Browse Prior Art Database

Stepping Motor Control for Document Feed

IP.com Disclosure Number: IPCOM000080116D
Original Publication Date: 1973-Jan-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Check, GP: AUTHOR [+3]

Abstract

This stepping motor control system provides for accurately starting and stopping a document transport. Further, provision is made to slew between lines or fields at high speeds, when line-to-line incrementing is not desired. Referring to Fig. 1, ferromagnetic gear 1 is mounted on one end of a stepping motor shaft. Reluctance probes 2 are positioned in a manner to furnish feedback pulses having different time displacement relations. Shaping circuits 3 shape output pulses from probes 2 to a suitable form for input to Select Logic 4. Select Logic 4 comprises circuitry to provide proper inputs to sequence triggers 5, which drive the four phases of the stepping 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 75% of the total text.

Page 1 of 2

Stepping Motor Control for Document Feed

This stepping motor control system provides for accurately starting and stopping a document transport. Further, provision is made to slew between lines or fields at high speeds, when line-to-line incrementing is not desired. Referring to Fig. 1, ferromagnetic gear 1 is mounted on one end of a stepping motor shaft. Reluctance probes 2 are positioned in a manner to furnish feedback pulses having different time displacement relations. Shaping circuits 3 shape output pulses from probes 2 to a suitable form for input to Select Logic 4. Select Logic 4 comprises circuitry to provide proper inputs to sequence triggers 5, which drive the four phases of the stepping motor.

The motor starts with a start pulse and is accelerated by feed-back pulses from the low-speed probe to a constant velocity, shown in Fig. 2 (a). Control is then transferred to the high-speed probe at some point as selected by Select Logic 4. To increase the stepping rate, transition must be made immediately after a low-speed pulse. This supplies an additional pulse for advancing the field of the stepping motor to an advance position, effective to accelerate the motor to high-speed operation. The motor is then under control of feedback pulses on the high-speed probe, Fig. 2 (c).

To decelerate from high speed to low speed, the transition is made just prior to a high-rate pulse. During transition a control pulse is skipped to retard the field of the stepping motor. T...