[PLEASE READ] GX4000 with original power brick and C4CPC

[ukmarkh]

What king of proof do you expect ? I mean, what is your level of understanding on what happen within a IC when exposed to ESD.
Not having fried an IC in your life does not mean you will never do it in the future.

Supporting evidence...

[Bryce]

Define supporting evidence? You can prove it yourself. Put on some wooly socks, shuffle your feet on the ground and then touch something that's earthed. The fact that you feel anything at all means that it's already above what any standard IC can take. Now grab any datasheet and check what the maximum voltages are. You've just proved the theory.

Or what process would you require as proof?

Bryce.

[ukmarkh]

Define supporting evidence? You can prove it yourself. Put on some wooly socks, shuffle your feet on the ground and then touch something that's earthed. The fact that you feel anything at all means that it's already above what any standard IC can take. Now grab any datasheet and check what the maximum voltages are. You've just proved the theory.

Or what process would you require as proof?

Bryce.

I wan't to know if the charge from a human is enough to zap an IC. How do you know it's above what the IC can take, are you aware of + and - charge of sodium and potassium ion's. Where in your hypothesis does it list the well documented evidence, for all activities mentioned, that the level of charge from a human, is dangerous to an IC?

How many millivolts do you think the human body can produce? 

[robcfg]

It's not how much the body can produce, but how much can go through it if the body is the path of least resistance for an electron flow...


Never happened to you to try to shake someone's hand and get a spark between your hands?

[Bryce]

I wan't to know if the charge from a human is enough to zap an IC. How do you know it's above what the IC can take, are you aware of + and - charge of sodium and potassium ion's. Where in your hypothesis does it list the well documented evidence, for all activities mentioned, that the level of charge from a human, is dangerous to an IC?

How many millivolts do you think the human body can produce? 

Millivolts?? I'm sure you've had that experience where a visible spark jumped from your finger to the door knob (if the room is dark enough). Well that means that your body had a charge of at least 500V (Paschen's Law) otherwise there wouldn't have been a spark. I remember an experiment back in my school days where we measured all the pupils with an old fashioned Electrometer and we managed to get well into the kilovolt range. So yes, the body can easily produce a voltage many orders of magnatude above what an IC could take.

Yes, I am well aware of how ionic charge works. However, I don't see what it has to do with this subject.

Bryce.

[seanb]

Ah making sparks from my hands onto metallic objects in maths.

Got into trouble because I was zapping anyone that walked past.

Wished I'd worked harder instead now.

[ukmarkh]

The human body can produce 10 to 100 millivolts, when you convert 100 to volts the result is 0.1 volts. So I don't see how Paschen's Law is relevant, as that discusses the amount of voltage needed over distance of objects. 

[ukmarkh]

Ah making sparks from my hands onto metallic objects in maths.

Got into trouble because I was zapping anyone that walked past.

Wished I'd worked harder instead now.

Yeah, but your body wasn't producing 500 volts as suggested. 

[seanb]

I wasn't saying anything of the sort.
This conversation reminded me of doing that and I decided to share.
Nothing more.

[Munchausen]

The human body can produce 10 to 100 millivolts, when you convert 100 to volts the result is 0.1 volts. So I don't see how Paschen's Law is relevant, as that discusses the amount of voltage needed over distance of objects.

The human body isn't producing the voltage, just carrying it for a while, it's an electrostatic charge. There's a lot of stuff about this online: https://www.google.co.uk/search?q=static+electricity+measurement+on+human+body

But I think you might be trolling 

[Bryce]

The human body can produce 10 to 100 millivolts, when you convert 100 to volts the result is 0.1 volts. So I don't see how Paschen's Law is relevant, as that discusses the amount of voltage needed over distance of objects.

Now you are just splitting hairs to try and justify an invalid point, but ok, if that's what you mean by "producing" then yes, the body (on its own) can only produce millivolts, but here we are talking about what charge the body can build up and store, and that is many Kilovolts. Who cares how it was produced, the main thing is that the charge is there, it is stored in a human body and it can destroy ICs so needs to be removed and the most effective way of doing this is with a wristband.

Bryce.

[ukmarkh]

The human body isn't producing the voltage, just carrying it for a while, it's an electrostatic charge. There's a lot of stuff about this online: https://www.google.co.uk/search?q=static+electricity+measurement+on+human+body

But I think you might be trolling 

That's because you don't understand... 

[ukmarkh]

Now you are just splitting hairs to try and justify an invalid point, but ok, if that's what you mean by "producing" then yes, the body (on its own) can only produce millivolts, but here we are talking about what charge the body can build up and store, and that is many Kilovolts. Who cares how it was produced, the main thing is that the charge is there, it is stored in a human body and it can destroy ICs so needs to be removed and the most effective way of doing this is with a wristband.

Bryce.

You still haven't answered the question?


No I'm not splitting hairs, you're not answering or understanding the reasoning behind it. Now you're switching and describing a scenario of a conduit. Go over my posts and clearly show me where I am splitting hairs?


I'm happy to leave it there, for the good of the forum.   

[Bryce]

Ok, I've reread the thread. Your original comment was that people who use anti-static bands are clueless. I then attempted to explain why that's not the case. You then went off on a tangent about the ionic charge of Potassium or something?? No idea where that one was going?? And your current discussion is the source of the charge that causes static discharge from a human and the definition of the word "produce".

To put it as simple as I can: Humans are one side (plate) of a massive capacitor. The other side happens to be the planet we're standing on. This capacitor tends to charge itself (usually unnoticed) from many different (well documented and proven) physical effects, up to several thousand volts. Discharging this massive capacitor through an IC is a bad idea, especially if it an expensive component. Wearing a wrist band greatly reduces the chance of this happening by connecting a resistor across the capacitor. So no, it's not clueless, it's quite sensible actually.

If I truely have mis-understood what your question is, then please do inform me.

Bryce.

[ukmarkh]

Ok, I've reread the thread. Your original comment was that people who use anti-static bands are clueless. I then attempted to explain why that's not the case. You then went off on a tangent about the ionic charge of Potassium or something?? No idea where that one was going?? And your current discussion is the source of the charge that causes static discharge from a human and the definition of the word "produce".

To put it as simple as I can: Humans are one side (plate) of a massive capacitor. The other side happens to be the planet we're standing on. This capacitor tends to charge itself (usually unnoticed) from many different (well documented and proven) physical effects, up to several thousand volts. Discharging this massive capacitor through an IC is a bad idea, especially if it an expensive component. Wearing a wrist band greatly reduces the chance of this happening by connecting a resistor across the capacitor. So no, it's not clueless, it's quite sensible actually.

If I truely have mis-understood what your question is, then please do inform me.

Bryce.

Obviously you didn't read it!

And you've just described a type of insurance policy.
As mentioned in a post earlier on, I’m not stating that it can't happen. I stated it’s clueless to have desks, floors and Wrist bands! I don't recall calling people clueless, so where did I call them clueless? In a large company you're forced to wear them. This is a belt a braces style approach, that companies instil, especially medium to large companies, who don't fully understand, and go overkill i.e. Belt and braces.

I said, and I quote “The first electrical job I ever had was repairing monitors and PCB components. The first thing you notice on day one, is that everyone is wearing anti-static wrist bands, earthed to the desk. but if you ask 'em why, they don't fully understand, but often say "it's the build up of static from the human body, it will zap the chip if we don't wear it". I later read that today's (This was in 1995) Microchips are built to be protected from ESD, but the problem is bigger, we shouldn't call it "static," we should call it "charge imbalance". Just having charged particles is not enough to damage a chip, but Anti-Static wrist bands are worn as a belt braces style approach. Like an insurance policy.”

[Bryce]

This is where you called them clueless:

Like I said, the wrist band is like an insurance policy. I've seen companies with anti-static floors, furniture and wrist bands... Clueless!

Anyway, messing around with old retro tat, I think I'll give the wrist band a miss 

Anyway, ignoring that, to answer the question/comment directly: Firstly, yes ICs are more robust these days, but definitely not safe, they are still easily destroyed by static discharge, it happens regularly. It's not really "belt and braces" because all the other measures taken, such as anti-static carpet/furniture only reduce the chance of charging "the human capacitor", the band is the only device that actually safely and permanently discharges the capacitor.

The last comment about the mis-understanding is of course correct, many people who wear them don't really understand why. But that doesn't make them any less necessary.

Bryce.

[ukmarkh]

I was calling the companies clueless, and it feels as though you tried to twist my words around. I.e. The process and expense needed for all three.


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[Bryce]

I was calling the companies clueless, and it feels as though you tried to twist my words around. I.e. The process and expense needed for all three.


Sent from my iPhone using Tapatalk

No, I didn't want to twist your words, I just interpreted it wrong.

Regarding the expense. I have worked with some massive electronics companies over the years and believe me, they are vultures. If they could save half a cent from production costs by sawing a leg off the table they would. If you look at it economically. If I have 100 workers handling a 500 dollar device and  2 of these die a year due to static discharge, but only one or none per year when I implement a 50cent wristband, then I'd be stupid not to.

Bryce.

[Gryzor]

The original quote was:

I've seen companies with anti-static floors, furniture and wrist bands... Clueless!

By any reasonable reading this doesn't mean "they wear them without knowing what for, but the devices they employ are still good". It means they shouldn't be doing it, so if anyone (and, I guess, all of us) misunderstood it it's not our fault.


But then your whole process of argumentation was about "proving" etc etc which was totally irrelevant to whether these people are clueless or not, or whether they know or not why they're wearing bands.

[ukmarkh]

But, as the conversation evolved, it got bogged down with other things as well.


When you ask the facilities managers or people with the budget, who installed all this stuff, they haven't got a clue why, other than we need it. Believe me, check my linkedin profile if there's any doubt, I've worked for many technology companies, especially international. Even the engineers don't understand the principle behind why, they're just instructed to wear, so they do. It's quite scary, but as mentioned, it's became a status quo, nobody ever questions why?


   

[Gryzor]

By the way, I've seen a board being fried because of static; I was re-harnessing an arcade cab to be used as a MAME machine. The cab was on a rug that looked very static-friendly, and the board was unscrewed and ready to be removed. Another guy went it and took it out. I do think I saw a led flashing for a fraction of a second as he grabbed it, though I'm not sure; the board, however, did not work afterwards: it would turn on but wouldn't give out any signal. We didn't mind because it was some shitty clone on a dual-ROM board that was covering for an illegal gambling game, but it was telling..

[Bryce]

But, as the conversation evolved, it got bogged down with other things as well.


When you ask the facilities managers or people with the budget, who installed all this stuff, they haven't got a clue why, other than we need it. Believe me, check my linkedin profile if there's any doubt, I've worked for many technology companies, especially international. Even the engineers don't understand the principle behind why, they're just instructed to wear, so they do. It's quite scary, but as mentioned, it's became a status quo, nobody ever questions why?

The facility manager isn't required to know the specific reason behind everything he's told to order, but if any of my Engineers admitted they didn't understand a basic principle of physics such as static discharge, I'd seriously question whether they should be working there at all.

Bryce.

[1024MAK]

Not knowing the details when it comes to electricity and electronics is not that uncommon for lay people. Even for  some who are not considered to be uneducated.

In the industry where I work, we are working on electrical systems all the time. Sometimes we work on electronic systems (mainly "change a card" type work). But if I was to ask "using ohms law, work out....", a lot of them would not be able to answer. Even though they are suppose to have either demonstrated this knowledge when they joined, or went on training that included electrical and electronic basic theory....

This static discharge chat, reminds me about a complaint from an operator in a control room. He asked "can you check the earthing, I keep getting electric shocks from the control panel". So without thinking about it, I went and got the schematics out and had a look to see how it was earthed.

Then I remembered that all the 24V indication lamps are fed from a earth return 24V AC power system. Sure enough, in the rear of the control panel, a large cable acts as bothe the earth return and the return supply conductor for the 24V AC supply.

When I returned to inform the operator, I noticed that he was using his chair (which had rollers on) to move around without getting up out of it. This must have been causing a static charge to build up. Of course when he touched the metal control panel, the static charge discharged via his hand to the earthed panel... 

Two things not talked about:-
Man made fibres used in carpet and clothing are known to generate high levels of static voltage.
With semiconductors, a high voltage can (and does) "punch" a hole through the insulated gate in metal oxide transistors (like in ICs made using CMOS technology). You even have to take precautions with individual discrete FETs.
Yes, modern ICs often have diodes connected to the input pins, that try to shunt the charge to the power pins. But they can only carry a relatively small current. If the amount of energy resulting from the discharge is too great, they may fail.

Mark

[ukmarkh]

The facility manager isn't required to know the specific reason behind everything he's told to order, but if any of my Engineers admitted they didn't understand a basic principle of physics such as static discharge, I'd seriously question whether they should be working there at all.

Bryce.

Most managers come from a technical background, the one I'm talking about certainly did. The staff I presume, would never admit to it then... Especially since you'd probably sack 'em. By the way, and I've mentioned this a few posts back, it not technically correct to call it static discharge, it's known in the field as charge imbalance, i.e. The result from an imbalance of protons and electrons [emoji6]


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[Bryce]

Technical managers would have a technical background, but not a facilities manager (at least where I work).

The technical term used universally and in all technical documents is ESD = Electro-Static Discharge. The proton / electron imbalance you are talking about is the triboelectric effect (also known as contact electrification), which is how the charge built up in the first place. All electron flow is due to a charge difference, otherwise they'd have no reason to flow. ESD is just one of many types of charge imbalance.

Bryce.