Constant velocity tape drive system

摘要: This system moves magnetic tape past the read/write head at a constant velocity by separately servo controlling source reel motor and take-up motor. Separate fine encoders are associated with each reel, encoder providing multiple pulses for revolution of respective reel. Two radius calculation circuits receive from one calculate therefrom values on both reels. A information selector then selects, use in motors, that set which is calculated circuit receiving greater sampling rate. drive two motors angular velocities determined utilizing selected values. In circuit, multiplied actual velocity, as indicated time duration between consecutive Each maintains this product equal to preselected linear value, thereby causing separate rotate reels so establish desired velocity.