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:
Sep. 30, 1980
Filed:
Mar. 15, 1979
Hugh McPherson, West Linton, GB;
Ferranti Limited, Hollinwood, GB;
Abstract
Apparatus for controlling the gains of a pair of gain-matched amplifiers includes means for applying a pilot tone of constant amplitude to each amplifier through separate attenuators during a repeated correction time interval. Three control loops are provided, one of which compares the output of one amplifier with a reference signal at times other than a correction time interval to control the gain of that amplifier. A second loop compares the output of the other amplifier with the same reference signal only during each correction time interval to control the gain of the second amplifier. Finally, the third loop compares the output of the first amplifier and the reference signal during each correction time interval to produce a signal controlling the two attenuators.