Two-Speed Fan

Project Number: 13

Parts Needed For Circuit: B1, M1, Fan Blade, S2, L1, 2, S1, 2, 1, 1, 2, 2, 2, 2

OBJECTIVE: To show how switches can increase or decrease the speed of an electric fan.

Description: Build the circuit shown on the left by placing all the parts with a black 1 next to them on the board first. Then, assemble parts marked with a 2. Finally, add the 2-snap wires that are marked for level three. When you close the slide switch (S1), current flows from the batteries through the slide switch (S1), motor (M1), The lamp (L1), and back to the battery (B1). When the press switch (S2) is closed, the lamp is shorted and the motor speed increases. The principle of removing resistance to increase motor speeds is only one way of changing the speed of the motor. Commercial fans do not use this method because it would produce heat in the resistor and fans are used to cool circuits by moving air over them. Commercial fans change the amount of voltage that is applied to the motor using a transformer or other electronic device.