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Why Aren't Laptop Computers Grounded?

BobTheDonkey said:
The light switch itself isn't grounded - the screw holding the cover on may be...but the switch itself is usually plastic (for good reason - insulation). And even then, the screw head might be painted and therefore present less of a solid ground.
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Some of the screws on some of my light switches are not painted, and usually provide a good source for draining static electricity.

I don't seem to have any metal furnature.
 
1. If your laptop power supply has a three prong plug, it still does ZIP for grounding your laptop. The AC ground only goes as far as the power supply.
2. The low voltage DC side of your laptop power supply is galvanically separate from the AC side. This is a MUST so that if the power supply goes Tango Uniform you won't get zapped.
3. The third prong (ground) on the plug is NOT there to drain static electricity from the equipment. The ground prong is connected to the metal housing or frame of the equipment to provide a short circuit to ground should a "hot" wire somehow come loose inside the equipment. This will cause a circuit breaker or fuse to blow, but most importantly it will keep you from getting zapped.
4. If your laptop were properly grounded, you would be MORE likely to get a static zap than if it weren't. Grounding the equipment but not your self guarantees that one of you (the laptop) will be drained of static charge and that one of you (yourself) will not be drained. If there's no ground on the laptop, then it might be charged up as much as you are and thus REDUCE the static zap you could get.

To reduce static zap:
1. Wear either anti-static shoes or leather soled shoes.
2. Wear cotton or linen clothing, avoid synthetics and wool.
3. Use humidifier or ion source to make the air more conductive.
4. Use a grounding strap on your wrist.
 
Wowbagger said:
The laptop is used in a variety of locations: On a wooden table (that might shift on the carpet, every now and then); on a soft ottoman-like thingy; sometimes directly on the carpet; rarely on the bed. (But I take special care not to smother the vents.)

Here's an experiment I might try:

1. "unground" the machine and have it sit someplace, untouched for a while.

2. Rub my feet on the carpet, with socks, in dry air

3. VERY IMPORTANT: Touch something that is grounded, such as a light switch, to release the static electricity. I would expect to get a spark, here. But, this is important, because of the next step:

4. THEN (after touching a ground), immediately touch the laptop. See if I still get another spark.

Theoretically, I should not get one in step 4. But, what does it mean if I do?!!

Any recommendations for locations, in step #1?

Should the computer be on or off during this experiment? Would it make a difference?

Not intentionally. (At least not yet.)
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Post the YouTube url please :)
 
This thread is a nice example of the verbose ignorance on these threads.

The line power to your laptop stops at the power converter. - after that it's 10-15 volts and you couldn't hurt yourself unless you tried very hard. It's not grounded for the same reason your wall-worts and lamps aren't generally grounded - no exposed parts.
 
Funny thing is: I have tried all day to get a spark from my laptop in various circumstances and settings. I think I might have felt a relatively minor tingle early in the day, after walking normally on the carpet (no intentional scruffing the feet along with socks) and touching it without the grounding thing. But, barely. And, I haven't gotten anything else resembling a spark since.

And, no, I won't do the foot-scruffing right before touching it, because:
A. I already know that will work, just as reliably as touching the light switch screws. I only experimented with the steps I outlined above, and normal walking.
B. I don't want to risk (even if it is a tiny one) damaging the thing.

realpaladin said:
Post the YouTube url please :)
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http://www.youtube.com/watch?v=xpcUxwpOQ_A&#t=01m18s

(A nice, joyous song preceeds it.)

stevea said:
This thread is a nice example of the verbose ignorance on these threads.
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Which responses seemed particularly ignorant, to you?

stevea said:
The line power to your laptop stops at the power converter. - after that it's 10-15 volts and you couldn't hurt yourself unless you tried very hard. It's not grounded for the same reason your wall-worts and lamps aren't generally grounded - no exposed parts.
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Repeating what others had stated, in different words.... is addressing verbosity.... how exactly?
 
stevea said:
This thread is a nice example of the verbose ignorance on these threads.

The line power to your laptop stops at the power converter. - after that it's 10-15 volts and you couldn't hurt yourself unless you tried very hard. It's not grounded for the same reason your wall-worts and lamps aren't generally grounded - no exposed parts.
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Speaking of verbose ignorance...everyone* knows it's amperage, not voltage that does the damage.

Thousands of volts are of concern because of the amperage that it represents.

SO, being as the power brick for my laptop claims an output of 19V, 7.9A (DC) and a (relatively) small current of 300-500mA (that's approx 1/16 of the output current, btw) is enough to cause death in humans...your ignorance is showing ;)


*ok, so, not really everyone...but I'd wager most of the people on this thread who have readily apparent backgrounds in electronics know this :)
 
I'll just state that grounded plugs are just good. Might not apply here for static electricity but it is a good start to protect the laptop/power-supply against surges, spikes, and brownouts (UPSs designed to protect against this are better, of course). I'm definitely not an electrician or electrical engineer. I just pointed to possible solutions from the given information.

I'm more acclimated to guitar electronics where grounding is *very* important. On a guitar itself it just stops the tingling when touching metal parts and output hum but a faultily-grounded amp or sound system (monitors, mikes, PAs) could *kill* you. There are a few actual cases of this or close calls.
 
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There are high voltages present in laptops specifically to do with the LCD screen which may require several hundred volts, so don't go digging around inside if you don't know what you're doing.
 
stevea said:
This thread is a nice example of the verbose ignorance on these threads.

The line power to your laptop stops at the power converter. - after that it's 10-15 volts and you couldn't hurt yourself unless you tried very hard. It's not grounded for the same reason your wall-worts and lamps aren't generally grounded - no exposed parts.
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wall wort?
 
commandlinegamer said:
There are high voltages present in laptops specifically to do with the LCD screen which may require several hundred volts, so don't go digging around inside if you don't know what you're doing.
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Can you provide a reference for that? When this thread started the display was the one component I didn't know the voltage for off the top of my head. On topic internet references were hard to find but most suggested 5V for an LED display (did you mean LED BTW? Similar low voltages for LCD but LCD isn't too common anymore is it)

Dancing David said:
wall wort?
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Wall wart. Nickname for the ugly transformers that plug in to outlets.
 
RecoveringYuppy said:
Can you provide a reference for that? When this thread started the display was the one component I didn't know the voltage for off the top of my head.
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The screen backlight may require between 500 and 700 VAC, supplied via an inverter. Finding a decent article seems to be problematic; this is a typical diy guide to replacing it (which I wouldn't recommend to the novice no matter how easy it looks):

http://www.pchub.com/uph/content/fq2_dis_lcd_inverter.html
 
shadron said:
The reason you got sparks in the first instance is that you grounded yourself to the computer and the static electricity drained by that path to ground. After you grounded yourself with the wrist strap, the static drained off there, and not longer when you touched the computer.
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This. When you build up some static on yourself, if you touch something and it "zaps" you, it's because the thing you touched is grounded.
 
BobTheDonkey said:
Speaking of verbose ignorance...everyone* knows it's amperage, not voltage that does the damage.

*ok, so, not really everyone...but I'd wager most of the people on this thread who have readily apparent backgrounds in electronics know this :)
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That saying is an example of ignorance trying to masqurede itself as knowledge.
BobTheDonkey said:
SO, being as the power brick for my laptop claims an output of 19V, 7.9A (DC) and a (relatively) small current of 300-500mA (that's approx 1/16 of the output current, btw) is enough to cause death in humans...your ignorance is showing ;)
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Steva is right. You'd have to be an abject retard to kill yourself with that power supply. You would have to jam the wires into an open wound, be sopping wet, or jam the wires straight through to your heart. And the only way I'm certain that you could kill yourself with that power supply is the last one because a freaking hearing aide battery is capable of stopping your heart in that last scenario. Hell lets not even mention the fact that you picked the one frequency that I have never heard of anyone dying from besides from having their body parts vaporized due to heating. Your ignorance is burning so brightly I have to wear welding googles or I will go blind.
 
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technoextreme said:
That saying is an example of ignorance trying to masqurede itself as knowledge.

Steva is right. You'd have to be an abject retard to kill yourself with that power supply. You would have to jam the wires into an open wound, be sopping wet, or jam the wires straight through to your heart. And the only way I'm certain that you could kill yourself with that power supply is the last one because a freaking hearing aide battery is capable of stopping your heart in that last scenario. Hell lets not even mention the fact that you picked the one frequency that I have never heard of anyone dying from besides from having their body parts vaporized due to heating. Your ignorance is burning so brightly I have to wear welding googles or I will go blind.
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You could also get killed if you offend someone who will be using that powersupply to beat you to a bloody pulp... but that is neither here nor there...

I am more interested in Wowbaggers adventures.
 
BobTheDonkey said:
Speaking of verbose ignorance...everyone* knows it's amperage, not voltage that does the damage.

Thousands of volts are of concern because of the amperage that it represents.

SO, being as the power brick for my laptop claims an output of 19V, 7.9A (DC) and a (relatively) small current of 300-500mA (that's approx 1/16 of the output current, btw) is enough to cause death in humans...your ignorance is showing ;)


*ok, so, not really everyone...but I'd wager most of the people on this thread who have readily apparent backgrounds in electronics know this :)
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Given that skin resistance is usually in the thousands of ohms, your 19V powersupply will have a hard time killing you - UNLESS you do something spectacularly stupid so that the current flows through your blood and goes through your heart.

Face it, there's folks around who understand this stuff better than you.

The reason the thousands of volts involved in a static electricity discharge don't kill you is because a.) there's not enough electrons stored for there to be much current flow and b.) it doesn't typically go near your heart.
 
technoextreme said:
That saying is an example of ignorance trying to masqurede itself as knowledge.

Steva is right. You'd have to be an abject retard to kill yourself with that power supply. You would have to jam the wires into an open wound, be sopping wet, or jam the wires straight through to your heart. And the only way I'm certain that you could kill yourself with that power supply is the last one because a freaking hearing aide battery is capable of stopping your heart in that last scenario. Hell lets not even mention the fact that you picked the one frequency that I have never heard of anyone dying from besides from having their body parts vaporized due to heating. Your ignorance is burning so brightly I have to wear welding googles or I will go blind.
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DC doesn't have a frequency. But, nice try. Thanks for playing ;)

And how many amps is that hearing aide battery?

Here's a few examples of your pleasure:

A 9V battery has 500-800mAh (that means 500-800mA over an hour)
A AAA battery has 1150mAh (that means 1150mA over an hour)
A AA battery has 2850mAh (that means 2850mA over an hour)

All very low current. I would expect a hearing aid battery to be somewhere lower than the 9V...of course it can't kill you, the amps aren't there.


Interestingly, I work on this stuff for a living - but, ya know, I guess I don't really know much about the dangers of voltage/amperage (not like I have had this beat into me via quarterly safety training for the past, oh, 10 years).
 
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realpaladin said:
You could also get killed if you offend someone who will be using that powersupply to beat you to a bloody pulp... but that is neither here nor there...
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Bob diserved the sarcastic response.
DC doesn't have a frequency. But, nice try. Thanks for playing
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Actually it does and its ridiculously obvious.
 
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