Elenco Snaptricity&reg - Manual (Page 51)

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And NOt Project #41
Educational Corner:
Suppose you wanted to monitor the voltage
to a circuit, to see if the batteries were
getting weaker. You could use the meter to
measure the voltage, then read and record
every hour. Then you have a series of
numbers showing how the voltage was
changing. Even if you watched the meter
continuously, you probably wouldn’t
remember what the voltage was a week
later unless you wrote it down.
Representing an electrical signal as a
series of numbers is
digital electronics.
Computers store and process almost all
their information as series of recorded
numbers.
Sometimes it is easier to process
information as a digital series of numbers
(computers), and sometimes it is easier to
use a continuously changing voltage (AM
radios). Many products use both methods
on the same information but at different
times. The disadvantage of digital systems
is that they are more complex since they
have to store and process all the numbers.
The advantages are that IC technology
makes it inexpensive to store and process
information, and digital systems are more
protected from interference.
Electric Paths
+
Hold down the press switch (S2), then use the slide
switches (S5) to turn the fan on or off.
Operation
If the press switch is on, then the fan will be off unless both
lamps (L4) are on. In other words, the fan will be off if the
left lamp
AND the right lamp are NOT off.
Description
Build the circuit shown.
Assembly
!
WARNING: Moving parts.
Do not touch the fan or
motor during operation. !
WARNING:
Do not lean
over the motor.
+
Snappy says: this type of
switching combination is a
NAND sub-circuit (short for
“NOT this AND that”). It
has its own symbol.
NAND Gate