Elenco Snaptricity® - Manual (Page 67)

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1mA
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Make Your Own Generator Project #57
1mA
Educational Corner:
In electric power plants, the same thing happens but on a
much larger scale. High-pressure steam or water spins a
shaft, which uses magnetism to make an electric current
in a coil of wire.
Changing the direction you spin the shaft changes the
direction of the magnetic field produced, which changes
the direction of the electric current produced. This is
known as Lenz’s Law, after Russian physicist H. F. E. Lenz
who studied electromagnetic induction in the 1800’s.
Magnet Coil of Wire
Water Flow
Snappy says: gears are used between
two wheels or shafts. One wheel spins at
low speed but with great force, while the
other wheel spins at high speed but with
much less force. This can increase
efficiency or give greater control.
This circuit is a true generator, using motion (and magnetism) to
make an electric current.
Notice that this circuit used the 1mA meter setting while the
preceding circuit used the 1A setting (1000 times greater). You can
produce a much higher current by spinning the shaft much faster.
Hand-cranked generators like this are used in some flashlights
instead of batteries. They use gears to spin the shaft much faster.
Description
Spin the motor (M1) top clockwise with your fingers and watch
how much current is produced. (Clockwise means in the direction
in which the hands of a clock rotate.)
Now spin the motor in the other direction (counter-clockwise). You
won’t see much current produced now because it is produced in
the other direction - the meter needs to be flipped around. Instead
of flipping the meter around, flip the motor around to see this.
Operation
Build the circuit and set the meter (M5) to the 1mA scale.
Assembly
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