Patent ID: 7868559

Claim:
A device including an electronic ballast, the electronic ballast comprising: a switching circuit receiving a DC input voltage and outputting a DC bus voltage on a DC bus, the switching circuit being responsive to a switching control signal to generate the DC bus voltage; a DC bus voltage feedback adjustor sensing the DC bus voltage output by the switching circuit and in response thereto supplying a sensed DC bus voltage signal; and a DC controller comparing the sensed DC bus voltage signal to a reference DC bus voltage signal and generating the switching control signal in response to the comparison, and a voltage divider connected between the DC bus and common, the voltage divider having a first resistor connected between the DC bus and a connection and a second resistor connected between the connection and the common, the voltage divider generating the sensed DC bus voltage signal at the connection wherein the DC bus voltage feedback adjustor adjusts the sensed DC bus voltage for a predetermined time during each startup period, such that a startup DC bus voltage during the predetermined time is greater than a steady state DC bus voltage during a steady-state operation of the electronic ballast, and wherein the DC bus voltage feedback adjustor switches a third resistor in parallel with the second resistor.