How to test if I am grounded properly to work with electronics? - Page 1
Forum section: electronics / beginners

author: SoulReaver009
author_rank: Newbie
timestamp: March 20, 2023, 02:04:38 am
content: Hello people of "EEVBlog"!,I am new to electronics. Been fascinated by it for a while, have studied physics (not Electricity, yet, but its my next unit). I got a multimeter and an Ardist DIY kit for my birthday and I am very excited to start testing, experimenting, and building!I have been googling and youtubing a little bit, watching some reviews on my multimeter, and reading my manual and such.For some reason I cannot find a video or webpage to test and confirm if I am properly grounded.I can only work in my room, and it has carpet, so I am very nervous. I cannot work anywhere else, sadly.I watched a youtube video that said to plug in a 3-prong laptop charger, and then connect the alligator clip of my ESD anti-static wrist strap to the outside metal part of the charger (the part that goes into the laptop).Lots of people have commented that it works and i believe them. If you know other ways to ground, I would be interested. Would also be cool to test each method of grounding, and compare results.Being the experimentalist that I am, I would like to have a procedure to test and confirm (as closely to absolutely, as possible) if I am indeed grounded, or at least within a safe range to "work with electronics". please forgive me if my terms or sayings are inaccurate or wrong. I am new to this!Can't wait to hear back and get started!!

author: jonpaul
author_rank: Super Contributor
timestamp: March 20, 2023, 02:10:38 am
content: Bonjour cher MonsieurIf,you restricted your first projects to low voltage, eg 5, 12, 15V battery or wall transformers powered, you have no issues with ground.If,you build,mains powered or high voltage equipment then there is,a potential shock hazard.To test a,ground, measure the resistance between earth ( cold water pipe, electric box grounded housing or,metal conduit) and the ground under test, should be under 25 Ohms, really near 0..1 ohm.for info on safety ground, see Mike Holt.com or a professional electrical forum.Bon courageJon

author: james_s
author_rank: Super Contributor
timestamp: March 20, 2023, 02:15:45 am
content: Most modern stuff is pretty robust so if it's just hobby circuits I wouldn't worry about it too much, if you're working on expensive gear, production circuits that will go to paying customers or handling old CMOS ICs then ESD control is far more important. You can wear a static dissipating wrist strap if you're worried about it, and ESD bench mats are readily available.

author: SoulReaver009
author_rank: Newbie
timestamp: March 20, 2023, 02:29:56 am
content: I would like to know how to test my body to confirm i am grounded.surprisingly, I cannot find any procedures on this anywhere.I thought it would be one of the first steps in testing, and tinkering with electronics.While, your message to me does reassure me, I would also like the joy of testing and confirming it. I am surprised there is no easily findable procedure on this.

author: SoulReaver009
author_rank: Newbie
timestamp: March 20, 2023, 02:31:55 am
content: How do I test myself tho?I am surprised to not find any procedure on how to do this. I would've thought this wouldve been the first thing your taught, in testing and tinkering.Kind of like how, print "hello world" is the first thing ur taught when learning to program. hahaIf you know of a way to do this, I would greatly appreciate it.

author: Stray Electron
author_rank: Super Contributor
timestamp: March 20, 2023, 02:49:38 am
content: Take a look at item 154377536864 on Ebay. The company that I worked for could have had anything on the market but all of their testers were made by 3M.If you want to know more, here is a manual for the 3M 740 model.https://www.pctronics.com.br/manuais/740-5702c659c9043.pdf

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 20, 2023, 06:54:55 am
content: Like james_s wrote I would not worry to much about it. I have worked on many stuff throughout my life and not bothered with grounding myself through a strap while working with simple cheap stuff. Nothing got damaged so far.When should you worry is when you notice to be very static often. For instance when you touch a big body of steel and zap you feel the spark. (Heating radiators or big computer cases, etc) Or when you touch the ground pin directly and you feel the spark.

author: tooki
author_rank: Super Contributor
timestamp: March 20, 2023, 08:36:07 am
content: Quote from: pcprogrammer on March 20, 2023, 06:54:55 amI think it’s important to mention that this argument is a very, very weak one: one rarely knows if they’ve caused ESD damage, because it often manifests as a problem down the line, for example as a component that fails after a few years, or that works but is no longer in-spec.See e.g.http://www.cisl.columbia.edu/courses/spring-2002/ee6930/papers/00899057.pdfhttps://www.ti.com/lit/an/ssya010a/ssya010a.pdfhttps://catalogimages.wiley.com/images/db/pdf/9780470511374.excerpt.pdfI’ll be honest that I rarely use an ESD strap, but I do use an ESD mat. At home I am normally barefoot, which produces less static than wearing insulating shoes, and at work I wear ESD slippers instead of shoes, for the same reason. (At my previous job we had actual ESD flooring, so straps truly weren’t necessary. I’ve considered buying an anti-fatigue ESD floor mat for at home to accomplish the same thing.) When I worked in the field doing computer service, we normally just kept the system plugged in but turned off to maintain the ground connection, frequently touching bare metal of the case to ensure equipotential.I also found this interesting guide while searching, on how to protect circuits:https://www.ti.com/lit/sg/sszb130d/sszb130d.pdf

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 20, 2023, 09:20:15 am
content: Quote from: tooki on March 20, 2023, 08:36:07 amTrue, but for a hobbyist not a big deal. With computers I do the same as you, keep the case grounded and touch it once in a while. When working with small MCU boards I don't bother. When I carry them between my two work spaces (up and down the stairs) I keep them in their anti static bags, but on my computer desk they lie on the desk and get connected and disconnected via USB a lot. The computer is grounded though.When one gets a job working in a lab, they most likely will have guidelines and tools that need to be followed and used.But on the subject Linus did a video with someone and an ESD gun to test the effect on memory boards. They can take quite the beating, although they did not look into longer term effects.

author: Shock
author_rank: Super Contributor
timestamp: March 20, 2023, 12:28:05 pm
content: This depends on your geographic location as some people don't have earthed/grounded household mains power outlets.Typically you would attach your wrist strap to your soldering station or esd mat, or your esd socket on your workbench. Aside from the soldering station (which connects to the mains directly) these then connect to a earth/grounding bond plug that you plug into your mains power outlet.So looks something like this:Wrist strap >> ESD mat >> Bond plug >> MainsWrist strap >> Soldering station >> MainsWrist strap >> Bench socket >> Bond plug >> MainsFrom there your household mains connects your electrical grid and ground/earth rod.To test your wrist straps connections you can use a multimeter on ohms and measure the resistance between the button on your wrist strap and the unplugged (removed from the mains) ground/earth pin of your bond plug.You will normally see up to a couple of megaohms resistance. This resistance helps avoid being electrocuted easily, connected directly to the earth/ground with no resistance is a bad idea as it makes a high current path.You can also follow something like this which gives instructions on how to perform a functional test the wrist strap while wearing it.https://www.newark.com/pdfs/techarticles/3M/wristStrapFuntionalTesting.pdfTo test if your mains outlets are wired correctly you can use an outlet tester which lights up LEDs to indicate incorrect or missing wiring.Don't mess with the mains or go near the grounding rod. You need a bunch of experience and in most cases trained and licensed to understand how not to get electrocuted and test the household mains properly.I'd avoid the Chinese wrist straps as many are fake and do nothing, save up and buy a genuine 3M branded one from a reliable source (as ebay and amazon will have counterfeits).https://docs.rs-online.com/3e6e/0900766b81446fd1.pdfA static dissipative ESD mat is the next thing to get, but the idea is work as best as you can with what you have.

author: bidrohini1
author_rank: Contributor
timestamp: March 20, 2023, 01:21:48 pm
content: Here is a discussion about how to ground yourself:

author: Shock
author_rank: Super Contributor
timestamp: March 20, 2023, 01:50:18 pm
content: You could also try testing the wrist strap separately off your body. You should be able to use some household aluminum foil folded in a strip and use clothes pegs or paper clips to secure it around the inside of the strap. Test that you have a 1-2 megaohms resistance between the foil and the end of the wrist strap cable and unplugged mains bond plug earth/ground pin. After you have confirmed this pass some current through the whole circuit from a 9V battery or your bench supply. It should be under 10mA or 100uW with those resistances in place.By using the voltage drop method you can measure volts or millivolts between the foil and button on the strap and between the foil and the other end of the cable and between the cable and the bond plug pin. Manipulate the foil to see where the conductive parts of the strap are.You can of course try measuring current if your multimeter goes this low but check ohms law first. If there is no or low resistance and you are putting non limited current through your multimeter (high current) you can blow your fuse or break a cheap multimeter. Not only that, your 9V battery may catch on fire or if you don't have OC or current limiting protection on your power supply it's not a good idea.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 20, 2023, 04:19:30 pm
content: Quote from: pcprogrammer on March 20, 2023, 09:20:15 amOn that basis, smoking is safe, X-rays are harmless and it's perfectly OK to breathe asbestos.Joking aside, this is a really important point that many - if not most - people working with electronics seem not to 'get'. ESD doesn't necessarily stop something working completely and immediately, but it can decrease long-term reliability, or just cause a part to no longer meet specification.What's particularly odd, not to mention frustrating for anyone who has had the training and worked in a proper ESD-safe environment, is the sheer number of people who are actively resistent to the idea that they need to follow correct ESD precautions. ESD is cold, hard science - yet for some reason people who might ordinarily relish opportunities to show off their technical knowledge and skill instead recoil from the idea that ESD is a thing, that it matters, and that they might be unknowingly damaging their brand new games machine by failing to follow some really simple precautions.I even saw this in a former job, where I was the senior hardware engineer. From time to time people (software engineers, working on PC plug-in cards) would hand me boards and say, in a disparaging tone, "it just stopped working", as though it were somehow my fault.After a while I got sick of this, ordered a roll of ESD matting, and one evening after everyone had gone home, I went round installing ESD mats on the desks of all the software engineers. It didn't go down well, and I even had someone say in so many words "you don't actually expect us to use this stuff, do you?".Yes. Yes, I do. Because science.Nobody ever handed me a board that "just stopped working" again.

author: m k
author_rank: Super Contributor
timestamp: March 20, 2023, 05:54:51 pm
content: Quote from: SoulReaver009 on March 20, 2023, 02:04:38 amBeing professional with it is not easy.If your multimeter has a peak hold use that.Set the meter to high current and connect one lead to ground and other to something you're going to discharge your self.Select discharge thingy so big that you can slap it, zap is not so nasty if you slap the conduit and strong zap can be truly nasty but for that you need more energy than just static of you.Then just start experimenting.Shoes and floor are major things, chair and clothes surprisingly less.You can obviously generate more charge with bad clothes but shoes and floor are doing it naturally.I've measured 10A from me to ground.Actual peak is most likely much higher.Finally you just must believe that no zap means your potential is the same.I use wrist wrap when I have it.Other times I touch metal frame every now and then and try to move less.In case you're zapped when exiting a car just grab metal door frame early on.If I remember correctly 3/4 of zaps are damaging only partially.Means that the device is still somewhat operational.One test device included a socket for two pins, a buzzer and a component with four legs.Two extra legs were not connected, touching one of those silenced the buzzer and the other made it buzzing again, until it didn't.

author: richnormand
author_rank: Unknown
timestamp: March 20, 2023, 08:02:56 pm
content: For my bench at home and the computer bench I have esd dissipative flooring (stapled over 3/8" plywood ) on the carpet (and properly grounded, see at the corner on the photos). They are connected to the ground of the electrical outlet.ESD straps are through a 1M resistor for safety.The mats were from ebay (except the GamesNexus that was a gift for the sem) . Some large companies (US, Canada) have remnants from contracts and sometime sell the leftover stuff at discount on ebay. The sizes are plenty for a small bench and they get recycled instead of going in the dumpster but you might not get your choice of colour (see the crappy poo brown flooring for the main bench....) Much better quality than what I found from cheap stuff from China.For testing, if you have a megger or an electrometer (Keithley 617), but you can also find testers sometime on ebay. The real test is that in winter (low humidity from heating) my monitor does not reset when I touch the keyboard now ....Maybe a bit overdone for a home setup but I do get things that are pretty expensive to rework from friends sometime (like a main board smd repair from a Hitachi SEM a few months ago or similar stuff).Don't forget that esd damage can be cumulative and has been shown to result in increased failures several month down the line. You can find several photos on the web from failure analysis companies on this.I would encourage you to do it properly, with good stuff and it will last a lifetime.

author: Infraviolet
author_rank: Super Contributor
timestamp: March 20, 2023, 10:21:22 pm
content: Another point to mention is protecting things from ESD when storing or moving them, a lot of common packing materials give of so much static you can feel it in the hairs on the backs of your hands. Getting the silvery or pink electrostatic bags (keep as spares those which come when you buy components in them) can help,and for big boards need more mechanically sound wrapping to be transpoted or store the pink anti-static bubble wrap is a good idea.I don't think I've ever encountered, knowingly, an ESD issue. But I've mostly worked with components which are not the latest and fanciest, and haven't done much with bare field effect transistors (the FETs inside larger ICs usually have some protection diodes within the overall chip). And I'm in the UK where, I think, the climate isn't as ESD incuding as drier centre-of-continent climates are. Plus I don't tend to wear wool or other "fluffy" fibres. I would swear by a wrist-strap to mains earth as a precaution whe working on a computer's insides or anything expensive, we used a lot of anti-static stuff in a job I once had involving £100K boards with fancy ASICs on them, at another job I had where the most expensive component used was <£10 nobody but myself took any ESD precuations and all I took was grabbing something earthed for a few seconds upon first entering the room.

author: james_s
author_rank: Super Contributor
timestamp: March 21, 2023, 12:25:46 am
content: I have definitely damaged parts from ESD, at least I very strongly suspect that's what happened. I have only experienced this with SRAM and DRAM though, the former in particular seems to be especially fragile. Laser diodes are also known to be fragile, especially older ones.I'm not meaning to minimize the importance of ESD precautions, but if you're a hobbyist playing with an Arduino for example, the chances of damaging a part to the point that it malfunctions seems to be minimal and most of the stuff is cheap enough that it doesn't seem like a big deal. The greatest cost is frustration should something be not working properly. I am much more careful when it's winter and the air is dry causing me to get zaps all over than the rest of the year when the humidity is much higher.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 21, 2023, 08:35:07 am
content: Quote from: m k on March 20, 2023, 05:54:51 pmAn ESD event is far too short to be measured by a multimeter.Ironically, that's why they're damaging in the first place; it's not that they contain a great deal of energy, but that they transfer it from one place to another in a very short time - hence a very large current, and enormous I2R heating of a very tiny transistor inside whatever device you're handling.If your meter reads anything, it's more likely because an ESD discharge results in very high frequency RF interference being generated, which couples into the meter's input circuits and causes a temporary read error.I've been to EMC labs where equipment resets (or otherwise misbehaves) during ESD testing; it's not the flow of current through the board's GND plane that causes the fault, but radiated RFI from the spark coupling into digital logic.

author: m k
author_rank: Super Contributor
timestamp: March 21, 2023, 11:17:36 am
content: Quote from: AndyC_772 on March 21, 2023, 08:35:07 amHave you tried?I remember that my old Fluke 77 was pretty rational, small zap and small current type rational.Though the set is obviously also quite small, zapping constantly is uncomfortable.And categorizing small and big by feeling is also a bit less scientific.What I can't remember is how the zap happened through the wrist wrap.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 21, 2023, 12:46:08 pm
content: Compare and contrast the frequency spectrum of an ESD event with the manufacturer's stated bandwidth of the meter.

author: m k
author_rank: Super Contributor
timestamp: March 21, 2023, 05:02:07 pm
content: Yes, but can that energy actually flow differently.If I see an arc of current is it timely true and/or accurate.Everybody with regular eyes can see camera flashes but how fast is too fast.Lightning has an after glow but is it same with mini zap.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 21, 2023, 05:48:01 pm
content: It's not that you build up significant static charges suddenly out of blue. Unless you are working with some super-sensitive special RF MOSFETs in production where 0.0000% failure rate must be maintained, you don't need to use actual grounding strap at all. ESD mat grounded through a 1Mohm resistor on your working table is more than enough practice for hobby or professional prototyping and manufacture (most sensitive special circuits or red tape requirements from quality assurance systems aside), because your arms rest on that mat most of the time, and even if you are "ungrounded" for some seconds, no significant charges build up.This is not to say ESD practices are completely useless, not at all. Sane level of ESD protection stops mysterious failures which otherwise take a lot of time and effort to debug as you don't know exactly where the problem is. The same as using those 0.1uF decoupling caps on every power pin of an MCU as the datasheet suggests.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 21, 2023, 06:25:29 pm
content: To my shame I'll admit that I've never really bothered with antistatic precautions. I can only recall (no I'm not senile) one occasion where I zapped a board or a semiconductor with static. A small signal mosfet.Thats once in 50 years of electronics.It was a winter's day in rainy London and I was..... rambling.

author: tooki
author_rank: Super Contributor
timestamp: March 21, 2023, 07:04:18 pm
content: Quote from: pcprogrammer on March 20, 2023, 09:20:15 amThat doesn’t make sense. A sensitive part can’t tell that you’re a hobbyist and become more forgiving. A damaged part is equally damaged whether you’re a company or hobbyist. Just because you’re your own customer doesn’t mean you’re any happier about a failed or compromised part.

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 22, 2023, 06:11:59 am
content: Quote from: tooki on March 21, 2023, 07:04:18 pmI meant that money wise. I don't care if a 2$ proto board gets damaged due to ESD. Sure it can be a pain in the ass to figure out why it is not working properly, but just like Terry Bites, in the ~40 years of playing and working with electronics, I can't recall something failing on me due to ESD. Latest bigger thing I build, also containing mosfets, is working fine, day in and day out for >4 years. Only thing that died in it was an old PC power supply. ESD, I doubt it. Old age more likely, being from a system from <1996.

author: tooki
author_rank: Super Contributor
timestamp: March 22, 2023, 07:10:54 am
content: Quote from: pcprogrammer on March 22, 2023, 06:11:59 amThere’s a great saying that you should value your time off at twice the hourly rate of your wages.Quote from: pcprogrammer on March 22, 2023, 06:11:59 amThat you know of.“I don’t recall having caused ESD damage” ≠ “there was no ESD damage”.It’s literally the point of ESD precautions: because a) it’s usually too small to be detected by human senses, and b) the effects may not manifest until much later, it’s essentially impossible to associate a failure to a specific ESD event, so the only protection is to take proper precautions.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 22, 2023, 07:59:03 am
content: Quote from: pcprogrammer on March 22, 2023, 06:11:59 amThat time could be spent so much better. The issue with ESD damage is this: it comes in totally unexpected ways. It's not that your $10 devboard just dies and you get a new one. Instead, for example, a microcontroller might work perfectly for a week, and out of blue some ADC reference voltage or brown-out detector limit shifts by 0.5V and now you are getting spurious resets in interaction of your code. Then you can waste days wondering what's wrong with your code, and as a beginner, you haven't figured out effective ways of doing that (say, revision control system + binary search of changes).This randomness of problems is why you can see people make comments like this: "I can't recall something failing on me due to ESD". This is logically obvious, because knowing something faileddue to ESDrequires sophisticated lab with equipment like electron microscope. Not going to happen anywhere else except component manufacturers if you are buying in millions and have problems and get the manufacturer to investigate. Instead, we all have random problems that remain mystery.For same reason, avoid counterfeit eBay/Aliexpress components, try to follow datasheet advice on bypass caps etc. These are surprising time wasters, and as a beginner, mistakes where you can see the cause and effect are good for learning, but totally random-looking problems are not.The silver lining is, decent level of ESD protection can be had easily. Grounded ESD mat is excellent, but if you can't afford it (~$20), just remove that fluffy carpet from your lab floor and make it a habit to touch some grounded metal (e.g., oscillosscope BNC posts) when you sit down to work, and every now and then.

author: m k
author_rank: Super Contributor
timestamp: March 22, 2023, 10:46:14 am
content: One may wonder what kind of a time periods are those every now and then, forget it, you will know.In my case it's something where last touch is longer than just a moment ago.It's also automatic, movement stops and you feel a need to touch the frame.You know you are there when your movement stops before picking something secondary, like a resistor maybe or a heat sink.I remember feeling uncomfortable if my wrist wrap was not connected to storage frame before taking something out, be that a sticker or a screw, in a pink bag of course.Some other habits are also still present.I'm grabbing computer add-on cards from the back plate and put them component side down.New people will also look a bit differently when I first grab their wrist and only after that the module they are carrying.Or tell them to put it down on those papers component side down and then lift it from diagonal corners with finger tips, after slapping some assumed ground potential.Living in a schuko world has at least one positive aspect, naked ground connections.

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: March 22, 2023, 12:18:09 pm
content: Quote from: tooki on March 22, 2023, 07:10:54 amSo if no one can be sure an ESD related failure occurred how do we know precautions must be taken. I run into a similar situation with industrial power systems and harmonics mitigation. No where in the history of earth or electricity can anyone point to a device failure as being caused by harmonics. Yet I need to install $1M in filtering equipment to reduce harmonics below an arbitrarily decided limit set by IEEE who in there own standards never claim that a failure will occur or provide any evidence of one, but use words like 'may affect' equipment. It's all about risk tolerance.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 22, 2023, 12:35:59 pm
content: Quote from: Ground_Loop on March 22, 2023, 12:18:09 pmhttps://www.bondline.co.uk/esd-training

author: tooki
author_rank: Super Contributor
timestamp: March 22, 2023, 03:55:33 pm
content: Quote from: Ground_Loop on March 22, 2023, 12:18:09 pmWell, you and I can’t be sure of a particular incident or failure. Semiconductor manufacturers certainly can, since they have scanning electron microscopes and proper decapping facilities and whatever else is needed to actually find ESD damage. You can see examples in the links I provided earlier.The problem is that individual people don’t make the association becausethey did not sense any discharge at any point. That doesn’t mean the discharge didn’t happen.The point is, basic ESD protection is easy to do, so there’s really no excuse not to.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 22, 2023, 06:47:34 pm
content: Quote from: Ground_Loop on March 22, 2023, 12:18:09 pmWhat a ridiculous strawman argument. Of course some people know - manufacturers and scientists who have researched ESD. This does not mean a beginner should be wasting decades of their time and tens of millions of USD in budget to replicate research in ESD. Instead, they should be spending single-digit dollars andminutesof their time by implementing known-good practices which are result of the research done by others. This is how we collaborate as a species; that's how we can have all the nice things (such as opportunity to create interesting hobby devices with least amount of distractions).

author: SoulReaver009
author_rank: Newbie
timestamp: March 27, 2023, 05:32:47 pm
content: Thank youi so much for the warning about messing with the sockets. i saw some youtube videos and did something stupid, luckily nothing happened, but i will avoid any high voltage/amp in the future. low voltage/amp is the same the experience, without the dire consequences. i will stick to that until i have more experience/knowledge.

author: SoulReaver009
author_rank: Newbie
timestamp: March 27, 2023, 05:37:15 pm
content: My brother, mentioned that i could take a copper wire and wrap it around my coax cable. We have a coax cable feed into my room that plugs into our main Ethernet/wifi router/station.Here is a pic of what i did. will this ground me?The alligator clip is going to my ESD anti-static wrist strap. I tried to measure continuity from the copper wire to the metal piece which contacts my skin, but there was no continuity measured from my DMM. Weirdly enough, there was no continuity from the alligator clip to the metal contact either. So i guess that is normal. My Ohm resistance measured 0.994 MegaOhms from the copper wire to the metal skin contact plate on my ESD strap.Thank you for reading and thank you all for replying. I'm very cautious. Probably overly cautious, but good habits are developed early. So I'm trying to adopt these habits now.

author: helius
author_rank: Super Contributor
timestamp: March 27, 2023, 05:50:23 pm
content: I will go out on a limb and suggest that, if you live in a developed country, you should be able to have a reliable earth connection in your lab without too much trouble or expense. If your building was wired more than 80 years ago with cap-and-tube wiring, and therefore has no protective earth wiring to the power point, you could consider upgrading it for fire safety reasons as well as the availability of ESD grounding.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 27, 2023, 07:36:14 pm
content: Bear in mind, the important thing with ESD is not that everything "is grounded". What's important is that everything - you, the bench, the packaging for your components and so on - are all at the *same* potential as each other.You could have a perfectly functional ESD lab in which the flooring, bench mats, wrist straps etc were all connected to each other, but not to any point arbitrarily labelled "earth", or to any other point.

author: SoulReaver009
author_rank: Newbie
timestamp: March 27, 2023, 09:03:44 pm
content: I dont know what that means lol. im really new to this. I live in CA, dont know how old my house is, but we have 3 prong sockets (hot, neutral, and ground). How do i get a reliable earth connection? and how do i ground myself with that?i talked to my brother about a ground plug, that plugs into a socket. He said not to trust one of those (100%) as the ground in those is very close to the hot and neutral, and any imperfections in the wire could result in dire consequences. I am in the process of making a ground spike, and tying it into my room, but I probably wont be able to do that until a few weeks. So, I am looking for a method to ground myself in the mean time.

author: SoulReaver009
author_rank: Newbie
timestamp: March 27, 2023, 09:06:25 pm
content: How would i accomplish this? I hear a lot of people say that and i have no clue what it means. I havent been experimenting with anything or my kits, yet, as i still dont even know how to ground myself and my stuff properly.I am getting a rework station tomorrow. Other users have suggested alligator clipping everything to the station (my ESD strap, my mat, and such). Will this work?

author: SoulReaver009
author_rank: Newbie
timestamp: March 27, 2023, 09:10:30 pm
content: I am trying to read all the posts, but some of them use terms I do not know. Or give advice that requires other prior knowledge (which i am lacking in lol). I am watching yt videos on this, and trying to research terms and electrical processes. I just watched 2 15m videos the other day tha explained how hot, neutral, and ground gets wired through your house, as well as how the current flows through your house. and the difference between AC/DC. Very informative, but I am still not sure how to simply ground myself in my carpeted room. lol

author: Shock
author_rank: Super Contributor
timestamp: March 29, 2023, 08:51:56 am
content: Quote from: SoulReaver009 on March 27, 2023, 09:10:30 pmESD wrist strap connected to a bond plug, then that gets plugged into the mains outlet.It will connect the ESD strap to the earth/ground wiring of your house mains. If you are unsure you can purchase an outlet tester. If any of this is unclear ask an adult or get an electrician in.Don't mess around making another grounding rod, you have no idea what you are doing. Many households now have earth leakage detection and you can circumvent this and also put yourself at additional risk..

author: m k
author_rank: Super Contributor
timestamp: March 29, 2023, 10:47:32 am
content: Quote from: AndyC_772 on March 27, 2023, 07:36:14 pmYes but I would be uncomfortable.Dry room with floor heating and 0-class round two prong wall sockets.Forget the neutral, it's there but forget it.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 29, 2023, 03:15:11 pm
content: Quote from: SoulReaver009 on March 27, 2023, 09:03:44 pmEasy - just connect your ESD mat to the protective earth - what you call Ground. Through a 1 Mohm (megaohm) resistor to prevent things you are working with from short-circuiting through the straps/mats etc.Before someone chimes in to say it's dangerous, remember that metal-cased appliances all connect their exposed parts directly to this "ground". It's the whole point of safety earthing. So doing this is perfectly normal, and safe.Now where I live (Schuko sockets,https://cdn.productimages.abb.com/9IBA202718_720x540.jpg) we have this earth connection directly accessible, making it easy to just put a crocodile clip there, but I realize in the US 3-prong socket the ground is actually a hole, so you need to plug something into that hole, basically get a plug for the job. Needless to say, this must go 100% absolutely correct so that you don't accidentally plug the ESD mat into line or neutral, which are considered live.Note that an oscillosscope for example has its BNC posts already grounded through that 3rd prong, so you can always just touch those posts to ground yourself. As oscillosscopes usually come with a separate earthing post on the front (next to the compensation signal generator metal thing), it would be trivial to connect your ESD mat there. Problem solved.

author: Jester
author_rank: Frequent Contributor
timestamp: March 29, 2023, 10:15:08 pm
content: Just for giggles, you could try what worked for "Ben"https://www.history.com/this-day-in-history/franklin-flies-kite-during-thunderstorm

author: agehall
author_rank: Frequent Contributor
timestamp: March 30, 2023, 04:49:33 am
content: For hobbyist, I’d say it is much more important to do the basics to not become statically charged than to try to dissipate charge with ESD equipment. (Sure, an ESD mat is always nice though).I have hardwood floor in my office and rarely wear socks or anything else on my feet when working with electronics. I also avoid all kinds of fleece etc that generate static electricity.For hobbyist work, this will be enough 99% of the time. Doesn’t cut it for a professional environment though.

author: tooki
author_rank: Super Contributor
timestamp: March 30, 2023, 06:55:41 am
content: Quote from: agehall on March 30, 2023, 04:49:33 amI very much disagree. The problem with ESD is that you can’t feel it. So you don’t know whether your measures have actually succeeded in reducing ESD risk. (By the time a static discharge becomes something we can detect with our body, we arefarbeyond the charges needed to damage parts.)And as I said above:Quote from: tooki on March 21, 2023, 07:04:18 pmIf basic ESD measures were super expensive, I’d understand not doing them as a hobbyist. But given how cheap an ESD mat is, I just don’t see why youwouldn’tdo it. And it protects your bench, too.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 30, 2023, 07:07:04 am
content: Quote from: m k on March 29, 2023, 10:47:32 amWhy?Uncomfortable about some residual risk to the equipment? Or to yourself?Bear in mind that the thing an ESD event and an electric shock have in common is that they require current to flow between two points that are at a different potential.If everything is connected together, and therefore at the same potential, no current flows when they come into contact.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 30, 2023, 07:15:51 am
content: Quote from: Arslan John on March 30, 2023, 07:01:17 amSorry, no, this is a poor quality resource riddled with errors and bad advice.For example:QuoteNo, it shouldn't. The gate is insulated from the channel, no current flows, and a multimeter in diode mode will show 'O/C' or a similar indication - not 0V.If the meter reads zero voltage, then the gate is shorted to the source which is a common failure mode in MOSFETs that have been damaged.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 30, 2023, 07:44:30 am
content: You clicked a random spambot's link (they got what they wanted) and are now replying to the spambot.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 30, 2023, 08:13:07 am
content: Yes, but my comment is primarily for the benefit of anyotherpeople reading who may not realise that the content of that site is poor.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 30, 2023, 08:13:42 am
content: Expect the message to disappear as soon as moderators wake up. (edit: I have obviously already reported it.)

author: tggzzz
author_rank: Super Contributor
timestamp: March 30, 2023, 08:17:47 am
content: Quote from: Siwastaja on March 30, 2023, 07:44:30 amThe website is ChatGPT output. Seehttps://www.eevblog.com/forum/testgear/bench-multimeter-for-someone-learning/msg4786409/#msg4786409Report Arslan John to moderator!

author: paulca
author_rank: Super Contributor
timestamp: March 30, 2023, 09:47:20 am
content: Beginner to beginner.Low voltage breadboards. Safest bet if you don't yet have an actual current limited PSU is to use 9V batteries and buy yourself some linear LM78* regulators for your breadboards. This should prevent "finger burns" and keep some magic smoke in the parts.Grounds:When anything at all goes wrong with your circuit, especially if it's "weird" and unexpected. Check ALL grounds first. Ground, 0V, -, whatever your particular learning material or PSU/battery calls it. The "common" thing (other than the + voltage) that all connects everything together. It is usually the most critical part of the circuit that all of those remain connected and uninterrupted. Any of them coming adrift will usually case the circuit to behave badly until fixed.Beyond that. If you are referring to "ground" in terms of the protective earthing in your house, or the mains ground. STAY WELL AWAY. Stay on the save end of a galvanically separated low voltage DC power supply.The only exception would be the use of an anti-static braclet or mat connected to a plug earth.The theory of "grounding" and "earthing" will follow you throughout your electrics and electronics learnings and dabblings throughout your life. It always gets more complicated. No matter how deep you dig into that rabbit hole it keeps opening new chambers.You will encounter a few in beginner experiments. Pay attention to them and ponder about them a good while. Experiments involving "floating" gates on transistors etc. It's worth pondering what is actually happening there. Especially as you are studying physics. If/when you do those experiements, go and read your physics chapters on Maxwell. It will open your eyes to what electricity is.

author: tggzzz
author_rank: Super Contributor
timestamp: March 30, 2023, 10:10:06 am
content: Quote from: paulca on March 30, 2023, 09:47:20 amPrecisely"Ground" and "earth" are fictions that have some use in some circumstances.Many parts of electrical wiring and installation codes appearon the surfaceto be weird and unnecessarily proscriptive/restrictive. They are there because of edge cases, unwarranted presumptions, lack of understanding, and the imperfections found out there in the wild. Ignore the codes at your peril (I don't care) and other people's peril (I do care).

author: paulca
author_rank: Super Contributor
timestamp: March 30, 2023, 10:44:13 am
content: As a beginner."The only exception would be the use of an anti-static braclet or mat connected to a plug earth."Even this needs understanding. There are many circumstances when you absolutely do NOT want to be grounded!As already warned, avoid "mains" anyway, but ifyouare grounded and a mains ground go away, YOU can technically become the ground. Needless to say that is somewhat non-ideal.>3V don't stick it up your ***>10V don't stick it in your mouth.>30V don't touch it with wet hands>50V don't touch it.>100V don't do it.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 30, 2023, 11:24:38 am
content: This is one reason why ESD wrist straps contain a 1MOhm resistor. The idea of grounding the operator is to allow static charges not to build up over time, and since triboelectric charging results in a high voltage on a small capacitance, even this resistor doesn't stop the charge from leaking away harmlessly.The resistor does, however, prevent a hazardous current flowing from energised equipment (say, at 240V) up one arm, through the chest, down the other, and to earth via the wrist strap.Tip: despite this, it's still standard practice NOT to wear an ESD wrist strap when working on live equipment.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 30, 2023, 11:36:10 am
content: There are zero circumstances where you would not want to connect the ESD mat into the protective earth of the building, if that is available in the plugs of the same room. It is always the right thing to do, and all 3-prong appliances do that, expose this safety earth directly accessible to user's touch (not through any resistors). If you fear touching the ESD mat, then you can't use any metal cased 3-prong appliances, they are all dangerous.1-Mohm resistor is not for safety, debugging live mains-powered things requires completely different approaches and would not recommend doing that at all. Although if everything else fails and you are doing things you definitely should not be doing, that 1Mohm resistor can then work as a final safety layer it's not intended to be. As long as you don't touch the radiator, toaster etc. which stillexposethatscary mains thing(protective earth), without any 1Mohm resistors.Theory of "grounding" is simple in this case: the protective earth happens to be the connection which carries most parasitic paths to all sorts of building materials around the house. Thus by connecting to it, you have best chances of equaling charges and prevent ESD zaps.

author: m k
author_rank: Super Contributor
timestamp: March 30, 2023, 11:59:25 am
content: One misguiding thing is to think that connected things are a single point.Quote from: AndyC_772 on March 30, 2023, 07:07:04 amTo the equipment.Something like that there is still something that is far from something else.It's also psychological.Feeling that high is bad and low is good.I also know that low can still move a limb, especially if other end is a transformer and behind it is a can size elco, but that is different.

author: m k
author_rank: Super Contributor
timestamp: March 30, 2023, 12:05:31 pm
content: Quote from: tooki on March 30, 2023, 06:55:41 amLifting an empty styrox coffee cup from the table can be it, if moon phase is right and great maker approves.

author: paulca
author_rank: Super Contributor
timestamp: March 30, 2023, 12:21:19 pm
content: HVDC shocks are not fun or funny. AC Mains shocks are even less funny.I have had both. DC throws, AC sucks is at least partly true.My DC shock (at 13yo.) resulted from trying to find out what is under the sucker on the back of a 14" CRT monitor, 2 minutes after it had been disconnected from the mains. For me it was instant, but I am not sure if it was or not. I felt the thump of the wall and then I was wondering why I was shaking like a leaf and too weak to move much. I lay in shock for a good few minutes, but the feeling of panic subsided as my muscle control came back.I've had a multitude of minor encounters with mains. Getting zapped by cheap DC adapters after you unplug them because they don't have a decent snubber. That produces an "Awwooo!! DAMN!" response.Finding the one weakness in a UK mains plug was my more series mains shock. I grabbed a plug to pull it from the wall. My thumb on the top of the plug and fingers on the other corner. The back popped off the plug and my thumb found the Earth pin and my fingers the Live pin. That HURT. Worse I was parallized. I couldn't move. I believe I was trying to cry out in pain, but just making a horrible gurgling mumbling sound. As panic set in I realised I still had some control over my legs and so I let my knees go and fell to the ground, pulling my hand clear of the plug. Not even a burn mark, but I shook for hours afterwards.Either of both of those events would be considered "automatic fatality" in safety literature. I am a very lucky boy.

author: tggzzz
author_rank: Super Contributor
timestamp: March 30, 2023, 12:57:23 pm
content: Quote from: m k on March 30, 2023, 11:59:25 amI've been trying to point that out to someone experiencing noise on a breadboarded circuit. While they seem to have some knowledge of electronics and components, I don't think the point has sunk in.Oh well.

author: tggzzz
author_rank: Super Contributor
timestamp: March 30, 2023, 01:00:48 pm
content: Quote from: paulca on March 30, 2023, 12:21:19 pmI lightly brushed the finger on one hand against a live thyristor can and a finger on the other against neutral. Both biceps contracted very fast, breaking contact.Another lucky person.