| 摘要 |
<p>A circuit for voltage-controlled dimming of light emitting diodes comprises first and second light emitting diode groups connected between an input port and an output port, a switching circuit coupled to the first and second light emitting diode groups, wherein the switching circuit switches the first and second light emitting diode groups between series-connection and parallel-connection, and first and second devices each connected in parallel with, respectively, the first and second light emitting diode groups, each device having a threshold voltage for conducting current which is greater than or equal to combined forward voltage drops at maximum current for all light emitting diodes within the respective light emitting diode group, wherein each device provides an alternate current path upon failure of any light emitting diode within the respective light emitting diode group.</p> |
