DIMMABLE LIGHT GENERATING DEVICE

摘要

A wake-up lighting device is described, comprising a gas discharge lamp (10) and a lamp driver (1; 2) comprising a power source (100) capable of generating spaced-apart current bursts (51) of alternating lamp current (I). The wake-up lighting device is capable of operating in an off-mode in which no lamp current is generated, and is adapted to switch from its off-mode to a wake-up mode in which the power source (100) operates to: -initially generate an alternating lamp current (I) with a minimum duty cycle value (?T) and a reduced current amplitude (IR) close to zero; -subsequently gradually increase the current amplitude while keeping the duty cycle (?) constant at the minimum duty cycle value (?T), until the current amplitude reaches a nominal current amplitude (IM); -subsequently gradually increase the duty cycle (?) while keeping the current amplitude constant at the nominal current amplitude (IM).