Browse Prior Art Database

Tape Drive Acceleration Control

IP.com Disclosure Number: IPCOM000075787D
Original Publication Date: 1971-Nov-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Martin, H: AUTHOR [+2]

Abstract

For maintaining tape-to-head relationships during acceleration, a reel-to-reel tape transport uses asymmetrical acceleration characteristics to accommodate differing reel inertias. Transducer 10 is disposed between tape-driving capstan 11 and first reel 12. When tape 13 is accelerated in a so-called forward direction toward take-up reel 14, capstan 11 pulls tape over transducer 10 maintaining head;to-tape relationships. In this direction of acceleration, maximum acceleration is permitted. When accelerating tape in the reverse direction toward reel 12, many reel-to-reel tape drives have insufficient acceleration characteristics for the take-up reel to maintain proper tension on tape 13. In such a situation, tape 13 separates from transducer 10.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 2

Tape Drive Acceleration Control

For maintaining tape-to-head relationships during acceleration, a reel-to-reel tape transport uses asymmetrical acceleration characteristics to accommodate differing reel inertias. Transducer 10 is disposed between tape-driving capstan 11 and first reel 12. When tape 13 is accelerated in a so-called forward direction toward take-up reel 14, capstan 11 pulls tape over transducer 10 maintaining head;to-tape relationships. In this direction of acceleration, maximum acceleration is permitted. When accelerating tape in the reverse direction toward reel 12, many reel-to-reel tape drives have insufficient acceleration characteristics for the take-up reel to maintain proper tension on tape 13. In such a situation, tape 13 separates from transducer 10. By making the acceleration in the backward direction soft (slow) to accommodate reel 12 inertia in worst case situations (most of the tape is on reel 12), head-to-tape relationships are maintained enabling transducing operations.

Capstan motor 15 is controlled by a motor control circuit including monostable multivibrator 16, constructed in accordance with known circuit techniques. Periodicity of the monostable multivibrator is varied by the repetition rate of trigger pulses supplied over terminal 17. These signals are referred to as the "A" pulses; in the forward direction, the signals are "AF" pulses; in the backward direction, they are "AB" pulses. The duration of the motor driving pulses "B" (BF and BB) supplied...