PoE switch needs AC

PoE switches do not strictly need AC power; they can operate on either AC or DC, but DC is typically used internally to power devices efficiently.Power Requirements of PoE SwitchesAll PoE switches require an external power source to function, as they contain active electronics such as processors, memory, and power circuits that manage both data and power delivery to connected devices . While most PoE switches are commonly powered via a standard AC connection from a wall outlet, some models can also be powered by a DC source, especially in environments with centralized DC power systems .Why DC is Used in PoEPoE technology delivers power over Ethernet cables, which requires a direct current (DC) supply. DC is preferred because it does not pass through Ethernet transformers, avoiding interference with data transmission . Additionally, computer and network components require a steady, unidirectional flow of electrons to operate correctly, which DC provides. DC power is also safer and more energy-efficient for long-distance transmission within networks .AC vs DC in PracticeAC Power: Most commercial PoE switches are designed to plug into AC mains. The switch internally converts AC to DC to power its electronics and the PoE ports .DC Power: In specialized setups, such as telecom or industrial environments, PoE switches can be powered directly by DC sources. This is useful where AC is unavailable or where a centralized DC power system is used .SummaryWhile PoE switches are often connected to AC power for convenience, they fundamentally operate on DC internally, and some models can accept DC input directly. The choice between AC and DC depends on the deployment environment, power infrastructure, and efficiency considerations. Regardless of the input type, the switch must be powered to deliver both network connectivity and PoE to connected devices .