Elenco Green Projects - Manual (Page 27)

50mA
-26-
Project #26 Crank Motor
Crank Motor Voltage Project #27
Build the circuit shown. Set the meter
(M6) to the 50mA setting. Push the
press switch (S2) and watch the current
on the meter when the hand crank (HC)
spins. Compare the current with it to the
current when using the motor (M4) and
other parts.
The hand crank is a motor with a gearbox attached.
The gearbox spins the crank handle slower but with
more force than when the motor shaft is spinning.
The slow-spinning crank handle may look boring
compared to the fast wind fan on the M4 motor, but
using a gearbox allows a low-power motor to move
heavier objects than they normally could.
The motor in the hand
crank is different from the
M4 motor, but similar. Did
you see how much more
voltage and current you
can generate using the
hand crank than with the
M4 motor?
5V
Modify the preceding circuit into this one. Set the
meter (M6) to the 5V setting. Set the slide switch (S5)
to position B and watch the voltage on the meter
when the hand crank spins.
Set the slide switch to position B to disconnect the
battery. Turn the crank handle counter-clockwise and
see how much voltage you generate. You can switch
the meter to the 50mA setting to see how much
current you produce when you spin the fan.
Set the meter back to the 5V setting and the slide
switch back to position C. While it is spinning,
CAREFULLY AND WITHOUT USING MUCH
FORCE, try to turn the crank handle in both
directions. Feel how much easier or harder it is to turn
the crank when the battery voltage is helping or
opposing you. USING EXCESSIVE FORCE MAY
DAMAGE THE HAND CRANK!
See projects 1 & 3 if you need to recharge the battery (B4).