Elenco Snaptricity® - Manual (Page 30)

1A
-29-
Educational Corner:
Series Swapping Project #20
Which way does electricity
really flow? In the Electric Paths
drawings (schematics), electricity
is shown flowing from the “+”
battery terminal, through the
circuit, and back to the “–” battery
terminal. This is how electricity
was presumed to flow beginning
with discoveries by Benjamin
Franklin in 1747. Later
discoveries in sub-atomic physics
showed that the charged particles
that were moving (electrons) had
a “–” charge, and that they were moving from “–” to “+” charged
materials.
However, understanding circuits
is easier if you assume electricity
flows from “+” to “–”, and all circuit
analysis is done this way.
1A
Electric Paths
Push the press switch (S2); the lamps (L4) light and the
meter (M5) measures the current through the circuit.
Now swap the positions of any of the lamps, 3-snap wires,
the press switch and the meter (the meter should always be
placed so it hangs out of the circuit). Read the current on the
meter, it should be the same however the parts are arranged.
Note: Your M5 meter is a simple meter. It may read zero on
this scale even though a small current is flowing.
Operation
This circuit shows that rearranging parts that are connected
in series does not change the circuit, because the meter
measured the same current for each arrangement.
Description
Build the main circuit and set the meter (M5) on the 1A
setting.
Assembly
Examples
Snappy says: In the first moment after you press
the switch, the meter will show a higher “surge”
current. Light bulbs have less resistance when
you first turn them on, then increase resistance as
they get bright.