RS PRO offer this range of miniature ceramic cartridge fuses which are either ultra-rapid fuses (FF) or fast acting fuses (F). The ultra-rapid fuses operate at higher temperatures so are ideal to provide circuit protection to semiconductor devices. The fast-acting fuses are ideal to protect less sensitive components.

Fast acting fuses are the most popular fuse and are ideal for providing protection to devices or internal circuits from short circuits and overcurrent. They are deliberately weaker components which, when too much current is drawn, will blow. Once the fuse has blown it will need replacing in order to make the circuit complete and allow the flow of current.