The IC3600ACLS1B is a Current Limit Card for the Mark I/Mark II Speedtronic series from GE. These series for steam or gas turbine management were developed by General Electric in the late 1960s and early 1970s. Over the last forty-five years, both systems have accumulated millions of hours of operating experience as remote utility peaking gas turbines, base-loaded industrial generator drives, pipeline pumping stations, offshore platform marine drives, and other utility, process and combined cycle machines. Both systems may be used in ambient temperatures ranging from plus to minus 50 degrees Celsius and can manage turbines from 4000 hp to 400 Mw (combined cycles). The IC3600ACLS1B is a FANUC component. It has a small front panel attached to the PCB. This panel has two openings that line up with the two potentiometers attached to the board. Above the first of these openings, the panel states ‘Pos Bias,’ and next to it it says ‘R34. ‘Above the second opening the panel states ‘Neg Bias,’ and next to it it says ‘R33. ‘ The bottom of this small panel is labeled ‘ACLS1. inThe IC3600ACLS1Bis factory-drilled in two corners. It has twenty-five pins attached to the opposite edge. The board is numbered from two to fifty by tens in this edge. When used in tandem, these pins function as a backplane, and when wired together connect the IC3600ACLS1B into the rest of the Speedtronic system. The IC3600ACLS1B is marked with the GE logo. Its board number appears halfway down its surface. The board is populated with two trim potentiometers (mentioned above,) and eight transistors. It has several carbon composite (CCR) transistors and capacitors made of aluminum electrolytic material and others made of polyester vinyl. Some components have been mounted to the board in a vertical position.