4

147

Chips, Ahoy!

Before I get into the fascinating topic of integrated circuit (IC) chips, I have to
make a confession: some of the things I asked you to do in Chapter 3 could
have been done a bit more simply. Does this mean you have been wasting
your time? No, I firmly believe that by building circuits with old-fashioned
components—capacitors, resistors, and transistors—you acquire the best
possible understanding of the principles of electronics. Still, you are going to
find that integrated circuit chips, containing dozens, hundreds, or even thou-
sands of transistor junctions, will enable some shortcuts.

Shopping List: Experiments 16 Through 24

Tools

The only new tool that I recommend using in conjunction with chips is a logic
probe. This tells you whether a single pin on a chip has a high or low voltage,
which can be helpful in figuring out what your circuit is doing. The probe has
a memory function so that it will light its LED, and keep it lit, in response to a
pulse that may have been too quick for the eye to see.

Search online and buy the cheapest logic probe you can find. I don’t have any
specific brand recommendations. The one shown in Figure 4-1 is fairly typical.

Supplies

Integrated circuit chips
If you buy everything on this shopping list, and you bought basic parts
such as resistors and capacitors that were listed previously, you should
have everything you need for all the projects in this chapter.
As chips are quite cheap (currently around 50 cents apiece), I suggest you
buy extras. This way, if you damage one, you’ll have some in reserve. You’ll
also have a stock for future projects.
Please read the next section, “Fundamentals: Choosing chips,” before you
begin chip-shopping. Chips should be easily obtainable from all the major
electronics retail suppliers, and sometimes are found on eBay shops. Look
in the appendix for a complete list of URLs.

Figure 4-1. A logic probe detects the high or

low voltage on each pin of a chip, and re-

veals pulses that may occur too quickly for

you to perceive them with the unaided eye.

In thIs chAPter

Shopping List: Experiments 16 Through 24

Experiment 16: Emitting a Pulse

Experiment 17: Set Your Tone

Experiment 18: Reaction Timer

Experiment 19: Learning Logic

Experiment 20: A Powerful Combination

Experiment 21: Race to Place

Experiment 22: Flipping and Bouncing

Experiment 23: Nice Dice

Experiment 24: Intrusion Alarm

Completed