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:
Jul. 04, 1978
Filed:
Dec. 01, 1976
Julius M Liptak, Columbia, SC (US);
Square D Company, Park Ridge, IL (US);
Abstract
A circuit for sensing the motor stator voltage on any one or more phases of an AC electrical drive system. In a three phase system, all three phases of the motor terminal voltage are applied to a modified six-pulse rectifier bridge which in turn feeds a loading resistor. A resistor is added in series with each diode pair of the six-pulse rectifier bridge in order to provide any degree of attenuation of the peak voltage developed across the load resistor by simply varying the resistance values of these series input resistors and the load resistor. The resulting DC voltage generated across the load resistor is then fed into a differential amplifier (stage) where the voltage is attenuated and impedance isolated from the source to provide a DC output which is proportional to the average applied AC motor stator voltage.