Author Topic: EEVblog #768 - Cordless Anti-Static Wristbands BUSTED! (Read 50349 times)

EEVblog · « **on:** July 17, 2015, 03:18:28 am »

Dave debunks cordless anti-static wristbands you can buy on ebay for $1. Do they do anything at all?
Controlled quantitative static voltage measurements with a surface DC voltmeter are done to prove they are 100% bullshit!
And a direct comparison with a proper anti-static wrist strap and bonding point is included.
And a bonus tutorial on how to calibrate a surface DC voltmeter.
Dave's 555 Timer T-Shirt is here: http://teespring.com/555timer-grey3

pickle9000 · « **Reply #1 on:** July 17, 2015, 03:46:29 am »

Upside down dips are no problem, TO-3's really hurt. Won't stop me going barefooted though.

poot36 · « **Reply #2 on:** July 17, 2015, 03:58:18 am »

I have socks on carpet in my room when I work on electronics. Could you test the foot rub test with socks as well to see what voltages you get?

scopeman · « **Reply #3 on:** July 17, 2015, 04:26:36 am »

Dave,

It looks like if you could find a spare cord somewhere your dollar is not a total loss as you could make a real ESD strap from it!

Sam
W3OHM

station240 · « **Reply #4 on:** July 17, 2015, 04:44:46 am »

Wow, 0.2 cent resistor inside an average build quality wrist strap, just $1 bargain.

Wonder if the seller is the con, or someone in the west ordered 10,000 of this made, then vanished when it was time to pay up.

timelessbeing · « **Reply #5 on:** July 17, 2015, 04:58:00 am »

I'm disappointed at the lack of "Fail" button use.

EEVblog · « **Reply #6 on:** July 17, 2015, 05:10:56 am »

Quote from: timelessbeing on July 17, 2015, 04:58:00 am

I'm disappointed at the lack of "Fail" button use.

Completely forgot that!

EEVblog · « **Reply #7 on:** July 17, 2015, 05:11:42 am »

Quote from: scopeman on July 17, 2015, 04:26:36 am

It looks like if you could find a spare cord somewhere your dollar is not a total loss as you could make a real ESD strap from it!

It's a horrible design, wouldn't even trust it for that.

sleemanj · « **Reply #8 on:** July 17, 2015, 05:40:33 am »

A nice simple test setup.

Only thing I would have suggested to really ram it home what this is about, is charging yourself up separately from the plate, then touching the plate to simulate an actual ESD event.

And zapping yourself in the process.

NF6X · « **Reply #9 on:** July 17, 2015, 05:58:44 am »

Thanks for making this video! I've been looking forward to it since you first mentioned your intent to make one.

What I don't get is why they even bothered to include a real resistor inside.

barnacle2k · « **Reply #10 on:** July 17, 2015, 06:00:29 am »

I can see one possible use case for this thing:

When walking around the office (pvc floor) in the winter (very dry air) one can built up a quite a lot of charge.
So much in fact that it is rather painful to touch any earthed object. (big metal objects are also an option even when not earthed)
In that case one could touch the screw on that strap to the nearest earthed object for a non-painful discharge.

pickle9000 · « **Reply #11 on:** July 17, 2015, 06:06:34 am »

Quote from: barnacle2k on July 17, 2015, 06:00:29 am

I can see one possible use case for this thing:

When walking around the office (pvc floor) in the winter (very dry air) one can built up a quite a lot of charge.
So much in fact that it is rather painful to touch any earthed object. (big metal objects are also an option even when not earthed)
In that case one could touch the screw on that strap to the nearest earthed object for a non-painful discharge.

I wind a resistor on my keychain.

dadler · « **Reply #12 on:** July 17, 2015, 06:29:15 am »

Maybe cordless means "supply your own cord"? Lost in translation?

Else, why even bother with the 1meg resistor? Save production costs and leave it out...

AlfBaz · « **Reply #13 on:** July 17, 2015, 06:34:15 am »

What was the thinking behind presuming this would ever work... anodic protection?

pickle9000 · « **Reply #14 on:** July 17, 2015, 06:37:22 am »

Quote from: AlfBaz on July 17, 2015, 06:34:15 am

What was the thinking behind presuming this would ever work... anodic protection?

I'm pretty sure it's hamster related.

rs20 · « **Reply #15 on:** July 17, 2015, 06:46:12 am »

Quote from: AlfBaz on July 17, 2015, 06:34:15 am

What was the thinking behind presuming this would ever work... anodic protection?

The box says it's an antistatic wriststrap, so it must be?

Some of the wireless wrist straps contain lots of very fine hairs of wire which kinda hypothetically work via corona discharge (I'm sure they don't at only 1kV, and the idea that the air itself is neutral/"earthed" is fishy as well). Not saying that this works, indeed I'm quite certain that it doesn't; but what Dave has is arguably a scam copy of a scam, not just a scam. Obviously the 1megaohm resistor is just pointless in any case.

TheSteve · « **Reply #16 on:** July 17, 2015, 07:34:24 am »

Quote from: barnacle2k on July 17, 2015, 06:00:29 am

I can see one possible use case for this thing:

When walking around the office (pvc floor) in the winter (very dry air) one can built up a quite a lot of charge.
So much in fact that it is rather painful to touch any earthed object. (big metal objects are also an option even when not earthed)
In that case one could touch the screw on that strap to the nearest earthed object for a non-painful discharge.

I would assume that is pretty much what it was really designed for. Or perhaps they intend you to touch a grounded object with it each time you sit down at the with bench. Maybe they think that will be good enough ESD protection until you get up and walk again. Either way clearly no replacement for a real ESD strap.

daqq · « **Reply #17 on:** July 17, 2015, 08:25:06 am »

Huh, so it doesn't work? Now there's a shocker!

Thanks for the video Dave! Next up: Directional cables!

McBryce · « **Reply #18 on:** July 17, 2015, 09:07:47 am »

Time for me to start an Indiegogo campaign... Now should my cordless ESD strap use bluetooth or would a Wifi connection discharge quicker?

McBryce.

Ian.M · « **Reply #19 on:** July 17, 2015, 10:45:39 am »

Infrared. See https://www.eevblog.com/forum/projects/static-discharge-using-lasers/

Fungus · « **Reply #20 on:** July 17, 2015, 11:28:59 am »

Quote from: TheSteve on July 17, 2015, 07:34:24 am

I would assume that is pretty much what it was really designed for. Or perhaps they intend you to touch a grounded object with it each time you sit down at the with bench.

Why would you need a wrist strap for that? You can just touch it with your hand.

Much more useful would be an anto-static seat cushion or something like that.

(Maybe sit on a grounded metal spike? I dunno.)

MiataMuc · « **Reply #21 on:** July 17, 2015, 12:24:21 pm »

anti-static car interior would be nice.. hate getting zapped when leaving the car..

vlad777 · « **Reply #22 on:** July 17, 2015, 12:35:00 pm »

You should have grubbed with your foot, WITH the real wrist strap ON just to show no buildup.

coppice · « **Reply #23 on:** July 17, 2015, 01:25:43 pm »

Does anyone make a genuine cordless personal static dissipater? Some type of body worn ioniser, perhaps?

rs20 · « **Reply #24 on:** July 17, 2015, 01:27:47 pm »

Quote from: coppice on July 17, 2015, 01:25:43 pm

Does anyone make a genuine cordless personal static dissipater? Some type of body worn ioniser, perhaps?

Is the atmosphere grounded? (Genuine question)


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Author Topic: EEVblog #768 - Cordless Anti-Static Wristbands BUSTED! (Read 50349 times)

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