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:
Nov. 09, 2004
Filed:
Jul. 19, 2002
William Edward Hughes, Scottsdale, AZ (US);
Richard W. Faith, Phoenix, AZ (US);
Fender Musical Instruments, Inc., Scottsdale, AZ (US);
Abstract
A transimpedance amplifier ( ) receives an audio signal from a power audio amplifier ( ) and provides a variable power level to a loudspeaker ( ). A first variable gain amplifier ( ) receives the audio signal and provides a variable gain to a power amplifier ( ). The output signal of the power amplifier drives the loudspeaker. A sense amplifier ( ) subtracts a voltage representative of current flowing through the loudspeaker from a voltage applied to the loudspeaker and provides a difference signal. A second variable gain amplifier ( ) receives the difference signal and provides a variable gain to a load amplifier ( ). The gains of the first and second variable gain amplifiers are inversely proportional. A resistive element ( ) having a real impedance is coupled between an output of the load amplifier and the input of the transimpedance amplifier to maintain the complex impedance of the loudspeaker at the output of the power audio amplifier.