AC-powered LED light engines, integrated circuits and illuminating apparatuses having the same

Abstract

Disclosed are novel AC-powered LED light engines for Solid State Lighting (SSL) able to achieve a high PF and a low THD without a traditional PFC. Getting rid of bulky, and costly magnetic components, short-life electrolytic capacitor, and EMI-causing fast switching, the disclosed AC-powered LED light engines ushers in a cost-effective, and energy-efficient LED driver design while eliminating the short-life electrolytic capacitor in an LED driver and reducing the Total Cost of Ownership (TOC). Thanks to no bulky components, the disclosed AC-powered LED light engines in a discrete or an integrated circuit form could be applied to the increasingly popular Driver-on-Board (DoB) design. Aside from being TRIAC-dimmable via legacy phase-cut dimmers, the disclosed LED light engines could also be made PWM-, analog-, or rheostat-dimmable with the incorporation of an appropriate dimming circuit to modulate the average LED current, adding more flexibility and versatility to dimming applications.

Description

technical field [0001] The present invention relates to an LED light engine (light engine) powered by AC, which is used to control the number of lighting or extinguishing of multiple LED sub-arrays and the current value of the LEDs according to the voltage level of the rectified sine wave input voltage The light engine, and in particular, can maintain the line current waveform as a good waveform close to a sine wave during the entire dimming range, maintain almost the same high power factor and low total harmonic distortion (Total Harmonic Distortion, THD), and Smoothly brighten or dim external LED sub-arrays through a shared current sensing and modulating unit. Background technique [0002] Light-emitting diode (LED)-based lighting devices have a relatively long lifespan, are less susceptible to interference from external environments, and are less susceptible to damage, so they have gradually become the first choice for lighting equipment. [0003] Technically, LEDs requi...

AI Technical Summary

Problems solved by technology

The first problem is that traditional LED drivers have to use complex, expensive and short-lived drivers such as electromagnetic interference filters (EMI filters), bridge rectifiers, and short-lived power factor correctors (power factor correctors, PFCs). circuit

[0005] The second problem is that during the no-load period, no current flows through the LEDs, causing flickering of the lighting equipment

The third problem is the low power factor, which usually occurs in small power power factor correctors, which cannot accurately detect the weak loop current to correctly correct the AC input current waveform as a sinusoidal waveform, and the power factor corrector cannot properly Maintain the line current and the waveform and phase of the line voltage to achieve high power factor

[0006] In addition, the traditional phase-cut dimming method can also achieve the dimming effect by cutting off the leading or trailing edge conduction angle of the line current waveform. Will lead to serious total harmonic distortion and power factor drop

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