US Patent 7208885 Dimming control method and lighting system with dimming control

A dimming control method and a lighting system having dimming control, in which the lighting system (200) includes an input unit (210), a light-emission unit (260) and a current control circuit (220). The dimming control method is characterized by outputting a continuous current with a varying amplitude to the light-emission unit under a higher brightness, and clamping the amplitude of the current output to the light-emission unit to a fixed value and outputting a discontinuous current with a fixed amplitude and a varying duty cycle to the light-emission unit under a lower brightness.