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Rules for Lead Angle Bounding in a Stepper Motor

IP.com Disclosure Number: IPCOM000051276D
Original Publication Date: 1981-Jan-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Clancy, DE: AUTHOR [+2]

Abstract

Lead angle is the relationship between a stepper motor's electrical position and its mechanical position. The lead angle affects the motor's torque and needs to be kept within certain bounds in order to maintain control of the stepper motor. The lead angle bounds change is a function of the motor speed. The article "Stepper Motor Lead Angle Bounding" M. H. Skeleton Ed al, appearing in the IBM Technical Disclosure Bulletin, July 1980 at page 439 provides the general principles of an algorithm for monitoring the lead angle and modifying the motor phase switching to keep the lead angle within bounds but having the capability of changing these bounds during motor operation to obtain the best motor performance. In accordance with that algorithm, the operation is not at a fixed lead angle, i.e.

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Rules for Lead Angle Bounding in a Stepper Motor

Lead angle is the relationship between a stepper motor's electrical position and its mechanical position. The lead angle affects the motor's torque and needs to be kept within certain bounds in order to maintain control of the stepper motor. The lead angle bounds change is a function of the motor speed. The article "Stepper Motor Lead Angle Bounding" M. H. Skeleton Ed al, appearing in the IBM Technical Disclosure Bulletin, July 1980 at page 439 provides the general principles of an algorithm for monitoring the lead angle and modifying the motor phase switching to keep the lead angle within bounds but having the capability of changing these bounds during motor operation to obtain the best motor performance. In accordance with that algorithm, the operation is not at a fixed lead angle, i.e., switching occurs only at fixed lead angles. Rather, the switching may occur at variable lead angles provided, however, that the lead angle always stays between a minimum and maximum bound. To implement this algorithm, the present article sets forth specific lead angle bounding rules to be followed by the electrical and mechanical systems in the stepper motor to prevent them from wandering sufficiently out of phase to cause the motor to jump synchronization. The rules will be set forth for electrical lead angle bounding for a four-phase stepper motor. It will be clear that the same rules could be applied to other motor phase confi...