Lighting Strikes: a Bolt From the Blue More Information

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Sources for lightning protection hardware

Delta Lightning Arrestors, Inc., P.O. Box 1084, Big Springs, TX 79721.

PolyPhaser Corp., P.O. Box 9000, Minden, NV 89423-9000.

Cushcraft Corporation, P.O. Box 4680, 48 Perimeter Road, Manchester, NH 03108.

Information sources

Insurance Information Institute.

Edison Electric Institute.

Lightning Protection Institute.

Underwriters Laboratory.

National Fire Protection Association/

Books available at your public library:

All About Lightning, Martin A. Uman, Dover Publications, 31 East 2nd St., Mineola, NY 11501, ISBN 0-486-25237-X.

Lightning, Martin A. Uman, Dover Publications, ISBN 0-486-64575-4.

The Lightning Discharge, Martin A. Uman, National Geophysics Series Vol.39, Academic Press, Inc., division of Harcourt Brace Jovanovich, ISBN 0-12-708350-2. (Uman is a professor of electrical engineering at the University of Florida, Gainesville.)

Violent Storms, Jon Erickson, TAB Books, Blue Ridge Summit, PA 17294-0214, ISBN 0-8306-9042-5.

Coiled Lightning: From the April 1994 "Letters":

Editor: Barry Willis's lightning-strike horror story in the February issue states that "[t]he final line of defense is the electrical outlet itself" and recommends MOV surge protectors, ferrite chokes, isolation transformers, and the like. This is all well and good, but the "final line of defense" is actually the power cord itself.

Here's a tweak that gladdens the heart—it doesn't cost a cent, takes three minutes to perform the procedure on your entire system, and, most importantly, it works: Just form a neat coil with the surplus slack in each of your power cords. I've actually seen a household with coiled cords after a lightning strike. Each coiled power cord was burned through and severed at the wall-outlet end of the coil. The juice never got to the components.—Martin R. Needleman, Annapolis, MD

Charles E Flynn's picture

Laszlo's picture

The Brickwall company makes an excellent and reliable product which does not rely upon sacrificial MOVs. I use it on my stereo gear and on my computer as well.

Charles E Flynn's picture

If I recall correctly, Brickwall and a few other companies license ZeroSurge's patents. It should serve you well. ZeroSurge reports that they have never had a failure.'s picture

Great reprint Barry. In the '89 quake, we were Sony TV dealers. Many, many 27" Trinittrons came crashing down from dressers, cabinets etc. At that time, the major Sony service station was in Santa Clara. Sony fixed the sets for free, back in their profitable days.

IgAK's picture

While it is laudable that the Brickwall brand is guaranteed not to fail, there is this, from their website:

"We believe that surge protectors should not fail. At the heart of our Series Mode Surge Protector is a massive inductor"

This is unfortunate because a series inductor will limit transients of not only the lightning type, but, also the audio type, and will blunt the leading edge rising transient. Inductors are also prone to ringing. Their device also has:

"No surge diversion to ground"

While this seems laudable on the face of it, actually shunting the surge to ground would be done by a parallel circuit such as with the use of TVS (Transient Voltage Suppression) diodes which have super-fast reaction times or GDT's (Gas Discharge Tubes) which are relatively slow to react but can handle huge amounts of current, which will not affect sound quality because they do not limit normal audio transient draw, only coming into use when needed for damaging surges.

Common (and cheap - "get what you pay for") surge suppressors use MOV's which are "medium fast" compared to the two above, about the same or somewhat less capable in current handling than the TVS type but are also parallel shunting types. But they have limited lifetimes that are unpredictable and those green "protected" lights are dangerous eyewash that doesn't go off when the MOV expires, leading you to false confidence in safety that is gone. These must be replaced frequently and regularly but you have no way of knowing when they are dead (or about to be with even one last small transient)...and there's that green light fooling you. MOV's are also considered poor sonically by many as they can distort the AC waveform after they age - another reason to replace them frequently. (See the Zerosurge or Brickwall articles.)

Both the Brickwall and Zerosurge devices are large inductor-based and therefore transient-limiting *all* the time, not just when that is needed for a surge.

A combination of carefully chosen TVS and GDT devices can give super fast picosecond response times and prodigious peak current protection in a non-"sacrificial" package that does not expire under any situation short of a *direct* lightning hit - in which case it may or may not die (depending on lightning hit severity and duration) *after* saving your equipment.

I am not aware of anyone offering such a combination as of yet, so I designed one that has already withstood a lightning hit less than 1,000 feet from my house while all my equipment and computer were on. Not financed for production yet but watch for it. Designed by an audiophile for audiophiles (even includes a nice also shunt-type noise filter)...and, shockingly for audiophile-meant products, is actually inexpensively cheap insurance for your precious gear. Watch for it. Even has a catchy name I can't reveal until that is trademarked.