Motor-Controlled Lamp

Project Number: 73

OBJECTIVE: To turn a lamp on and off using the voltage generated when a motor rotates.

Description: Use the circuit from Project #72. Remove the whistle chip (WC) and connect the motor (M1) across points A & B. Turn the slide switch (S1) on and turn the shaft of the motor and the lamp (L1) will light. As the motor turns, it produces a voltage. This is because there is a magnet and a coil inside the motor. When the axis turns the magnetic field will change and generate a small current in the coil and a voltage across its terminals. The voltage then activates the music IC (U1).