Motor (Project)

Project Number: 23

Description: Build the circuit shown. Set the meter to the 50mA setting and place the wind fan on the motor (M4). Push the press switch (S2) and watch the current on the meter as the motor speeds up. Do you know why the current drops as the fan speeds up?

Snappy: How does electricity turn the shaft on the motor? The answer is magnetism. Electricity is closely related to magnetism, and an electric current flowing in a wire has a magnetic field similar to that of a very, very tiny magnet. Inside the motor is a coil of wire with many loops. If a large electric current flows through the loops, the magnetic effects become concentrated enough to move the coil. The motor has a magnet inside, so as the electricity moves the coil to align it with the permanent magnet, the shaft spins.