Low flicker AC driven LED lighting system, drive method and apparatus

An LED lighting device comprising:

• a bridge rectifier;
• a first LED circuit having at least four LEDs connected in series;
• a first switch connected in parallel with a first of the at least four LEDs;
• a second switch connected in parallel with a second of the at least four LEDs;
• a third switch connected in parallel with a third of the at least four LEDs;
• a fourth switch connected in parallel with a fourth of the at least four LEDs;
• a first capacitance circuit, the first capacitance circuit having:
• a first capacitor switch connected to the bridge rectifier and a controller;
• a second capacitor switch connected to at least one LED in the first LED circuit;
• and
• a first capacitor connected to each of the first and second capacitor switches;
• and
• a second capacitance circuit, the second capacitance circuit having
• a third capacitor switch connected to bridge rectifier and the controller;
• a fourth capacitor switch connected to at least one of the first LED circuit, the second LED circuit and the third LED circuit and the controller;
• and
• a second capacitor connected to each of the third and fourth capacitor switches;
• wherein the controller dynamically controls the first, second, third and fourth switches to connect the first, second, third and fourth LEDs to each other in series in response to an input to the controller;
• and
• wherein the controller dynamically closes the first capacitor switch to charge the first capacitor during at least a first portion the input to the controller and dynamically closes the second capacitor switch to discharge the first capacitor to at least one of the at least four LEDs during at least a second portion of the input to the controller;
• and
• wherein the controller dynamically closes the third capacitor switch to charge the second capacitor during at least the first portion of the input to the controller and dynamically closes the fourth capacitor switch to discharge the second capacitor to at least one of the at least four LEDs during at least a third portion of the input to the controller.

An LED lighting device comprising:

• a bridge rectifier;
• a first LED circuit having at least one LED, the first LED circuit being connected to the bridge rectifier using at least a first switch;
• a second LED circuit having at least two series strings of LEDs, the series strings each having at least two LEDs connected in series, the second LED circuit being connected to the bridge rectifier using a second switch;
• a third LED circuit having at least four LEDs connected in series, the third LED circuit being connected to the bridge rectifier;
• a controller for dynamically controlling the switches to connect the alternately connect first LED circuit, the second LED circuit to the bridge rectifier in response to an input to the controller,
• wherein a substantially identical amount of power is consumed by the first LED circuit, the second LED circuit or the third LED circuit when each circuit is individually switched in and connected to the bridge rectifier and provided with any required forward operating voltage;
• and
• at least one capacitance circuit for storing charge and providing current to at least one of the first, second and third LED circuits, the at least one capacitance circuiting including:
• a first capacitor switch connected to bridge rectifier and the controller;
• a second capacitor switch connected to at least one of the first LED circuit, the second LED circuit and the third LED circuit, and the controller;
• and
• a capacitor connected to each of the first and second capacitor switches,
• wherein, the controller closes the first capacitor switch to charge the capacitor during at least a first portion the input to the controller and the second capacitor switch closes to discharge the capacitor to at least one of the first LED circuit, the second LED circuit, and the third LED circuit during at least a second portion of the input to the controller.

A method of driving an LED circuit, the method comprising the steps of:

• rectifying an input AC voltage;
• controlling at least a first switch to connect a first LED circuit having at least one LED during at least a first portion of a half cycle of the input AC voltage;
• controlling at least a second switch to connect a second LED circuit having at least two series strings of LEDs connected in parallel, the series strings each having at least two LEDs connected in series during a second portion of the half cycle of the AC input voltage;
• and
• connecting at least a third LED circuit having at least four LEDs connected in series to the output of a rectifier providing the rectified voltage.

An LED lighting device comprising:

• a bridge rectifier;
• a capacitor;
• a current controlling device connected in series with the capacitor;
• at least four LED circuits connected in parallel, each LED circuit having at least one LED and being connected in series with two switches;
• at least three cross-connecting switches, each cross-connecting switch connecting an output of one LED circuit to an input of an adjacent LED circuit;
• and
• a controller, the controller receiving an input and dynamically controlling each of the switches and cross-connecting switches to connect the at least four LED circuits to the bridge rectifier in a parallel, series-parallel or series relationship in response to the input received by the controller.