BC Series Swing Arm slip line plates rheostat for voltage not exceeding 500 volt industrial electrical equipment for voltage, current regulation and AC DC generator voltage regulator and DC motor speed regulation. Kang copper or nickel-chromium wire rheostat resistance materials around on the skeleton of round ceramics, resistance materials in addition to the sliding contact surface is coated with high temperature enamel paint and glue in the ceramics chassis, the center together with the shaft driven brush grip and brush sliding resistance value to change. Rheostat divided into two kinds of open type and protection type its protection type rheostat plus a protective metal box shell, and with a hand wheel adjustment.