The Sliding Rheostat (BX7D) ' s principle is to tight lock constantan wire which is processed by oxidation and tnsuiatton on porcelain pipe, then fix the porcelainpipe on the metal protecting bracket. Sliding Rheostat(BX7D) can changethe value of rheostat by the rnoving of conductive electric brush of contacesystem on the surface of constantan wire. The hand-push style can be classified to single tube and doubie tube according to theircapablify.
