Anti-static precautions?...
- Thread starter PMarge
- Start date
Don't build on the carpet and ground yourself to your case before you touch anything.
lucasbytegenius
Well-Known Member
Do you have to have the power supply plugged into a wall outlet for grounding to happen?
Plug the PC into power, make sure the power is turned OFF at the wall, touch a part of the case that is bare shiny metal (a screw usually works) and then you are done. Try not to move around too much as you will build up charge again. To ground yourself again, just touch the same screw or bare metal part of the chassis you touched before. The earth is always active regardless of power switch on wall or PC.
All you need to do is touch the bare metal of the case to discharge any static electricity built up inside you.
Yes. Otherwise the case isn't grounded.
lucasbytegenius
Well-Known Member
Being plugged into a grounded outlet has nothing to do with it... Ever walked across carpet and built up static electricity and then touch something metal and get shocked? That means you have been discharged. You don't need to plug it in, just touch the metal part of the case before touching any electronic parts...
However, of all the systems i've built, i've never done this and have never killed any components. But if you walk across carpet, you better take the precaution and touch the metal of the case.
However, of all the systems i've built, i've never done this and have never killed any components. But if you walk across carpet, you better take the precaution and touch the metal of the case.
FuryRosewood
Active Member
yea, or touch a bare metal surface on a electrical outlet screw ( the thing that holds the faceplate on )
Motoxrdude
Active Member
You don't have to have the computer plugged in. Static electricity is just the difference in electric potential between two objects. As long as you have a like charge with the computer case you will be OK. You could have 17k V static buildup but as long as the computer has the same charge, you wouldnt damage anything. Simply touching the case is sufficient to avoid static discharge.
With that being said, static electricity isn't a huge problem when building a computer. Most electronics are built with dissipative materials and TSVs so the danger of actually destroying something is pretty slim. I'm not saying totally ignore static electricity, but it's not a major issue.
With that being said, static electricity isn't a huge problem when building a computer. Most electronics are built with dissipative materials and TSVs so the danger of actually destroying something is pretty slim. I'm not saying totally ignore static electricity, but it's not a major issue.
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gigabiteme
New Member
power does not have to be plugged in/ just touch any part of the steel computer case/ you r grounded to the case itself- not you whole house
or neighbourhood power mains- just by walking across a carpet u build up to 15000 volts- <--.00005 amps or less- that discharge can blow computer components ,so just touch the case/ i usuall have my elbow or bare skin touch at all times.any doubt get a strap
or neighbourhood power mains- just by walking across a carpet u build up to 15000 volts- <--.00005 amps or less- that discharge can blow computer components ,so just touch the case/ i usuall have my elbow or bare skin touch at all times.any doubt get a strap
Okedokey
Well-Known Member
If the case isn't grounded, it doesn't matter how many times you touch it.
Basically, to the OP, put simply, keep the pc plugged in, with PSU and wall swtich off, and touch the chassis before anything else.
I agree with the others though, not a bit issue anymore. But given how easy it is to keep it plugged in (and off), worth the precaution.
Basically, to the OP, put simply, keep the pc plugged in, with PSU and wall swtich off, and touch the chassis before anything else.
I agree with the others though, not a bit issue anymore. But given how easy it is to keep it plugged in (and off), worth the precaution.
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Motoxrdude
Active Member
It doesn't need to be grounded. Your computer could be grounded all day long but if you build up a static charge there is going to be a potential difference.
This only works if the person is grounded as well. If the two objects (you and the computer) have a common ground then you will always be at the same charge. If you only ground the computer you are no better off.
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Okedokey
Well-Known Member
You're missing the point. Everything will be at a relatively different voltage. By having a single earth point on the chassis, it neutralises and discharges the voltages to the same as the components that you're working on (by touching the chassis).
Thats why you touch the chassis (which is now the same potential as the components = earthed)
Which is the same as the 'person' being grounded.If you don't earth the chassis, and touch it with static charge, you're actually discharging the static into the components (if you discharge it at all). This is the whole point of an earth.
But of course, if im wrong, my 5 year avionic engineering degree is wrong and the professional associations are wrong, i apologise.
The point is that this is a low risk but its very easy to keep the pc plugged in, earthed, and make sure you touch the chassis.
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Motoxrdude
Active Member
You're missing the point. Everything will be at a relatively different voltage. By having a single earth point on the chassis, it neutralises and discharges the voltages to the same as the components that you're working on (by touching the chassis).
The principle of ESD doesn't change because of experience lol. But with that said im an avionics technician as well.
Thats why you touch the chassis (which is now the same potential as the components = earthed)
If you don't earth the chassis, and touch it with static charge, you're actually discharging the static into the components (if you discharge it at all).
Yes, exactly. Now you and the computer have the same charge, aka zero voltage potential and there is no chance for ESD. What you fail to realize is that you could have an astronomical electrostatic charge, but as long as it's the same charge as the computer itself there is no risk of ESD.
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Okedokey
Well-Known Member
You're talking theoretical, of course if there is no potential difference you don't have an issue, but it is virtually impossible to forsee a random (uncontrolled) situation where that would exist in the real world. What you're failing to recognise is that unless the computer is cruising around on the carpet, wearing clothing and its own pink velvet love making suit, you're always going to have a difference in potential energy between you and it. And unless that potential has somewhere to go (ie a case insulated is not a circuit), you have an issue because ICs and capacitors react differently to a metal case.
Thats why you ground it, and touch the chassis. you have a central reference point, (ground) and you control your actions.
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Motoxrdude
Active Member
Right, I see what your saying. But whats the difference between touching an un-grounded and grounded case? Doesn't it achieve the same thing?
Btw i'm an A&P, FAA and FCC certified avionics technician as well :good:
Okedokey
Well-Known Member
The difference is the components can be charged (capacitance, inductance etc) and it will all be at that +ve charge when unearthed.
You have a seperate charge and different potential (electrons picked up from materials).
You touch the chassis (unearthed) and you will dump that voltage into any available circuits with resitance/inductance until that charge is at quiescence.
You touch an earthed chassis and it will go straight to earth (path of least resistance) thereby protecting/bypassing your circuits.
Its good to see you're quals bro, i was an avionic engineer rather than a tech with the airforce.
You have a seperate charge and different potential (electrons picked up from materials).
You touch the chassis (unearthed) and you will dump that voltage into any available circuits with resitance/inductance until that charge is at quiescence.
You touch an earthed chassis and it will go straight to earth (path of least resistance) thereby protecting/bypassing your circuits.
Its good to see you're quals bro, i was an avionic engineer rather than a tech with the airforce.
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