www.DataSheet4U.com Variable Transformers Controllers l Types FRC-20, MP ISE, Inc. - 10100 Royalton Rd. - Cleveland, OH 44133 USA - Tel: (440) 237-3200 - Fax: (440) 237-1744 - http://instserv.com Variable Transformer Controllers FRC-20 Controller The STACO FRC-20 Controller is designed to position and regulate any STACO motor driven variable transformer; and, can be controlled with a 0-5 VDC or 4-20 Ma set point, a 1 k ohm potentiometer, or a fixed resistor network. It maintains a full rang.