Page 448 - Robot Builder's Bonanza

USING PREDRILLED STRIPBOARDS 417

3. For components that are right next to one another, wrap leads that connect. One or
two turns is enough.
4. For connecting components that are more than an inch or two from one another, use
30- gauge wire meant for wire wrapping (see the section on wire wrapping, later in the
chapter), strip off about 1/2″ of the insulation from the end of the wire, and hook it
around the component lead.
5. Use a soldering pencil to flow some solder to the wires.
6. Repeat until all the components are mounted and wired together.
7. Trim off any excess wire lengths to avoid short circuits. Double- check your work.

Perf board wiring is often referred to as bird’s- nest construction— you can guess why. For
G circuits using more than a couple of components, use a copper layout board, detailed next.
Since circuits on point- to- point perf boards are delicate, mount them on your robot using one or
two small fasteners or a cable tie. Avoid having the board just flop around loose.

ALTERNATIVES TO PERF BOARD MOUNTING
A variation on the theme of point- to- point wiring on a perf board is to simply do away with
the perf board. Over the years, a variety of techniques have been developed; here are some
of them:
• Dead bug wiring is sometimes used with a single IC connecting to just a few components.
It’s called “dead bug” because when the chip is turned upside down,and things are soldered
to its pins, it looks a bit like a little, black, dead bug. When soldering on resistors, capaci-
tors, and similar components, cut the lead to length, then bend the end to make a U shape.
Solder the U directly to the IC pin.
• Wire wrap sockets have extra- long pins for attaching to wires. The IC itself plugs into the
socket after construction is complete. As with dead bug wiring, you can form fairly strong
solder joints by bending the end of the component lead into a U and hooking it around the
socket pin.
• Lead- to- lead construction is suitable when you’re soldering the leads of one discrete com-
ponent to another— for example, a resistor to an LED. Prepare the leads of both compo-
nents by cutting them to the desired length, then form small hooks to make a good
mechanical joint. Solder the two together.

Using Predrilled Stripboards

A stripboard has holes drilled in it, just like a perforated board. But on at least one side of the
board is a series of copper metallic pads and/or strips that run through the center of the holes.
These boards come in a variety of sizes and styles. All are designed for use with ICs and other
modern- day electronic components. One application of the stripboard is circuit construction
using wire wrapping, as detailed later in this chapter. But many circuits can be soldered
directly onto the board.
Choose the style of grid board depending on the type of circuit you are building. Figure
33- 3 shows a selection of basic grid layouts. Variations include:

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