Ordinarily, electronic systems are powered by a single main power supply, but when high availability is important, as in computer servers and network equipment, the systems are typically powered by at least two power supplies to provide redundancy. If one supply fails, the other can still power the system for uninterrupted operation. In this scenario, each supply can handle the entire load current. This is known as 1+1 redundancy, the first “1” denoting the number of operational supplies, while the second “1” denotes the extra supply. This discussion will be limited to the two supply system as that is the most common one for redundancy. Another situation where supplies are paralleled is to build a bigger supply from smaller ones. Current sharing is an essential requirement for this kind of power system.