FORREST M. MIMS III: TOY ORGAN KIT | JAMECO PART NO. 2155508
VISIT WWW.JAMECO.COM/TOYORGAN FOR COMPLETE KIT BUILD AND VIDEO
Experience Level: Beginner | Time Required: 1 hour
The Toy Organ kit is a music maker based on a simple 555 timer circuit. With the addition of a resistor, some
capacitors and some buttons, you can generate several different tones. With the addition of a couple potentiometers,
you can control the volume and the pitch of the note. Even more, when you press several buttons at the same time,
another unique tone is generated.
1) 555 Timer & Socket
U1. When installing ICs, it is good practice to use a socket. If the IC were to fail, it can be
easily removed and replaced. Notice there is a notch on one end of the socket. Be sure the
notch on the socket matches the notch printed on the PCB. The 555 timer also has a notch at
one end. Install it the same way you installed the socket. (Figure 1.)
FIG. 1
2) Capacitors
C1 – C8 are not polarized so they can be installed in either direction. You can install the capacitors in different
positions on the board. Since each value will create a different tone, you may choose to install them ranking from high
to low or low to high. You can also use other value capacitors to make different tones.
CODE
332
VALUE
Freq. (Hz)
472
333
473
104
224
0.0033µF 0.0047µF 0.01µF 0.022µF
0.033µF
0.047µF
0.1µF
0.22µF
3,252
348
230
111
52
2,240
103
1,173
223
490
C9 is polarized so watch the polarity! There is a stripe going down the side of the capacitor
indicating the negative lead. The negative lead goes in the round pad while the positive lead of
the capacitor goes through the square pad of C9 on the PCB. (Figure 2.)
FIG. 2 3) Resistors
R1 (100K) and R3 (1K) are potentiometers and will be installed in the enclosure. You will need to make wire
connections between the pads on the PCB to the terminals on the potentiometer.
R1 - Bridge pins 2 and 3 together with a small piece of wire. Connect a wire from pin 2 or 3 of R1
to the pad closest to the battery location on the R1 location. Connect a wire from pin 1 of R1 to
the other pad on the PCB; this pad is closest to R2. (Figure 3.)
R3 - Connect a lead from pin 1 of the 1K pot to the pad on R3 closest to the "Toy Organ" label.
Connect another wire from pin 2 of the pot to the remaining pad for R3.
FIG. 3
R2 is a 10KΩ resistor and can be installed in either direction. (Brown – Black – Orange)
4) Switches
S1 – S8 will also be mounted in the enclosure in whatever position you choose. You will need to make wire
connections from the PCB to the solder tabs on the switch. The switches are installed from the outside of the
enclosure, so you will have to solder lead wires to the switch before installing it in the enclosure. The alternative is to
solder lead wires to the PCB, then install the switches in the enclosure and complete the wire connections to the
switches.
5) Speaker
The speaker will also be mounted in the enclosure wherever you choose. Connect a wire
from the right side terminal (R) of the speaker to the square pad for SPKR. Connect a wire
from the other speaker terminal (L) to the round pad. (Figure 4.)
6) Battery Snap
L
R
FIG. 4 Connect the red wire from the battery snap to the positive (+) pad on the PCB labeled BT1. Connect the black wire to
the negative (-) pad.
7) Enclosure
This portion of the project requires your own creativity. Use white masking tape over the lid of the enclosure so you
can pencil in where you would like to mount the switches, speaker, and potentiometers. You will drill 0.5" holes for the
switches and 5/16" holes for the pots. You should also drill a shallow (not all the way through) 1/8" hole for the tab
that keeps the pot from free-spinning when installed. Drill 1/8" holes for mounting the speaker. You may want to set
the speaker on the lid and run the pencil inside the mounting circles to mark where to drill. It is also a good idea to drill
a few holes to let the audio from the speaker out of the enclosure.
VISIT WWW.JAMECO.COM/TOYORGAN FOR COMPLETE BUILD