Driverless AC LED Light Systems

Might the future of LED be driverless? Many consider the LED driver to be the bottleneck in LED fixtures and bulbs. But how can the LED get by without it, especially in a climate that is becoming ever-focused on the health effects of lighting (flickering and the like).

It is widely known that LED is 70-90% efficient when compared to incandescent and halogen, in addition to a much longer lifetime. But it has become reliant on the LED driver to be powered due to the fact that LED lights are driven by DC voltage while our mains power supply is AC. Thus the driver’s primary purpose is that of an AC to DC converter, converting the AC power from mains to a suitable DC voltage that will power the LED light.

Driver-less AC LED Lights – How did we get here?

While not prominent in the marketplace yet, Driverless LED light systems are starting to gain traction. AC driverless LED bulbs can be directly plugged into AC mains without an LED driver needed. This eliminates the power loss experienced during the AC to DC conversion, in addition to taking out one of the costs in manufacturing the LED. As mentioned above, one of the biggest considerations is the flickering caused in older LED lights, which can generally be attributed to the old LED driver circuits.

Driverless LED lights are powered by an AC LED light engine, which converts the electrical energy to the lumens of the light. These AC LED light engines can be a circuit board with LED chips mounted in it, allowing it to be easily affixed into an AC socket.

But it wasn’t easy getting it to work. Initial attempts at driverless AC LED light engines resulted in failure. The LEDs in these systems were connected in an anti-parallel way, as one side of the pairs is forward phased and the other is reverse phased. This led to an efficient system with a high power factor, but one plagued with flickering. These systems needed double the LEDs, as the forward set would go on and then switch to the reverse, producing a flash effect visible by the human eye.

The next attempt at driverless AC LED was developed, with the goal to lower the LED chip counts. Instead of double the LEDs, a bridge rectifier diode is utilized, allowing both negative and positive cycles to pass through the LED and keep it on during both cycles. But more work was needed to get the flickering to subside. A switching controller is added to the circuit to individually control the LED’s, keeping them at the same level as the LED voltage matches the power line voltage.

What are the Advantages of Driver-less LED Lights?

• Driverless LED systems are easier to manufacture and cost less with the driver component axed.
• Shape is no longer an issue – LED products can be designed in various shapes and sizes with the driver out of the equation.
• Improved flicker index, making it ideal for offices, hospitals and education applications.

Some of the leaders in Driverless AC LED light engines are the typical big LED names, from Cree to Samsung. Expect to see this technology researched and enhanced over time, as manufacturers look for improvements in efficiency and user experience with more and more consumers cognizant of the cost and health effects of lighting.