Getting Somewhat More Serious 111Experiment 12: Joining Two Wires TogetherI suggest you next practice your soldering skills on a couple of practical proj-
ects. In the first one, you can add color-coded, solid-core wires to your AC
adapter, and in the second one, you can shorten the power cord for a laptop
power supply. You can use your larger soldering iron for both of these tasks,
because neither of them involves any heat-sensitive components.
Modifying an AC Adapter
In the previous chapter, I mentioned the irritation of being unable to push the
wires from your AC adapter into the holes of your breadboard. So, let’s fix this
right now:
- Cut two pieces of solid-conductor 22-gauge wire—one of them red, the
other black or blue. Each should be about 2 inches long. Strip a quarter-
inch of insulation from both ends of each piece of wire. - Trim the wire from your AC adapter. You need to expose some fresh, clean
copper to maximize your chance of getting the solder to stick.
I suggest that you make one conductor longer than the other to minimize
the chance of the bare ends touching and creating a short circuit. Use
your meter, set to DC volts, if you have any doubt about which conductor
is positive.
Solder the wires and add heat-shrink tubing as you did in the practice session.
The result should look like Figure 3-51.
Figure 3-51. Solid-core color-coded wires, soldered onto the wires from an AC adapter, pro-
vide a convenient way to feed power to a breadboard. Note that the wires are of differing
lengths to reduce the risk of them touching each other.
Shortening a Power Cord
When I travel, I like to minimize everything. It always annoys me that the pow-
er cord for the power supply of my laptop is 4 feet long. The thinner wire that
connects the power supply to the computer is also 4 feet long, and I just don’t
need that much wire.
Choose the Right Tubing
If you use heat-shrink tubing on 110v
AC cord, as is being done in this ex-
periment, make sure you use tubing
that’s been rated for 110v use.