The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 1978
Filed:
Apr. 28, 1976
Eugene P Johnson, Jr, Arlington, MA (US);
Micro Communications Corporation, Waltham, MA (US);
Abstract
A motor speed control arrangement in which the back EMF of the motor is sensed in all operating modes and is used as a measure of the motor speed. The effect of commutator ripple due to varying rotor resistance is compensated by adjustment of resistors associated with an operational amplifier, so that the output of the amplifier provides the average value of the back EMF without distortion. A comparator compares the output of the amplifier with an input reference signal denoting the desired speed of the motor and applies an error signal to a driving circuit which drives the motor with current in a manner that tends the error signal to attain minimum or zero value.