Switching Basics and More 67Experiment 8: A Relay OscillatorYou’ll need some more 22-gauge wire, or some precut hookup wire, to supply
the power to your components, which are plugged into the breadboard as
shown in Figures 2-76 and 2-77. If you get all the connections right, the circuit
should function the same way as before.
The geometry of the metal connecting strips in the breadboard often forces
you to connect components in a roundabout way. The pushbutton, for in-
stance, supplies power to the pole of the relay but cannot be connected di-
rectly opposite, because there isn’t room for it.
Remember that the strips inside the breadboard that don’t have any wires or
components plugged into them are irrelevant; they don’t do anything.
I’ll include some suggested breadboard layouts for circuits as you continue
through this book, but eventually you’ll have to start figuring out breadboard
layouts for yourself, as this is an essential part of hobby electronics.
Figure 2-76. Two oversized LEDs, one resistor, and the necessary jumper wires have been
added to the breadboard.
Figure 2-77. Now the pushbutton, relay, and capacitor have been added to complete the
circuit shown in the diagram and the schematic. When the pushbutton is pressed, the
relay oscillates and the LEDs flash.
Larger versions of all schematics and
breadboard photos are available
online at this book's website: http://
oreilly.com/catalog/9780596153748.