loading

can i tie a chunk of metal to my leg for esd protection?


wrist straps are kind of annoying because the wire gets in the way. first of all would wearing it on my leg still work, or does it have to be on my arm or wrist? also, could i use a chunk of metal like an extra heat sync (since ground is essentially the same thing, just a bigger piece of metal)

sort by: active | newest | oldest
jeff-o6 years ago
You can wear a wrist strap almost anywhere on your body. At work, I wear mine on my upper arm just above my elbow. I find the cord stays out of the way, leaving my hands free to work.

ESD protection is a two-part equation though. The goal is to keep the operator (you) and the work at the same potential. The easiest way to do this is to pull both to ground. So, not only must you be grounded, but the work should be grounded too, usually through an ESD table mat.

Both the wrist strap and the table mat are connected to ground through a 1 megohm resistor, which helps dissipate charges slowly, rather than releasing them in one damaging jolt.
rickharris6 years ago
I have worked with electronics all of my working life, over 40 years and have never worn a wrist strap or other similar device nor broken any semiconductor device by not doing this.


Outside of mass production IMHO it isn't necessary. IF your susceptible to carrying static because of your clothing or environment then simply touch a radiator or water pipe before handling semiconductors.

I suspect a lot of the reason you and I have never bothered Rick is its so damned humid in this country we really don't have a static problem. There ARE dry environments, where folks have plastic flooring though, where there might be a problem.

. From what I've read (please don't ask for links, this was long before there was any WWW), the damage is cumulative. Ie, most components will survive a zap or two, but they become "weaker" each time and will fail sooner (and are more susceptible to the next zap).
. Not usually a big problem for DIYers, but can make a difference in an industrial setting where components may be worked on many times over their life.
Re-design6 years ago
An ESD is an electrical connection that will absorb excess electrons in your body so they don't zap delicate electronics. 

A ground has nothing to do with heat sinking.  A ground may be large to allow for a low resistance path.

A heat sink removes excess heat from a part.  It is usually made of metal but could be anything that conducts heat.  Like water in a radiator system.  A heat sink is usually insulated from the circuit but not always.
frollard6 years ago
As QA and Burf already said: You must maintain a ground connection -- 2 things to consider: be VERY VERY sure that you use a high resistance connection so you don't get a BIG jolt if you happen to grab a live wire while grounded.
2) a simple solution is to have a grounded floor mat, then an anklet that wires down to the bottom of your shoe such to contact the ground mat. You could modify the existing wrist strap to be ankle by sticking a short thumb-tack in your shoe and wiring the strap up to that.
You also have the option of using an ESD floor mat.

LINK

Any way you look at it, the ESD device must be grounded, usually through an earth ground. Wrist based ESD's can be grounded to the work piece, keeping the worker and the product at the same potential.

Qa
Burf6 years ago
If you're thinking of setting an anvil on your foot to act as an electro-static ground, don't to it!
In order to ground yourself you need to connect to something that is grounded itself. You can put the esd band around you ankle if you want, or any part of your body for that matter, but you must connect the strap to something that has its own ground in order to continuously keep your body discharged.