Elenco Circuit Maker Skill Builder 125 - Manual (Page 46)

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Project #86 Light Makes Light
Project #87
Go & Glow
Project #88 Spin & Stop
!
WARNING: Moving parts. Do not touch the fan or
motor during operation.
Build the circuit to the left. Cover the photoresistor, turn the switch on,
and notice that the LED is on for several seconds and then goes off.
Uncover the photoresistor and place the unit near a light and the LED
will light. Cover the photoresistor (RP) again and the LED will turn off.
The resistance of the photoresistor decreases as the light increases
activating the U1 IC that varies the voltage to the LED making it light.
Use the circuit from Project #86. Connect the motor (M1) across points
A1 and C1 on the base grid, and remove the photoresistor (RP). Turn
the switch on and the LED (D1) lights for several seconds then goes
out. Turn the shaft of the motor and the LED will light again. As the
motor turns, it produce a voltage. There is a magnet and a coil inside
the motor. When the axis turns the magnetic field will change and
generate a small current through its terminals. This voltage then
activates the music IC.
Place the fan on the motor and turn on the slide switch (S1). The motor
spins briefly as the 470mF capacitor (C5) charges up. Turn off the slide
switch and push the press switch (S2) to discharge the capacitor and
reset the circuit.
You can bypass the capacitor by pushing the press switch while the
slide switch is on. This lets the motor spin at full speed and also lights
the lamp.
CM-125_Manual_031514.qxp_CM-125_Manual_031514 4/2/14 12:20 PM Page 46