Building Alert: Construction Issues ...........................................................
The back of the dolphins — where all the resistors and LED leads are sol-
dered together — gets kind of hectic. Make sure that if a lead gets bent in the
course of putting it on the plywood that it doesn’t short. Rather than using
electrical tape, we used liquid electrical tape to coat the exposed leads.For a mounting surface, we used^1 ⁄ 4 " sheet plywood as the best bet. We tried
using PVC (a kind of plastic) sheets, but they weren’t rigid enough to support
the display.We won’t kid you: Stringing the LED and resistor arrays takes some time and
patience. There is no real shortcut to offer you here! We recommend that you
solder the resistors to the LED leads first and then attach and solder either
the red or black wires. If you try to attach all the wires before you solder,
some will get in the way of your soldering iron.You can use any artwork you like to create the images of your choice. We
found a simple clip art drawing of a dolphin, printed it, copied and enlarged
it, and used that as our stencil. We tipped the stencil at different angles
across the plywood, creating a feeling of movement. However, you can use
any graphic for your template as long as you avoid using anything so com-
plex that people can’t make it out by looking at a simple outline of lights.Perusing the Parts List ................................................................................
It’s time to go shopping for those electronic parts you use to build the cir-
cuits and assemble all those LEDs into dancing dolphins. This is where we
give you the parts lists for the circuit and the LED arrays.A circuit with a porpoise ...................................................................
The circuit that controls the timing of your light show involves the following
parts, several of which are shown in Figure 10-5:47 kohm resistor (R1)470 kohm resistor (R2)
LM555 timer (IC1)4017 decade counter (IC2)
1 microfarad electrolytic capacitor (C1)Chapter 10: Dancing Dolphins 221