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IP.com Disclosure Number: IPCOM000026635D
Original Publication Date: 1993-Feb-28
Included in the Prior Art Database: 2004-Apr-06
Document File: 2 page(s) / 48K

Publishing Venue

Xerox Disclosure Journal

Abstract

DC motors are frequency and line voltage insensitive. However, variations in load and power supply voltage can cause the speed of DC motors to vary significantly from their nominal values. One way to overcome this drawback is to use some sort of feedback system. This type of feedback can be relatively expensive, due mainly to the cost of including an encoder in the design of the package.

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XEROX DISCLOSURE JOURNAL

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Proposed W. Wafler U.S. C1.318/009 Classification

Int. C1. H02k 07/10

DC motors are frequency and line voltage insensitive. However, variations in load and power supply voltage can cause the speed of DC motors to vary significantly from their nominal values. One way to overcome this drawback is to use some sort of feedback system. This type of feedback can be relatively expensive, due mainly to the cost of including an encoder in the design of the package.

The disclosed invention proposes to use the inherent brush to commutator generated noise pulse as a digital encoder for the feedback system. This system would give a pulse whenever a brush crossed a slot in the motor commutator. The frequency of this pulse would be proportional to the product of the number of slots encountered by the brush and the rotational speed of the motor. The relationship between pulse fequency and shaft rotation would be linear.

XEROX DISCLOSURE JOURNAL - Vol. 18, No. 1 January/February 1993 11

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12 XEROX DISCLOSURE JOURNAL - Vol. 18, Yo. 1 January/February 1993

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