Elenco Green Projects - Manual (Page 54)

Project #82 Solar Light Charger
Project #81 Solar Light Clock
Solar cells are often
used with rechargeable
batteries, since the sun
isn’t always shining.
Used together, the solar
cell and battery can run
the clock for a very long
time.
0.5mA
The solar cell only produces
a small amount of electricity.
The yellow LED needs a lot
more electricity than the
clock, so the solar cell can
only run the LED and
charge the battery if the light
source is very strong.
Assemble the pivot, mount the solar cell (B7) on it,
and place it next to the circuit as shown. Connect the
solar cell to the circuit using the red and black jumper
wires. Set the meter to the 0.5mA setting. Set the slide
switch (S5) to position B. Place the circuit so the solar
cell is in bright sunlight or close to an incandescent
light bulb. The display on the clock (T2) should be on.
Now set the slide switch to position C, to add the
rechargeable battery to the circuit. See if you can
adjust the position of the solar cell on the pivot to
make the meter (M6) measure a current.
If your light source is strong enough then the solar cell
will charge the battery while running the clock. If your
light source is weak then the battery will run the clock.
If you would like to set the time on the clock, see
page 4.
0.5mA
Assemble the pivot, mount the solar cell (B7) on it, and place it in the
circuit as shown. Connect the solar cell to the circuit using the red and
black jumper wires. Set the meter to the 0.5mA setting.
Set the slide switch (S5) to position B. Place the circuit in bright sunlight
or 3-6 inches from an incandescent light bulb. Adjust the position of the
solar cell on the pivot to make the yellow LED (D5) brightest.
Now set the slide switch to position C, to add the rechargeable battery
to the circuit. If your light source is strong enough then the solar cell will
charge the battery, and the meter will measure the charging current. If
your light source is weak then the battery will light the yellow LED.
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0.5mA
0.5mA