Elenco Green Projects - Manual (Page 17)

50mA
0.5mA
Project #6
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. Place the circuit so the solar cell is
in bright sunlight or near an incandescent light
bulb. Set the meter (M6) to the 0.5mA or 50mA
setting.
The solar cell is charging the battery and the meter
is measuring the current. The current depends on
the type and brightness of your light source, and
how much your battery needs recharging. Adjust
the position of the solar cell to make the highest
current; in bright sunlight it will be around 10mA.
When placed in sunlight or about 12 inches from a
60W incandescent light bulb, the solar cell will
typically recharge the battery in a few hours.
Current will flow into the battery even when it is
fully charged. You can’t hurt the battery by
overcharging with the power sources in this kit.
Solar Charger
Project #7
Modify the preceding circuit to match this one.
Set the meter (M6) to the 0.5mA setting. Place
the solar in sunlight or near an incandescent
light bulb. The solar cell is charging the battery
and the meter is measuring the current.
This circuit uses a resistor in the pivot stand to
change the 0.5mA scale on the meter to a 5
mA scale, so read the current on the 0-5
scale. Charging current is usually in this
range. Place your hand above the solar cell to
see how easily the current changes, and try
different light sources.
Solar Charger 5mA
Solar energy is free,
abundant, and causes no
pollution. However it is
difficult to harvest it
because even low power
solar cells are expensive.
0.5mA
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