What is a Fuse?
Pico Fuse
A fuse is over current protection device, which breaks the circuit in case of an excessive current flow, thus protecting the other electronic components of the circuit from any damage that excessive current may cause. The fuse normally consists of a metal strip or wire that melts when excessive current starts flowing through it.
Fuses are integral parts of power distribution systems to prevent any damage or fire that may be caused as a result of excessive current passing through them.
Fuses are defined to be of two basic types - the slow blow and the fast acting.
The slow blow type of fuse has a coiled construction inside it. These fuses break the circuit only when the excessive current is continuous and not just a current surge. Short circuits are this type of continuous overload which are best protected by slow blow type of fuses.
In fact acting fuses, on the other hand, the fuse opens the circuit very quickly in case of any current surge, even if temporary. This is ideal or analog meter movements which can quickly get destroyed if excessive current flows through them. While a fast acting fuse may be used in place of a slow blow fuse, the reverse should not be done as the fuse may not break the circuit in time to protect the electronic components from damage.
Fuses are given different ratings to determine which fuse is best suited to a particular circuit or system. Rated current of the fuse gives the maximum current that can pass through the fuse without causing it to break the circuit. The I2t value measures the energy required to blow the fuse and indicates the energy that the circuit elements need to withstand before the fuse breaks the circuit.
Author Resource:- Andy Bauer is a tech writer for West Florida Components - an internet based retailer of electronic parts and supplies. Visit West Florida Components for a large selection of electronic components and guides.