Static Buildup

[bernuli]

This is maybe not in the right forum, but I am anxiously awaiting the purchase of a Mac Pro so thought I would ask it here.

In the winter, everytime I sit down at my desk I end up with a static charge, which releases itself when I touch the keyboard of my MacBook Pro. While this has not done any known damage, it has been known to reset some of my USB devices and kill the mouse driver.

So I hooked up a ground wire to an outlet on the other side of the room and touch it after I sit down to let the zap go the other way. The MacBook and USB peripherals continue to feel it however. They occasionally reset right when I am bonding to the ground wire. Just now the MacBook woke up from sleep when I touched the ground wire, before sitting down or getting anywhere near the computer.

Is this normal? Any suggestions on safer static discharge? I suppose I could remove the rug, but it was just replaced and I would rather keep.

B

 

[derbothaus]

Humidifier? You could plug in an ESD bracelet to your desk.

 

[nanofrog]

Get an ESD mat and place it under the computer (aluminum must make contact with it). Another alternative is to wear an ESD wrist strap while at the computer (not convenient, and may feel a bit awkward). Please note that both of these devices require connection to earth ground in order to work.

BTW, are you on carpet or hard flooring?

If you're on carpet, there are such things as ESD floor mats as well, which will reduce the buildup of static electricity as you move in your chair (wheels on carpet, shifting your body on the chair's fabric).

 

[bernuli]

Humidifier, why didn't I think of that! Actually might give that a shot.

The ESD bracelet would be the same as what I am doing now by grounding myself before touching the computer. Just seems weird that the computer is affected even though everything is plugged in to an APC Smart UPS.

I think I need to replace the rug with an ESD mat maybe.

Humidifier? You could plug in an ESD bracelet to your desk.

 

[nanofrog]

Humidifier, why didn't I think of that! Actually might give that a shot.

The ESD bracelet would be the same as what I am doing now by grounding myself before touching the computer. Just seems weird that the computer is affected even though everything is plugged in to an APC Smart UPS.

I think I need to replace the rug with an ESD mat maybe.

You can still build up a static charge in a humid environment, so a humidifier isn't an absolute solution.

For example, I live in a humid climate, and even around 60% RH, I still get static charge build-up (still get nailed by a static charge when petting my cat @ ~60% HR). So although static charges do build up easier in winter due to low humidity, the problem doesn't totally disappear (humidity affects the rate of charge buildup, that's all).

As per a wrist strap, there's a small difference. The wrist strap has a resistor between the wearer and ground, which dissipates the charge slower (lowers the current flow between the charged object, the human, and ground). No "zap" like you get directly coming into contact with ground.

 

[MJL]

It can be a combination of both your carpet and the shoes you're wearing. Try walking around without your shoes, on socks. If that improves matters then look for different shoes. (had that at one stage)

 

[derbothaus]

You can still build up a static charge in a humid environment, so a humidifier isn't an absolute solution.

I meant it slightly tongue in cheek. Sometime the humidity makes the shocks stronga'. Your hair will suck as well.

 

[nanofrog]

I meant it slightly tongue in cheek. Sometime the humidity makes the shocks stronga'. Your hair will suck as well.

Keep in mind though, that a lot of people are under the impression static electricity only builds up under low humidity conditions, which is not true (even EE graduates).

I see/hear this question fairly often with electronics enthusiasts/hobbyists and recent grads, as well as the misunderstanding (there's companies and organizations that focus solely on ESD research).

BTW, the reason for my posts is that static electricity doesn't always kill semiconductors, but can cause unnoticed damage, usually leading to poor performance or a short life-span (think dead or damaged transistors, and the only way they could be seen, is to tear the chip apart and stuff it in a Scanning Electron Microscope).