Method and circuit for controlling an LED

A control circuit coupled to a power line controlled by a dimmer having a switching device, the control circuit comprising:

• (a) a hold network that receives a variable input voltage from the dimmer-controlled power line and maintains a minimum hold current for the dimmer when the switching device is in an “on” state;
• (b) a filter that receives the variable input voltage and is configured to damp inductive-capacitive (LC) resonances;
• (c) a bridge rectifier that receives and converts the damped variable input voltage to a fixed polarity variable input voltage;
• (d) a storage capacitor that maintains fixed polarity variable input voltage for the control circuit;
• (e) an active power factor correction circuit that receives power from the bridge rectifier and the storage capacitor and draws an average continuous current when the switching device is in the “on” state;
• (f) a current controlled flyback transformer having a primary winding, a load winding, and a sensory winding, each of the load winding and the sensory winding being set to a phase, the phases of the load winding and the sensory winding being substantially equal, the primary winding receives a controlled current from the active power factor correction circuit and the load winding generates an output current;
• (g) a rectifier and filter circuit that receives the output current from the load winding and generates a rectified and filtered output voltage;
• (h) at least one light emitting diode (LED) that receives the output voltage from the rectifier and filter circuit, the at least one LED outputting visible light;
• (i) a positive voltage feedback circuit that senses a feedback voltage across the at least one LED, through the current-controlled flyback transformer, and sends the feedback voltage to the active power factor correction circuit, the positive voltage feedback circuit being coupled to the sensory winding;
• (j) a series regulator electrically coupled to a series regulator winding of the current-controlled flyback transformer, the series regulator providing a regulated voltage to the control circuit;
• and
• (k) a pump back power circuit electrically coupled to the current-controlled flyback transformer that applies a bias voltage to an output of the bridge rectifier to power the active power factor correction circuit when the switching device is in an “off” state.