In a method of open andor closed-loop control of a welding tong movement by means of a welding tong drive, which comprises at least one primary and one secondary drive device, the primary drive device moves at least two welding tong limbs with welding electrodes towards a welding object from essentially opposite sides. The apparatus can include an external flow surface having a forward portion, and an engine inlet positioned at least proximate to the external flow surface and aft of the forward portion. The RCE reflector includes: an intrinsic or lightly doped Si multiplication layer, a Si contact layer which is heavily doped with dopants of a second polarity opposite the first polarity, a Si cavity length compensation layer, a buried oxide layer, and a Si substrate. A predetermined area, pad window is selected in the substrate. A dielectric layer covers a top surface of each mesa structure.