A fuse is basically a protective device in an electric circuit, which prevents it from overload, overcurrent, etc. An electric fuse was invented by Thomas Alva Edison in 1890. They come in various sizes but all have the same work. Different types of fuses are classified into two types AC fuses and DC fuses. This article explains one of the types of fuses, semiconductor fuse along with its working and applications.
Definition
Power electronic devices operate at very high speeds, enabling instantaneous operations due to their high switching speed. As the name suggests, semiconductor fuses use semiconductors in their construction, with major components including diodes, thyristors, and SCRs. Additionally, manufacturers design semiconductor fuses as a combination of components primarily used for protecting applications like MOSFETs, IGBTs, power supplies, rectifiers, and diodes.
Constructional Point
The construction of semiconductor fuse consists of fuse element surrounded and encased within filler material and fuse body. The fuse element in this fuse uses fine silver, which resists oxidants and has a melting point of 960 °C to withstand the limiter’s maximum operating temperature. Manufacturers compose the fuse body of alumina ceramic for its thermal stability. They design the semiconductor fuse as a high-breaking or current-limiting fuse, also known as ultra-fast fuses or rectifiers. They refer to the time it takes for the fuse element to melt as the preaching time.
Working
The function of a semiconductor fuse is to pass the current energy from the power source to the circuit so that the circuit can function properly. A current overload or short circuit, for instance, has the ability to crack the filament in the fuse and break the power source in the whole circuit. Thus, as the current supply approaches the set limit, the fuse disconnects a circuit. These fuses replace AC and DC fuse applications all over. Any damage to the circuit in case of overload currents will be suffered by the fuse when it disconnects the circuit. This kind of fuse is more applicable in semiconductor protection like transistors, integrated circuits, diodes, etc.
Features and Specialty
It does operate very quickly. The fault condition is detected, and immediately thereafter, the fuse will blow. The very fast response prevents any damage to the circuit. However, in operation, as it very quickly responds by use of semiconductors, it is not applicable to high-voltage rating devices such as motors and heavy-duty loads. So, this fuse is very much suitable for semiconductor devices which are low-current operation devices. Used in different applications, these fuses include the protection from short circuits, overvoltage and overcurrent, slew rate control, TSD (thermal shutdown), and RCB (reverse current blocking).
Applications
The main applications of semiconductor fuses cover protection of semiconductor devices in main power rectifiers, AC and DC Motor Drives, converters, soft starters, photovoltaic inverters, solid state relays, and welding inverters, etc. These fuses are very popular in almost every other power electronics application such as Variable frequency drives, thyristor DC drives & Uninterrupted Power Supplies. These types of fuses will be utilized in short circuit protection, overvoltage and overcurrent protection, slew rate control, TSD (thermal shutdown) & RCB (reverse current blocking) applications.
The protection devices protect the semiconductor devices from short circuiting. The semiconductor fuse is specifically effective in extremely fast acting qualified devices for the protection of semiconductor power devices.
