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:
Apr. 27, 1982
Filed:
Nov. 19, 1979
Institut de Recherche de l'Hydro-Quebec, Quebec, CA;
Abstract
A filtering circuit having the behavior of a low-pass filter capable of having a long time constant. The filtering circuit comprises an input circuit for receiving a voltage input signal to be filtered. A summator circuit is provided for monitoring the input signal relative to an analog output signal from an accumulator circuit and providing an error signal representative of the difference of the input and output signals. The error signal is fed to a voltage controlled oscillator to generate a frequency signal proportional to the error signal. The accumulator has a frequency dividing circuit is provided to divide the frequency signal by a predetermined division factor to control the low cut-off frequency of the filtering circuit whereby to increase the response time thereof. The accumulator also integrates the divided frequency signal. An output circuit provides an output of the stored integrated frequency signal to constitute the analog output signal.