An AC LED (alternating-current light emitting diode) is an LED which operates straight off of AC line voltage. Semiconductor light emitting diodes (LEDs) have advantages as light sources when it comes to output, efficiency, and reliability. On the whole, LEDs are driven at a low DC voltage. An additional circuit (e.g., an AC/DC converter) that delivers a low DC output voltage is needed to drive a light emitting diode at a normal voltage (e.g., AC 220V). Even so, the use of the extra driver circuit may not only complicate the configuration of an LED module, but also lower the efficiency and reliability thereof during a process of converting supply power. Furthermore, an additional electronic component together with a light source raises manufacturing costs and product size, and electro-magnetic interference (EMI) characteristics are deteriorated as a consequence of periodic components throughout a switching-mode operation. Contrary to conventional direct-current light emitting diodes (DC LEDs) which need an AC-to-DC power supply, AC-LEDs are revolutionary and appealing simply because they're directly driven by an AC power supply with higher efficiency and reliability than conventional DC LEDs. Through a design of the architecture of bridge-rectifying, the AC LEDs can directly make use of an AC power supply for driving. AC LED light engines feature longer life than traditional driver-based luminaires, whilst not having bulky traditional driver. The absence of a driver brings about many potential advantages, including lower cost, smaller system envelope, better efficacy, and improved reliability, whilst the chip-level architecture may result in improvements in efficiency as opposed to single-chip high-power LEDs. The devices offer uncomplicated assembly and built-in high temperature protection. The main advantage, nonetheless, is the compatibility with the existing lighting and electricity infrastructure. AC LED light engines provide a compelling platform tailored for retrofit lamps. Yet another benefit of the innovative configuration is the full range dimmability.