Elenco Green Projects - Manual (Page 7)

About Your Snap Circuits ® Green Parts
How does electricity turn the shaft in the motor?
The answer is magnetism. Electricity is closely
related to magnetism, and an electric current
flowing in a wire has a magnetic field similar to
that of a very, very tiny magnet. Inside the motor
is a coil of wire with many loops. If a large electric
current flows through the loops, the magnetic
effects become concentrated enough to move
the coil. The motor has a magnet inside, so as
the electricity moves the coil to align it with the
permanent magnet, the shaft spins.
When used as a generator, wind or water turns
the shaft. A coil of wire is on the shaft, and as it
spins past the permanent magnet an electric
current is created in the wire.
The meter (M6) is an important measuring
device. You will use it to measure the voltage
(electrical pressure) and
current (how fast
electricity is flowing) in a circuit.
The meter measures voltage when connected in
parallel to a circuit and measures the current
when connected in series in a circuit.
This meter has one voltage scale (5V) and two
current scales (0.5mA and 50mA). These use the
same meter but with internal components that
scale the measurement into the desired range.
Sometimes resistors in the pivot stand will be
used to change the 5V scale to 10V, or the 0.5mA
scale to 5mA.
The motor (M4) converts electricity into
mechanical motion. An electric current through
the motor will turn the shaft.
It can also be used as a generator, since it
produces an electric current when the shaft is
turned.
METER
MOTOR
Meter Symbol
Magnet
Coil
Pointer
Contacts
Motor Symbol
Magnet
Electromagnet
Shaft
Power Contacts
Shell
Meter (M6)
Motor (M4)
Fan
Inside the meter there is a fixed magnet and a
moveable coil around it. As current flows through
the coil, it creates a magnetic field. The
interaction of the two magnetic fields causes the
coil (connected to the pointer) to move (deflect).
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Water Wheel