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:
Feb. 28, 1984
Filed:
Oct. 30, 1981
David R Welland, Boston, MA (US);
dbx, Inc., Newton, MA (US);
Abstract
An improved multiplier circuit of the type including an input operational amplifier and a gain cell is disclosed. The gain cell is connected to the amplifier such that a first signal can be generated in response to and as a logarithmic function of an input signal, a control signal can be added to the first signal and a second signal can be algebraically generated as an antilogarithmic function of the algebraic sum of the first and control signals. The improvement includes means for providing a correcting signal as a function of the control signal at the output of the input amplifier substantially equal and opposite to signals produced at the output of the input amplifier by changes in the control signal.