Electrical model formulation for multicolor light‐emitting diode modules and its application to design dimmable driver

Tunability of correlated color temperature (CCT) and dimmability are the two major sought after features of functional solid-state lighting. This paper presents a low-cost, efficient, single-inductor-dual-output buck driver that facilitates CCT-control and dimming of a light emitting diode (LED) module composed of cool-white and warm-white chips. The proposed driver is designed based on two familiar integrated circuits (ICs), namely LM2596 and NE556. LM2596 serves as the main switching regulator and amplitude modulation (AM) controller whereas NE556 serves as the constant-frequency, dual-output pulse-width-modulation (PWM) controller. The exponential model of LED is exploited for improved estimation of the design parameters of the LED module and the driver circuit. The developed driver prototype is tested for its electrical, photometric, and colorimetric performances. The driver offers a full-load efficiency of about 90% for a 12-W test LED module. Under different operating modes, the LED system can produce warm, cool, or neutral white light and at the same time, the produced illuminance can be varied over a wide range. Moreover, the light flicker is imperceptible since the PWM frequency is set according to IEEE-1789 guideline.

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Design and Development of an Efficient, High Power Factor, Low-Cost, RGB LED System for Tuneable Lighting Application

Bakshi

2023

L&E

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Branded smart red (R) – green (G) – blue (B) light emitting diode (LED) products commercially available in developing countries are too costly to afford for most of the population, especially for household applications. Locally manufactured cheaper alternatives of such products suffer from poor power factor and reduced circuit efficiency. To address these technical issues, a smart RGB LED system is presented here which offers high input power factor, good circuit efficiency, and at the same time lower fabrication cost and user-friendly control interface. The unique features of the proposed system are the front-end AC/DC converter is a constant-voltage, multiple-output flyback converter that mitigates the need of multiple drivers and inductors. The second is that the same converter is operated in discontinuous conduction mode to achieve a high input power factor. The third is that for dimming and colour tuning, pulse width modulation (PWM) control of the MOSFET switches is accomplished by an Arduino Mega 2560 microcontroller instead of other costlier and more sophisticated options. And the fourth is that the microcontroller gets its command signal from a smartphone or computer through an HC‑05 Bluetooth module. Through laboratory testing, it is confirmed that the LED system offers close-to-unity input power factor (0.928–0.985) and high efficiency of (88.14–95.46) % for a wide range of colour and luminous intensity. A comparative study reveals that the developed system is a better option than the earlier reported prototypes of multicolour LED systems in terms of the bill of material, economy, power factor, and efficiency.

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Electrical model formulation for multicolor light‐emitting diode modules and its application to design dimmable driver

Cited by 3 publications

References 28 publications

Dual-output flyback driver topologies for tunable white LED lighting applications

Dual-output flyback driver topologies for tunable white LED lighting applications

An Integrated Circuit Based, Single-Inductor-Dual-Output Buck LED Driver for Dimmable and Color Temperature Tunable Indoor Lighting Application

Design and Development of an Efficient, High Power Factor, Low-Cost, RGB LED System for Tuneable Lighting Application

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