protection antiestic doubt

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micksmelanie

Joined Jun 27, 2020
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I am uncomfortable with wearing an antistatic wristband with a ground wire. Is there another good alternative protection option? I saw this cordless bracelet

 

SamR

Joined Mar 19, 2019
2,574
The "old school" method I have used for years is to grab a grounded chassis/etc. first to drain any charge on the body. Hasn't failed me yet, knock on wood (which won't ground you).
 

Tonyr1084

Joined Sep 24, 2015
5,060
The only way to diminish electrostatic buildup is for the user to sit on a steel bench bare butt with the bench tied to ground. And a lot of humidity. But that isn't good for soldering.

You can use ionized air blowers that blow a cloud of ionized air over the work and the work surface. But it's not as effective as a properly grounded wrist strap and grounding mat. Cordless is another word for making you "Cashless".

there is no grounding everywhere
Places that build electronic devices such as military electronics have grounded flooring. An employee is required to wear a static guarding smock that has conductive threads to distribute static charge over the person's body. ESD (Electro Static Discharge) safe shoes are conductive to the flooring with a high resistance. Off hand I couldn't tell you what that resistance is but it's up there. As a person walks they generate static. The flooring and the conductive footwear (or heel straps) conduct static buildup to ground. However, even wearing such footwear and having a conductive floor - the assembler is still required to wear their wrist strap when working. The wrist strap (with cord) is the #1 way to discharge static charge.

Even if you're not touching a static sensitive device, just getting close to it when you're charged can be dangerous. An employee wheeling a static grounded cart past a satellite, within 3 feet, caused a circuit to blow out because the static chain that drags on the floor had become dirty and/or corroded and could not conduct static to ground. The satellite had to be repaired. And the employee never came in contact with the satellite. Electronics in sat's can be static sensitive to charges as low as 50 volts. That's why everyone's wearing those bunny suits and wrist straps as well as conductive flooring and footwear.

I WISH there were a wrist band I could wear, but no such device can work. Even if the band is meant to ionize your body, the charge still has to GO somewhere. Through your project or work piece is the first most likely place for it to go. With damaging effects. Even if your device still works after being exposed to static, it's been damaged. It's like a six lane highway and a portion of the roadway falls away, limiting the traffic to just five lanes. Everything slows down. And in electronics - slowing electrons down causes heat. Which will further weaken your project. Just when you need it most - it can fail.
 

Tonyr1084

Joined Sep 24, 2015
5,060
Gloves are mostly intended to guard against contamination from things like finger oils and other potential contamination. That they're conductive (I've not heard of conductive gloves) offers very little value. More of the user believing they're doing more to guard against ESD. But a conductive glove is going to be just as conductive as human flesh.

Anti static - just means it's not a producer of static. Pink Polly has been long used as an anti static package, whether it's a bag or foam pad. However, it is not static shielding. ESD can penetrate Pink Polly just as easy as it penetrates any other plastic. Velostatic bags are plastic bags with a conductive coating over the entire surface and they create a Faraday Cage (FC). An FC conducts static AROUND the item inside and prevents static from reaching the contents. FC's are not just bags, they can be actual cages. Worked one job where they built a test stand inside a FC enclosure. It was to block out all stray radio signals. It worked.

Again, the best defense against static is to be grounded. That way any charge that develops on your clothing and body - the charges are dissipated to ground via a 1 meg ohm resistor. Or maybe it's now a 10 meg ohm. The reason for the high resistance is to protect the wearer from potential harm from contacting live power and conducting it through their body to ground. An inspection lamp (ring lamp with magnifier) would make the ESD monitor squeal like heck every time I put my hand on it to adjust it. Notified maintenance and they checked and repaired the ground on the lamp. Not once did I get a shock. Not one that I could ever have noticed. That's the purpose of the high resistance. As far as static is concerned, it will dissipate more quickly than passing through the work piece. But never make your own grounding system without the proper protection. If you simply wrapped a copper wire around your wrist and connected it to ground, then touched that inspection lamp - who knows how much of a shock you might have received.
 

crutschow

Joined Mar 14, 2008
25,416
The only way to get rid of a static charge is by transferring it to ground potential (or the potential of bench you are working on) through a conductor.
It's simple physics.
It a charge doesn't have a conductive path then it can't go anywhere.
This rules out "conductive gloves" , a wireless wristband, or any other scam device you can find you can find that doesn't have a conductor to ground.
 

AnalogKid

Joined Aug 1, 2013
8,590
something that doesn't tie me to wires or cables
What are your specific concerns with a grounding strap/wire? Note that many grounding systems have a resistor built into the wrist band between the conductive threads and the connection to the ground wire. This prevents dangerous currents if things are not wired correctly. IIRC it is something like 1 M ohms. That would limit direct contact with 220 VAC to 220 uA - less than 10% of UL1950's safe current level (3.5 mA).

ak
 
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