Elenco Snap Circuits® Deluxe Sound & Light Combo - Manual (Page 89)

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Project 174 Light Buzz
Project 176 Delay Lights
Project 175
Light Buzz
(II)
Turn on the switch (S1). If there is
enough light on the phototransistor
(Q4), then nothing will happen. Cover
the phototransistor with your finger,
now the speaker (SP2) makes noise
and the color LED (D8) flashes. Wave
your fingers over the phototransistor to
vary the sound.
Use the preceding circuit, but
replace the 0.1mF capacitor (C2)
with the larger 1mF capacitor (C7).
The sound is different now.
Turn on the slide switch (S1), and push the press switch (S2). The color
and white LEDs (D6 & D8) come on slowly but will stay bright for a long
time after you release the press switch. Connect the red jumper wire
across points A & B if you get tired of waiting for the LEDs to turn off.
Replace the 5.1kW resistor with the 100kW resistor. Now you have to
push the press switch for much longer to make the LEDs bright.
Replace the 100mF capacitor (C4) with the smaller 0.1mF capacitor (C2).
Now the LEDs turn on and off much faster, because C2 does not store
as much electricity as C4.
SCC-350_Manual_Part_B.qxp 7/25/14 2:05 PM Page 33