AC LEDs: What are they and what benefits do they offer?

By Roger ElliottJune 10, 2016

This is part two of our four part LightFair 2016 series.   

AC LED is one of the most exciting things happening in the LED industry in recent times and it’s a trend we saw at LightFair this year. So what is AC LED and why is it gaining momentum?

First off, this is a technology that allows LEDs to be driven directly from a 120V AC without the use of any capacitors, coils or resistors. By eliminating the costly AC to DC LED drivers, the AC LEDs reduce the system size and cost, all the while delivering high quality of light.

How AC LEDs Work

In traditional DC LED lights, there’s a driver that regulates the constant voltage or current to the LED light engine. The AC LED scheme, however, doesn’t require a typical driver. Since the module can be easily plugged to a direct line voltage, the power is transmitted systematically and used more efficiently.

Usually for each half-cycle of the AC LED’s sinusoidal waveform, half of the LEDs emit light and the rest of the half remains dark. The same process is reversed during the next half of the cycle. This configuration, often referred to as “true AC” or an antiparallel approach, enables a large number of LEDs in series to operate directly from mains power.

Essentially, by loading up LEDs directly on the end, the power is distributed and delivered more effectively without the intervention of complex electronics.

Bypassing the Driver Provides Significant Benefits

The most distinguishing feature of an AC LED is it doesn’t need to have a LED driver. Eliminating the LED driver and operating directly from the mains voltage make the system more reliable and increasingly flexible. Moreover, in a driver free system the failure rate is also considerably lessened due to the effective management of thermal requirements. Additionally, the removal of the external drivers saves space plus cuts weight.

Exceptional Management of Thermal Requirements

Efficient management of thermal requirements and optical outputs, make AC LEDs a compelling proposition. Effective administering of thermal requirement controls excess heating of the system, which helps deliver improved performance and enhanced productivity.

Dimming Effects

A significant element of AC LEDs is its dimming feature. Compatible with phase-cut dimmers, the AC LED lowers the light output without sacrificing color accuracy. A realistic dimming rate is considered to be something around five to ten percent, however dimming performances might slightly vary across different types of AC LEDs that are commercially available in the market today.

Key Features of the AC LED Scheme

AC LED technology offers tremendous benefits over more traditional DC LED lights. It helps luminaire manufacturers and designers reduce cost and curtail down complexities to a great extent. The most prominent characteristics of the AC LED are as follows -

  • AC driven without converter or driver
  • Simplified circuit design
  • No conversion loss
  • Reduced costs
  • No lifespan reduction by secondary components
  • Dimming available
  • No power supply to clog thermal path

The AC LED lighting is a revolution in LED technology. The progressive module delivers high quality light efficacy without the need to sacrifice power factor or luminous efficiency. AC LEDs are energy saving, reliable and a convincing platform for retrofit lamps, architectural and landscape lighting and other general lighting applications.

WPGA’s newest supplier, Seoul Semiconductor, provides LEDs for automotive, lighting, appliance, mobile and signage, as well as solutions for the back and smart lighting markets. Their Achrich family of products have one of the lowest THDs and one of the highest power factors in the world. Learn more about Seoul Semiconductor by visiting and contact your WPGA Lighting Solutions Expert today.