Browse Prior Art Database

Digital Velocity Compensation of Reel Drive Motor

IP.com Disclosure Number: IPCOM000073635D
Original Publication Date: 1971-Jan-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

VanPelt, RW: AUTHOR

Abstract

The vacuum column 1 of a magnetic tape unit is divided into zones by pressure sensitive switches L1-L8. The position of the loop of magnetic tape 2 along the column is determined by the relative speed and direction of rotation of capstan 3 and reel drive motor 4.

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Digital Velocity Compensation of Reel Drive Motor

The vacuum column 1 of a magnetic tape unit is divided into zones by pressure sensitive switches L1-L8. The position of the loop of magnetic tape 2 along the column is determined by the relative speed and direction of rotation of capstan 3 and reel drive motor 4.

Reel motor control circuit 5 receives the following input signals: conductors 6 and 7 provide signals indicating clockwise, stopped, or counter-clockwise rotation of the capstan; conductors 8-15 provide signals indicating the zone position of the tape loop in the column; and conductors 16 and 17 provide signals indicating the "up" and "down" status, respectively, of latch 18.

Switches L1-L4 are connected to logic network 19 to provide a signal on conductor 2O indicating that the tape loop is above L4 and has moved in a downward direction while above L4. Switches L5-L8 are connected to logic network 21 to provide a signal on conductor 22 indicating that the tape loop is below L5 and has moved in an upward direction while below L5.

Latch 18 is set to the "up" status by the signal on conductor 20, and is set to the "down" status by the signal on conductor 22.

The control order for the reel motor is shown in view B. Considering zones L3-L4, as an example, if the capstan is rotating clockwise, and if the tape loop is above L4 and is moving down, the latch is set to "up" and the order of control for the reel motor 4 is that the motor is dynamically braked as th...