Electronics_Projects_For_Dummies
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100 Part II: Sounding Off!
C4 from microphone TB to open region
C5 from IC1 Pin 7 to R24 TB
C6 from IC2 Pin 5 to ground bus
Figure 5-10:
Insert capacitors into the breadboard.
C3 from R7 TB to IC2 Pin 3
C2 from IC1 Pin 1 to R7 TB
C1 from microphone TB to open region
10.Insert one 2 kohm resistor (R19), two 47 kohm resistors (R20 and R21), one 100 kohm resistor (R22), one 5 kohm resistors (R21), two 1 kohm resistors (R25 and R26), and one 220 kohm resistor (R27) on the breadboard, as shown in Figure 5-13.
11.Insert wires to connect the collector pins of the transistors to the terminal blocks, as shown in Figure 5-14.
Chapter 5: Making Light Dance to the Music 101
R15 R16 R17 R18
Figure 5-11:
Insert resistors onto the breadboard.
R32 R33 R34 R35
Let there be lights
All the brains of the circuit assembled in the previous section are there to make the Dance to the Music light display work. Here’s the part where you assemble those lights.
Follow these steps to create your Dance to the Music display:
1.Select a series of musical notes, with eight high notes and eight low notes.
2.Draw a musical staff on the top of the wooden box in pencil and then draw a dot for the spot where each LED will go.
3.Drill test holes in a piece of scrap wood to determine the size of drill bit that you should use to give a press fit for the LEDs.
We used a 13⁄64" drill bit.
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R1 from C1 to +V bus
R2 from C1 to Pin 2 of IC1
R5 from Pin 1 of IC1 to Pin 2 of IC1
R10 from Pin 1 of IC2 to Pin 2 of IC2
Figure 5-12:
Insert more resistors onto the breadboard.
R9 from Pin 2 of IC2 to ground bus |
R4 from Pin 3 of IC1 |
R8 from C3 to ground bus |
to ground bus |
|
|
|
R3 from Pin 3 of IC1 to +V bus |
|
R6 from Pin 1 of IC1 to ground bus |
4.Drill holes for the LEDs at the locations you marked in Step 3.
5.With a permanent marker or paint brush, draw the musical notes and staff on the wooden box.
6.Insert LEDs in the drilled holes.
The box at this stage is shown in Figure 5-15.
See Figure 5-15 for help with this if you’re not musical!
Chapter 5: Making Light Dance to the Music 103
R21 from Pin 5 of IC1 to ground bus
R20 from Pin 5 of IC1 to +V bus
R23 from Pin 7 of IC1 to ground bus
R26 from Pin 6 of IC2 to ground bus
R27 from Pin 7 of IC2 to Pin 2 of IC2
Figure 5-13:
Insert the remaining resistors onto the breadboard.
R25 from R24 TB to C6
R22 from Pin 7 of IC1 to Pin 6 of IC1
R19 from C4 to Pin 6 of IC1
7.Attach resistors between the pairs of LEDs, as shown in Figure 5-16.
Attach the resistors to the short lead on one LED of each pair (four pair of each color) and to the long lead on the other LED of the pair.
8.Solder the resistors to the leads and clip the leads just above the solder joint.
Clip only the leads to which you have soldered resistors. Figure 5-16 shows how the LEDs and resistors should look at this point. Figure 5-17 shows a close up to help you see the soldering more clearly.
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Figure 5-14:
Connect the collector pins of the transistor to terminal blocks.
Wires connecting transistor collector pins to terminal blocks
Figure 5-15:
A bit of our favorite song created from marker and LEDs.
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Figure 5-16:
Resistors soldered and leads clipped.
Figure 5-17:
A close-up of the soldering job.
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Be sure to heed all the safety precautions about soldering that we provide in Chapter 2. For example, don’t leave your soldering iron on if you have to step away to let the pizza delivery guy in. And just in case a bit of solder has an air pocket that could cause it to pop, wear your safety glasses whenever you solder or clip leads and wires.
9.Connect and solder short lengths of 20 gauge red wire between the remaining long LED leads. Then attach a 12" 20 gauge red wire to the remaining long lead of the first LED pair, as shown in Figure 5-18.
These wires are the +V bus for the LED arrays; you attach the 12" wire to a terminal block to supply voltage to the bus.
Figure 5-18:
Red wires forming the +V bus for the LED arrays.
10.Clip the LED leads just above the solder joint.
Clip only the leads to which you have soldered the red wires; you need the remaining leads in the next step.
11.Connect and solder a 12" 20 gauge black wire to the remaining short LED lead on each pair of LEDs, as shown in Figure 5-19.
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Figure 5-19:
Black wires to connect each pair of LEDs to terminal blocks.
You will connect each of these eight wires to a terminal block. The upcoming Figure 5-20 shows these connections close up.
Figure 5-20:
Aclose-up of all the
connections.
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12. Clip the LED leads just above the solder joint.
Make sure that the LED leads and solder joints don’t touch each other. Coat them with liquid electrical tape to help prevent any shorts that could occur if you bend or push the wires together.
Adding the rest of the doohickeys
After the circuit and LEDs are pretty much taken care of, you have a lot of other things still sitting on your workbench, like the microphone, potentiometers, a switch, and one or two more things. You have to take care of assembling these before your project will work.
Follow these steps to take care of all the rest of the parts that make the music dance:
1.Solder a 12" black wire to the microphone ground contact and a 12" red wire to the microphone +V contact.
Figure 5-21 identifies the microphone contacts.
+V contact
Ground contact |
Black wire |
Figure 5-21:
Solder wires to the microphone.
Red wire
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2.Drill holes in the box where you will insert the microphone and on/off switch.
We put both the potentiometers and on/off switch on one side of the box and the microphone on another side, but the placement is really up to you. Chose a drill bit size for the microphone hole so that the microphone has a slip fit. The upcoming Figure 5-22 shows where we place these components.
See Chapter 4 for more information about choosing drill bit sizes for particular components and other pieces of wisdom on how to customize a box for your projects. Make sure you use safety glasses when drilling, and clamp the box to your worktable!
3.Slip the shaft of the on/off switch through the drilled hole and secure with the nut provided.
4.Slip the shaft of the potentiometers through the drilled holes and secure with the nuts provided.
5.Slip a knob over the shaft of each potentiometer and tighten the knob with the set screw provided.
The tread on potentiometers is about 1⁄4" long, so if the wall of your wooden box is 1⁄4" thick, you won’t be able to use the nut to secure the potentiometer. Instead, check to make sure that the potentiometer shaft extends far enough beyond the box to allow the knob set screw to tighten on the shaft. If the shaft extends far enough, glue the face of the potentiometer to the box, making sure that you don’t get any glue on the rotating shaft of the potentiometer. If the shaft doesn’t protrude quite enough, use a small chisel to remove some wood on the inside of the box to let the potentiometer shaft extend a little farther before you glue.
6.Slip the microphone into its drilled hole with a press fit.
Figure 5-22 shows the on/off switch, potentiometers, and microphone in place in the box.
7.Solder 12" black wires to each of the three potentiometer lugs, as shown Figure 5-23.
8.Solder the black wire from the battery pack to one lug of the on/off switch and solder a 12" black wire to the remaining lug of the on/off switch.
Figure 5-23 shows the switch after the wires are soldered.
9.Attach Velcro to the breadboard and the box and then secure the breadboard in the box.
10.Attach Velcro to the battery pack and the box and then secure the battery pack in the box.