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. 09, 1980
Filed:
Aug. 31, 1979
Barry Pearlman, Maryland Heights, MO (US);
W Kenneth Menke, Glendale, MO (US);
Public Safety Equipment, Inc., St. Louis, MO (US);
Abstract
An amplifier particularly suited for amplifying relatively low voltage level siren tone signals in an electronic siren. The amplifier includes an output transformer having first and second primary windings and having a secondary winding for connection to a loudspeaker. Each primary winding is connected during operation between a voltage source and ground and each includes first and second winding sections. Also included are first and second switching devices disposed between the winding sections of the first and second primary windings respectively for opening and closing the circuit between the winding sections of each primary winding in response to the signals which are to be amplified. Circuitry is provided for biasing each output transistor hard off when the other output transistor is conducting. Additional circuitry is provided to enable the amplifier to operate class AB to amplify speech signals.