Browse Prior Art Database

Tape Reel Drive Control

IP.com Disclosure Number: IPCOM000098550D
Original Publication Date: 1959-Feb-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Kochenburger, RJ: AUTHOR

Abstract

The reel drive motor is controlled by a signal which is indicative of the velocity of up and down movement of tape in a vacuum column. This signal is used as an error signal in a feedback loop which controls the speed of the motor.

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 100% of the total text.

Page 1 of 2

Tape Reel Drive Control

The reel drive motor is controlled by a signal which is indicative of the velocity of up and down movement of tape in a vacuum column. This signal is used as an error signal in a feedback loop which controls the speed of the motor.

The signal is generated as follows. The velocity of tape entering the column is measured by a tachometer and a signal indicative of the velocity of the tape at the capstan is subtracted from the output of the tachometer, thus giving a signal proportional to the velocity of the up and down movement of the tape in the vacuum column.

Due to the fact that in a pure velocity system there is a tendency for the position of the tape loop in the column to drift either up or down, limit position sensing is needed. Three sets of limits are selectively used depending upon the mode of operation, forward, stop or reverse.

Ordinarily, the tape loop operates between the two limit holes of any one of the three pairs of limit positions. When the tape is above or below a selected pair of limits, the error signal in the velocity feedback loop is modified to correct the position of the tape to place the bottom f the loop in between the holes of the limit pair. When the tape is between the limit holes of any limit pair, no corrective signal is supplied for modifying the error signal in the velocity feedback loop.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]