Schaefer Inc. (Ashland, MA) introduced its C5700 Series of 8kW, 6U/9U high, 19" rack compatible dc/dc and ac/dc converters. Applications include on-board locomotive controls and communications equipment, telecommunications systems, process control systems, power stations and virtually any other high-power requirement, according to Schaefer.The C5700 Series is available with dc input voltages from 20-900Vdc, as well as ac input voltage ranges of 93-264Vac. Three-phase ac input voltages from 320-530Vac are also available. The units can also be purchased with a power factor corrected front end. Outputs are available from 4.5-400Vdc and are adjustable and fully regulated to 0.2 percent or better (load) and 0.1 percent (line). All of the units in the C5700 Series feature remote sensing, overvoltage protection, and current limit protection on the output. "Zero switching" allows for efficiency as high as 93 percent, depending on input and output levels. Units are available with operating temperature ranges of -20 to +75 degrees C and extended range of -40 to +75 degrees C. Options available to allow reliable operation under a broad range of environmental conditions include increased mechanical strength, tropical protection, inrush limiting, temperature controlled forced air cooling, decoupling diodes for parallel operation, inhibit, power fail/dc-ok, system reset, active current sharing and wall mounting. Mechanical and electrical modifications to standard modules are available upon request. Base prices range between $3475-$4885 in quantities of 100; significant OEM quantity discounts are available.