magic smoke day (week) - Page 1
Forum section: electronics / general

author: charliex
author_rank: Frequent Contributor
timestamp: May 10, 2010, 09:17:58 pm
content: Today's just been one of those days, you know the ones where you take all the precautions and something just doesn't align... the fatal puff of grey smoke and the acrid smell, and bye bye to that $2,000+ 1U server you literally just took out of the boxwhich is meant to be a replacement for the one that died last week..made a decent sized hole in one of the chips though, but these things are 1600W. luckily the semiconductors all protected the fuses just as they're supposed too, so thats nice.Then i changed out a video card in my devbox and pushed the machine backwards slightly since it was a tight fit., which pressed the on/off switch, and of course its set to auto power on... eeep!, more smoke but this time no problems.So i'm spending the day not touching any electronics, except my lapt$%$%op...On an unrelated note, anyone done any studies on ESD and being barefoot ? I've already ditched my "wireless" ESD band as pseudo science, this isn't responsible for what happened, but it made me think about it.

author: Simon
author_rank: Unknown
timestamp: May 10, 2010, 09:35:38 pm
content: wireless ESD band ? you should have a band round you wrist that IS grounded, I normally use a short-cut called keeping the power plug in so that the unit is grounded even with the socket switched off, providing I touch the case frequently which is impossible not to do anyhow it should be ok... nothing blown yet

author: charliex
author_rank: Frequent Contributor
timestamp: May 11, 2010, 03:24:04 am
content: yeah i have a wired one that goes to a pad on the table thats grounded. I had a wireless one that i converted to a wired one..Yes yes i know, but i thought why not give it a go, once i actually looked at it and saw what it was i, i realised yes in some very closed definition of "works" it does, but in no way, shape or form is it going to work well enough to protect an electronics from an ESD. But marketing what it is, you can sell something that just doesn't work and caveat emptor.Funny thing is that lots of electronics shops sell them here.

author: Pyr0Beast
author_rank: Contributor
timestamp: May 11, 2010, 05:29:05 pm
content: Ever thought of that repairing things makes them even more broken ?

author: Polossatik
author_rank: Frequent Contributor
timestamp: May 11, 2010, 09:07:28 pm
content: Quote from: charliex on May 10, 2010, 09:17:58 pmROFL.. a wireless ESD band... como'n Charlie, thankx for making my day

author: Simon
author_rank: Unknown
timestamp: May 11, 2010, 09:11:27 pm
content: and I bet he bought it from maplin

author: charliex
author_rank: Frequent Contributor
timestamp: May 12, 2010, 06:50:41 am
content: No Maplin's hereI didn't actually use it, i just had to look at it to see it was junk. they were out of regular ones so i added a wire to the screw on it and connected it to a pad.. When you work on the road you've got to work with what you can get. Needs must as the devil drives !

author: thedigitalprincess
author_rank: Contributor
timestamp: May 14, 2010, 09:17:36 pm
content: Quote from: polossatik on May 11, 2010, 09:07:28 pmI also had a good LOL at that.

author: charliex
author_rank: Frequent Contributor
timestamp: May 14, 2010, 10:53:07 pm
content: Well i'm glad everyone got a laughbut I do feel sorry for the people actually using the things though. Maybe Dave should do a blog on debunking them as the pseudoscience they are.

author: thedigitalprincess
author_rank: Contributor
timestamp: May 15, 2010, 07:43:06 am
content: Do it Dave!!!I work in an ESD sensitive workshop, so I don't think wireless ESD straps would pass the ESD test that we have to do each day.

author: charliex
author_rank: Frequent Contributor
timestamp: May 18, 2010, 07:03:05 pm
content: I did some reasearch on it after i picked it up, just to see what the claims were. They basically claim its a corona discharge as used in laser printers etc. They do actually "work" in the marketing view, but not enough you'd protect anything. One review i found suggested cutting your hair short and applying conductive gel as an equivalent.me, i think its the corona effect, as in you have to drink enough to believe it works well enough.people are definitely buying them though, i see them go in and out of stock at frys all the time. I just opened it up and added a wire to the screw inside which originally had a 1M ohm resistor connected to atmosphere.

author: Unknown
author_rank: Unknown
timestamp: May 18, 2010, 07:25:49 pm
content: I agree that it's probably crap. A corona discharge will act based on the potential between the conductor and some other point. What is that other point? You need to make sure that your DUT and you are on the same potential, I don't see how this would be accomplished wirelessly, especially without special receiver that you'd clip to the DUT (you can charge a capacitor with an electromagnetic field, so why not discharge one?).It might work at some extremely high voltages by using the air as conductor, but only if there are a reasonable number of objects at ground potential close to you. It might protect you from painful shocks when you touch a doorknob (but so does any metal object like a key), but I wouldn't trust it to be safe for electronics.