Data Sheet

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23. Parts Connected in Series and Parallel
Build the circuit to the left, turn on the switch (62) and
you will light up the two LEDs and the lamp (76) at the
same time, but the lamp (76) is dim. Notice that the
lamp (76) isn’t as dim as it was in project 12. This is
because having two LEDs in parallel with each other
reduces the total resistance in the circuit since there
are two ways for current to ow, and thus more current
is now owing through the lamp (76).
24. Hand Crank Generator
Build the circuit, turn on the switch (62) and then turn the
hand crank generator (94 & 99) and you will light up the
lamp (76). A hand crank generator (94) is a machine
that turns mechanical energy (turning the crank) into
electrical energy (the lamp (76) lighting). Make sure
the hand crank (94) is connected to the generator (99)
properly (the end of the generator that is labeled ‘99’
and has pin connections on the bottom should be open
and connected to the rest of the circuit).
25. Reversing Current
Replace the lamp (76) with the bi-directional LED (71),
then turn on the switch (62) and turn the hand-crank
generator (94 & 99) clockwise and you will light up the
bi-directional LED (71) in red light. Turn the hand crank
generator (94 & 99) counter-clockwise and you will light
up the bi-directional LED (71) in blue light. This shows
that by turning the hand crank generator (94 & 99) in
opposite directions you are reversing the current.
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