Cobbald's design made what in retrospect seems like an obvious change; the read wire was threaded across the planes instead of one per plane. In this system the read wire really did pass through only one set of powered lines, and the problems of the "extra signal" were avoided completely. It is not entirely surprising that this solution was not hit on before; cores were constructed a plane at a time and then wired together, whereas this method required the entire core to be built before the read wires could be added. The only major downside to the design is that it required more power to run.