Solid-State Lighting With An Emergency Driver

An LED luminaire emergency driver comprises a rechargeable battery, a charger circuit, an LED driving circuit, and a charging and discharging control circuit. The LED luminaire emergency driver is intended to automatically supply a first supplied voltage to drive LED arrays in an event of a normal power failure. The LED driving circuit is configured to convert a terminal voltage from the rechargeable battery into the first supplied voltage when a line voltage from AC mains is unavailable. The charging and discharging control circuit comprises a relay switch and a transistor circuit assembly configured to sense a charging voltage, to control switching between normal power and an emergency power to operate the LED arrays, and to meet regulatory requirements without operational ambiguity and safety issues.