Elenco Green Projects - Manual (Page 64)

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Project #101 Energy Converter
Motor Speed LED
In this circuit we use the LED’s (D1 &
D5) and horn (W1) too indicate if the
motor (M4) is spinning. Set the slide
switch (S5) to position C, the yellow LED
lights, indicating the motor is not
spinning. Pushing the press switch (S2)
bypasses the yellow LED, and it turns
off. The voltage across the motor, red
LED, and horn increases so they
activate.
In this project you’ll convert one form of
energy to another. Place the solar cell in
sunlight or about 12 inches from an
incandescent light bulb of 60W or more.
Adjust the light on the solar cell to make the
red LED (D1) brightest. The solar cell
converts light energy into electrical that lights
the LED and charges the battery (B4).
The electrical energy charges the battery,
converting it into a chemical form. When you
press switch S2, chemical energy in the
battery makes electrical energy, which runs
the motor. The spinning motor shaft is
another form of energy called motion.
If you prefer, you can mount the solar cell on
the pivot stand, connect it to the circuit using
the red & black jumper wires, and then adjust
the pivot so the solar cell faces the light.
Project #100
+
Check your thermostats
at home and see if an
LED or fan symbol
lights when the heater
or air-conditioner is on.
See projects 1 & 3 if you need to recharge the battery (B4).