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. 25, 2012
Filed:
Aug. 13, 2009
Joshua James Barr, Bangor, MI (US);
Medford Alan Dyer, San Diego, CA (US);
Alan Dean Michel, Fishers, IN (US);
Christopher Todd Welsh, Fishers, IN (US);
Joshua James Barr, Bangor, MI (US);
Medford Alan Dyer, San Diego, CA (US);
Alan Dean Michel, Fishers, IN (US);
Christopher Todd Welsh, Fishers, IN (US);
Harman International Industries, Inc., Stamford, CT (US);
Abstract
A passive sound pressure level (SPL) limiter is provided that can be used with audio sources of varying drive levels and headsets, earbuds, etc. of varying sensitivity. The SPL limiter includes a control circuit that includes a rectifier and, in most configurations, a step-up transformer. The SPL limiter also includes a limiting circuit that utilizes a transistor to shunt current from the audio source in proportion to a control signal output by the control circuit. The control circuit may further include a low pass filter, for example an RC filter, and one or more fast limit diode paths. The limiting circuit may further include a feedback network to increase the linear behavior of the limiting circuit.