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:
Jul. 18, 1989
Filed:
Oct. 16, 1986
Applicant:
Inventors:
Akira Kanagawa, Saitama, JP;
Hiroshi Hattori, Saitama, JP;
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F / ; H03F / ;
U.S. Cl.
CPC ...
330259 ; 330107 ;
Abstract
A variable frequency characteristic circuit to be used in compensating the frequency characteristics in an audio device in a vehicle. A single operational amplifier is used. Different resonance circuits of different frequencies are connected from ground to either the inverting or non-inverting inputs in order to provide local peaks and dips. Two variable resistors are connected in parallel between the inverting and non-inverting inputs. Different resonance circuits of different frequencies are connected from ground to center taps of the variable resistors to provide treble and base control.