A converter for an LED driver for an LED light source. The converter has a flyback transformer. The primary receives a rectified AC voltage. A switching transistor is coupled in series with the primary. A controller controls the switching transistor on and off to generate a bus voltage across the secondary and a center tap voltage at a center tap of the secondary. The controller is powered by a first low-voltage DC voltage. A first power supply receives the center tap voltage and generates a second low-voltage DC voltage when the center tap voltage is above a cutover voltage. A second power supply has an output coupled to the first power supply output. The second power supply receives the bus voltage and generates the second DC voltage when the center tap voltage is below the cutover voltage.