UK Technology Education Centre
Independent Learning Packages

6. The Fuse Tester Circuit

under construction

These diagrams and drawings show one possible design for the fuse tester circuit and the way in which that circuit and its components should be arranged. It is especially important to ensure that the LED is connected correctly.

Circuit Diagram

Pictorial Drawing of the Circuit

A standard plug fuse measures about 20mm from cap to cap.

The fuse acts as a switch when it is held against the heads of the two bolts. If the fuse is good or not broken, then it will form a bridge across the gap, complete the circuit and light the LED. If the fuse is blown, it will not be able to form a bridge and therefore the LED will not light.

You may have noticed that on the opening page of this module the heads of the bolts were used to represent the clown's eyes. Click here to take another look.

Further Reading
A More Complicated Fuse Tester Circuit

4. The Light Emitting Diode
5. Resistors

The Starting Point

The Pivot Point