Servo device for the regulation of the drive of the band running coil of a magnetic tape machine

摘要

During a search operation in a rotating magnetic head tape transport, the tape is transported from a supply spool via guides and a vacuum column past the rotating head read/write station to a take-up spool. As the tape is wound onto the take-up spool in layer-by-layer convolutions, air is entrapped between the layers. The entrapped air forms a layer of air film and as a result the tape is loosely wound on the take-up spool. A "Hard Step" voltage is generated and is applied to the capstan motor at the end of the search operation to tighten any loose wraps caused by the air entrapment during the search.