Timeline for Anti-static mat connected to earth directly or 1E6 ohm resistor?
Current License: CC BY-SA 3.0
18 events
| when toggle format | what | by | license | comment | |
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| Dec 14, 2016 at 14:18 | comment | added | Bimpelrekkie | I interpret that as: "Beware, this product has no resistor, connect it to a grounding point via a resistor !". If having the resistor was irrelevant then they would not mention the absence of the resistor explicitly. At least, that is my opinion. | |
| Dec 14, 2016 at 14:10 | comment | added | user127725 | @FakeMoustache, good question. But as i pointed out, that company sells grounding points with and without resistors. The grounding point in the video looks very much like the dome style snap without internal resistor. | |
| Dec 14, 2016 at 14:08 | comment | added | Bimpelrekkie | Not in the wire, OK, there can still be a resistor in the mat's connector and/or the grounding connector. And did he measure the whole setup between mat connector to ground connection with a multimeter ? | |
| Dec 14, 2016 at 14:05 | comment | added | user127725 | @FakeMoustache, that guy says: "This is a green wire. It has no resistor in it." | |
| Dec 14, 2016 at 14:03 | comment | added | Bimpelrekkie | Especially after watching this operator connecting the mat directly to earth Can you prove or confirm that there is no series resistor hidden somewhere in the connection to the mat, the cable itself or the ground connector ? No you can't because you would have to measure that yourself. It is easy to hide a resistor. Let's assume that guy in the video got the right stuff and the resistor is there but you just cannot see it. | |
| Dec 14, 2016 at 13:59 | comment | added | Bimpelrekkie | ESD protection is about high voltage, low current. So, resistance is needed. For the ESD protection itself, no, resistance is not per se needed. Only if you do your utmost to make the ESD discharge current as large as possible (metal grounded table, you on isolating shoes all charged up firmly holding a metal object, then discharge yourself through a component on that metal table) only then will that resistor save your component. In practice there will always be some series resistance. The 1 M ground resistor is mainly for safety reasons. | |
| Dec 14, 2016 at 13:59 | comment | added | Wesley Lee | @Marty -- "no current" at equilibrium with no fault condition. In case of a fault, the resistor is there as extremely cheap insurance. That's it. | |
| Dec 14, 2016 at 13:36 | comment | added | user127725 | @TomCarpenter, yes, ESD protection is about every part being at the same potential, for example at earth potential. But, you want to reach that equilibrium with low current flows. So, before: relative high voltage. After (when everything is at equilibrium): zero voltage, no current. | |
| S Dec 14, 2016 at 13:32 | history | suggested | Peter Mortensen | CC BY-SA 3.0 |
Copy edited (e.g. ref. <http://english.stackexchange.com/questions/4645/is-it-ever-correct-to-have-a-space-before-a-question-or-exclamation-mark#comment206109_4645>).
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| Dec 14, 2016 at 13:09 | comment | added | Tom Carpenter | @Marty ESD protection is about ensuring that you don't build up a charge by allowing any static charge to dissipate through to ground. Additionally a human is somewhere in the region of a 100pF capacitor, the RC time constant of a human with a 1MOhm to GND is about 100us, so even with a 1MOhm resistor, you'll still be discharged in less than a millisecond. | |
| Dec 14, 2016 at 13:00 | review | Suggested edits | |||
| S Dec 14, 2016 at 13:32 | |||||
| Dec 14, 2016 at 12:44 | comment | added | user127725 | @FakeMoustache, ESD protection is about high voltage, low current. So, resistance is needed. Not in the last place for the operator's safety. I was just wondering whether the resistance of the dissipative layer would be enough. Especially after watching this operator connecting the mat directly to earth. | |
| Dec 14, 2016 at 10:58 | history | edited | Bimpelrekkie | CC BY-SA 3.0 |
deleted 4 characters in body
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| Dec 14, 2016 at 10:56 | comment | added | Bimpelrekkie | If you prefer to rely on that and not use the 1 Mohm resistor to ground feel free to do so despite all the good reasons to use that 1 Mohm resistor. There are only advantages in using that 1 Mohm resistor and no disadvantages. If you think that ESD protection will be worse because of that resistor then you have not understood ESD very well. | |
| Dec 14, 2016 at 10:42 | comment | added | user127725 | The earthing connection of the mat is covered in insulative material. | |
| Dec 14, 2016 at 9:37 | comment | added | AndrejaKo |
+1 for the when part!
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| Dec 14, 2016 at 8:30 | history | edited | Bimpelrekkie | CC BY-SA 3.0 |
added 15 characters in body
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| Dec 13, 2016 at 20:10 | history | answered | Bimpelrekkie | CC BY-SA 3.0 |