Elenco Snap Circuits® Deluxe Sound & Light Combo - Manual (Page 70)

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Project 121
High Power Buzzer
Project 123
Photo Buzzer
Project 124
Step Beeper
Project 125
Wacky Buzzer
Project 122
Buzz Fan
!
WARNING: Moving parts. Do not touch
the fan or motor during operation.
Build the circuit as
shown and turn on the
switch (S1). Move the
lever on the adjustable
resistor (RV) to vary
the pitch of the buzzing
sound. The motor (M1)
may not spin.
Use the preceding circuit, but place the 5.1kW
resistor (R3) directly over the 100kW resistor
(R5) using a 1-snap. The pitch of the tone is
higher now, and the fan spins. The circuit may
not make noise on all settings for the adjustable
resistor. The motor may not spin.
Use the circuits from projects 121-122, but add the
phototransistor (Q4) across base grid locations B2-
B4 (between RV and R1, “+” on the left), on level 3.
Shine a bright light on the phototransistor to change
the sound, while also moving the lever on RV.
You can also place the phototransistor directly
over the 100kW resistor, as done for the 5.1kW
resistor in project 124. For this arrangement,
“+” on Q4 should be on the right.
Use the circuits from projects 121-122, but replace the 0.1mF capacitor
(C2) with the 100mF capacitor (C4), “+” to the right. The motor will move
in small bursts, with long intervals or almost continuously, depending on
the resistors and phototransistor.
Next, replace the color LED (D8) with the white LED (D6). See how the
circuit works now.
Repeat projects 121-122, but add the 100mF capacitor (C4) across the
points marked A & B in the drawing (“+” to A). The motor may not spin but
the sound is different. The sound may not be very loud.
SCC-350_Manual_Part_B.qxp 7/25/14 2:05 PM Page 14