Elenco Electronics 202 - Manual (Page 125)

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Project #296
OBJECTIVE: To control an oscillator circuit using light.
Set the adjustable resistor (RV) to the middle position and then turn on
the slide switch (S1). Wave your hand over the photoresistor (RP) and
the sound changes. You can adjust the sensitivity by moving the
adjustable resistor to a different position.
Light Oscillator
Project #297
OBJECTIVE: To build a stepper circuit that powers a motor,
speaker and LED.
Set the adjustable resistor (RV) to the far left and turn on the slide
switch (S1). The circuit produces around two pulses per second,
which power the motor (M1), speaker (SP) and LED (D1). Increase
the rate by moving the adjustable resistor to the left.
Change the 10 μF capacitor (C3) to the 100μF(C4) and see how the
time changes.
Sound, Light & Motor
Stepper Circuit
!
WARNING: Moving parts. Do not touch the fan or
motor during operation.