A Hidden Threat To Handhelds 214
Logic Bomb writes: "An article from the San Francisco Chronicle focuses on a lawsuit against Palm, but talks about a larger issue: static and handheld computers. Basically, as computing equipment becomes smaller and more likely to be carried around, major damage from static becomes a serious threat. As the blurb at the end of the article says, it takes 3500 volts for a human to feel a shock, but only 200 to potentially scramble a microchip." We already mentioned the lawsuit, but this has more information about the supposed risks to your motherboard.
is this a case... (Score:1)
If they prove that Palm knowingly sent out these devices knowing they could toast h/w, then unleash the hounds...but if it was a simple oversight (which is highly unlikely), well thats where things get interesting....
personally, i think we're getting a little too sue happy these days...
Re:is this a case... (Score:1)
I always figured sueing was a national sport in the US. Just after baseball and basketball in popularity.
We live in a vary litigious society... (Score:2)
--CTH
ESD hardening means $$$ (Score:1)
Sure, they could ESD harden the motherboards, but are you willing to pay for the increase in cost?
Basically Mr. Sue-Happy is gonna raise the price of your computer components. I'd rather have cheaper components than pay for someone elses uneducated electronics bumblings.
Re:Sure (Score:2)
$5.00 per component may be cheap when buying a motherboard or Palm as a consumer. It's quite a different matter for the manufacturer. When making millions of motherboards a year, multiply the number of units made by $5.00 and you get a large chunk of cash that any electronics manufacturer will refuse to spend, especially in the highly competitive, low profit margin computer industry.
Add five dollars to the manufacturing cost of a motherboard? Ain't gonna happen. Most managers go ape-shit when asked to put in a component that increases manufacturing cost by 15 cents per unit.
Looking at my Palm m505, it's apparent that there is some decent ESD protection. The connector that connects the Palm and the cradle has two metal hooks that contact two metal latches on the Palm before the gold connector pins make contact. I'd bet good money that they're grounded. There's also a ferrite cylinder attached around the cable to the USB port. Between that and the aluminum case, I'd say that it's pretty hard to static-zap your Palm or system in the process of cradling your palm for a sync. But that's just the Palm m500 & m505. Other Palms have different connectors.
Re:We live in a vary litigious society... (Score:2)
Which is it? Palm/mobo should handle ESD better, or users should be more careful? If the Palm/mobo really should handle ESD better, shouldn't the users sue? How else would the get better ESD handling? If the users really should be more careful, why should Palm/mobos waste money on better ESD handling?
Hmmmmmmmm it doesn't make much sense. (Score:1)
equipment becomes smaller and more likely to be
carried around, major damage from static becomes a
serious threat.
So don't stay static and yer safe! Keep on moving boy
It's a class B computing device... no big deal (Score:1, Offtopic)
A bunch of lawyers just decided that they might be able to make a quick buck here...
--CTH
Re:It's a class B computing device... no big deal (Score:2)
I'm not even sure a (single) static discharge would show up on an EMI scan (which is done for class B certification) It would probably show up as a slight increase in the baseline noise level, but not push it beyond the class B limits.
Re:It's a class B computing device... no big deal (Score:2)
Re:It's a class B computing device... no big deal (Score:3, Informative)
But the device isn't emitting it- the person is the source of the static discharge. The static charge is absoulutely *not* generated by the operation of the device- If it was, then I agree that it would have to be taken into account.
For static discharge, the FCC class rating of the device is a non-issue. It is a concern safety-wise, but the FCC rating is about emissions, not about safety. There are other, separate, certifications about safety.
I've taken part in EMI testing for class B certification- static discharge is not a part of it.
Re:It's a class B computing device... no big deal (Score:2)
A serial port (RS-232 interface) that can be damaged or destroyed by the static electricity from a user is poorly designed.
Re:It's a class B computing device... no big deal (Score:2)
As for your other point:I completely agree, although I believe one of the PC manufacturers who the users claim can be affected by this problem is DELL, which as far as I'm concerned isn't known for their poor design. I would certainly expect them to have sufficiently grounded serial ports.
--CTH
Re:It's a class B computing device... no big deal (Score:5, Informative)
is a serious problem. It IS possible to design interfaces which offer useful resistance. But it is suprisingly hard to design and build in practice and it causes problems throughout the electronics industry. To build a Port (USB, serial, whatever) which can resist electrostic discharges requires that you use most of the following :
Protective devices which can dissipate the energy. The risetime from Static discharges is very fast and overwhelms all but the best protective devices.
Drivers/receivers which are hardened against static (the major semi manufacturers who do such chips do now make some - but they tend to cost more
Careful mechanical design to further reduce the problem - arrange that the "grounds" always touch first - preferably through a few hundred thousand ohms of resistance.
Optical isolation (although many people fail to understand the limitations of this technique - the stray capacitance between the isolated section and everything else is almost always high enough to allow static damage to happen.
More importantly manufacturers need to test their designs properly using realistic test models. Much equipment - including from the big name manufacturers pays little or no attention to this issue. Presumably for cost reasons - although if the right measures are "designed in" from the start the premium is going to be pretty small. It's interesting to compare the serial interface from a top branded PC with a functionally-identical interface from some serious telecomms kit.
I'm an engineer - not a lawyer. But I do know that I'd hate to have to do the finger pointing in the "Palm v motherboards" issue. If forced to comment I'd say that both sides should share the responsibility.
Re:It's a class B computing device... no big deal (Score:2)
Careful mechanical design to further reduce the problem - arrange that the "grounds" always touch first - preferably through a few hundred thousand ohms of resistance.
Ummm... how the hell is ground to be effective with that kind of impedance? Ground potential should be equal.
Re:It's a class B computing device... no big deal (Score:2)
But ideally you want the "first touch" to be a high impedance. That dramtically slows down the rise time - which is likely to prevent damage.
Most likely static "sources" can be effectively discharged to safe levels by a leakage impedance of megohm or so - and within a few ms.
Re:It's a class B computing device... no big deal (Score:2, Funny)
I just can't keep up. I know about RMS and ESR, but who are these new guys?
Re:ESD protection is always present in ICs (Score:2)
Maxim are one example. They do some nice application notes on the subject too.
Go to http://www.maxim-ic.com/
Look for "interface and interconnect" under "products" - then click on "product trees"
You'll see several Tx and Rx families boasting of 15kV protection. Follow the links and you will find data sheets and app notes which go into quite a lot of detail.
NB - I will never again design another single-sourced Maxim chip into one of my designs ever again. And if the alternate source is Linear Technology then it might as well be single-sourced. I am not alone in thinking like this!
Re:ESD protection is always present in ICs (Score:2)
But 16 week lead times and minimum quantities of 5000 are fun!
Re:ESD protection is always present in ICs (Score:2)
16 weeks I can (just about) cope with. When they routinely start looking at next year's calender - then I get worried.
What's worse is when they've promised you 32 weeks or whatever, you've waited 30 weeks and you've only got two weeks to go - and they suddenly phone you to say that they're not going to deliver for another 12 weeks.
The best comment I ever saw goes "Maxim won't deliver this year - LT won't deliver this decade"
Re:It's a class B computing device... no big deal (Score:2)
Very true. But there are plenty of crap parts out there - which certain manufacturers suggest are suitable for this kind of application when they aren't. And because many designers regard this kind of thing as a "black art" and don't seem to know when they're been offered rubbish.
>Most companies opt for an all-MOS technology these days
Indeed. However even that need not be a problem.
I agree about the bipolar stuff BTW - its just that sometimes you want/need to use the MOS stuff - and with good reason.
It's a frigging computer (Score:1)
Anybody who uses a computer without knowing how it works deserves whatever evil befalls him.
3500 volts for a human to feel a shock? (Score:4, Funny)
Re:3500 volts for a human to feel a shock? (Score:1)
Re:3500 volts for a human to feel a shock? (Score:1)
Re:3500 volts for a human to feel a shock? (Score:1)
as long as you are standing with bare feet on a water-soaked floor. But on shoes with rubber soles you NEED that 2nd paperclip
Not true. I had a friend in high school who stuck a paperclip into a socket during class. it shocked the hell out of him. he was shaking the rest of the class. all of the students saw it and were laughing there asses off. the teacher was writing on the board and missed the entire thing.
God that was funny.
Re:3500 volts for a human to feel a shock? (Score:1)
well, there was a huge (transformator, i think) metallic thing on the wall, and I stuck that hairpin into it. Next thing I remember was a flash in my eyes. No shaking, however. Nice jolt anyways. Oh, and I held that pin in one hand, between index finger and thumb. I remember touching that hand, it had something black (like powder) on it, but it went off as I touched it (oddly, it didn't stick to the other hand). The touching surface on fingers was burnt (skin went off where pin touched it).
It happened on the back of a class, but no-one noticed anything, so the flash must have been just my own receptor overload..
after that I asked my dad "how do you check the power in socket"..
Re:3500 volts for a human to feel a shock? (Score:1)
Re:3500 volts for a human to feel a shock? (Score:1)
Coils can increase the voltage quite a lot - that's likely to be what happened.
If you 'charge' a large coil even with a low-voltage battery, and then remove the battery, the coil will try to discharge. Since there is no longer any connection to discharge through, the voltage will increase until it can discharge with a spark (or through leakage currents, whatever comes first).
Re:3500 volts for a human to feel a shock? (Score:2)
I also know that in the past, I could touch my phone line posts, no problem. Now they have a ZING to them. Maybe they increased the voltage.
What about batteries, or toy racing tracks? (Score:1)
Somehow I also managed to get my tongue stuck on my toy racing track once (which was like 12 or 18v or so).
THAT HURT!
OT: What about batteries, or toy racing tracks? (Score:1)
DC vs AC (Score:2)
Re:3500 volts for a human to feel a shock? (Score:2)
BTW, if you unkink the paper clip, bend it into a "U" shape, then push it through a pencil eraser (so that it looks like a fork), you will be protected from the shock an average outlet will deliver. Fries the eraser eventually, though.
Re:3500 volts for a human to feel a shock? (Score:2)
Re:3500 volts for a human to feel a shock? (Score:3, Informative)
Electrical Misconceptions (Score:3, Informative)
Yes and no. It takes about 0.183A (IIRC) to cause your heart to go into an irregular pattern, resulting in a heart attack. Higher current loads through the heart are different; They cause it to stop, and (likely) start beating again. This is the principle used to start your heart again after it's stopped beating.
Much has to do with the resistance in ohms of your skin when you have the electrical shock applied; Are you doing something stupid like working on a grounded metal roof in wet bare feet with power tools (case study in class, that one), etc etc etc.
Many variables are at play here; Power is dangerous and something to be resepected at any level. I zapped myself real good with 25kV once, never again .. :)
Re:3500 volts for a human to feel a shock? (Score:1)
The main danger for the body are muscle cramps, which may lead to respiratory or cardiac arrest at strengths of more than 20-50 mA after few minutes. A few 100 mA may cause cardiac arrest if lasting longer than a full heartbeat (about 0.8 sec).
A static discharge will last only a very brief moment, so in most cases there is little reason to worry ...
Speaking of Crack... (Score:2)
Static discharges can destroy many an integrated circuit if there is improper internal protection. Think about it, if one external pin of a device is connected to the gate of one MOSFET (which can happen sometimes), and that pin suddenly accumulates charge through ESD, it won't take much for the oxide to break down between the gate and the substrate, and then you've got a chip that won't work.
Say the ESD pulse happened on the power (or gnd) line. Suddenly, across your entire chip, you have a 200V difference between power and gnd for a fraction of a second. Unless you've specifically added extra circuitry to cope with this (and any knowledgable designer will), something's gonna blow, even if it is for just a fraction of a second. With a 200V potential difference, it doesn't take long for 77 angstroms of SiO2 to break down.
Standard ESD protection within a chip consists of control circuitry that will turn on a low-resistance path between any two pins whenever the potential difference becomes too great. The plan is to make the current flow through a large internal ESD bus, rather than through the delicate core circuitry of your device.
Of course, a good defense is to prevent static discharges from ever reaching your device. Anti-static bags provide a conductive path around the outside of the bag, so that the least resistive path is not through your device, but rather around the outside of the bag. They are in general a very good idea, because there is no telling what kind of ESDs you can encounter during shipping and handling, whereas when a component has been installed somewhere, the ESD that it will encounter can generally be predicted.
PS - Charge is measured in Coulombs, capacitance is measured in Farads.
err (Score:2, Informative)
excuse me? it depends on the current flowing and stuff.. for example, I got shocked by 240v two days ago, and i bloody well fealt it.
Re:err (Score:1)
Voltage = the rate at which energy is drawn from a source that produces a flow of electricity in a circuit
Amperage = The strength of an electric current
Re:err (Score:1)
Voltage is the electric potential between two points.
-Jeff
Gimme a break - what about water? (Score:4, Interesting)
You can say the same thing about water - it takes quite a few drops for humans to notice that it's raining, but just one well-placed droplet will fry your motherboard. Do you see me suing Toshiba because I can't use my laptop by the pool?
Stats ahoy.. (Score:2, Funny)
I wonder if the Damage by static is the default option in the returns database of these manufacturers
getting shocked.... (Score:2, Informative)
The problem is relitively simple to fix... (Score:2)
--CTH
Re:The problem is relitively simple to fix... (Score:1)
Not as difficult as you would think since fact hardly ever enters the equation. As a private pilot, I follow the inevitable lawsuits that occur whenever someone gets hurt/killed in a plane crash. Juries routinely reward an incompetent pilot with millions from whatever deep pockets the lawyers can find despite the obvious (to anyone with an IQ of over 15) neglect on the part of the pilot. Real-life example: some idiot goes out and flies his twin engine plane into the side of a mountain. The plane itself was older than 17 years, so the manufacturer was off the hook. The magnetos in the engine had been replaced recently, though, so Bendix got sued instead, and ended up losing millions. How do the magnetos cause you to fly into a mountain? They don't, but juries don't care when they're presented with the weeping widow and teary eyed orphans. Someone has to pay, and any deep-pocketed corp. will do.
Re:The problem is relitively simple to fix... (Score:2)
Doesn't fix the Palm III or Palm VII. Also, what if the user doesn't plug in the power cord?
Re:The problem is relitively simple to fix... (Score:1)
The RS232 port's ground is also connected to system ground.
Not to mention the outer part of the db9 connector is connected to chassis ground of the case in turn connected to power ground.
They could just make sure that the ground of the serial port is 0V, and connect that to chassis ground.
Need sleep, not sure if I made sense....
Re:The problem is relitively simple to fix... (Score:1)
I've still got a Palm III that runs on replaceable batteries. Should I just give it the odd bit of air guitar [omvf.net] ?
Easily Dealt With (Score:4, Insightful)
Of course, the story was misquoted (Score:3, Informative)
It doesn't take 3500 volts for a human to feel a shock, naturally. It takes 3500 volts for a human to feel a static discharge, which is what the story asserted.
Re:Of course, the story was misquoted (Score:1)
Static and New Pants (Score:1)
Instead of keeping your Palm in a proper case, you carry it around in fabric where it can move around and possibly create some static and then you go to unzip and grab it and you don't even feel the zap, but then the Palm won't turn on.
And those x-ray glasses in the ad really fool ya too.
So what, replace the card? (Score:1)
Why is everything so all integrated into one device? Why is there a chance the videocard gets broken when something happens to my serial port?
Uh-huh... (Score:2, Insightful)
Great example to give... certain to frighten every non-tech out there. Of course, how many times have you 'smelled smoke' from an ESD? Sheesh.
Re:Uh-huh... (Score:2)
shock (Score:1)
Static Electricity (Score:2, Informative)
The reason behind this is that chip manufacturers have been working on modelling the kinds of static electricity that humans produce (human body models) and machines produce (machine models), and designing I/Os to accomodate the new parameters.
Yes, some companies take their chances, ignoring static electricity (and there are some performance benefits to doing that), but these are risks that most of us can weigh.
Lawsuits, lawsuits and lawsuits... (Score:1)
Of cause it should be able to withstand some amount of static, but how much is the limit before you risk a lawsuit? If we create an environment with the right combination of carpets and shoos; I believe we could kill any device. Should the manufacture then put a lawsuit against us?
What about shock absorption? Should we put up a lawsuit, just because we dropped our palm on the floor? I think its common sense that things being dropped on the floor break... but I also thing it's obvious that high levels of static's will destroy electronics. If I produce hardware is I then responsible of educating people? What about water and electronics? Should I tell people not to plug the palm into the power sockets? Etc...
I know it is difficult to put up the line between a bad piece of hardware and a bad use, but it appears that everything goes into lawsuits rather than trying to counteract the actual problem. Hardware may be damaged if it is badly produced and/or is misused.
Having to deal with this... (Score:3, Insightful)
Good mobos will have protection right at the port, including zener diodes and possibly MOVs (MOVs break down and conduct at high voltages, zeners prevent the voltage going above a certain point, in this case above or below 13 volts or so).
The actual IC will generally also contain similar protection.
But this isn't an issue of whether it happened, or is even a remote problem. This is the "The coffee burnt my lap" problem. In our increasingly litigious society we sue people for not warning us of possible problems. All computer and electronic devices say "Static electricity may cause damage to device." What these laywers apparently want is Palm to put in big bold letters that "This device may act as an additional path for static electricity to damage your computer or other palm attached device." Which is silly. The user, had they read their documentation, knows that both devices are sensitive to static. Do they think they are immune to it by ganging the devices up?
Another lowest common denominator problem...
-Adam
Re:Having to deal with this... (Score:3, Informative)
The real problem here is that nearly every integrated mobo has the serial port contained in the northbridge/southbridge chipset, so discharge to the port means discharge to a critical IC in the computer as well.
I doubt that it fried anything bigger than a TTL<-->RS232 converter IC. The reason? The designs of the large ICs don't work well when designing conversion circuitry. Sure, the UART will be part of the chipset but the signals on the I/O will be TTL or CMOS level outputs.
Those signals will then hit an IC like the MAX232 (An RS232 converter IC from Maxim Electronics) which contains the charge pumps and converts that +5/GND (or +3/GND) signal to +12/-12V required to meet the RS232 spec and back. Chipmakers like Maxim also make static-protected versions as well. (In Maxim's case, they usually designate ESD-protected devices with an E suffix.) These chips are good for a 11kV direct zap using the human body model.
No, I don't work for Maxim. Burr-Brown (Now part of TI), National Semiconductor (now spun off to Fairchild) and a host of others make these chips. I'm just most familliar with Maxim's.
If the motherboard fried, they used substandard (IMO) converter ICs. I've hit my laptop and several PCs very hard with ESD and I've yet to have a problem. The biggest problem is that ESD is a slow killer. Rarely does it fry something outright. Usually it just weakens the oxide layer on the semiconductor FETs and causes early death and spurious operation.
Palm should be no more liable for this than every company which manufactures serial, parallel, USB, FireWire and really ANY external device. If the guy bought a shit motherboard, deal with it. It's not Palm's fault.
Re:Having to deal with this... (Score:2)
Re:Having to deal with this... (Score:2)
Palm should be no more liable for this than every company which manufactures serial, parallel, USB, FireWire and really ANY external device. Most external devices (printers, modems, mice, video cameras) are hardly ever unplugged from the computer. Palm-tops are going to be in and out of their cradle all the time. They should have put static protection in the cradle.
ESD isn't a joke - but everyone thinks it is (Score:4, Insightful)
Serial ports (I'll stick with RS-232 and 485 - I'm most familiar with them) use voltage & logic shifters to handle the conversion of the port voltages to internal logic voltages. For years, most RS_232 ports on PCs used the MC148x or MAX232 type serial inetrface chips - got news for you, NONE of these chips have ESD hardening. RS-485 ports were even worse - they used a chip called a 75176 - those things would blow when you pulled one out of a pack to insert it in place of a blown chip. Ever notice how many cards with 1489type interface ICs had them in sockets? There was a reason - I've replaced a fw in mine.
I've designed embedded boards for Home automation and our boards used RS_485 which gives you long distance (1000-4000') over twisted pair at decent speeds for system control. The original design (which I didn't do and which was done BEFORE ESD variant chips were available) used the 75176. I had customers calling for replacements all the time. Those long twisted pair cables connecting nodes together were asking to induce surges AND when folks wired them up with bare hands and no static strap - they induced charges into the wires connected to all other nodes!
Maxim IC came to the rescue by developing the MAX232E and MAX485E which were ESD hardened interface ICs for RS-232 and 485 respectively. These things are amazing. One article I read had a guy sending massive (like 40kV) pulses into these chips and they survived. They are rated for +15kv and man do they work. When we switched to these chips (our main controller had both RS_232 and RS-485) our serial bus failures went away. TO dtae I have not had a customer complain about a failed ESD hardened chip from Maxim. Only problem is they ARE more expensive - about double. But WELL worth it IMHO.
Obviously - anyone handling motherboards or any other bare electronic board without using a static strp is an idiot - you're just ASKING for it - and um if you unplug your PC and then ground your strap to the case - it doesn't help much sinc ethe case is only grounded when its plugged in! You have ot ground your strap to somethign thats grounded!
But ddesigning your system with external ports and not using ESD haardened ICs and surge supressing devices is just asking for trouble - but these things cost money. Surge problems are worse than ESD often. But the savings in customer satisfaction and warranty repair costs often outweigh the extra pennies - but its hard to measure.
As for static straps - its amazing how people hate them so. I managed a 10k sq ft data center with almost 700 servers, from small $5000 machines to monster Auspex boxes costing millions. We implemented a policy that every tech in teh room had to wear a static strap on theri wrist, shoe, or static shoes and had to test the device when they entered (testers at every door) This was for ISo compliance but it was also smart. A single board for an Auspex might cost $50,000 to $250,000!!!! Yet I constantly had to police the situation and hassle people because they refused to wear the straps. The worst were the Sysadmins - they figured since they didn't touch teh cards themselves it was OK, yet they were plugging serial cables into exposed serial ports to hook up root terminals (before we had a networked root term setup) It was amazing the resistance I encountered for such a simple thing.
The bottom line is, if you are design a device for end use - spend the $$$ on ESD and surge suppression. If you are a tech or even a hobbiest working on teh guts of a PC or even hooking UP a PC that might not have said ESD protection, wear the strap or shoes. All it takes is one zap and thousands of dollars go up in a spark!
Re:ESD isn't a joke - but everyone thinks it is (Score:3, Flamebait)
if you connect your strap to a case and DONT plug it in, that is fine. the strap is there to allow you and the case to be at the same potential. As long as this is the case, you will NOT zap anything.
Simply holding the case whilst manipulating components is enough to protect them as you insert them.
In fact, hooking the case to mains ground is asking for MORE failures, as the harware you pick up is likely NOT to be at ground potential, so you will still zap it even then.
Re:ESD isn't a joke - but everyone thinks it is (Score:5, Informative)
Wrong - when you pick up that motherboard sitting on teh table and zap it (cause you may not be at the same potential) you still hate it. Ground a strap to GROUND is important. Why? Because it disappates the charge from your body. Storing boards in ESD bags? They disappate any stored charge on teh board when you picj it up. Grounding your PC case - again, disappates any charge in the case.
So yes, if you strap yourself to an ungrounded case, you won't zap the case cause you are at the same potential, but you can still zap external compnents you pick up. Yes its rare and something is betetr than nothing - I agree. But for proper protection every thing MUST be grounded. But at the bare minimum, always touch the metal of the case before messing with a PC - that helps but you STILL can zap something in a dry environment.
Re:ESD isn't a joke - but everyone thinks it is (Score:2, Informative)
Not quite. If I remember my ESD training I got at one place I worked for, most ESD bags shield and don't dissipate.
Re:ESD isn't a joke - but everyone thinks it is (Score:2)
You're right - my bad....
Re:ESD isn't a joke - but everyone thinks it is (Score:2)
Re:ESD isn't a joke - but everyone thinks it is (Score:1)
"if you unplug your PC and then ground your strap to the case - it doesn't help much sinc ethe case is only grounded when its plugged in! You have ot ground your strap to somethign thats grounded!"
I've never quite understood this. Current only flows when you have a potential difference, right? So if you equalise yourself against the case using a strap, regardless of whether or not it is at real "ground", you still won't get any sparks generated between you and your equipment because you are both at the same potential. Or am I missing something?
Q.
Re:ESD isn't a joke - but everyone thinks it is (Score:2)
got news for you, NONE of these chips have ESD hardening.
If you used which which weren't able to withstand ESD and you did nothing to protect them... you're a pretty shitty designer, or you had a shitty management (financial) decision laid down on you. It's not hard to put a 10 ohm resistor in series with the input pins, throw on a bit of a filter and finish it off with some good fast 1W transzorbs. Takes care of ESD and EMI/RFI.
As for static straps - its amazing how people hate them so. I managed a 10k sq ft data center with almost 700 servers, from small $5000 machines to monster Auspex boxes costing millions.
Static straps and other such protective measures are a pain in the ass. Get used to it. It probably would have been better for everyone if you just used ionizing air filters and kept the air relatively humid.
The worst were the Sysadmins - they figured since they didn't touch teh cards themselves it was OK, yet they were plugging serial cables into exposed serial ports to hook up root terminals (before we had a networked root term setup) It was amazing the resistance I encountered for such a simple thing.
Whenever I have to touch a computer, I make special note to touch the case often. It may not drain every last volt of potential difference from the case and I, but I've never had troubles. I'd bitch and complain if I were a sysadmin too. Or rather I would touch the case and the connector before plugging anything in.
Re:ESD isn't a joke - but everyone thinks it is (Score:2)
err, read my post - I stated I didn't do the original design, it was inherited. and later in my post I speak the praises of using ESD and surge protection in a circuit design - but thanks for the description of my abilities all the same. I'll admit that some early designs of mine as well didn't have ALL aspects of ESD covered, but you learn as you go - or did you know it all from the start? ;)
As for straps - they are a PIA. Agreed. But we also provided shoe straps (slip it on in the morning - take off when you leave) which wern't too bad. The HW techs got static sneakers to drain away charges since they were always swapping stuff out - the shoes used to be klunky but had become fairly stylish and felt like normal sneaks. And the bottom line is - tough shit. Your fooling around with millions of dollars of corporate hardware and you work for the company - deal with it or take a walk/find new job. I can't tell you how nervous my HW techs got holding processor cards worth hundreds of thousands of dollars - its scary! And I can tell you the heat from on high if the company faild an ISO inspection because of folks in teh computer room without ESD protection would have been immense.
I'm still amazed that Mobo makers don't toss in dispoable straps with their retail boxed boards - hell they only cost 50 cents or so.
Re:ESD isn't a joke - but everyone thinks it is (Score:2)
You can put the wrist strap on your ankle instead, if that's more convenient. (Under the socks, of course, and if you're too hairy it might take a dab of conductive lotion. But the strap tester will tell you that, anyway...)
All of this is beside the point in regards Palm's responsibility. We assemble circuit boards, we handle semiconductors, we've got to learn this stuff and buy the necessary equipment. So do electronic techs and anyone else who is going to get inside the electronics box. Palm's customers are mainly businessmen, not techies -- they never open the box and aren't going to learn ESD control. Palm should have designed to handle it -- it just takes a few cents worth of diodes and ferrite beads.
Re:ESD isn't a joke - but everyone thinks it is (Score:2)
The strap provides good, continuous protection. The problem with holding your hand on the case is that 1) your hand -- especially the pads of your fingers and the palm -- is not a good conductor, and 2) it takes only a few milliseconds to build up enough charge to zap a component (just lifting your shoe off the carpet can build up a destructive charge). I consider a grounded strap essential when you've got your hands in the guts of a piece of equipment.
That said, I usually don't bother when I'm playing with cheap computers at home. I'm lazy and I can afford to replace the whole machine if it fries.
Ionizers aren't as good as you think. Oh, when you have people wandering around with semi-enclosed, semi-hardened modules, they can help some, but they are no substitute for direct grounding.
If you hooked an electrometer up to yourself while doing this, I think you'd be surprised at just how fast a few hundred volts can build up.
That doesn't help when you're holding the board by its edges, and maybe accidentally touching chips in the middle of the board.
It's basic economics. Most mobos are installed professionally by people who have nice $20 straps just laying around. Paying millions extra for the few people who don't already have straps is unjustifiable.
It's easy! (Score:1)
Instead of soldering the chip to the motherboard, just fasten it with a piece of play-doh. Or better yet, an eraser - they're made of rubber so the static electricity can't pass through them - problem solved!
All I want to know is ... (Score:1)
Static Electricity (Score:2)
This quote says it all... (Score:4, Insightful)
See, here's why there are so many lawsuits and bad stuff (like the DMCA... do I get extra karma points for mentioning the DMCA in a completely unrelated discussion? Ah well, nevermind) happens.
Expectations. If you don't expect people to be educated, then they never will be. Instead of having so many lawyers going "my poor client didn't knew thay you shouldn't stand at the top of a 15-foot metal ladder in the middle of a thunderstorm, while installing his TV antenna", you should get more judges who think "Serves you right for being such an idiot. Next case!".
I agree that sometimes consumers must be protected from Evil Corporations Who Want To Take Over The World, but there's a big difference between: a) not letting oneself get screwed by the Evil Corporations etc.; and b) blaming the Evil Corporations etc. for each and every stupid accident that could have been prevented with a little common sense.
As usual, let's blame the lawyers instead.
Re:This quote says it all... (Score:2)
It still exists (Score:1)
In addiontal to "common sense", a reasonable man never comits a tort, nor does he ever fail to read everything he agrees to, nor the instruciton manual of anything he gets.
A simple "warning, these are very succeptible to static electricty" would probably suffice for the PDAs, but then again, IANAL.
The problem with "reasonable mind" (Score:2)
Re:The problem with "reasonable mind" (Score:2)
Indeed. Which is why the standard was a "reasonable man" and not, say, a "well-educated man". The idea is, there are certain rules of living that one evolves as one moves through the world, and -- quite a hypothesis here! -- such rules are, within a certain fuzzy box, common to everyone and recognizable by anyone reasonable.
"Reasonable man" and "common sense" are not exactly the same thing but are very related.
Re:This quote says it all... (Score:2)
Re:This quote says it all... (Score:2)
Wall sockets Vs. Palm Pilots (Score:2, Interesting)
It's not about AC vs. DC at all. The article is referring to static discharge, which is the equilization of differing voltage levels. Here [google.com]'s the google cache of the first decent explanation I dug up on google. I'm sure you can find more yourself.
How is this different or than any other device? (Score:2, Interesting)
Re:How is this different or than any other device? (Score:2)
I can speak firsthand about PDA/Desktop damage. (Score:4, Insightful)
3 months into my new Visor, I had one final hard reset incident, and after that my USB port became non-functional (I also have a USB Zip drive that I use several times a day, so I can tell you precisely when it died). Hardware support happily arrived and replaced the system board in my Dell, but I was wondering what could possibly by the problem that caused the failure in the first place?
Eventually, I exchanged the Visor, and brought the new one back to work. I put it in the sync cradle. *reboot*.
At this point, I knew it wasnt the Visor, and I knew it wasnt the Dell, but it was obviously some combination of the two. As an experiment, I went a week with a grounded anti-static wriststrap wrapped around the back of the sync cradle. I made a point of touching it before I set the Visor in the cradle. Lo and behold, no more hard resets!
I decided to make this modification more or less permanent. I found the ground cable in the cradle, and the corresponding copper spring clip where it mates to the Visor. Using a trusty set of hemostats, I bent and extended it up to where it is the first bit of the cradle that touches the Visor. On the other end of the sync cable, I ran a little pigtail wire from the metal sheath of the male USB port to a screw on the back of the case.
This has the benefit of directing any static directly to the ground of the case, instead of routing the discharge through the USB controller, to *it's* ground.
Now, I dont really know whether or not this worked, because static shocks are pretty rare here in the summer (St. Louis, MO, where the humidity rarely drops beloe 75%). I'll have to wait until this winter, when the central heat kicks in, and the relative humidity in the office is about 15% before we see whether or not I've improved my sync cradle.
Volts? (Score:2)
When will the world catch on that it is not the volts that matter, but the amps! I can hit you with a million volts at
USB or just serial? (Score:1)
Who cares about static (Score:2)
It's rather silly that the plastic plates are not available separately. But I guess they have calculated that they make more money selling entire new screens or even new PDAs...
I'd call that level of repairability as useless. People really should pay more attention to this kind of problems.
10000V can wake you up! (Score:2, Informative)
(The funny thing is, the 220V (110V US) we use daily is less dangerous than the 24V in your phone when ringing.)
How much current is dangerous? Well, 5 milliamperes can be felt, 10 will be felt and hurts, 15 will really hurt, 30 will freeze you on to the current source. And we are just talking about milliamperes people.
Steam heat, no humidifier, large arc (Score:2)
If you're running ANY electronics in an environment like that, you'll see it die, eventually, if not sooner. It doesn't matter what you connect, once you put a wire outside of the computer, it's another route for things to get zapped.
--Mike--
Since we're on the subject (Score:2)
Testing for ESD (Score:2, Informative)
Uh... (Score:2)
Would that include lightning strikes? (If I remember gradeschool science correctly, lightning is static electricity on a big scale...)
$45 billion dollars? that sounds kind of high - Any chance Bill Gates will off himself scuffing across the carpet in his slippers next year?
Cheers,
Jim in Tokyo
I do static discharge tests for a living (Score:2)
I do electrostatic discharge and interference tests for a living. We can produce electrostatic discharges ranging from a few hundred volts to over 300 thousand volts (landing aircraft) in house. We also radiate products with radio frequency interference from a few hundred kilohertz up to the microwave range. Sometimes we just listen to what products put out as well.
Most of the devices we test are safety-critical. Your home computer likely will never be seen in our lab. We recently conducted a test where a product in its box was shocked with a 300 kV static discharge. The spark (besides traveling three feet) went through the box, in one terminal of the item, and out another.
While charges on your body are not nearly that strong (the highest you'll build up likely is 25-30 kV), you shouldn't laugh at them.
Many modern manufactuers no longer include safety components ment for repair technicians. Often saving less than a fraction of a cent (in bulk), the lack of these parts make it an extreme risk to open things like microwaves and televisions. Not to be dismal, but don't open these items unless you know what you are doing; I have heard of experienced technicians putting their hand in the wrong place and regretting it.
Problem solved (Score:2)
On another topic: Your comment violated the postercomment compression filter. Comment aborted
Lose the lameness filter, Taco.
Modern computers are quite sturdy (Score:2)