LED current balance apparatus

摘要

The present invention provides an LED current balance apparatus, which utilities capacitances coupled to secondary windings of a transformer to store voltage differences between LED strings. Thereby, the driving voltages applied to LED strings are respectively modulated to make the LED strings flowing through a same driving current. A current regulating apparatus is coupled to all LED strings to stabilize total current of the LED strings at a predetermined current.

主权项

1. An LED current balance apparatus, comprising:
a transformer, having a primary winding and a secondary winding, wherein two terminals of the secondary winding are respectively coupled to an LED unit to drive the LED unit lighting; two rectifying energy-storage circuits, respectively coupled to corresponding LED units, wherein every rectifying energy-storage circuit comprises a rectifying unit and an energy-storage unit, the rectifying unit is coupled to a corresponding terminal of the secondary winding for rectifying an electric power supplied by the secondary winding, and the energy-storage unit is coupled to the rectifying unit for storing the rectified electric power; at least one capacitive unit, coupled to a corresponding terminal of the secondary winding for storing a bias voltage; and a current regulating apparatus, having a common node coupled to the LED units and stabilizing a sum of currents flowing through the LED units at a predetermined current.