Elenco Snaptricity® - Manual (Page 57)

Iron Core Rod
Rubber Grommet
Note: the compass needle
may point opposite to how
it’s shown here, depending
on how you connected the
jumper wires.
Project #47
1. Use the circuit from the preceding project, with the
iron core rod in the electromagnet (M3). An electronic
magnet has a magnetic field just like an ordinary
magnet. Hold your compass next to the
electromagnet and push the press switch (S2). Move
the compass all around the electromagnet and watch
where the compass points.
2. The magnetic field created by a magnet occurs in a
loop. You can see this using paper clips.
3. Remove the iron core rod from the electromagnet.
Now push the press switch again and try to pick up
things with the electromagnet. The attraction is now
very weak.
The iron core rod concentrated the magnetic effects
of the electromagnet. You can use the compass to
see that electronic field is now much weaker.
4. Materials made of iron concentrate their magnetic
effects at both ends. The center of the material is
magnetically neutral because the attraction from
each end is the same.
The magnetic field created by the electromagnet
works the same way. It is strongest at both ends but
neutral in the center. But the electromagnet is hollow
- so iron at one end will be sucked into the middle.
Lay the electromagnet on its side. Hold the thin rod
next to the center hole and push the press switch to
suck it inside. Hold the switch and gently pull the rod
to see how much suction the electromagnet has.
Operation
1
-56-
2
3
4
ElectroMagnet Magnetic Field
Snappy says: you can turn on
the switch to pick up things with
the electromagnet, then release
the switch to drop them. This is
done with large magnets at
factories or junk yards.