BEAM Pieces is a BEAM
What to buy, how to
Diodes (including LEDs and
Since BEAMbots don't have very high current
requirements, we'll be using diodes optimized for fast,
low-resistance switching of low currents.
Three particular Silicon diodes seem to be the
most-popular ones in BEAMbots:
These guys are interchangeable, small signal diodes.
You'll use these for most of your circuits since
they're small and work for logic, or loads to 200
This guy is a rectifier diode, and doesn't show up as
often in BEAMbots, since its only advantage over the
1N914 / 1N4148 is in current capability -- up to 1A.
BEAMbots never draw nearly this much power, but
remember this diode for loads near (or over) 200
voltage drop is an issue, you can use a Germanium
diode (tho' they're much more expensive than their
Silicon cousins). The most common is the...
Small-signal Germanium diode -- sometimes salvageable
from a variety of circuit boards
In some instances, diodes are marked with part codes;
a guide to deciphering them is here.
LEDs (Light Emitting Diodes)
A tutorial on using LEDs is available here.
The things you'll need to consider are current drain
(general rule: small is better than big), and LED type
(regular vs. infrared vs. flashing).
Most any photodiode will do for BEAMbots; I'd suggest
you select one based on what has a convenient "field of
view" (some are sensitive to light from such a broad field
that you'll need to build them "blinders" so they'll only
respond to light from a given range of directions.
For more information...
Details on the physics of diodes, and the
background of the various types are available both
on the BEAM
From the Ground Up diode page, as well as in
And don't forget to visit the online "LED