Abstract: Methods and systems for improved dimming of LED based illumination devices are described herein. An AC input voltage provided to an LED driver is rectified and the rectified signal is monitored by a Rectified Voltage Monitor (RVM) circuit. The RVM circuit generates a low voltage monitor signal indicative of the shape and peak voltage of the rectified signal. The monitor signal and the rectified signal are communicated to a power converter of the LED driver. The controller of the power converter employs the monitor signal to maintain efficiency and stability of the LED driver over an extended range of AC input voltage. The instantaneous voltage of the rectified signal is divided-down, and the peak value of the divided-down rectified signal is captured and stored on one or more capacitive elements. In another aspect, the peak voltage stored on one or more capacitive elements is less than 100 Volts.

Abstract: Methods and systems for improved dimming of LED based illumination devices are described herein. An AC input voltage provided to an LED driver is rectified and the rectified signal is divided down by a voltage divider circuit to supply electrical power to a dimming interface circuit. The fraction by which the voltage divider circuit divides down the rectified signal is controlled by a Dynamic Input Voltage Compensator (DIVC) based on the peak value of the rectified signal. In this manner, the DIVC increases the range of AC input voltage to the LED driver while maintaining efficiency and stability of the LED based illumination system by reducing the variation of the voltage supplied to the dimming interface circuit over a larger range of AC input voltage.

Abstract: Methods and systems for controlling current provided to one or more LEDs for a period of time after power supplied to the LED driver is shut down are described herein. By controlling current through the one or more LEDs after shutdown, the light emitted from the one or more LEDs transitions to zero at a predictable rate with a predictable lag time. An LED based illumination system includes an energy storage element and a controlled luminous drawdown module electrically coupled between one or more LEDs and an electrical power converter employed to control current provided to the one or more LEDs during normal operation. The controlled luminous drawdown module senses a reduction in voltage at the output of the electrical power converter and operates to control current flow through one or more LEDs of the LED string until electrical energy stored in the electrical storage element is depleted.

Abstract: Methods and systems for improved control of dimmable, white color tunable, multiple channel LED based illumination systems are described herein. The methods and systems described herein improve the utilization of LEDs comprising a multiple channel white light LED based illumination system, along with improved control of brightness and color of emitted light. In one aspect, a multiple channel electrical power driver includes an independent current controlled Direct Current/Direct Current (DC/DC) electrical power converter electrically coupled to each LED string having a different color output. The use of independent DC/DC power converters enables current to be supplied to each LED channel simultaneously up to the rated maximum continuous operating current level in each channel. Thus, the sum of the current provided to each LED channel exceeds the rated maximum continuous operating current of each of the LED channels.