Make Electronics

Getting Somewhat More Serious 103

Shopping List: Experiments 12 Through 15

Components

Power plugs, sockets, and binding posts
After you finish a project and put it in a box, you’ll need a convenient way
to supply it with power. Buy yourself a pair of insulated binding posts, such
as RadioShack part 274-661, shown in Figure 3-27. Also obtain a panel-
mounted power jack, size N, such as RadioShack part 274-1583, and DC
power plug, size N, such as RadioShack 274-1573. The plug-and-socket
pair is pictured in Figure 3-28.
Finally, you will need interconnects that are sized to fit a perforated board
that is drilled at intervals of 1/10 inch. Sometimes known as “single inline
sockets and headers,” but also known as “boardmount sockets and pin-
strip headers,” they come in strips of 36 or more, and you can snip off as
many as you need. Examples are Mill-Max part numbers 800-10-064-10-
001000 and 801-93-050-10-001000, or 3M part numbers 929974-01-36-
RK and 929834-01-36-RK. You can buy them from the usual electronics
suppliers. Figure 3-29 shows headers before and after being snapped into
small sections. Make sure that the interconnects have a terminal spacing
of 0.1 inch.

Battery
After you complete Experiment 15 at the end of this section of the book,
if you want to use the project on a practical basis, you’ll need a 12-volt
battery. Search online for “12v battery” and you’ll find many sealed, re-
chargeable lead-acid batteries that are designed for alarm systems, some
measuring as small as 1×2×3-inch and costing under $10. You need a
charger with it, which will probably cost you about $10.

Switches and relays
You will need the same DPDT relay and the same SPDT toggle switch that
were mentioned in Chapter 2 shopping list.
For Experiment 15, you’ll need magnetic switches that you can apply to
doors or windows, such as the Directed model 8601, available from doz-
ens of sources online.
Also you will need a DPDT pushbutton switch, ON-(ON) type, with
solder terminals. Examples are model MPG206R04 by Tyco or model
MB2061SS1W01-RO by NKK (with optional cap). Or search eBay for “DPDT
pushbutton.”

Diodes
Buy at least half-a-dozen red 5 mm LEDs rated for approximately 2 volts,
such as the Optek part number OVLFR3C7, Lumex part number SSL-LX-
5093IT, or Avago part HLMP-D155. Buy half-a-dozen similar green LEDs at
the same time.
In addition, you’ll need a signal diode, type 1N4001 (any brand will do).
Figure 3-30 shows an example, highly magnified. They’re cheap, and likely
to be useful in the future, so buy 10 of them.

Figure 3-27. These terminals, also known

as binding posts, enable a solderless con-

nection with wires that have stripped ends.

Also available in black.

Figure 3-28. The socket on the right can be

mounted in a project box to receive power

from the plug on the left.

Figure 3-29. Single inline sockets (top) and

headers (middle) allow you to make very

compact plug-and-socket connections

to a PC board. They can be sawn, cut, or

snapped into smaller sections (bottom).

The terminals are 0.1 inch apart.

Figure 3-30. This 1N4001 diode is about

1/4 inch long and can handle up to 50

volts.