What's mean Protection Circuits (1)?

What's mean Protection Circuits (1)? What's mean Protection Circuits (1)?
Most battery packs include some type of protection to safeguard battery and equipment, should a malfunction occur. The most basic protection is a fuse that opens if excessively high current is drawn. Some fuses open permanently and render the battery useless once the filament is broken; other fuses are based on a Polyswitch? which resembles a resettable fuse. On excess current, the Polyswitch?creates a high resistance, inhibiting the current flow. When the condition normalizes, the resistance of the switch reverts to the low ON position, allowing normal operation to resume. Solid-state switches are also used View the rest of this article