Tape transport control system with a feedforward capstan drive to the reel motors

摘要

A feedforward circuit applies a capstan drive current, or its equivalent, to the reel tension servo circuits whose associated reels are transporting the tape. The additional drive current to the reel drive motors increases the rotational velocity of the reels to maintain the same resultant acceleration between the tape driven by the capstan and the tape being transported between reels. Since the tape pack affects the gain of the feedforward circuit, a preselected average gain corresponding to the mean tape pack diameter is used to match different cassette sizes. A microprocessor may be used to provide the various signals and may vary the gain of the feedforward circuit not only in response to reel size but also in response to instantaneous reel tape pack diameter.