A 30-watt constant current LED driver with a dimming function using a thyristor. It is compatible with both leading-edge and trailing-edge dimmers and remains flicker-free throughout the dimming process. The dimming range is 0–100%, with a maximum dimming depth of 0.1%. The input voltage range is 198–253 volts AC. The output current can be adjusted using a DIP switch from 400 mA to 750 mA in 50 mA increments.