Control of Solid-State Lamps Using a Multiphase Pulsewidth Modulation Technique

摘要: This paper describes a multiphase pulsewidth modulation (MPWM) technique used for controlling the luminance of solid-state lamp (SSL). For SSL consisting multiple high-brightness LEDs (HBLEDs) that are electrically connected as series-parallel network, desired output is obtained by modulating average current through each parallel HBLED string. In conventional (PWM) and pulse code techniques, string controlled simultaneously varying “on” time duration regulator circuit, resulting in large transients pulsating light output. The proposed MPWM operates uniformly time-shifting individual on/off control signal pulses, thus avoiding transients. When compared to PWM dimming, dimming reduces risk visible flicker lowers magnitude audible noise. reduced results lower electromagnetic interference enables optimization size passive components. this paper, operation explained detail. Experimental presented 27 W boost converter powering 64 HBLEDs with digital voltage loop implemented using Virtex-4 field programmable gate arrays.