Elenco Snaptricity&reg - Manual (Page 59)

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Educational Corner:
If a current through a coil can
magnetize an iron bar, what if
you had another coil from a
different circuit wrapped around
the same iron bar? The
magnetization of the iron bar
would create a current in the
other circuit. This is a
transformer , which allows one
circuit to create a current in
another circuit using magnetic
fields.
Transformers allow
circuits to be
isolated from each
other, since the
connection between
them is magnetic
and not electrical.
Transformers can
also change the voltage by
using coils with more or less
loops of wire.
When electric power companies
transport electricity across great
distances (like between power
generating plants and cities),
they use very high voltages and
low currents since this reduces
power loss in the wires. Large
transformers convert this to
120V, which is supplied to
homes and offices. Many
products (like computers) then
use small transformers to
convert this to smaller or larger
voltages as needed.
Iron Bar
Created
Current
Original Current
Electric Paths
High Voltage
Power Lines
Transformer 120V House
Power Line
Power Plant
Typical
Transformer
ElectroMagnetic Suspender Project #49
Set the slide switch (S5) to both positions and push the
press switch (S2) several times; compare how high the thin
rod will go. Next, flip the switch slide back and forth WHILE
keeping the press switch pushed; the thin rod stays
suspended but its height changes.
The lamps (L4) are used to reduce the current through the
electromagnet, they will not light.
Operation
Build the circuit as shown and drop the thin rod into the
electromagnet (M3).
Assembly
A transformer is a magnetic
bridge, since we use
magnetism to cross an air
gap that electricity cannot
cross by itself.