Elenco Snaptricity&reg - Manual (Page 46)

1A
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WARNING: Moving parts. Do not touch
the fan or motor during operation.
!
WARNING: Do not
lean over the motor.
3-Speed Motor (III) Project #36
Educational Corner:
Turn off the slide switches (S5
position B) and get the fan
spinning fast. Now turn on one of
the other lamps (S5 position C)
and watch how long it takes to
light. The lamp takes a few
seconds to get bright because it
takes time to heat up the filament
with a low current. Electric Paths
1A
-45-
Operation
Here you control the motor speed by diverting some of the
current to the lamps (L4).
Description
Build the circuit and set the meter (M5) on the 1A scale.
Assembly
Push the press switch (S2) to turn on the motor (M1) and
use the slide switches (S5) to control its speed. The meter
measures the current through the motor. Be careful not to
touch the motor or fan while it is spinning. You may need to
give the fan a push to get it started, but do not touch it while
it is spinning.
Snappy says: the current is
lower when the lamp is bright,
because the lamp filament
has the most resistance when
it is glowing hot.
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