What exactly is the role of fuses in electronic circuits? Sorry if this is a naive question from a beginner.
I ask this because over the many years I've had electronic gadgets and equipment stop working or start smoking or otherwise fail and I've lifted the lid to look inside, I've never yet found a single instance of a repair that involved simply replacing a fuse.
I've always followed the standard advice: check the fuse first but without exception what I've found is one of two things:
1. One or more components on the PCB AND the onboard fuse has blown.
2. One or more components on the PCB have blown BUT the onboard fuse is undamaged.
Apart from these, I can't remember ever finding the fuse in the mains plug blown. It's possible to imagine something like an AC mains electric motor with no electronics involved, blowing a fuse if say, the motor is overloaded or overheated. Replace the fuse and everything will probably be fine.
My assumption has always been that the fuse is a deliberate weak point designed to fail first before current overloads cause damage to the rest of the circuit or something like that. But clearly this can't be right because something must have go wrong within the circuit in the first place which then either causes the fuse to blow afterwards or not.
So in short, what is the fuse supposed to protect?
Thanks for reading.
Trevor
I ask this because over the many years I've had electronic gadgets and equipment stop working or start smoking or otherwise fail and I've lifted the lid to look inside, I've never yet found a single instance of a repair that involved simply replacing a fuse.
I've always followed the standard advice: check the fuse first but without exception what I've found is one of two things:
1. One or more components on the PCB AND the onboard fuse has blown.
2. One or more components on the PCB have blown BUT the onboard fuse is undamaged.
Apart from these, I can't remember ever finding the fuse in the mains plug blown. It's possible to imagine something like an AC mains electric motor with no electronics involved, blowing a fuse if say, the motor is overloaded or overheated. Replace the fuse and everything will probably be fine.
My assumption has always been that the fuse is a deliberate weak point designed to fail first before current overloads cause damage to the rest of the circuit or something like that. But clearly this can't be right because something must have go wrong within the circuit in the first place which then either causes the fuse to blow afterwards or not.
So in short, what is the fuse supposed to protect?
Thanks for reading.
Trevor