that bracelet without the wire has a screw that must touch some metal to dissipate the load is this information false? the bracelet accumulates the load on the body and dissipates when touching the screw on some external metal


On the table or bed that I handle the devices it is far from the grounded socket of my house so the difficulty of using the corded bracelet was why I thought about the cordless bracelet and the antistatic glove

https://www.aliexpress.com/item/327...earchweb0_0,searchweb201602_,searchweb201603_

https://www.aliexpress.com/item/328...earchweb0_0,searchweb201602_,searchweb201603_

 

On the table or bed that I handle the devices it is far from the grounded socket of my house

Assuming the table or bed is conductive (which it should be) then you connect the ground strap to the table/bed.
The idea is to always keep your body potential the same as the device you are working on, not that it's at some "ground" potential.

 

that bracelet without the wire has a screw that must touch some metal to dissipate the load is this information false? the bracelet accumulates the load on the body and dissipates when touching the screw on some external metal

I see @crutschow has beaten me to the punch. There've been times I've worked on my personal computer without the benefit of a static grounding station. The key to keeping the electronics safe is to - as crutschow said - keep yourself at the same potential.

It was (I believe on a different thread) that we were discussing potential. Will have to look back and see; but if your charged to 30KV Static and you touch the frame of the computer then you and the frame are at the same potential. As long as you remain in contact with the frame you can't harm anything through an ESD event. However, if the computer is plugged in and you touch the frame you and the computer will be brought to ground potential. And potentially, if you contact any live wires greater than low voltage you risk an electric shock. That's why you ground yourself, your work station and anything sitting on the station. That may sound a little misleading. Let me explain: You put your computer on a conductive mat that is properly grounded and the computer is grounded through contact with the mat. And when you touch it, since you're wearing a wrist strap - all chances of an ESD event are virtually eliminated.

The bracelet with the screw CAN NOT withdraw static from your body and store it safely away. It CAN'T do that. The notion that when you touch ground with the screw is simply saying the same thing as the wrist strap with the cord. The cord is always in contact with ground through a 1 meg ohm resistor, keeping you and your project safe from ESD and from potentially dangerous line voltages. The magic wrist strap can not hold a greater charge than your body is holding. If you touch components while charged - ZAP goes your project.

 

Perhaps there is a 1Meg resistor between the screw and a conductive surface on the underside of the strap, touching the skin. If you are charged from scuffing across the carpet and touch a "ground" with the screw, it might prevent that OUCH! from an arc. But it won't do a thing at your ungrounded workbench.

 

see this video the guy disassembles the bracelet inside it has a resistor, a partemetalica of the bracelet touches the skin of the arm and on top of the bracelet there is a screw if I touch the screw in any metallic place will the electrostatic charge be completely discharged in the metal part?

will the cord bracelet always need this ground to discharge the energy? doesn't have this grounding everywhere

 

Are you thinking just this fake device verses a real wired wrist strap to a ground or a real wired wrist strap and an antistatic pad to a ground?

Think about it. You scuff across the carpet. You reach for the door knob. ZZZZZap. Is the door knob grounded? No, it's just at a different potential than you. If there is a resistor in there {There better be, or it could be lethal.), it will slow the transfer of charge at a lower current than the ZAP. When you touch a "real" ground you will share the charge you are carrying with the entire earth. The charge left on you will be proportional to your conductive mass verses the entire earth's conductive mass. You will only have a tiny number of electrons left on you. These few electrons will not damage your static sensitive electronic parts.

 

ESD wrist straps typically include a 10 or 1 MEG resistor in the ground strap path to ground. You do not want an individual actually "grounded". A simple Google of ESD Workstation Drawings will yield a dozen or more illustrated images of what an ESD workstation should look like and how it should be configured. ESD workstation mats are also grounded through a resistor.

There is also a very big difference between a home electronics workbench and an industrial workbench where an ESD workstation (here in the US) must meet certain ESD specifications including but not limited to ESD Shoe, Flooring, Chair, Table, Fabric, Test and a dozen more specifications.

Your second ground image doesn't tell me much? What is the rod alloy, how deep is it driven into the ground and what is the ground (dirt) conductivity as in soil PH? There are specifications for all of that also.

Ron

 

Does the antistatic wired bracelet only work if you place the claw on that ground bar?
I handle the electronics on a table or bed very far from this bar

 

Answer is no. My wire is too short to reach that far.
There are other ways to make it work.

 

Since you don't state what country you're in, is your house wired with 3-wire outlets, as in the US?

 

I am from Brazil and here the socket has 3 pins with grounding but the workplace is distant if I connect this claw to any metal will it work to unload the statics and protect the electronics I'm handling?

 

Creating an ESD workstation.



Reference: https://www.rs-online.com/designspark/creating-an-esd-workstation

 

connect this claw to any metal

No, the metal must be grounded. Looking at that ground rod, when the ground wire was clamped to the rod, it seems the wire is not clamped under the clamping bolt. Looks like they missed the wire and just wrapped the wire around the rod. The wire should be crimped between the clamp and the rod on the side away from the tightening bolt. In order to ensure integrity, it has to be "Megged" to determine if the ground is actually going to earth!

 

if I connect this claw to any metal will it work to unload the statics and protect the electronics I'm handling?

No, because that metal may be at a different potential than the device.

As I clearly stated, the main consideration is to have you and the device/workbench/table are at the same potential.
Whether that potential is at "ground" potential is of secondary interest.