Strange static electricity issue


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Lately, I've been having this strange static electricity problem with my laptop and desktop. It's winter here, and the air is pretty dry, so we have lots of static buildup. Normally, I'll try to discharge myself on something before I touch my computer, but sometimes I forget, and I end up touching my laptop (an Acer Aspire S3) which has an aluminum lid. About half the time, if the static shock is strong enough, I'll hear my desktop computer make the Windows 8.1 device connect/disconnect sound. My laptop, which is asleep most of the time is plugged into a wall outlet, via a surge protector. My desktop, in the same room, only a few feet away is on it's own surge protector in a different wall outlet. I'm thoroughly confused as to why a static shock on my laptop will effect my desktop. I don't notice anything odd on either machine, they're both working without problem.

 

Any ideas?

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I have the same problem with my car in winters. I've been shocked so many times now and everytime I say I'll remember next time to discharge before touching the body but I just can't seem to.

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that's odd... sounds like your desktop machine isn't grounded properly... ground should disperse the static shock back into the ground as the least path of resistance... and go that way instead of to your system..

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About half the time, if the static shock is strong enough, I'll hear my desktop computer make the Windows 8.1 device connect/disconnect sound.

 

You connected to your laptop so your desktop disconnected you, hence the sound? :huh:

 

Seriously though, I have the same issue, just not with the sound thing. I get shocked so many times a day it's not even funny. I get shocked when I touch light switches, when I touch metal, I've shocked my phones a few times and I've actually killed a PS3 controller because of all the static electricity in me. I bought a humidifier at home, which helps when I'm at home, but at work I just make sure to touch something metal that's not connected to any electronics to get rid of some of the static when I wake to or from my desk.

 

Normally, I'll try to discharge myself on something before I touch my computer

 

Am I the only one thinking dirty here? :laugh:

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You connected to your laptop so your desktop disconnected you, hence the sound? :huh:

 

Seriously though, I have the same issue, just not with the sound thing. I get shocked so many times a day it's not even funny. I get shocked when I touch light switches, when I touch metal, I've shocked my phones a few times and I've actually killed a PS3 controller because of all the static electricity in me. I bought a humidifier at home, which helps when I'm at home, but at work I just make sure to touch something metal that's not connected to any electronics to get rid of some of the static when I wake to or from my desk.

 

 

Am I the only one thinking dirty here? :laugh:

You don't discharge yourself daily? :P

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You don't discharge yourself daily? :p

 

lol, well depends what kind of discharge you're taking about, lol. If you mean static electricity, then yes, several times per hour actually.

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Do you only get these results when the laptop is plugged in to the wall outlet?  If so, I suspect neufuse's theory is probably right.  The fact that they are on two separate surge protectors doesn't really isolate the two from one another.  Surge protectors basically just have MOVs that would probably be insensitive to static spark energy levels.  But what you can get is a high voltage transient from the spark that something on the PC side is probably "seeing".  In dry conditions, you can be charged upwards of 35kV.

 

I suspect that you may not have a good ground...

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Unless the laptop is somehow connected to the desktop and the shock is causing a connection drop of some sort, I don't see any feasible way this could be related. There's no way a static discharge could affect something on a different outlet (or something at a distance for that matter). Even if you had some sort of floating ground, the charge is going to disperse rapidly and evenly along the floating ground and is only going to be a high potential difference (voltage) at the point of contact (finger and aluminum of the laptop).

 

EDIT: To clarify this a bit more, suppose you have a high potential difference in charge on your body from that of a piece of steel that is just sitting on a chair. When you touch the piece of steel, there is going to be high potential difference in voltage along the connected boundary of your skin and the steel. Why? 

 

The reason is primarily related to the fact that there is only a small surface area for charged particles to disperse. Resistance is inversely proportional to contact area, so the smaller the area the large the resistance. And if you take into account that Current*Resistance=Voltage (IR=V) and Charge/time=Current (Q/t=I), you can see why there would be a large voltage in this case, because we have a large resistance and a quick dispersion of charge across the boundary or to say it another way: high current (I) and high resistance ( R ) is going to result in high Voltage (V).

 

Fortunately though, these conditions are only going be momentary and the charge is going to disperse rapidly across the boundary and evenly into the material with lower charge so even in the case of a floating ground in terms of something like a piece of steel, the high voltage is only going to be momentary at the boundary. If you had for example connected a large area of your body the metal, you would generate a proportionally lower voltage during the static electric discharge (perhaps not even a noticeable amount). The point I'm making here is though it sounds like huge numbers in terms of volts, it is something that is transient and only a result of the conditions that are present at the boundary. The reality that not much charge is really involved and that the large potential voltage and current won't last far behind the boundary simply because the charged particles will disperse evenly through floating ground after the boundary.

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that's odd... sounds like your desktop machine isn't grounded properly... ground should disperse the static shock back into the ground as the least path of resistance... and go that way instead of to your system..

Interesting that you mention this. I'm using an older case for my current desktop build. I got the case back in 2006 and the first winter that I had it, I was having tons of static problems. Even if I would just touch the computer with a little bit of static, the computer would shut off. Since then, I've gone through a complete rebuild (literally the only component that didn't change is the case), but I've had absolutely no static problems with it since then (aside from the laptop thing that this thread is about).

 

Do you only get these results when the laptop is plugged in to the wall outlet?  If so, I suspect neufuse's theory is probably right.  The fact that they are on two separate surge protectors doesn't really isolate the two from one another.  Surge protectors basically just have MOVs that would probably be insensitive to static spark energy levels.  But what you can get is a high voltage transient from the spark that something on the PC side is probably "seeing".  In dry conditions, you can be charged upwards of 35kV.

 

I suspect that you may not have a good ground...

I'll leave it unplugged from everything for a bit and I'll see if I accidentally touch it with a decent amount of static again.

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Does your monitor on the desktop have built in USB ports that hook to your desktop? Perhaps it is causing a ground/surge in the AC line and the monitor is power cycling quickly which disconnects the USB ports from your monitor/desktop, hence you hear the noise?

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There's no way a static discharge could affect something on a different outlet (or something at a distance for that matter).

 

Not that I disagree with the rest of your post, but that is a bit of an overstatement...

 

I think a floating ground is probable.  The disconnect reconnect sound is probably due to high voltage from the spark and exceeding some devices CMRR.

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Not that I disagree with the rest of your post, but that is a bit of an overstatement...

 

I think a floating ground is probable.  The disconnect reconnect sound is probably due to high voltage from the spark and exceeding some devices CMRR.

Consider that even if you had electrostatic discharge or even a surge on the PSU ground line itself that there is reverse voltage/current protections in place on the PSU circuit board and the system mainboard in the form of diodes to ground (these are ESD protections that no doubt exist internally in each IC also -- it's a typical thing to do). These prevent reverse current from flowing and would make any sort of back feed effectively impossible so it's not just that ESD would discharge before the line (as I was saying in my previous post), even if you had a surge on your line, you aren't going to get feedback into your system unless you manage to physically damage the diodes by pushing huge voltage/currents in reverse above the diodes threshold, but at that point your equipment is no longer going to function because you'll burnout the diodes or worse. So to put this in perspective, the static discharge would have to bypass the ESD protection diodes on the surge protector, in the PSU (and ICs), and the main board (and ICs) and end up on a USB peripheral line, and on top of that it would have to not damage anything along the path while at the same time being large enough to cause an interruption to the peripheral equipment's connection. There are numerous good reasons why this is not really a feasible mechanism.

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Yeah same here. Many times I can even see sparks and it is painful. I have managed to make a habit of grounding myself 98% of the time.

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Yeah same here. Many times I can even see sparks and it is painful. I have managed to make a habit of grounding myself 98% of the time.

I would try touching on something with a larger portion of your body (don't do like an electrostatic co-worker of mine does and touch with only your finger tip). I'm not sure how well it will work since it probably is kind of hard to get a large surface area connected at the same time, but I'd be interested to know if helps reducing the sparks in practice.

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I would try touching on something with a larger portion of your body (don't do like an electrostatic co-worker of mine does and touch with only your finger tip). I'm not sure how well it will work since it probably is kind of hard to get a large surface area connected at the same time, but I'd be interested to know if helps reducing the sparks in practice.

Thanks. I am doing exactly that. Rather than touching a door handle with finger pointing towards, I am making a habit of entire palm making the surface contact.

 

Worst is when I am getting out of the car as the window tint has some form of metal in it and as soon as I step out and touch the door, bamn. Now I keep touching the door frame/window frame/window until I am out of the vehicle and ground myself.

 

Takes time but I am used to them now. Still get odd big sparks once in a month though when I am absent minded!

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 I'm thoroughly confused as to why a static shock on my laptop will effect my desktop. I don't notice anything odd on either machine, they're both working without problem.

Any ideas?

 

  Understand what this current is.  You have created charges on both sides of your shoes.  The discharge is a current path that leaves the finger, passes through items (ie laptop) to connect to charges beneath your feet.  Things you consider not conductive (ie floor) actually are conductive.  Just not conductive enough that we call it non-conductive to AC electricity.  But conductive enough for static electricity.

 

  So, how did that current get from your finger tip to beneath your shoes?  One possible path is into the laptop, out via the safety ground wire, over to the other electric socket, into the desktop's chassis, into the floor, and connecting to those charges.

 

  Well, that would not explain the noise.  However some minor variation in that path might.

 

  One known fact is that an electrical connection is made from your finger to charges beneath your shoes.  How it gets there and how it might affect computers is a mystery that only you have sufficient information to answer.

 

  BTW, static electric discharges are a superb diagnostic tool.  As may become obvious with further discussion.

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I have the same problem with my car in winters. I've been shocked so many times now and everytime I say I'll remember next time to discharge before touching the body but I just can't seem to.

  Some tires no longer contain carbon black.  Therefore are much less electrically conductive.  Charges build up between the car's body and earth.  Your body connects those charges causing a static discharge.

 

  Vehicles such as ambulances sometimes have chains hanging from the undercarriage.  When stopped, those chains immediately discharge the vehicle.  Others sometimes used a conductive black strap.  Toll collectors had what looked like an antenna in the toll lane.  These made necessary because some tires are less electrically conductive.

 

  Everything is electrically conductive.  Eventually even tires without carbon black will discharge a car.  Or you touch something much less conductive when exiting.  You are still discharging that car, albeit much slower.  So you do not notice the discharge.

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