Elenco Circuit Maker Skill Builder 125 - Manual (Page 24)

Project #25 Discover the Diode
Project #24 Don’t Make a Sound
-23-
Use the circuit from Project #23, but now place a 3-snap wire and the
LED (D1) as “shorting bars” under the paper sheet as shown on left.
Setup: Player 1 sets the “Quiet Zone” by placing the 3-snap wire and
the LED (D1) under the paper on columns 2, 3 or 4, leaving only one
open. Player 2 must NOT know where these “shorting bars” are
located under the paper.
Both Player 1 and Player 2 are given 10 points. The object is for Player
2 to guess the location of the “Quiet Zone” by placing the paper clip at
positions X, Y, or Z and pressing the press switch. If Player 2 places
the paper clip on the correct column, and a sound plays when he
presses the press switch, this means he has not found the “Quiet
Zone” and he loses 1 point. He has three (3) tries to find the zone on
each turn. Each time sounds are made he loses a point.
Player 2 then sets the 2, 3 or 4 side and player 1 starts searching. Play
continues until one player is at zero points and makes sound during
that players turn.
Paper sheet
to hide
position of
shorting bar
Diodes are electronic components that allow current to flow in only one
direction, blocking it in the other. The red LED (D1) is a special diode
that can emit light, and the transistor (Q1) can also be used as a pair
of diodes.
Turn on the slide switch (S1), the lamp (L1) 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 470 mF capacitor (C5) 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 C5 discharges through it.
The transistor/diode isolates the capacitor from the lamp.
CM-125_Manual_031514.qxp_CM-125_Manual_031514 4/2/14 12:19 PM Page 24