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:
Dec. 28, 1976
Filed:
Oct. 23, 1974
Applicant:
Inventor:
Michael C Cowpland, Ottawa, C;
Assignee:
Mitel Canada Limited, , C;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04Q / ;
U.S. Cl.
CPC ...
179 / ;
Abstract
A modified Sallen and key active filter useful for generating tones in a tone generator which can be connected to a telephone line. The modification allows a broad range of frequencies to be generated with a relatively constant output amplitude, the output signal of which can be usefully employed for D.T.M.F. or interoffice multifrequency signal generation.