Elenco Electronics 202 - Manual (Page 102)

-101-
You will only hear music if you turn on the slide switch (S1) AND press
the press switch (S2). This is referred to as an AND gate in
electronics.
This concept is important in computer logic.
Example:
If condition X AND condition Y are true, then execute
instruction Z.
Project #242 Lamp, Speaker & Fan
in Parallel
Project #241
OBJECTIVE: To build an AND gate.
Music AND Gate
!
WARNING: Moving parts. Do not touch the fan or
motor during operation.
OBJECTIVE: To show the power drop of components connected
in parallel.
Leave the fan off the motor (M1). Turn on the slide switch (S1), the
motor spins and the lamp (L2) turns on. Place the fan on the motor
and press the press switch. The lamp is not as bright now, because it
takes more power from the batteries (B1) to spin the motor with the fan
on it, which leaves less battery power available to light the lamp. If you
have weak batteries, the difference in lamp brightness will be more
obvious because weaker batteries don’t have as much power to
supply.
The speaker (SP) is being used as a low-value resistance here to
make the above effects more apparent.