Elenco Snap Circuits SOUND &reg - Manual (Page 67)

Project 135
Tone Stoppers (II)
The sound is a little
louder now because
the larger 1
m F
capacitor passes
more of the tone
than the smaller
0.1
m F capacitor did.
Project 136
Tone Stoppers (III)
The sound is much louder now because
the larger 470
m F capacitor passes
much more of the tone than the smaller
1
m F capacitor did. Now pressing S2
does not increase the sound, because
C5 is already passing all of it.
C7 will give less change on
high frequency tones than
on low frequency tones; you
should be able to notice the
difference as you vary the
tone using RV3. The smaller
C2 will affect both high and
low tones a lot. The larger
C5 will have little effect on
both high and low tones.
Use the circuit from project 135 (with the 1 m F capacitor (C7)), but
add the 500k W adjustable resistor (RV3) as shown here. Slowly
turn RV3’s knob to vary the pitch (frequency) of the tone from
lowest to highest possible (there will only be sound for a small
part of RV3’s range). At the same time, press S2 on and off
several times, to see how C7 is changing on the sound.
Next, replace C7 with smaller C2 or larger C5, and compare the
capacitor’s effect as you vary the tone frequency.
Use the preceding circuit, but replace
the 1
m F capacitor (C7) with the much
larger 470 m F capacitor (C5). Compare
the sound volume to the preceding
circuits. How much difference does
pressing S2 make now?
Use the preceding circuit, but replace
the 0.1
m F capacitor (C2) with the
larger 1 m F capacitor (C7). Compare
the sound volume to the preceding
circuit.
Build the circuit and turn the slide switch (S1). Press any key on the
keyboard (U26). You hear a tone from the speaker (SP2), though it may
not be very loud.
Now push the press switch (S2) while pressing the same key. The
sound is louder now, because the press switch bypassed the 0.1
m F
capacitor.
Project 134 Tone Stoppers
Capacitors can store electricity in small amounts. This
storage ability allows them to block stable electrical signals
and pass changing ones, making them useful in filtering and
delay circuits. Capacitors with higher values have more
storage capacity, and can pass changing signals more easily,
In this circuit the 0.1 m F capacitor blocks most of the keyboard
tone signal. You can hear the difference when you press S2
to bypass the capacitor.
Project 137
Tone Stoppers (IV)
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