POWER SOURCE/SUPPLY
January 14, 2022
Most LED systems use electronic drivers to convert AC mains voltage to forward voltage DC (Direct Current). Some LED chips can work on AC, but DC operation is most prevalent.
The current delivered to LED chips rises exponentially with the applied voltage. A slight change in voltage can cause a substantial change in current. Therefore, current through the LED must be regulated by an external circuit such as a constant current source to prevent damage. Since most common power supplies are constant-voltage sources, LED fixtures must include a power converter, or at least a current-limiting resistor.
Installers and specifiers pairing various LED lighting components should understand whether the system is “Constant Current” or “Constant Voltage”. This understanding ensures compatibility between the power supply and the LED array. LED fixtures with combined components already take this into account.