Figure 1 This circuit drives a string of LEDs with a constant current over the entire worldwide range of ac-mains voltages. The resistor in series with the LED string provides a convenient point to ...

Lighting a string of LEDs at a constant ... sense resistor drops to zero. The control circuit responds by increasing the PWM on-time to boost the output voltage higher in a failed attempt to increase ...

1 example includes LED loads D1 + D2, D3 + D4, D5 + D6 and a power-supply output voltage, with a constant output current, providing the circuit input voltage (V IN). With each string containing ...