公开(公告)号：US3604992A

公开(公告)日：1971-09-14

申请号：US3604992D

申请日：1970-02-10

申请人： AZMI S AUDEH ,  ANIL N DEODHAR ,  HENRY G GLATTFELDER

发明人： AUDEH AZMI S ,  DEODHAR ANIL N ,  GLATTFELDER HENRY G

IPC分类号： G11B15/58 ,  B65H59/38 ,  H02P7/68

CPC分类号： G11B15/58

摘要： A reel servosystem for a digital magnetic tape transport responds to tape loop length signals from two spaced-apart linear sensors in a vacuum chamber and a reel motor braking signal which is proportional to tape velocity at some point between the vacuum chamber and the associated tape reel. A Schmitt trigger increases the tape loop length signals by a selected amount whenever they exceed a threshold magnitude thereby providing a more rapid response and cancelling the effect of the braking signal. A summing junction provides a signal representing the sum of the tape loop length signals and the reel motor-braking signal to drive the reel motor. During steady state operation the reel motor drive signal is proportional to the length of the tape loop and maintains the tape loop at selected reference positions within the vacuum chamber dependent on direction.