Project #654, Ic motor speed, Project #655 – Elenco Projects 512-692 User Manual
Page 68: Sound & light flasher

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Project #654
OBJECTIVE: To modify project #653 so the motor slows down.
IC Motor Speed
Turn the slide switch (S1) on. As the output from the IC (U2) drives the
transistor (Q1), the motor (M1) spins and the display (D7) lights.
Instead of turning off as in project #653, the motor slows down and the
red LED (D1) lights.
Modify the circuit by placing a jumper wire across points A & B. Now
the circuit pulses and then runs continuously for a short time.
Project #655
OBJECTIVE: To use the alarm IC to drive the motor, speaker,
LED and bulb.
Sound & Light Flasher
Turn the slide switch (S1) on and the speaker (SP) outputs the sounds
from the alarm IC (U2). The IC also drives the transistor (Q1) causing
the motor (M1) to spin and lights to flash.
!
WARNING:
Moving parts. Do not touch the fan or
motor during operation. Do not lean over the motor.
!
WARNING:
Moving parts. Do not touch the fan or
motor during operation. Do not lean over the motor.