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:
May. 22, 1990
Filed:
Apr. 07, 1989
Benno Doemen, St. Georgen, DE;
Papst-Motoren GmbH & Co. KG, St. Georgen, DE;
Abstract
A circuit arrangement for generating a useful direct voltage signal associated with the frequency of an alternating current signal serves, in particular, to regulate the synchronism of an electric motor. It includes a comparator circuit (7) which converts the two opposite polarity half-waves of the alternating current signal of a tacho coil (2) into pulses whose edges trigger a measuring and control circuit (18) which generates direct voltages corresponding to the half-period durations of the alternating current signal measured from the respective zero passages. The comparison voltage input (9) of the comparator (7) is connected with the output of a differential amplifier (10) whose two inputs (29, 30) are each connected to a storage capacitor (27, 28) which can be connected, via associated first and second switches (80, 81), with the useful direct voltage signal (22), with the first switch (80) being used to periodically couple out the useful direct voltage signal associated with the first half-periods and the second switch (81) being used to periodically couple out the direct voltage signal associated with the second half-periods.