There is disclosed a compact design for the electronic circuits required to provide electrical contact to a SED roll of a segmented electrode development unit. In this invention, all the required high voltage and low voltage circuitry is placed on a printed flexible circuit which is folded and rolled into a cylindrical circuit to be connected to the SED roll. The flexible printed circuit has a plurality of output terminals each of which will be connected to one of the electrodes of the SED roll. In this invention, a spool is used to support the connection of the cylindrical circuit to the SED roll.