Abstract: A method and apparatus for rolling discrete successive sheets of material into a coreless roll assembly comprising means for folding successive sheets of material and guiding and advancing the sheets to a winding station which comprises an axially translatable spindle having ports in its circumferential surface coupled to an air supply. Cooperating with the spindle are translatable belt guide means which substantially circumscribe the spindle so as to guide and aid the advancement of the folded sheets around the spindle, and timing means actuated after a predetermined number of sheets are wound onto the spindle for forcing air out through the ports in the spindle to provide an air bearing layer thereat. The spindle is then axially retracted from the bore of the roll thereby discharging the roll assembly.

Abstract: First and second batteries each connected in parallel with a load and a battery isolator connected between the first battery and the second battery and the load including a series pass transistor connected in series with the first battery and the load and circuitry for comparing the voltage across the load to the voltage across the first battery and turning off the series pass transistor when the voltage of the first battery drops below the voltage at the load plus a predetermined offset voltage, which offset voltage is developed by the battery isolator. The battery isolator operates like a diode isolation circuit having a near perfect diode therein.