Constant power supply for LED emergency lighting using smart output resetting circuit for no load conditions
AssigneeABL IP Holdings LLC
InventorJie Wang
Life of this patent
Estimating the term…
Abstract
A constant power backup power supply for LED lighting fixtures is disclosed. The power supply includes a storage battery that is charged while an AC power source is in an ON condition. When AC power transitions to an OFF condition, a capacitor bank charged by the battery supplies current to the primary side of a flyback converter operating in discontinuous conduction mode. The secondary side of the flyback converter supplies constant output power to the LED lighting fixture for an arbitrary output voltage within a predetermined range.
Claims18
A power supply for driving an LED light source, the supply comprising:
- a power source adapted to provide DC electrical current;
- a constant power LED driver circuit comprising a flyback converter comprising a transformer having a primary inductor winding that is electrically coupled to the power source, and a secondary inductor winding that is selectably electrically coupled to the LED light source;
- further comprising one or more capacitors electrically interposed between the primary inductor winding and the power source, the one or more capacitors having a capacitance sufficient to supply sufficient current to the primary inductor winding to supply constant power to the LED light source over a predetermined output voltage and power range
- wherein the power supply is electrically interposed between an AC current source and the LED light source, and wherein the power supply further comprises an emergency LED driver and external AC LED driver switcher circuit that electrically couples the AC current source to the LED light source when the AC current source is in an ON condition, and which alternatively electrically couples the LED driver circuit to the LED light source when the AC current source is in an OFF condition.
A method of providing power to an LED light source, the method comprising:
- providing a power source adapted to provide DC electrical current;
- and
- providing a constant power LED driver circuit comprising a flyback converter
- comprising a transformer, wherein
- the flyback converter has a primary inductor winding that is electrically coupled to the storage power source, and
- the flyback converter has a secondary inductor winding that is selectably electrically coupled to the LED light source;
- and
- further comprising providing one or more capacitors electrically interposed between the primary inductor winding and the power source, the one or more capacitors having a capacitance sufficient to supply sufficient current to the primary inductor winding to supply constant power to the LED light source over a predetermined output voltage and power range.
Dependencies are inferred from the claim text.