| 摘要 |
<p>PURPOSE: An LED(Light Emitting Diode) driver circuit is provided to improve a power factor by enabling an input current to flow through all phase regions. CONSTITUTION: An LED driver circuit comprises a rectifier circuit, a voltage detection circuit, and a plurality of LED modules. The rectifier circuit rectifies an input AC voltage. The rectifier circuit is a bridge diode circuit. The peak value of an output voltage of the rectifier circuit is partitioned into a plurality of voltage regions(V1,V2,V3,Vp). The voltage level detection circuit detects the output voltage of the rectifier circuit belongs to which voltage region. A plurality of LED modules are operated in a plurality of voltage regions, respectively. A constant current circuit is serially connected to a plurality of LED modules.</p> |
