Patent ID: 6989807
Filing Date: 2006-01-24
Classification: H05B

Abstract:
1. A LED driving device lighting a plurality of LEDs by the positive part of a power source directly without the existing of a filtering capacitor so that said LED driving device has better power factor and better efficiency in comparison with conventional LED driving device, said LED driving device comprising: a LED array connected in parallel across said power source; said LED array composed of one LED string or at least two LED strings connected in parallel, each of said LED strings is composed of a series of connected LED sets, each of said LED sets is composed of at least one LED in any electric configuration; a voltage detecting circuit detecting the voltage level of said power source; a current switching circuit coupled to said voltage detecting circuit and to said LED sets so that when said voltage detecting circuit detects the different voltage level of said power source, said voltage detecting circuit sends a signal to said current switching circuit and said current switching circuit is automatically activated to electrically rearrange said configuration of LED sets with a predetermined current value by lighting the greatest number of LEDs; and wherein the greatest number of LEDs illuminated per LED set varies based on the voltage level detected by said voltage detecting circuit.