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run the wire along the wall so you don’t trip over it. Set a loop of the wire at

the edge of your worktable where it’s handy to attach the alligator clip on the

end of it to your wrist strap.

If you don’t happen to have a metal cold water pipe nearby, the best method

is to use a metal rod that you insert into the ground. The standard rule is to

sink it three feet deep.

Second, wear clothing that is less likely to accumulate static charge. For

example, polyester, acetate, and wool fabrics easily accumulate static charges

whereas as cotton is less likely to accumulate the static charges necessary

for ESD.

Using an anti-static wrist strap and wearing cotton clothing will usually be

sufficient.

Third, if you plan to do electronics projects long-term, consider buying a

static-dissipative mat for your work surface. You connect the mat to a ground,

as you do with the wrist strap, and the mat dissipates charges from compo-

nents you’re working on as you lay them on the mat. However, the mat has a

high enough resistance that it won’t short together the pins of components.

There are also static-dissipative floor mats; however, these are more likely to

be used in a manufacturing setting when a worker needs to move between

workstations.

Anti-static wrist straps and static-dissipative workbench mats can be pur-

chased at most electronics distributors. See Chapter 15 for a list of electron-

ics distributors. The prices for wrist straps vary widely but start at just over

$6; prices for workbench mats start at about $10.

Don’t try rigging up a homemade anti-static wrist strap. The ones you buy have

a high resistance that slowly dissipates current. If you use a material without

that resistance, the current would rush to ground — which could cause you

serious injury — instead of slowly dissipating. For $6, why take a chance?

Finally, don’t forget to ground your tools. Some tools, like the better soldering

irons, have a three-prong plug that provides a ground connection. (Cheap

tools might use only two-prong plugs, so avoid them at all cost.) Other than a

grounded soldering iron, however, most metal tools (such as a screwdriver)

dissipate static through you when you wear your handy anti-static wrist strap.

Working with the Tools of the Trade ...........................................................

In addition to keeping yourself safe from electricity, you will find a few

other dangers with working with electronics projects. Using a variety of

Chapter 2: Safety First 23