Abstract: A universal adapter for enabling truss foundations to support conventional single-axis trackers. In some cases, the adapter has a main body with an upper portion that presents a standard I-beam interface with pre-drilled holes to interface to a specific single-axis tracker. A pair of connecting portions point down and away from the main body and enable upper leg sections to connect the adapter to a pair of driven screw anchors located below it. The connecting portions may orient the truss so that the rotational axis of the single-axis tracker is aligned with the work point of the truss foundation made from the adapter, upper legs, and driven screw anchors. This will enable to the truss to interface with many different trackers much like conventional plumb-driven H-pile foundations.

Abstract: A machine for rotary driving screw anchors into underlying ground and related. The machine has a mast with a rotary driver and a mandrel driver oriented on a common axis. The mandrel driver passes a mandrel through the rotary driver and the screw anchor to allow the mandrel to be actuated ahead of the screw anchor while the rotary driver drives the screw anchor into the ground. Alternatively, the mandrel driver may also drive a hammering drill through the screw anchor to clear a path ahead of it through subsurface rocks.

Abstract: A welding system and method provide for generating a controlled waveform for welding power output, the waveform comprising a plurality of successive peak phases followed by a short circuit between a welding wire electrode and an advancing weld puddle. Each then present peak phase is regulated based upon at least the immediately preceding short circuit to control the short circuit that will occur following the then present peak phase. Some embodiments permit regulating at least one waveform phase based upon at least the immediately preceding short circuit to control the next short circuit that will occur, and regulating at least one short response phase based upon at least the immediately preceding short circuit to control the next short circuit that will occur.

Abstract: A method and system for pulse welding provides an output pulse waveform. The waveform has at least a frequency from a range of available frequencies not limited to harmonic frequencies. The waveform provides power suitable for welding, and has a plurality of background portions alternating with a plurality of peak portions. A transition down occurs from the peak portion to the background portion with a first acceleration and a transition up occurs from the background portion to the peak portion with a second acceleration. At least one of the first and second accelerations are non-zero over at least most of the transition. The waveform is preferably created by switching an inverter. Both accelerations may be non-zero, and each transition may have two accelerations, one negative closer to the peak, and one positive closer to the background. The accelerations may be constant with opposite polarity. Preferably the process is current controlled during the transitions. The process frequency may be fixed or varying.

Abstract: A method and apparatus for welding is disclosed. The output is preferably a cyclical CV MIG output, and each cycle is divided into segments. An output parameter is sampled a plurality of times within one or more of the segments. The CV output is controlled within the at least one segment in response to the sampling. The parameter is output power, a resistance of the load, an output current, an output voltage, or functions thereof in various embodiments. The control loop is preferably a PI or PID loop. The loop may be applied only within a window. The set point may be taught or fixed. The system can be used to weld with a controlled arc length.

Abstract: A method and apparatus for welding is disclosed. The output is preferably a cyclical CV MIG output, and each cycle is divided into segments. An output parameter is sampled a plurality of times within one or more of the segments. The CV output is controlled within the(at least one segment in response to the sampling. The parameter is output power, a resistance of the load, an output current, an output voltage, or functions thereof in various embodiments. The control loop is preferably a PI or PID loop. The loop may be applied only within a window. The set point may be taught or fixed. The system can be used to weld with a controlled arc length.