The Fuse

Project Number: 14

Parts Needed For Circuit: All The Parts Used From Project #13

OBJECTIVE: To show how a fuse is used to break all current paths back to the voltage source.

Description: Use the circuit built in Project #13. When you close the slide switch (S1), current flows from the batteries, through the slide switch (S1), the lamp (L1), motor (M1), and back to the battery (B1). Pretend the 2-snap wire marked fuse in the drawing on the left is a device that will open the circuit if too much current is taken from the battery. When the press switch (S2) is closed, the light is shorted and the motor speed increases due to an increase in he current to the motor. While still holding down the press switch (S2) down, remove the 2-snap wire marked fuse and notice how everything stops. Until the fuse is replaced, the open circuit path protects the electronic parts. If fuses did not exist, many parts could get hot and even start fires. Replace the 2-snap wire and the circuit should return to normal. Many electronic products in your home have a fuse that will open when too much current is drawn. Can you name some?