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. 11, 2003
Filed:
Jan. 09, 2001
David P. Dornfeld, Killingworth, CT (US);
Whelen Engineering Company, Inc., Chester, CT (US);
Abstract
An electronic siren emulates the sound of a mechanical siren using a dynamic algorithm and look up tables to generate a series of wave sets, each wave set including one fixed frequency wave and one variable frequency wave. A micro controller stores the algorithm and look up tables and executes the algorithm on command to produce a digital output emulating the mechanical siren. The digital output is converted to an analog signal that is applied to a class D amplifier. A switching power supply provides 70 VDC to the output stage of the amplifier. This arrangement produces 126 dB of sound pressure at a distance of 10 feet from the reverse folded horn speaker. The electronic siren generates little heat and requires only 10 amps of current from the vehicle electrical system.