Semiconductor fuses are used, as the name implies, in semiconductor products to prevent damage from overloads. They aren't usually found in consumer products, but rather in solid state relays and other semiconductor applications. Semiconductor fuses are used because of their fast reaction times. Semiconductors can be sensitive to conditions that cause a fuse to blow; to prevent damage to the system a quick arrest of the overload is needed. Semiconductor fuses limit short circuit times drastically. They are often designed using a series of silver strips--the higher the amp rating, the greater the number of strips. The silver is housed in a tube or ceramic enclosure filled with sand made from pure quartz. Under normal conditions, the silver remains intact, but melts the moment a fault is detected.
|Jennifer Mathes, Ph.D.|