A predictive current feedback system for a switched mode regulator including a sample and hold network for sampling voltage across a lower switch of the regulator and for providing a hold signal indicative thereof, and a predictive current feedback network which adds an offset adjustment to the hold signal based on a duration of a pulse width of a pulse control signal developed by the regulator. The method and apparatus selects a final lens position for the lens based on the predetermined nonuniform lens position data. Each frame also includes a bogie connector that enables the frames to connect to bogies for transportation in a rail mode. The controller includes an output reduction circuit that reduces the magnitude of the welding power by a variable amount in the event the engine is likely to stall, so as to reduce the likelihood of a stall, but maintain sufficient power for a welding arc. In response to the modulation waveform, the oscillation frequency of the VCO is modulated, and the output clock that varies its frequency as illustrated in FIG.