LED LIGHTING DRIVE CIRCUIT

摘要

An LED lighting drive circuit supplying power for N groups of LED loads, the drive circuit comprising N current paths, N groups of LEDs, and a constant current section (600); the N current paths comprise: a voltage dividing section (100) connected to a half sine wave power supply, and used to reduce a supply voltage to a voltage usable by the corresponding current path; a comparator section (200) comprising N comparators used to output a corresponding control signal when the voltage changes; a logic control section (300) used to respectively output N enabling signals according to the control signal outputted by the comparator section (200); a power drive section (400) used to provide N voltages according to the N enabling signals; a switch section (500) used to switch off or on according to the N voltages provided by the power drive section(400) so as to control the power-on or power-off of the N groups of LEDs; and the logic control section (300) enables, via logic control, the switch section (500) of the N current paths to sequentially switch on and off. The LED lighting drive circuit enables the current of LED lamps to change in a sinusoidal half-wave form with the utility AC input, and keeps the current a constant effective value.