Patent ID: 7067987

Claim:
An electronic ballast to regulate power to a load, comprising: A. An integrated circuit (IC) having a driving terminal, the integrated circuit being adapted to generate a train of high-frequency drive pulses at said driving terminal; a feedback terminal and an internal reference voltage; the integrated circuit being adapted to compare a feedback signal received at its feedback terminal with the reference voltage and to adjust the duration of said drive pulses via the input according to said comparison; B. a polarity-reversing bridge connected between the drive terminals and the load, the bridge being driven by separate drive signals and generated by a pair of integrated circuits and providing low-frequency polarity-reversal of the load; C. a feedback system connected to the feedback terminal and to the load, the feedback system deriving an average feedback signal from current consumed by the load combined with a voltage feedback signal from voltage impressed on the load, the feedback system combines, by addition, the current and voltage feedback signals to provide said composite feedback signal to the feedback terminal.