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:
Jun. 13, 1989
Filed:
Nov. 03, 1986
Georg Heinle, Erlangen, DE;
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Abstract
A method is presented in which at least one of the sinusoidal voltages (U.sub.S) which is induced in the stator windings by the residual magnetism or remanence of the rotor in a rotating-field machine, the frequency of which corresponds to the rotor speed is converted into a symmetrical square wave signal, (U.sub.R), the frequency and the phase of this square wave signal (U.sub.R) matching with the frequency and the phase of the induced sinusoidal voltage (U.sub.S). From this square wave signal (U.sub.R), an output signal (U.sub.DA) proportional to the frequency thereof is generated. Thus, a method is obtained by which the time required for finding the operational speed of the rotating-field machine (2) is reduced considerably so that a frequency converter can be connected to the rotating-field machine (2) rapidly at a synchronous speed.