Elenco Circuit Maker Sound Plus 200 - Manual (Page 27)

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Project #38
Diodes are electronic components that allow current to flow in only one
direction, blocking it in the other. The red LED (D1) are special diodes
that can emit light, and the transistors (Q1 & Q2) can also be used as
diodes.
Turn on the slide switch (S1), the lamp (L4) will be bright and the LED
(D1) will be lit. The NPN transistor (Q2) is used here as a diode, allowing
the batteries to charge up the 100mF capacitor (C4) and light the LED.
Turn off the slide switch, the lamp will go dark immediately but the LED
will stay lit for a few moments as capacitor C4 discharges through it. The
transistor/diode isolates the capacitor from the lamp; if you bypass the
transistor by placing a 3-snap wire over it (on level 4 across base grid
locations B2-B4) then the lamp will drain the capacitor almost instantly.
Diode
Project #39
Turn on the slide switch (S1) and you hear space war sounds as the LED
(D1) flashes. If you wave your hand over the photoresistor (RP), the
sound changes. If you keep the photoresistor covered, then the sound
will stop.
Press the press switch (S2) and you will hear music in addition to any
space war sounds that are playing. Press the press switch again to
change the music. You will also hear any recording you had made
previously with other projects.
Musical Space War
CM-200_Manual_031914.qxp_CM-200_Manual_031914 4/2/14 12:04 PM Page 27