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. 13, 1984
Filed:
Jan. 26, 1982
Applicant:
Inventors:
Sunao Suzuki, Kobe, JP;
Koji Maeda, Takatsuki, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R / ;
U.S. Cl.
CPC ...
324 / ; 324 / ;
Abstract
The disclosed frequency detection system samples a sinusoidal input V(t) with a predetermined constant sampling period h to form four sampled values V(t.sub.o -2h), V(t.sub.o -h), V(t.sub.o +th) and V(t.sub.o +2h) and calculates ##EQU1## where .omega. designates an angular frequency of the sinusoidal input after the conversion to corresponding digital values to provide a measure of its frequency. Further the absolute value of the frequency may be obtained by making an arc-cosine of one half the y(h).