NSI50350AD, 120 Vac, Low-Cost, Dimmable, Linear, Parallel-to-Series LED Driving Circuit. Circuit consists of a full-wave bridge rectifier (D1-D4), a threshold detection and switching circuit (D5-D6, Q1-Q3, and M1), two LED strings (LED1-LED3 and LED4-LED6), and two ON Semiconductor Constant Current Regulators (CCR1 and CCR2)
