There are few categories of electrical products as scammy as “surge protectors”. At the Las Vegas Fall COMDEX show in 1982 where we introduced AutoCAD, it seemed like every fourth or fifth booth was somebody of whom you’d never heard flogging their “surge protectors”, which looked remarkably like the cheapest outlet strips you could buy from manufacturers in the Orient, with bold stickers applied proclaiming their stalwart defence of your vulnerable electronics from the perils of the power line. (This was the same show which had about as many booths showing hard disc drives you’d never heard of before [or since], leading me to wonder whether the market was likely to support more than a hundred manufacturers of generic storage devices.) Anyway, since this was a show oriented toward computer dealers, the usual pitch for these “surge suppressors” was how store owners could boost their profit on every sale by warning the rubes customers of the hazards that lurked behind every power socket and selling them their high-markup “solution” (“Ask about our hundred quantity discount!”). This was, you see, before the “extended warranty” grift came into its own.
While competently designed power supplies should be able to cope with the routine slings and arrows that come down the power line, that doesn’t mean there aren’t nasty surprises which can lead to expensive consequences if your electronic equipment is not adequately protected. This is especially true if, like Fourmilab, you are located in a region where lightning strikes are a frequent occurrence. By far, the best protection is a high quality uninterruptible power supply (UPS) which places a robust transformer, filtering circuitry, and transient voltage diversion in front of your gear and provides, in addition, the ability to ride out power outages of limited duration with a built-in battery backup.
But for some applications, such as decorative lighting, a UPS may be expensive overkill and there are genuine, useful surge suppression solutions available. You just have to be careful that’'s what you’re buying and not one of the far more numerous scams masquerading as a similar product.
Big Clive starts by tearing down and analysing a high-end surge protector manufactured by MEAN WELL to protect industrial and commercial LED lighting installations. This unit meets all of the requirements: it has robust components, excellent separation between high voltage conductors, thermal protection of the surge diverting varistors, and LEDs which monitor operation of the protection devices and indicate failures which would compromise protection.
And then, we have the following device, being sold on eBay for £10 for four. Can you guess how many dangerous, scammy, and fraudulent features they managed to pack into these devices, ready to lurk on a DIN rail and provide a false sense of security until disaster strikes?
