| 摘要 |
An LED array circuit (30b) includes a number of series connected LED pairs (32), each pair (32) including two parallel connected oppositely polarized LEDs. The array is coupled to a standard AC voltage source (34) in series with an inductor having Q>5 and a reactance which is equivalent to the resistance of a current limiting resistor. The use of an inductor in place of a resistor increases the efficiency of the array to approximately 80%. The efficiency of the array is increased even further by coupling a capacitor parallel to the array and by tuning the inductor and capacitor to the frequency of the AC voltage source (34). According to one embodiment of the invention, a single module is provided with a plurality of LED arrays (31a-31c), with each LED array (31a or 31b or 31c) having its own capacitor coupled in parallel thereto, and its own series coupled switch (36a or 36b or 36c). The module is coupled to and across the AC voltage source (34), with one node of the module coupled to the AC voltage source (34) by an inductor. |
