Large scale networks used for cloud computing, search engines, and similar applications, typically include tens or hundreds of servers for load sharing and for redundancy. These networks need to be highly scalable, so there is a need to frequently add more servers to the network infrastructure.
Large scale server networks consume very large amounts of electric power and generate a lot of heat. Any manner of reducing power consumption is desirable.
Fuses and/or relays may be used to cut delivery of power to a server in case of a fault, for example in the occurrence of a short-circuit. However fuses are typically slow to react and must be replaced after a short-circuit. Relays may protect a server from a short-circuit, and may be rearmed, but are very slow to react. Additionally, current that is provided to a server must flow through contacts of a relay, causing important power losses. Measurements have shown that, typically up to 4% of the power delivered to a server may be lost in a relay. The energy wasted in the relay causes heat accumulation in the power supply that, for a large server bank, translates into important cooling needs.
Availability requirements for large scale server networks are extremely high, so maintenance activities, including connection of additional servers and replacement of failed units must be done without delay and without service disruption.
One particularly disturbing circumstance to personnel who install servers is that inrush of electrical current into a server when initially plugged into a power supply oftentimes causes sparks at the level of a plug-in connection. Such sparks can be quite disturbing to the operators who install the servers and may also cause the accumulation of carbon deposits on connectors. The carbon deposits create undesired impedance on the connectors, causing of power losses and eventually causing failed connections to some servers. These carbon deposits may eventually lead to fire hazards.
Thus, there is a desire for power supplies that address the aforementioned drawbacks.