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Zapping Things With ESD Ė Just One More Service I Offer

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zeeglen
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Re: Maybe...
zeeglen   8/21/2014 4:34:29 PM
@studleylee I still keep a A/D converter I bought from Analog Devices that cost me $100 in 1984. I zapped it.

An engineering lab actually had a carpeted floor.  Was supposed to be anti-ESD carpet, but the installer got it wrong, and it had to be sprayed weekly with some kind of chemical.  Back then we did not have heel straps or wrist straps.

Anyway, on a cold dry winter day in the Great White North, a colleague had just installed the 1st of 10 samples of his brand new ASIC into the socket.  It was in a ceramic package with a metal top. We fired the board up, then we wondered how warm the ASIC was running.  My friend reached out to feel it - I said "Static!" but it was too late.  We could hear the 'snap' of a strong ESD discharge.

He said "It's not very hot."  Then a few seconds later "But it sure is getting hot now!"

One down, nine to go.

studleylee
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Re: Maybe...
studleylee   8/21/2014 4:13:53 PM
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You just put it into a known state.....

I still keep a A/D converter I bought from Analog Devices that cost me $100 in 1984. I zapped it. Now it's a reminder. -Lee

JLBrake
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Rookie
Re: Laptop grounded?
JLBrake   8/21/2014 3:44:31 PM
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There's lots of stuff going here, but let me try to clarify some things.

 When working on the something like a laptop, there are really two options of grounding for ESD purposes.  

1.  Ground all conductors and dissipative materials (people, product, worksurface, etc) through an electrical ground (third wire).  This is the preferred method for electronics manufactures because the electrical ground is where other equipment (soldering iron, scopes, etc) used in the production environment if grounded, but not always available in "field" applications. 

2. If grounding to the electrical ground is not possible, you can use equipotential bonding. Equipotential bonding connects all conductors and dissipative materials in the environment together.  If you are working on something such as a laptop, you would use an alligator clip to connect the wrist strap to the housing of the laptop. 

Both methods essentially do the same thing in creating an equipotential balance between all items and personnel.  ESD events can only occur when there is a difference in the potential. Note that only conductors and dissipative materials can be grounded, insulators require ionization to control ESD. 

Based on this post we are going to make some samples of a USB to banana jack adaptor to see how this would work.  The adaptor will allow a standard wrist strap to be connected to the USB.

Max The Magnificent
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Re: Maybe...
Max The Magnificent   8/21/2014 9:58:32 AM
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@MeasurementBlues: A man without two cities.

But you'll always have the memory of bagels to see you through the hard times...

William.Biehler_0623
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Rookie
Re: Laptop grounded?
William.Biehler_0623   8/20/2014 7:22:41 PM
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There are several kits for grounding to an outlet strip. One can be found at the site below.

http://www.stanleysupplyservices.com/static-solutions-sp-101-receptacle-ground-tester-with-wrist-strap-plug/p/479-077

And there are portable mats etc. at the site.

http://www.stanleysupplyservices.com/search.aspx?f=1%3a983


I have some of these in my field service kit along with travel adapters for the different power connectors in countries I travel to.

There are probably several other ways to get ESD safety, but the outlet adapter seems to work for me.

Measurement.Blues
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CEO
Re: Maybe...
Measurement.Blues   8/20/2014 8:32:53 AM
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All this talk of accents.

I was born in Brooklyn but moved to New England (north of Boston) at age 13. Some people in New England say I still sounds like a NYer, but those in NY say I sound like I'm from New England.

A man without two cities.

antedeluvian
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Re: Maybe...
antedeluvian   8/18/2014 11:32:25 AM
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Max

 to me it always sounds a bit like they are singing (plus they have a great sense of humor).

 

Well here they actually are singing. Now I am going to have Lindisfarne's "Fog On The Tyne" as an ear-worm for the rest of the day.

Max The Magnificent
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Re: Maybe...
Max The Magnificent   8/18/2014 10:20:20 AM
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@Antedeluvian: A light Irish lilt begorrah, or even Welsh, look you.

Have you ever heard a "Geordie" accent from the Tyneside area of England -- pretty close to the boarder between England and Scotland in the scheme of things -- I love that accent -- to me it always sounds a bit like they are singing (plus they have a great sense of humor).

Max The Magnificent
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Re: Laptop grounded?
Max The Magnificent   8/18/2014 9:30:39 AM
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@Reinhardt: Your idea sounds good a first look, but are you sure our laptop is really grounded? Many laptop PSUs I have seen have only a two pin power plug, no protective earth pin.

If you read the comments below starting from the beginning, you'll see that my suggestion "crashed and burned" for thsi very reason -- it would work with a tower computer with a 3-pin plug and a grounded power supply, but that's not what I've got.

However someone offered a really good solution -- use a power strip with some banana plug to ground adapters, then oplug the banana plugs on the strap & mat inrto ths strip.

Max The Magnificent
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Blogger
Re: What everyone's waiting for
Max The Magnificent   8/18/2014 9:27:52 AM
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@zeeglen: I still think ESD safety needs wires, seaEE was making a joke.

Let's hope he doesn't give up his day job LOL

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