors, such glitches are unlikely. The various regulatory
agencies would not issue a sticker if the appliance dumped power back
into the AC line. It is possible with large DC motors, such as the
starter motor in your vehicle, but the typical AC motor will only
create a voltage sag (decrease), usually caused by faulty or
overloaded wiring. Voltage swell (increase) is unlikely.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558