Why a lamp tester or fuse tester? Testin cables, wires, lamps… belongs to a repair job and sometimes this becomes too cumbersome since one has only two hands and too often, one has to hold the part being tester and the two probes of an ordinary continuity tester all at the same time.
This fuse and lamp tester enables easy testing of lamps and fuses by using the conductivity of the human body. One of the test probes is connected to the part under test while the other probe is hel dby the normal hand.
When the lamp or fuse is working properly, your eyes will glow in the dark! Just kidding 🙂 . When the lamp or fuse is working properly, a small amount of current flows through the hand which is enough to switch the transistors and light the LED.