MFDC weld controls have been examined and tested with results not as favorable as the CD process. For example, Figure 7 shows an Amada Miyachi 4000 amp MFDC weld control reaching 83 kA in 6 ms. This is an extremely fast rise to current for a MFDC welder but the cost of the equipment and additional cost of facilities (800 amp 3 phase primary feed) can add up quickly. Another issue associated with this technology is the closed loop feedback. Normally, a constant current closed loop process is preferred, but these systems work best when the weldment resistance is consistent. Hot stamped boron steels with either an AlSi coating or an uncoated shot peened surface have a hard time presenting a consistent surface resistance, so the end result is inconsistent heat generation.