Browse Prior Art Database

Tape Reel Motor Control System

IP.com Disclosure Number: IPCOM000075080D
Original Publication Date: 1971-Jul-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Werner, AJ: AUTHOR

Abstract

This motor control system provides control of the reel motor of a magnetic tape unit by binary input signals indicating (1) the direction of the capstan rotation, (2) a comparison of the speed of the tape on opposite sides of the vacuum column, and (3) the position of the tape loop within the vacuum column.

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Tape Reel Motor Control System

This motor control system provides control of the reel motor of a magnetic tape unit by binary input signals indicating (1) the direction of the capstan rotation, (2) a comparison of the speed of the tape on opposite sides of the vacuum column, and (3) the position of the tape loop within the vacuum column.

View A shows a magnetic tape unit having a single bidirectionally rotatable capstan 1 which moves tape 2 across head 3.

The tape is stored on file reel 4. During forward movement of the tape (FWD), cause by counterclockwise rotation (CCW) of the capstan, tape 2 leave the file reel 4, forms a loop in file vacuum column 5, passes the head, forms a loop in machine vacuum column 6 and is wound on machine reel 7.

The speed of the tape on the capstan side of the vacuum column is sensed by digital tachometer 8. The speed of the tape on the reel sides of each vacuum column in sensed by digital tachometers 9 and 10.

Frequency comparators 11 and 12 compare the speed of the tape on opposite sides of the vacuum columns and originate a binary "reel slow", or "reel fast" output signal, when the speed of the tap adjacent a reel is either slower or faster than the speed of the tape at the capstan.

Reel motor control logic circuits 13 and 14 control machine reel motor 15 and file reel motor 16, in accordance with the schedule shown in View B. When the capstan is rotating in a direction to move tape out of a column, a transition of the associated...