Patent ID: 8008866

Claim:
A hybrid light source adapted to receive power from an AC power source and to produce a total light intensity, the total light intensity controlled throughout a dimming range from a low-end intensity and high-end intensity, the hybrid light source comprising: a high-efficiency light source circuit having a high-efficiency lamp for producing a percentage of the total light intensity; a low-efficiency light source circuit having a low-efficiency lamp for producing a percentage of the total light intensity; and a control circuit coupled to both the high-efficiency light source circuit and the low-efficiency light source circuit for individually controlling the amount of power delivered to each of the high-efficiency lamp and the low-efficiency lamp, such that the total light intensity of the hybrid light source ranges throughout the dimming range, the percentage of the total light intensity produced by the high-efficiency lamp being greater than the percentage of the total light intensity produced by the low-efficiency lamp when the total light intensity is near the high-end intensity; wherein the percentage of the total light intensity produced by the high-efficiency lamp decreases and the percentage of the total light intensity produced by the low-efficiency lamp increases as the total light intensity is decreased below the high-end intensity, the control circuit operable to turn off the high-efficiency lamp when the total light intensity is below a transition intensity, such that the low-efficiency lamp produces all of the total light intensity of the hybrid light source when the total light intensity is below the transition intensity.