A PFC Modified Landsman Converter-Based PWM-Dimmable RGB HB-LED Driver for Large Area Projection Applications

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In this paper for power factor correction (PFC) a modified-Landsman converter is introduced. The application is targeted for high brightness (HB) projection application with brightness control for high brightness red-green-blue (HB-RGB) LED. A pulse width modulation (PWM) technique is used for intensity control to achieve brightness control of LED driver. The proposed PFC converter is used to feed a dual output flyback DC-DC converter which supplies power to the forced cooling unit and the LED module with galvanic isolation. The brightness control of LED is performed by synchronous-buck converter. The modified-Landsman converter operates in discontinuous output inductor current mode for PFC at universal AC mains. A prototype of the proposed LED driver is experimentally verified. The performance of proposed driver is evaluated at full and light load condition for universal AC mains (90V-265V) over a full range of brightness. The power quality parameters are found within the acceptable limits of harmonic standard IEC 61000-3-2 for universal AC mains.

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