Abstract: The adjacent terminals of adjacent battery cells are grouped in regularly spaced pairs of contacts. A first commutating member has a plurality of regularly spaced contact members effective to connect the contacts of each pair but one and is movable sequentially through a plurality of positions to vary the unconnected contact pair. One of the contact members adjacent the unconnected contact pair provides a first output terminal. A second commutating member has a single contact member effective to connect the contacts of one of said pairs and provide a second output terminal and is movable sequentially through a plurality of positions to vary the connected contact pair.

Abstract: A switch system for interconnecting a plurality of balanced line inputs with a plurality of balanced line outputs is disclosed. The lines are crossed in a matrix with a pair of rotatable switch means mounted at each crosspoint. Each pair of the switch means provides straight through connections for the input and output lines while in a first position, and a cross connection at the matrix point while in a second position. The switch means provides identical path lengths for each side of the balanced line before and after switching. The switch system also includes means for grounding the unused contacts and the inactive line sections remaining in the matrix after an interconnection has been made. The matrix is formed of a plurality of interchangeable modules that allow quick and convenient expansion of the matrix when needed.