Fuse Monitor / Alarm
A simple way
to see if a fuse has blown without removing it from its holder. Its not
often you can design a circuit using just two components, but with just one
resistor and an LED this circuit
provides visual indication of when a fuse has blown.
LED 1 is normally not lit, being
"short - circuited " by the fuse, F1. Should
the inevitable "big-bang" happen in your
workshop then LED1 will illuminate and led you know all about it! Note
that the LED will only light under fault
conditions, i.e. a short circuit or shunt on the load. In this case the supply current is reduced to a
safe level by R1.