Antistatic wristband strap

[bhagavanec67]

Hello,

I want to know how an anti-static wrist strap will ground the charge of our body. I found a five line contacts on the band which has no relation with each other. so there comes this doubt.It will be helpful if I got the answer for it.

thanks in advance.

 

[KlausST]

Hi,

The wristband should be connected with a resistor of some megaohms to earth ground.

Klaus

 

[bhagavanec67]

Thanks for reply,
When I am testing my wrist trap its showing 1Mohm but when I am checking my bands conducting lines to metal placed on the cuff its not buzzering. then how it will discharge my body's charge to ground

 

[KlausST]

HI,

the buzzering surely is only below 1 kOhm maybe below 100 Ohms.

A wrist band with low resistance (below 100k Ohms) is considered to be dangerous in case the user accidentally touches mains voltage or other high voltage.

DO NOT USE LOW RESISTANCE WRIST BANDS.


Klaus

 

[bhagavanec67]

Thanks again,

but still I have a confusion about it. can you help me to know the "exact working of Wristband"

Regards,
Bhagavan.

 

[betwixt]

Your body ----- wrist band ----- resistor ------- ground (with wire somewhere to allow you movement)

Your body is probably insulated from ground by soles of your shoes and floor covering, usually these are synthetic materials which tend to build up charge on you as you move. There is also a direct path from your body to any charged object you touch. Ideally, you want to discharge to ground in a safe way. The wrist strap will either be made from a conductive plastic or have tiny wires woven through it, this is to allow it to contact the skin on your wrist. From the band there will be a cable which you attach to a grounded point, completing the connection from you to ground so you 'discharge' to ground potential. At one end or the other of the cable there will be a resistor, usually 1M value, which is a compromise between how fast it discharges you against the risk of electrocution if you touch something 'live'. For example, if you directly grounded the wristband and touched something at high voltage with the other hand, you would pass high current through your body and risk injury, the resistor limits the current to a safe level.

Brian.