Surge Protectors

[JerryM]

Are the small, approx 1.5 in, surge protectors they make for laptops of any real value?Jerry

[Tushman]

Are the small, approx 1.5 in, surge protectors they make for laptops of any real value?Jerry

You'll have to be more specific Jerry. Can you post a link for the product which you're referring to?

[JerryM]

You'll have to be more specific Jerry. Can you post a link for the product which you're referring to?

I think this is the ones I have seen in Best Buy. They are the two small items in the picture. I don't know what the larger item is, but what Ihave seen is a package with the two in it. It appears that there is a two prong and three prong protector. I am not sure how they fit with the power cord or the notebook.http://www.bestbuy.com/site/olspage.jsp?sk...d=1051826232713Best,Jerry

[epp_b]

Those little things are adapters to plug into the cable that is normally attached from the power brick to the wall outlet.I think the cable coming from the main unit attaches to the power brick. The connector on the other end is connected to cable which is connected to a wall outlet.

[JerryM]

Thanks.Jerry

[Cluttermagnet]

Are the small, approx 1.5 in, surge protectors they make for laptops of any real value?Jerry

Hi, Jerry-Your question is not really precise. It can be answered either way. Depends on just what it is you 'value'. What sort of 'surges' do you wish to protect against?I see two problems here, right out of the gate. First, these inexpensive devices probably have only MOV's (metal oxide varistors) inside for implementing the transient suppression function. They will give some measure of protection against power line transients caused by big equipment switching on and off and producing voltage spikes on the power line. Big equipment is typically refrigerators and air conditioners and such. Could also be bigger stuff like electric resistance welders, etc. but not normally in residential neighborhoods. You never know. They do garbage up a power line somewhat when switching on or off. Already we have trouble here, even with this limited goal. The manufacturer seems to be trying to be all things to all people, i.e. he has a single model for protecting against transients on both 120VAC and 240VAC power lines. This is, in my estimation, a big mistake, as it gives a lesser measure of protection when operated at 120V. Note the following two items from the website:* 500-joule protection at 330 volts* Multivoltage support for both domestic and international use (100/240V)The rated voltage for the MOV's to conduct and shunt current past the load (computer) must be high enough so that they do not conduct when the line voltage is normal, 240V. So that's where that 330V rating is coming from, it appears. In other words, you will get better voltage spike suppression at 240V than at 120V. The voltage level for transient clipping is apparently fixed at 330V. Normally, we'd expect to see MOV's with 230V or more likely 250V ratings used to protect a 120VAC line. IMO the manufacturer should really have two different models, but I guess their calculation is that a lot of 240V users would buy and burn up any 120V units, if they existed. OTOH, the two supply voltages are usually served out of very different connector types, so there should normally be little or no danger of getting the two mixed up. But the problem here is that the devices in question may not plug directly into an outlet. Rather, they may be 'inline' devices inserted between the laptop and whatever does plug into an outlet. Ouch! I can see their predicament. It's not clear to me, but I think the devices are actually mounted in the bigger unit shown in the website photo. Those two smaller gadgets appear just to be some sort of adaptors. Too small to fit both MOV's and an EMI/RFI filter in there (but not impossible). Add in the phone/LAN line connectors, and by default, only the bigger piece could fit all that stuff in. I'd need to see these up close to be sure of what they have designed here.The second problem is the false sense of security these devices might give the user, leading them to believe they are protected against lightning and inducing them to continue operating during lightning storms instead of powering down and disconnecting from the grid. Big mistake, IMO. For nearby lightning hits, these devices could prove to be no match, and the connected device could definitely suffer major electrical damage despite being on these 'protectors'. Personally, I never count one bit on any MOV suppressors for lightning protection. I unplug all power and internet cables when lightning is in my area, or if I go out and there might be lightning. And my gear lives on.The "Excess Current Detection" 'feature' is laughable. It's sort of like saying "sugar- with added sweetness option". The 'current detection' is an intrinsic property of MOV's, I suppose they are saying. Well, duh! And it's excess voltage detection, anyway, not current. Shunt current happens in the MOV when it 'detects' (encounters) an excessive voltage.The "EMI/RFI noise filter protection" feature is not a *benefit* to the laptop user. They make it sound like it is. Rather, it is a feature protecting the users of all sorts of radio gear against EMI that is usually produced in switching power supplies, which are usually found in *computers and computer-related electronics*. It's not protecting Mr/Miss Laptop user against the world's RFI, it is protecting the world's radio tech users against Mr/Miss Laptop. Heh! I honestly can't say for sure whether or not this offering is of any significant benefit to you. It certainly offers at least some degree of transient voltage spike mitigation, which might prevent the early failure of your laptop power supply, should you happen to connect to a really dirty power source. For lightning protection, forget it, 75,000 supposed dollars protection not withstanding. And just try to prove your case and get any actual settlement if lightning gets you. Good luck. Well, maybe you will. I don't know. It's probably relatively cheap for this manufacturer to settle a few claims. Actual lightning damage to computers is a statistically tiny possibility for most of us- but it does happen all the time. It has happened to me personally and I do know others it has happened to. BTW I know from personal experience that a lot of lightning-damaged gear has no visible scorching/charring etc. And it often doesn't even have that 'burnt electronics' smell, either. But the damage is real and it is there and the device is very, very dead. Assemble a skilled team of scientists and engineers and they can analyze a failed unit and dissect components and show you where this or that little piece of silicon gave up the ghost and got vaporized. But such damage is often invisible and microscopic. So go ahead, try to prove your case to that manufacturer- that your dead electronics failed due to lightning and the MOV's failed to protect. Good luck. But sometimes they do fail to protect. And if you really want to know why, you might have to study engineering enough to understand the AC circuit principles involved and know how to *really* mitigate against lightning when you are really serious about it, and how very, very difficult a task this really is to achieve.I personally wouldn't buy this gadget. Or if I felt that I needed this protection, I'd build up one myself for less than a dollar in parts. But then I'm a geek with some radio engineering experience, and a reasonably well-stocked shop. 25 dollars seems a bit pricey to me. But then I notice that they really make laptop users pay through the nose for every little accessory gadget. It's a pricey niche, in my view, but the little gizmos (laptops) are admittedly popular. I don't own one, don't want one. Well, Ok, you could give me one, but I wouldn't buy myself one. Heh! Edited January 8, 2006 by Cluttermagnet

[JerryM]

Cluttermagnet,Thanks for the answer. I suspected that such a device could not give much protection. I have not bought one, and don't think I will.I know that nothing I have will protect from a lightning strike, and usually I connect to a surge protector that comes with most machines. I do not have much confidence in them. When a storm comes up I generally unplug my computer including the phone line.Have a good day.Jerry

[Pete!]

Trivia (slightly off topic):Back when computers were too expensive to risk....A motor/generator set was used to protect industrial computers against transients and lightning. The inertia (flywheel effect) of the armature would prevent transients from changing the voltage supplied to the computer. In the case of lightning, the motor would get "smoked" (or blow a fuse) before it could speed up enough to send a spike to the computer.Not worth the cost for a desktop or a laptop.

[lewmur]

Cluttermagnet,Thanks for the answer. I suspected that such a device could not give much protection. I have not bought one, and don't think I will.I know that nothing I have will protect from a lightning strike, and usually I connect to a surge protector that comes with most machines. I do not have much confidence in them. When a storm comes up I generally unplug my computer including the phone line.Have a good day.Jerry

IMHO, that is a mistake. While they might not protect against "THE BIG ONE," I have seen them burned to a crisp with no damage done to the computer. If you are not Obsessive/Compulsive, you might forget to unplug everything, every time you go to sleep! I know that I have been awakenned, many times, by thunderstorms, when I had accidentally dozed off with the computer running.

[Tushman]

I know that nothing I have will protect from a lightning strike, and usually I connect to a surge protector that comes with most machines. I do not have much confidence in them. When a storm comes up I generally unplug my computer including the phone line.Have a good day.Jerry

Jerry - do yourself a favor and buy a UPS (uninterruptable power supply). If a lightning storm strikes, your PC/ laptop will be protected by it.

[JerryM]

Jerry - do yourself a favor and buy a UPS (uninterruptable power supply). If a lightning storm strikes, your PC/ laptop will be protected by it.

Where do I find such a thing, and is there a best brand?I do not get up in the middle of the night. Some things are not worth that degree of effort, and my computer is not worth that much worry. I always unplug when I go out of town, and we do not have many thunder storms here is southern NM. I'll look into the power supply.Thanks,Jerry

[Cluttermagnet]

I'm not very OCD (obsessive-compulsive). Sometimes I forget to unplug. Almost always, one gets away with it. But one time I remembered to unplug the power line, forgot to disconnect the phone line. A nearby lightning strike was energetic enough to ride in on that line and take out my mobo, video card, hard drive, and modem. BTW the mobo was still barely functional- I could still see the floppy drive, but I had lost my IDE controllers. It was toast, and wouldn't POST. Adios! (It does not fit- you must acquit!) Heh!I think a standard 'surge protector' power strip offers as much protection as this fancy laptop gadget- for about a half to a quarter the cost. But it might still be worth it, on the theory that any protection is much better than none at all. All I'm quibbling with is the price of the item, and the somewhat nebulous claims, some of them obvious hype.Regarding UPS surge 'solutions', that too is a complicated issue, but it is safe to say that disconnecting power and internet connections during lightning storms is still a *very* good idea. A close enough lightning hit will simply overwhelm the 'protection' and get you anyway. OTOH if you have disconnected, as you really should anyway, it will not get you. Unless you get a really energetic one, then all bets are off. Lightning can even take out completely disconnected gear, at times. UPS's are great for their main purpose- avoiding data loss due to power drops. They are greatly oversold as a cure all for lightning mitigation, however- large cash guarantees not withstanding. BTW those fried MOVs you saw were probably simply 'self-destructs' and not necessarily burnt as a result of mitigating lightning. The do have a wearout/failure mechanism, and they generally proceed first towards short-circuit, unless a really energetic pulse- such as lightning- literally blows them apart. Ultimately, they fail open-circuit. As their resistance decreases as they degrade, they begin drawing more and more current from the power line during normal (non-voltage spike) times. They dissipate more and more power, thus the visible blackening. The ones you saw may have 'opened up' (failed open-circuit) but did not blow apart because the cause of their demise was simply the normal AC power line current, and not lightning. But they did fry for a while before they opened up, as the blackening makes obvious.

Edited January 8, 2006 by Cluttermagnet

[teacher]

In support of your basic UPC surge protector, I must tell a tale. Six years ago I was teaching in a small country school. Since it was in the country, there were no codes to be followed when construction took place. My classroom was created by stringing wires, installing walls and a ceiling in the library.Many times I had gone up on the catwalk (it was really an old gym) and followed lines that lay on top of the ceiling tiles to figure out where lines went.One day I was standing outside my classroom door during class change (being the good teacher for a change and doing what I was suppose to be doing rather than watching the students as they came in and logged on). Students quickly pulled me into my classroom. I had ten surge protectors on the floor and they were all dancing across the floor. I ran upstairs and shut off the power to my classroom.To make a long story short, we discovered a mouse (this is a country school) had gotten in the wall and chewed a line in two. It dropped and shorted out another line. The end result is that I had ten power supplies with holes in them where they burned up. I had 20 computers and not a single one had any damage. The school was quite happy to replace those surge protectors and we promptly rewired my classroom. Any surge protector is better than no surge protector.

[JerryM]

Hi Julia,Having grown up in some small "communities" I can understand what you experienced.I am not sure if such still exist. The "bathrooms" were not the warmest in the winter or the coolest in the summer. Jerry

[Tushman]

Cluttermagnet - nothing personal here but I completely disagree!

Regarding UPS surge 'solutions', that too is a complicated issue....

A UPS is not a "surge" protector. They serve two completely different functions one should not confuse the two devices. A UPS is a much more capable device than just providing protection from electrical surges.

...but it is safe to say that disconnecting power and internet connections during lightning storms is still a *very* good idea. A close enough lightning hit will simply overwhelm the 'protection' and get you anyway.

Sure if you're that worried about a lightening strike hitting your home, then yes go ahead and disconnect your PC and while you're at it disconnect your TV, major appliances...so forth. To me there is no point in doing that when one is utiliizing a UPS as a source of protection. It is probably the single most important piece of investment that anyone could make in protecting their computer.

UPS's are great for their main purpose- avoiding data loss due to power drops. They are greatly oversold as a cure all for lightning mitigation, however- large cash guarantees not withstanding.

The main purpose of a UPS is to not only provide a steady source of power during black-outs (or brown outs for that matter) but to also protect your hardware. My impression is that you're painting a UPS unit to be just a large battery backup for a computer. That's greatly over simplifying it. Should you be so unlucky to be hit by a lightening storm, a good UPS unit will sacrifice itself and protect the computer. The circuitry is designed for that kind of catastrophy. And that, my friend, is why UPS manufacturers are willing to back that up with cash guarantees should your PC ever become damaged while using their equipment. Edited January 9, 2006 by Tushman

[Cluttermagnet]

In support of your basic UPC surge protector, I must tell a tale. (snip) Students quickly pulled me into my classroom. I had ten surge protectors on the floor and they were all dancing across the floor. I ran upstairs and shut off the power to my classroom.To make a long story short, we discovered a mouse (this is a country school) had gotten in the wall and chewed a line in two. It dropped and shorted out another line. The end result is that I had ten power supplies with holes in them where they burned up. I had 20 computers and not a single one had any damage. The school was quite happy to replace those surge protectors and we promptly rewired my classroom. Any surge protector is better than no surge protector.

A memorable word picture. So these were basic 'surge strips' with nothing more than some outlets and some MOV's inside, I take it? Sounds like those MOV's basically did their job. Whatever happened, the voltage seen by the MOV's must have been abnormally high- *and* they were seeing a steady state overvoltage, not just 'spikes' or a highly energetic lightning hit. They would have probably been getting red hot and exploding inside those boxes. They definitely would have been hot enough to melt away parts of a plastic enclosure. They would blacken paint and char a metal box. Unless this abnormal current then triggered a fuse or circuit breaker inside those boxes, the computers would have also been seeing this steady over-voltage. That would have been pretty hard on the computer power supplies. They would have been dealing with about 250-300V steady state, in that case (roughly). Could have been more if/after the line-to-line MOV blew away. At some point, a fuse or circuit breaker should have been tripping out, back at the service entrance, anyway, if not in the boxes themselves. An impressive sight, for sure.Getting back to JerryM's original question, he could get the same degree of protection for probably 4-7 dollars with a single MOV plug adaptor instead of spending 25 dollars on this laptop accessory. And he would have the same kind of protection you are talking about for his power supply, though not his internet lines. Pay your money, take your choice. I have a goodly sprinkling of MOV devices around my place, too. I just don't count on them for lightning mitigation.

[Cluttermagnet]

Cluttermagnet - nothing personal here but I completely disagree!

Nothing wrong with a healthy debate. I know you are trying to be helpful. I was a bit disappointed to find myself being (perhaps) labeled OCD just because I understand- and respect- the electrical laws under which lightning operates. I'll continue to disconnect during lightning storms or when going out during the summer months. If you knew what I know, you would too.

A UPS is not a "surge" protector. They serve two completely different functions one should not confuse the two devices. A UPS is a much more capable device than just providing protection from electrical surges.

You are really trying to have it both ways. For all intents and purposes, in this discussion, you *are* viewing UPS's as glorified 'surge arrestors'. You're counting on them to mitigate all kinds of 'surges' including power line spikes from big equipment switching on and off, wierd 'fault' conditions such as the one Teacher describes, or even lightning.

Sure if you're that worried about a lightening strike hitting your home, then yes go ahead and disconnect your PC and while you're at it disconnect your TV, major appliances...so forth. To me there is no point in doing that when one is utiliizing a UPS as a source of protection. It is probably the single most important piece of investment that anyone could make in protecting their computer.

OK. Well, it seems to me that it all depends on what type and degree of 'protection' we are talking about. Are we limiting the scope of our discussion to power and data line surge protection? I could make an equally valid argument that the security hardware and software we (hopefully) all use is the most important protection- by far! Actual destruction caused by lightning is relatively rare. Destruction caused by evil hackers is widespread and causes a lot of misery.

The main purpose of a UPS is to not only provide a steady source of power during black-outs (or brown outs for that matter) but to also protect your hardware. My impression is that you're painting a UPS unit to be just a large battery backup for a computer. That's greatly over simplifying it. Should you be so unlucky to be hit by a lightening storm, a good UPS unit will sacrifice itself and protect the computer. The circuitry is designed for that kind of catastrophy. And that, my friend, is why UPS manufacturers are willing to back that up with cash guarantees should your PC ever become damaged while using their equipment.

Nope. I understand the difference. I own several UPS's here, and do understand the subtleties of their design and construction. There are different types, some better, some worse. I will still unplug in the summer, because I know lightning and I understand the limitations of the circuits and components inside those UPS's.I know it well because of my experience as an electronics design engineer and also as a licensed amateur radio operator with some 43 years of practical experience in the field. Radio operators develop an especially vigilant attitude towards lightning, as many of them erect antennas that can be struck by lightning. If you don't know how to mitigate against it, you may suffer lightning damage eventually. I know some who have.While it is true that UPS's can be effective in lightning mitigation, and do indeed have front-end components on the power line that try to clamp such transients and shunt them safely past your 'protected' devices, there are limits to any protection scheme. It all comes down to how nearby and how energetic a particular lightning strike is. Do you really believe that a handful of tiny components will always stop a bolt of energy which built up millions of volts to create an ionized, conducting tube from cloud to ground (miles long) and which can exceed a hundred thousand amps in current density? You get a frisky enough strike and it laughs at your puny protection, jumps the small gaps involved, and finds any darned path to ground that it darned well pleases. I don't care how 'good' a UPS may be, there are limits to what it can do for you. Yet it is so unbelievably simple and effective to set up the average home computer system so that a single line plug and a single modular phone plug or LAN plug or coax cable are all that need to get pulled to render you nearly invincible. I'll unplug *every* time, because I know what lightning can do. Just to make it even more clear what I'm saying here, I *do* believe in the utility of UPS's for surge suppression. I buy them and I use them here. And I will *still* disconnect, every time, if there is any chance of lightning. I don't usually bother for about 4 months in winter- *but* we just recently had some rare winter lightning activity and I do know personally a man who had to get a work computer fixed by Dell after those overnight strikes. Fried mobo. No proof it was lightning, of course, but guess what I'm thinking? After a while, you do start to see a causal relation, if you but look for one. Yeah, I disconnected for a while that night, until the storm passed over. You are mistaken to compare computers with major household appliances, like, say, your refrigerator or whatever. The latter are more rugged against lightning-induced power line transients, though lightning spikes are hard on any electrical appliance. Computers, stereos, TV's, etc. are far more fragile because they contain sensitive semiconductor devices that get zapped easier- so if your jazzy new refrigerator has some on board electronics, that makes it of a more vulnerable class like computers. But most don't. It is anything electronic that is the most vulnerable. It is in the nature of lightning that it induces a lot of smaller currents in wires everywhere in the vicinity of the strike. A direct strike in your yard or a neighbor's is bad news! A direct strike on your house is really bad news. In either case, there can be enough induced current in nearby wires in your house to produce voltages sufficient to do a lot of damage, perhaps enough to overpower any protection scheme of the MOV-in-a-box type. And note carefully that lightning is a bit 'playful', in that it can directly induce damaging currents in conductors downstream from any protective device, if the strike is nearby and intense enough.There is good news. There are some mitigation schemes that actually are nearly bulletproof. The bad news is, you can't afford them. The way the pros do lightning mitigation goes roughly like this: They completely rewire the service entrance if necessary, so that every (and I do mean *every*) conductor going into that building enters through a single point. At that point, they place a heavily grounded metal 'bulkhead'. Starting from that bulkhead, they dig a perimeter ditch around the entire building and put in deep ground rods at frequent intervals. They bond this perimeter ground all together with rather wide copper strap, not just thick wire. And at the bulkhead, each and every conductor- power, telephone, cable, etc. gets its own gas tube arrestor that will shunt the energy of a strike to ground. Gas tubes, OK? Not MOV's. The consensus is that gas tubes are far more robust. Not as much of a wearout mechanism as MOV's have. Are you still with me? And of course this scheme costs a few tens of thousands of dollars or more to implement. This is what you will see at radio stations where they have a big tower outside that *will* get struck by lightning, and they can't afford a minute of down time. You might not be sitting right next to as big a 'lightning rod' (tower) as they are, but the principles still apply. Your 'tower' may be your overhead power lines or telephone lines or cable, whatever. Once you have understood the savage intensity of lightning and the physics of its propagation, you will come to see that MOV-in-a-box solutions are sooooo iffy. They do indeed protect in a lot of cases, say when lightning hits a block away from you. It's ultimately a crap shoot. Even if they used gas tubes instead of MOV's. It's fairly critical as to how the utility conductors and incidental grounding are deployed (physically routed). Luck of the draw, in most cases. Pray that lightning doesn't strike too close. Or unplug. It's simple, and close to bulletproof. The pro scheme, above, is closer yet to bulletproof. Edited January 9, 2006 by Cluttermagnet

[Cluttermagnet]

Trivia (slightly off topic):Back when computers were too expensive to risk....A motor/generator set was used to protect industrial computers against transients and lightning. The inertia (flywheel effect) of the armature would prevent transients from changing the voltage supplied to the computer. In the case of lightning, the motor would get "smoked" (or blow a fuse) before it could speed up enough to send a spike to the computer.Not worth the cost for a desktop or a laptop.

Interesting, Pete- thanks! Yeah, good old magnetic components, the clunky old things. You know, they have some very effective 'brute force' filters that do a pretty good job of smoothing out step changes in supply voltage (transients). They consist of series inductors and shunt caps in each line, and resemble a Pi filter, as I remember. The 'with' and 'without' oscilloscope presentations of transient response will make you a believer. I bought one for myself, a 5A model "Islatrol Plus". I put it in the line after my UPS. Oh, and they do sprinkle a few MOV's in them too. Heh! :whistling:Motor generators were a pretty elegant but simple method of lightning protection. Neat! I bet you wanted to use an insulated shaft coupling with a pretty healthy HV breakdown voltage rating, eh? (Sorry guys, I couldn't resist one more gob of geekiness from the wonderful old analog days of yore- now back to the Future, which is already in progress...) Edited January 9, 2006 by Cluttermagnet

[Cluttermagnet]

Where do I find such a thing, and is there a best brand?I do not get up in the middle of the night. Some things are not worth that degree of effort, and my computer is not worth that much worry. I always unplug when I go out of town, and we do not have many thunder storms here is southern NM. I'll look into the power supply.Thanks,Jerry

Sounds like a UPS is overkill for you- at least if lightning mitigation is your objective. Southern NM? Why don't you go to Radio Shack and look for one of those line plug adaptors that have the MOV's inside? Probably about 5 bucks. Probably enough for you. One fifth the price of the laptop accessory. But it only protects the power line, not your data line. I think they make models that do both pretty cheap, too. Bet you find one of those, too, if you look. Maybe 10 bucks? Usual form is as a power strip. Cheapest UPS's on sale seem to start around 35 bucks, but more often 50 bucks. Do you really need power drop protection of your data? Then get one. I like mine. It's maddening if you type for 20 minutes and then the power drops and you lose your unsaved data when your computer reboots. Respectfully, I think Tushman has you way oversold on your need for and the effectiveness of UPS's. Your call. BTW the ad copy writer for that Best Buy ad was really blowing smoke in his specmanship. Not your best option.Regards, Clutter

[Pete!]

...Motor generators were a pretty elegant but simple method of lightning protection. Neat! I bet you wanted to use an insulated shaft coupling with a pretty healthy HV breakdown voltage rating, eh? (Sorry guys, I couldn't resist one more gob of geekiness from the wonderful old analog days of yore- now back to the Future, which is already in progress...)

Actually, the coupling between the motor and the generator, contained a rubber cushion. There was no metal-to metal contact in the drive, ( I guess a direct strike could probably jump the gap, but spikes were the real problem). The plant where we installed the first system was in the outskirts of Memphis in an area where spikes large enough to blow SCR drives were quite common. This may be what happens when you ask a couple of mechanical engineers to protect electronics in the early '80s.

[FuzzButt]

As one who had a lightning strike at the pole outside my house. Less than 40 feet away. It was enough of a jolt to blow the 13KV-110V Transformer mounted on said pole. I have my equipment plugged into a APC UPS1000. In the AV room is another APC UPS1000. My Wife's PC is on the UPS500. In addition I had a surge supressor before the UPS since I did not have enough outlets. I fried $2700 worth in equipment. I was a few miles from home so my laptop was with me. I lost: all the networking gear, a 425W powersupply, the PC that that PSU was in was trashed as well. My AV amp was cooked an a few other items including a phone and a ceiling fan.Part of these items were simply just plugged in to a 110V AC line. The PC's also had the phone cable and the RG6 cable from Comcast HSI and Cable into the TV card in said PC.Simply put any outside source needs "surge" protection. On your laptop I would be more worried about the RJ11 Telephone connection if you have a modem or the RJ45 LAN connection if you have a wired LAN.

[lewmur]

Nothing wrong with a healthy debate. I know you are trying to be helpful. I was a bit disappointed to find myself being (perhaps) labeled OCD just because I understand- and respect- the electrical laws under which lightning operates. I'll continue to disconnect during lightning storms or when going out during the summer months. If you knew what I know, you would too. too close. Or unplug. It's simple, and close to bulletproof.

I didn't mean to imply that YOU were OCD. In fact, someone who was OCD would do both. Install surge protectors AND uplug everything every time. My point was that we sometimes forget to unplug and that therefore surge protectors can be helpfull. My surge protector has protection for the ethernet cable as well as the power line. Don't use dial up so the phone line is never connected.BTW, where I live, it can be a bright sunny day and you can turn you back for a minute and have a thunderstorm hit. In fact, I have seen it when one side of the street is sunny and the other side amidst a downpour. IOW, by the time the lightning is striking, its too late. Edited January 9, 2006 by lewmur

[JerryM]

I appreciate all the discussion, and am learning. I may go for the UPS, but in any case will go with the MOVs. I have one on my TV, and there is a surge protector that came with my computer that I use. I assume that is about as good as anything short of a UPS.I will continue to unplug everything if I see a lightning storm coming or when I take a trip away from home.Jerry

[Tushman]

You are really trying to have it both ways. For all intents and purposes, in this discussion, you *are* viewing UPS's as glorified 'surge arrestors'. You're counting on them to mitigate all kinds of 'surges' including power line spikes from big equipment switching on and off, wierd 'fault' conditions such as the one Teacher describes, or even lightning.

Your points are well taken CM. However, your statement above is an incorrection interpretation of what I was trying to say.As i said yesterday, the two primary purposes of a UPS (hardware and data protection) should not be confused nor construed as a surge protector. Since you own and use UPS units for yourself, you should be familiar w/ the distinct differences between the two. I never claimed the sole purpose of a UPS to be protection from just "electrical surges".

[Cluttermagnet]

I didn't mean to imply that YOU were OCD. In fact, someone who was OCD would do both. Install surge protectors AND uplug everything every time.

I do both.BTW my doctors say that my OCD is responding very well to the medication.

My point was that we sometimes forget to unplug and that therefore surge protectors can be helpfull. My surge protector has protection for the ethernet cable as well as the power line. Don't use dial up so the phone line is never connected.BTW, where I live, it can be a bright sunny day and you can turn you back for a minute and have a thunderstorm hit. In fact, I have seen it when one side of the street is sunny and the other side amidst a downpour. IOW, by the time the lightning is striking, its too late.

Seriously, this has been a great discussion, and I've enjoyed it. You and Tushman are right that UPS's are designed for surge mitigation, including lightning, and often will 'save your bacon' from that unexpected 'bolt from the blue'. Also that it is worthwhile having them because we can forget to unplug or we can take a lightning hit unexpectedly- completely without warning.Fuzzbutt is sort of our 'poster child' in the Forums for lightning safety. I'm always very happy to see him weigh in during any discussion about it. He really got clobbered. His account is a sobering tale of just how much damage a close hit can do. And he is very wise to be running behind his APC power supplies now.This subject is pretty much guaranteed to flush me out if I happen to be lurking in the Forums. Sort of like a bass fisherman's lucky lure, I suppose. Heh! My issue is that most folks really have no idea what they are up against when it comes to the ferocity of lightning strikes, and their incredible sneakiness so far as slipping by 'protection'. It is very wise to stay informed as to your local weather trends, and to unplug if there is active lightning within 5-10 miles of you, also to unplug when going out during the summer months. Most folks are lulled into a false sense of security if they are running behind surge arrestors, UPS's, etc. The $75,000 guarantees don't help, in this regard. The difference between 'protection' and no protection is significant. By all means, use some 'protection'. But the difference between 'protection' and unplugging is far more significant. You'd have to spend a pile of money to get much closer to 'bulletproof'.BTW it's very important to understand that the 'unplugging' concept is unforgiving. It requires complete unplugging. Lightning can sneak in via the cabling of any peripheral unit in a computer setup. This concept is pretty much useless unless you arrange it so that all devices plug into a common power strip. Then you only have to pull one power plug, and you can do it quickly. You also have to pull your outside telephone, LAN, or cable connections at the same time, perhaps even 2 or 3 of these if you have multiple means of connecting to the internet, or if you have TV and computer setups close together and sharing connections. Lightning will be perfectly happy to sneak in over your TV cabling to take out your computer setup, or vice versa. During the summer, 2 years ago, it snuck in on my phone cable to fry one of my computers, even though I had pulled the power plug. I forgot, and I paid. The rule is, if any unit is cabled across to any other unit, then they should be on a common power buss and you should be able to disconnect everything by pulling one and only one power cable. Ditto for any phone, cable, LAN etc. cabling. If there are any lateral connections between units at all, you will need to include them in your 'pull them all in a hurry' group. Any cables that connect to the outside world (not between-unit cabling) must be disconnected.Oh, one last thought- it is not sufficient to simply have all units on the same branch of your electrical service, and to plan to run and quickly click off one circuit breaker. Remember, lightning has a 'zillion' volts behind it, and it has no problem jumping small gaps of the sort you'd find inside a circuit breaker, On/Off switch, fuse, etc. Nope, you have to actually pull an electrical plug and get at least a few inches separation going there. Lightning is looking for the shortest, easiest path to ground, that's all. A disconnected power plug is not the easiest path. It qualifies as a 'large' gap (sort of). Don't you be the shortest path. "You are the Weakest Link- good bye!" Zzzzzzap!!! Edited January 10, 2006 by Cluttermagnet

[Cluttermagnet]

Actually, the coupling between the motor and the generator, contained a rubber cushion. There was no metal-to metal contact in the drive, ( I guess a direct strike could probably jump the gap, but spikes were the real problem). The plant where we installed the first system was in the outskirts of Memphis in an area where spikes large enough to blow SCR drives were quite common. This may be what happens when you ask a couple of mechanical engineers to protect electronics in the early '80s.

Cool! Makes sense. The rubber cushion could have the dual function of HV insulation plus that of a mechanical clutch, should a transient cause shaft torque to get too far out of hand (?) This is sooooo 1930's-40's-50's. It probably gives better transient voltage protection than the old constant voltage transformers ever could, and even a bit of lightning protection. Love it! Remember the old military 'dynamotors'? Put a radio, a whip antenna, and a couple of dynamotors in a jeep. 12VDC into the motor, and the generator spins out 300 to 800VDC for the plate supply on those vacuum tubes. They did a heck of a lot of stuff using motors for many years. OK, enough 'deep geek'. This is going to turn into an antique computers forum if we don't watch it. Back to the Future! "Look out- he's got an abacus!" Edited January 10, 2006 by Cluttermagnet

[b2cm]

[Pete!]

....... The rubber cushion could have the dual function of HV insulation plus that of a mechanical clutch, ......

Not really a clutch. It was a fairly standard coupling. The rubber element was an inexpensive means of allowing for minor misalignment between two shafts. Getting them "perfect" would take more effort than desirable. A flexible disc coupling, a bellows coupling, or a gear coupling would have been more expensive. The insulation effect was secondary (maybe even an afterthought). OR Now we're WAY off topic....

[lewmur]

Interesting, Pete- thanks! Yeah, good old magnetic components, the clunky old things. You know, they have some very effective 'brute force' filters that do a pretty good job of smoothing out step changes in supply voltage (transients). They consist of series inductors and shunt caps in each line, and resemble a Pi filter, as I remember. The 'with' and 'without' oscilloscope presentations of transient response will make you a believer. I bought one for myself, a 5A model "Islatrol Plus". I put it in the line after my UPS. Oh, and they do sprinkle a few MOV's in them too. Heh! :whistling:Motor generators were a pretty elegant but simple method of lightning protection. Neat! I bet you wanted to use an insulated shaft coupling with a pretty healthy HV breakdown voltage rating, eh? (Sorry guys, I couldn't resist one more gob of geekiness from the wonderful old analog days of yore- now back to the Future, which is already in progress...)

Back in 1985 I worked on one of the first "Microcomputer" systems. It was an S100 bus system in an autoparts store. They had a welding machine and a pipe bending machine for building exhaust systems. Everytime they turned the system on while the computer was writing to the 10mb harddisk, it would corrupt the disks. Built my own pi filter to cure the problem. The only "commercial" filters available at the time cost a bloody fortune. Got the design straight from the "Radio Amature's Handbook." Edited January 12, 2006 by lewmur

[Cluttermagnet]

Back in 1985 I worked on one of the first "Microcomputer" systems. It was an S100 bus system in an autoparts store. They had a welding machine and a pipe bending machine for building exhaust systems. Everytime they turned the system on while the computer was writing to the 10mb harddisk, it would corrupt the disks. Built my own pi filter to cure the problem. The only "commercial" filters available at the time cost a bloody fortune. Got the design straight from the "Radio Amature's Handbook."

Those welders are murder. If you have a neighbor who works on cars or farm equipment, or restores antique cars, you might be living next to one. A 'brute force' filter like the pi filter can clean up much of that. I think it makes a real good addition to low-end UPS's. I bet some of the more pricey UPS's incorporate them. I spent over 100 bucks on mine. I had a computer power supply that liked to turn itself on mysteriously. I suspected power line transients. Never proved it, but the behavior did seem to go away once I added the Islatrol Plus after my Cyber Power UPS.

i worked in the it dept of a major shipyard.power was anything but clean there.we had a huge transformer "blow up" sending a surge into our engineering bldg. we lost over a dozen pc's & monitors that had very expensive tripp lite surge suppressors.as mentioned above, their description says it all, they are "surge suppressors", not "arrestors".

Yep. They all have their limitations. Some lightning or power distribution system transients are just too energetic. Maybe the 'protection' will work (Teacher's example), maybe it won't (Temmu). And we can't always unplug. Sometimes there is just an electrical 'bullet' with our name on it.