EEVblog #768 – Cordless Anti-Static Wristbands BUSTED!


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
Forum HERE

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    • Zsola

      I can see one reason for this: when you want to zero, you can easily touch that screw to the post terminal (what is a larger metal sheet) and carry on. When you not move, maybe the charge not builds up so quickly. Btw, you not need the resistor for that.
      One more: they maybe ran out of springy wire, and tought they can sell the rest for good.
      “Cordless” – means it haven’t got a wire, but not necessary a working one.

    • Tyler Durden

      In the name of the community I wan’t to thank you, that you refrained from taking of the jumper and underware – even if it meant less accurate results. 😉

    • Paul

      While we are discussing crap, can I sell you some of my gold plated jack plugs ad sockets.

    • Peter O’Neill

      Had a quick look on Ebay for these and found some that had more “information” apparently these work best if you wear them for 5-15 minutes before you work on static sensitive equipment, by that time any charge would have dissipated anyway if you hadn’t moved.
      — Dave, you have a FAIL button, how about an analogue BULLSHIT meter that goes to 110%.

    • I took a tour of a local electronics factory here in the US, they had something that wasn’t entirely wireless, but somewhat clever that didn’t need a strap to the bench. Their floors were all anti-static grounded mats, and they had shoes that were connected down to them so they would just run the cable from their wrist strap to their shoes.

      • random blogger

        no-one thought to use an ankle strap?

        • I think they may have been using both, but it has been about 10-12 years since I visited the place.

    • Clyde R. Visser

      Back in the day, in my photog days, we used anti static brushes on the negatives before creating a print. Those brushes used a small piece of radioactive material to prevent static build-up. I’m curious, do you get a hit using a GM counter on the strap? Just a (very scary) thought.

    • TiN

      🙂 Busted.
      P.S. Is it just me, or actually sound is little bit out of sync on video?

    • Wireless, to them, must mean “wire not included”.
      The fact that the resistor was not attached to the screw is an entirely different QC issue. 🙂

    • tlhIngan

      I wonder if these were originally for those factory workers who have to convey static-sensitive material between stations – because not all of it fits on the conveyor belt. There’s always someone with a cart holding the components or finished boards,and it’s really meant more for them to tap their “wrist strap” on while carrying the stuff around. The resistor is there because it’s easier to find a ground point than it is a proper grounding point. Heck, I remember those grounding touch pads you were supposed to touch before sitting down and working.

      Of course, from there, we go from something a few people needed to “let’s sell these things as cordless! Those people moving the carts aren’t plugged into anything…”.

    • Antistatic bands are supposed to keep you and the electronic objects around you at the same level so you don’t transfer electrons when you touch them. Even if a band could adjust your electrical potential, how would it know which direction and how much to adjust? There is no real alternative to a grounding cord.

    • Torben Rune

      In theory, one could make a “wireless” discharge unit, that may work. On modern airplanes they use static dischargers known as static wicks or static discharge wicks (see: https://en.wikipedia.org/wiki/Static_discharger ).
      These wicks are corona discharge pins, designed to have a lower discharge voltage than the rest of the airplane, hence all discharge goes through the pins – not over the fuselage.

      Discharging into air will happen when the electrical field strength exceeds approx. 3 MV/m. So if the corona pin is pointy enough, in theory one could make a wearable corona discharge pin to fire at say 50 Volt. (May require special materials that do not burn their tip off with the discharge).

      I have no idea if this is possible in a real working environment, but theoretically at least – it would work.

      BTW – I really enjoy watching Dave’s videos and the blog. Great fun for an old E Engineer.

    • John Whitmore

      I like the barefoot idea …not. It requires housekeeping, a skill I lack, But some conductive booties and an ankle strap would work fine, in combination with a hospital-grade grounding mat on the floor. My problem with wrist tethers is all the workbench clutter … did I mention I lack housekeeping skills?

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