Patent attributes
A portable lighting device such as a flashlight, headlight, or electric lantern comprises an onboard power supply (e.g., one or more batteries), a light source (e.g., one or more LEDs), and an onboard controller for regulating the light emitted by the portable lighting device. The onboard controller is in communication with one or more sensors configured to monitor component characteristics, such as a light source temperature and/or a power supply voltage. Based at least in part on the monitored characteristics, the controller is configured to generate a start-up ramp profile to gradually increase the brightness level emitted by the light source according to a defined brightness rate of change. After a power switch for the portable lighting device is activated, the controller initializes the start-up ramp profile to gradually increase the brightness emitted from the portable lighting device to a steady-state brightness level.