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1. An LED lighting drive circuit, configured to supply power to N groups of LED loads, the LED lighting drive circuit comprising N current paths, N groups of LEDs, and a constant current section, N being an integer no less than 2, the N current paths comprising:
a voltage dividing section, connected to a half sine wave power supply, and configured to reduce a supply voltage of each of the N current paths to a voltage available for a corresponding current path; a comparator section, comprising N comparators for the N current paths, each of the comparators having an input terminal connected to an output terminal of the voltage dividing section, and another terminal connected to a reference voltage and configured to output a control signal when a voltage varies; a logic control section, having N input terminals connected to N output terminals of the comparator section and configured to output N enabling signals according to the control signal outputted by the comparator section; a power drive section, having N input terminals connected to N output terminals of the logic control section and configured to provide N voltages according to the N enabling signals; and a switch section, comprising N switch elements, the N switch elements having N input terminals connected to N output terminals of the power drive section and configured to be switched off or on and thereby to control the N groups of LEDs to be turned on or off according to the N voltages provided by the power drive section, wherein the logic control section is configured to control the N switch elements to be successively switched off and successively switched on through logic control, a first group of LEDs of the N groups of LEDs has a terminal connected to the half sine wave power supply and another terminal connected to a first current path and a terminal of a second group of LEDs; an ith group of LEDs has a terminal connected to an (i−1)th group of LEDs and an (i−1)th current path, and another terminal connected to an (i+1)th group of LEDs and an ith current path; an Nth group of LEDs has a terminal connected to an (N−1)th group of LEDs and an (N−1)th current path, and another terminal connected to an Nth current path; where 2i(N−1), and the constant current section is connected between the half sine wave power supply and the switch section such that a current passing through the N groups of LEDs varies in a half sine wave form with the input half sine wave power supply and has an effective value being kept constant. |
